Cement Kilns

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In this sheet, formulae in "Cement Chemists' Notation" are given in bold: ordinary chemical formulae are given in normal type.

Term Meaning, Synonym, etc
A cement chemist's notation for alumina, Al2O3.
A/F abbrev., Alumina/Iron ratio: alumina ratio: alumina modulus
Aberthaw limestone Blue Lias limestone selected by Smeaton for hydraulic lime manufacture for the Eddystone Lighthouse, 1756.
abietic acid constituent of pine resin: used as air entrainer.
abrasion value, Los Angeles a measure of the abrasion resistance of large aggregate. Sized aggregate is rotated in a drum with steel balls, and the weight loss is measured.
absolute error of measurement (ISO definition) the result of a measurement minus the true value of the measurand.
absorption (ASTM definition) (of aggregates) the process whereby a liquid is drawn into and tends to fill permeable pores in a porous solid body; also, the increase in mass of a porous solid body resulting from the penetration of a liquid into its permeable pores.
absorption coefficient, mass the relative rate of attenuation of X-rays per unit mass of absorbing medium. Varies with composition of medium and wavelength of incident X-rays.
absorption edge in XRF, sharp drop in the absorption spectrum of a material with increasing wavelength, close to an element's characteristic fluorescent wavelength.
absorption effect in XRF, matrix effect in which the primary and secondary radiations are attenuated by passage through the sample. The degree of attenuation varies with the concentration of all the elements present.
AC impedance spectra technique used for examining the structure of cement pastes.
accelerated curing curing of concrete completed at elevated temperature.
accelerated strength test strength test in which curing is performed at controlled elevated temperature.
accelerating admixture, (ASTM definition) admixture that accelerates the setting and early strength development of concrete.
Accelerator substance that speeds up a reaction, specifically an admixture that speeds up the setting or strength growth of cement.
accelerators, non-chloride accelerators not containing chloride: chloride corrodes concrete reinforcement.
acceleratory period period of hydration of cement during which C-S-H is rapidly formed, and setting and early strength development take place, usually between 3 and 24 hours. Follows the induction period.
Accuracy the ability of a test to give the true result, when performed on an accepted standard material.
accuracy of measurement (ISO definition) the closeness of the agreement between the result of a measurement and the (conventional) true value of the measurand.
acetic acid grinding aid constituent: accelerating effect.
acetone treatment used to instantly terminate cement hydration reactions.
ACI abbrev., American Concrete Institute.
acid/alkali titration assessment of acid-soluble carbonates in rawmix by treatment with standard acid followed by back-titration with standard alkali. Used as simple rawmix composition control technique.
ACPA abbrev., American Concrete Pavement Association.
AD basis Air-dry basis. Reporting format for material analyses in which the constituents are expressed as a percentage of the mass of material after allowing it to dry out to constant mass at room temperature.
addition (ASTM definition) a material that is interground or blended in limited amounts into a hydraulic cement during manufacture either as a "processing addition" to aid in manufacturing and handling the cement or as a "functional addition" to modify the use properties of the finished product.
additions, mineral minerals other than clinker and gypsum present in appreciable amounts in composite cements. These include pozzolans, latent hydraulic materials and fillers.
adiabatic condition a condition of a system in which it undergoes change in temperature or pressure without gain or loss of heat.
adjustment (ISO definition) the operation intended to bring a measuring instrument into a state of performance and freedom from bias suitable for its use.
admixture (ASTM definition) a material other than water, aggregates, hydraulic cement and fibre reinforcement used as an ingredient of concrete or mortar and added to the batch immediately before or during its mixing.
admixture, accelerating (ASTM definition) admixture that accelerates the setting and early strength development of concrete.
admixture, air-entraining (ASTM definition) admixture that causes the development of a system of microscopic air bubbles in concrete or mortar during mixing.
admixture, retarding (ASTM definition) admixture that retards the setting of concrete.
admixture, superplasticizing (high-range water reducer): water-reducing admixture, the air-entraining and retarding characteristics of which have been minimized, so that high doses, and major reductions in concrete water/cement ratio are possible.
admixture, water-reducing (ASTM definition) admixture that either increases the slump of freshly mixed mortar or concrete without increasing the water content, or that maintains the slump with a reduced amount of water, due to factors other than air entrainment.
admixture, water-resisting admixture used to reduce the water-penetrability of concrete. May be either a densifier that eliminates inter-connected voids, or a hydrophobic agent.
ADP ammonium dihydrogen phosphate, used as a dispersion crystal in XRF. The [101] plane has a d-spacing of 0.5320 nm.
aerated concrete, autoclaved light-weight concrete used for block manufacture.
AFm phases abbrev., alumina/iron monosulfate, the archetypes of which are sulfated hydrates of aluminates and ferrites with sulfur/(alumina+iron) molar ratio of 1. Hydrates consisting of hydroxylated layers, with calcium and loosely-bound water between.
AFt phases abbrev., alumina/iron trisulfate, the archetypes of which are sulfated hydrates of aluminates and ferrites with sulfur/(alumina+iron) molar ratio of 3. Hydrates consisting of hydroxylated chains, with calcium and loosely-bound water between.
Afwillite C3S2H3: one of a range of crystalline calcium silicate hydrates.
aggregate (ASTM definition) granular material, such as sand, gravel, crushed stone or iron blastfurnace slag, used with a cementing medium to form hydraulic-cement concrete or mortar.
aggregate, all-in an aggregate containing well-graded proportions of both coarse and fine fractions.
aggregate, coarse (ASTM definition) aggregate predominantly retained on the 4.75-mm sieve.
aggregate, fine (ASTM definition) aggregate passing the 9.5 mm sieve and almost entirely passing the 4.75 mm sieve and predominantly retained on the 75 μm sieve.
aggregate, gap-graded aggregate in which some intermediate size range is missing.
aggregate, heavyweight (ASTM definition) aggregate of high density such as barite, magnetite, limonite, iron or steel.
aggregate, lightweight (ASTM definition) aggregate of low density used to produce lightweight concrete, including: pumice, scoria, volcanic cinders, tuff and diatomite; expanded or sintered clay, shale, slate, diatomaceous shale, perlite, vermiculite or slag; and end products of coal or coke combustion.
aggregate, marine aggregates obtained by sea-dredging. Important in SE England.
ag-lime (ASTM definition) (agricultural lime) either ground quicklime or hydrated lime whose calcium and magnesium content is capable of neutralizing soil acidity.
agricultural lime (ASTM definition) (ag-lime) either ground quicklime or hydrated lime whose calcium and magnesium content is capable of neutralizing soil acidity.
agricultural limestone (ASTM definition) ground or pulverized limestone whose calcium and magnesium content is capable of neutralizing soil acidity.
air blaster device for breaking silo blockages or preheater build-ups; air cannon
air cannon device for breaking silo blockages or preheater build-ups; air blaster
air content (ASTM definition) (of freshly mixed mortar) the volume of air (and other gases) in mortar, expressed as a percentage of total volume of mortar.
air entraining agent a substance that leads to the formation of stable microscopic bubbles in a mix, used either as a concrete admixture, or as a component of the cement.
air void (ASTM definition) a space in cement paste, mortar or concrete filled with air; an entrapped air void is characteristically 1 mm or more in width and irregular in shape; an entrained air void is typically between 10 and 1000 μm in diameter and spherical or nearly so.
air/fuel ratio ratio (usually by mass) of air to fuel in a combustion process: dimensionless
air-cooled blastfurnace slag slag tapped from the furnace and allowed to cool slowly. Such slag is largely crystalline and has no latent hydraulic properties.
air-dry basis AD basis. Reporting format for material analyses in which the constituents are expressed as a percentage of the mass of material after allowing it to dry out to constant mass at room temperature.
air-entraining admixture (ASTM definition) admixture that causes the development of a system of microscopic air bubbles in concrete or mortar during mixing.
air-entraining agents cement additives, or mortar- or concrete admixtures used to introduce a small controlled amount of air into the mix, in the form of minute bubbles.
air-entraining hydraulic cement (ASTM definition) hydraulic cement containing an air entraining addition in such amount as to cause the product to entrain air in mortar within specified limits.
air-entraining portland cement portland cement produced by introducing an air-entaining agent at the grinding stage.
airflow flowrate (usually by volume) of air in a duct: units m3.s-1
airlift a device for conveying materials vertically, by means of low pressure air.
air-separate form of precalciner in which a substantial part, or all, of the combustion air used to burn the precalciner fuel comes from the cooler via the tertiary air duct.
air-slaked lime (ASTM definition) the product containing various proportions of the oxides, hydroxides, and carbonates of calcium and magnesium which results from the exposure of quicklime to the air in sufficient quantity to show physical signs of hydration.
air-through form of precalciner in which all the combustion air used to burn the precalciner fuel first passes through the kiln.
åkermanite magnesium end-member of the melilite series: Ca2MgSi2O7: found in air-cooled blastfurnace slag.
Al2O3 alumina, aluminium oxide, A. Major constituent of cement, 2-7%.
albite NaAlSi3O8, NAS6, sodium end-member of the alkali feldspar series. Common sodium-bearing mineral in clays and shales.
alcohols, polyhydric glycols and sugars: used as grinding aids and cement retarders.
alignment, kiln adjusting rollers to ensure that the centers of all the kiln tyres are co-linear.
alinite approximately Ca11Si3AlO18Cl, C21S6A.CaCl2. Major phase formed when chloride is added to rawmixes for the production of low-energy cements.
alinite cements high-chloride, low-energy cements containing alinite as major phase.
alite crystalline tricalcium silicate, C3S, usually containing small amounts of substituents: principally alumina, iron oxide and magnesia. Hydrates rapidly to form the strength-giving C-S-H.
alkali chlorides mainly NaCl, KCl. Important in kiln volatile cycles because they are almost completely (~99%) evaporated in the burning zone. The mid-kiln concentration is therefore typically 100 times that in the clinker.
alkali feldspar member of the solid solution series NaxK1-xAlSi3O8, end-members orthoclase (x=0) and albite (x=1).
alkali silica reaction reaction in which alkalis from the cement react with active silica in the aggregate to form an alkali silicate gel. imbibation of water into the gel causes disruptive expansion.
alkali waste material containing calcium oxide, hydroxide, carbonate and sulfide resulting from the Leblanc process, and the "causticisation" process. Used as a raw material in early Portland cement manufacture.
alkaline earth solutions (AES) (ASTM definition) an aqueous solution of the oxide or hydroxide of an element of group IIa in the periodic table, such as calcium or magnesium. These solutions may be strongly alkaline.
alkalis the alkali metals: specifically, in cement, the oxides of sodium and potassium.
alkalis, soluble alkalis determined on a water solution leached through a bed of cement. Correlates roughly with the alkalis present as salts in the cement.
alkali-silica gel gel formed when alkalis from the cement react with active silica in the aggregate. Imbibation of water into the gel causes disruptive expansion.
all in aggregate an aggregate containing well-graded proportions of both coarse and fine fractions.
almandine end-member pyralspite garnet of formula Fe3Al2(SiO4)3.
AlSi2O5(OH) S4AH, pyrophyllite, etc: typical phyllite clay mineral.
alternating current impedance spectroscopy technique used for examining the structure of cement pastes.
alternative fuels generally means fuels derived from materials that are otherwise discarded.
alumina aluminium oxide, Al2O3, A. Major constituent of cement, 2-7%.
alumina hydrates aluminium hydroxides – usually AH3 – with varying amounts of associated water, as hydration products of calcium aluminate cements.
alumina modulus mass ratio of alumina to iron (III) oxide
alumina ratio mass ratio of alumina to iron (III) oxide
aluminate (phase) various polymorphs of tricalcium aluminate (C3A) that form from the melt in Portland cement clinker.
aluminium oxide alumina, Al2O3, A. Major constituent of cement, 2-7%.
aluminium powder used as a component in expanded block manufacture. Reacts with alkali to release hydrogen, which foams the paste.
aluminoferrite, tetracalcium approximately C4AF , the system of solid solutions that forms from the melt in Portland cement clinker. Actual composition C4AnF2-n where n = 0 to 1.4 depending upon alumina ratio, plus substituted SiO2, MgO, TiO2, Mn2O3, ZnO etc.
aluminosilicates substances with structures containing complex networks of SiO4 and AlO4 tetrahedra. The main constituents of clays, shales, slates etc.
aluminosulfate C4A3Š. Preferred term calcium sulfoaluminate.
aluminous cement alternative name for calcium aluminate cement.
amorphous substance substance having no detectable regular atomic structure or crystal lattice, disordered in all directions.
analcime, analcite hydrated sodium aluminosilicate, NAS4.2H2O, feldspathoid mineral. Zeolitic constituent of trass.
andalusite aluminium silicate AS.
andesite basic extrusive rocks, forming lava flows, tuffs, trasses, etc.
andradite end-member ugrandite garnet of formula C3FS3.
Andreason pipette obsolete gravimetric sedimentation method for measuring particle size distribution of fine powders.
Ångstrom obsolete unit of length, approximately equal to 0.1 nm. Symbol Å. Used in specifying wavelengths.
anhedral crystal mineral crystal with no faces, deformed to fit the space in the surrounding matrix – indicative of late formation in a freezing melt.
anhydrite various forms of anhydrous calcium sulfate.
anhydrite process (or sulfuric acid process): process for cement manufacture using calcium sulfate instead of calcium carbonate as the lime component. The SO2 emitted by the kiln is oxidized and converted to sulfuric acid by the Contact Process.
anhydrite, insoluble or β-anhydrite, natural anhydrite: the most stable polymorph. Occurs naturally, or obtained by heating other calcium sulfate forms to around 700ºC.
anhydrite, natural or β-anhydrite, "insoluble" anhydrite: the most stable polymorph. Occurs naturally, or obtained by heating other calcium sulfate forms to around 700ºC.
anhydrite, soluble or γ-anhydrite. Form of bassanite with low water content (CaSO4.nH2O where n=0.05-0.2). Formed when gypsum or hemihydrate is heated above 150ºC. Metastable, gradually irreversibly converts to β-anhydrite ("insoluble" anhydrite) at higher temperatures. More soluble than gypsum.
anhydrite, γ- or "soluble" anhydrite. Form of bassanite with low water content (CaSO4.nH2O where n=0.05-0.2). Formed when gypsum or hemihydrate is heated above 150ºC. Metastable, gradually irreversibly converts to β-anhydrite ("insoluble" anhydrite) at higher temperatures. More soluble than gypsum.
anisotropic crystal crystal whose physical properties are different along different axes. All crystals other than cubic are anisotropic.
anorthite CaAl2Si2O8, CAS2, calcium end-member of the plagioclase feldspar series. Common in intrusive rocks.
ANOVA abbrev., analysis of variance.
ANSI abbrev., American National Standards Institute.
anthracite coal in which the content of volatile combustible matter is less than 8% DMF.
antigorite metamorphic rock of the serpentine series.
apatite Ca5(PO4)3OH, 3C3P.Ca(OH)2, common form of phosphate in raw materials. The hydroxyl group is often partially or totally replaced by fluoride.
APCA abbrev., American Portland Cement Alliance: government-lobbying organization run by the PCA (US).
aphthitalite a solid solution series of general formula NanK2-nSO4. n is usually around 0.5 in low-temperature forms.
AR abbrev., Alumina/Iron ratio: alumina modulus
AR basis as-received basis. Reporting format for material analyses in which the constituents are expressed as a percentage of the mass of wet material.
aragonite metastable polymorph of calcium carbonate, present in sea-shells, etc.
arcanite mineral name for potassium sulfate, K2SO4, . Minor phase in portland cement clinker.
arenaceous rocks rocks having sand-minerals as major components.
argillaceous rocks rocks having clay-minerals as major components.
argon/methane (P10): in XRF, used as a detector gas in gas-flow detectors – 10% methane.
artificial pozzolan pozzolan that has been produced by thermal decomposition of aluminosilicates (e.g. burnt shale), or as a byproduct of other high-temperature processes (e.g. silica fume).
AS air-separate. Form of precalciner in which a substantial part, or all, of the combustion air used to burn the precalciner fuel comes from the cooler via the tertiary air duct.
asbestos cement a composite of asbestos fibres and cement. Obsolete.
ash the calcined mineral matter left after a fuel has burned completely.
Aspdin, Joseph (?1778-1855) invented the term "Portland Cement" (1824) although the product he made was a hydraulic lime.
Aspdin, William (1815-1864) invented (1841) Portland cement, as the term is currently understood – i.e. a cement containing alite.
as-received basis AR basis. Reporting format for material analyses in which the constituents are expressed as a percentage of the mass of wet material.
assurance, quality (quality systems): all the planned and systematic activities implemented within the quality system, and demonstrated as needed, to provide adequate confidence that an entity will fulfill requirements for quality.
ASTM The American Society for Testing and Materials. Sets standards for cement in the USA.
AT air-through. Form of precalciner in which all the combustion air used to burn the precalciner fuel first passes through the kiln.
atmospheric pressure, standard pressure equal to 101.325 kPa exactly.
ATOX FLS version of roller mill
attapulgite swelling clay, typically M2AS8H.24H2O. Alternatively palygorskite.
attritor type of high-speed hammer mill, commonly used for grinding coal.
audit trail (quality systems): an quality auditing process in which the documentary history of an entity's movement through the quality system is examined and verified.
audit, quality (quality systems): systematic and independent examination to determine whether quality activities and related results comply with planned arrangements and whether these arrangements are implemented effectively and are suitable to achieve objectives.
Auger effect in XRF, a process that competes with the fluorescence process: on absorption of a primary photon, instead of emitting secondary radiation, the atom emits an energetic electron.
augite intermediate-composition pyroxenes, typical composition Ca0.3Mg0.3Fe0.4SiO3. Component of many natural pozzolans.
auto sampler a sampler designed to withdraw a sample from a process stream continuously, or intermittently at pre-determined times, automatically.
autoclave expansion test ASTM test method (C 151) for soundness of cement
auxiliaries ancillary equipment associated with a unit process, aside from the main drive.
availability the percentage of time that a piece of equipment is available for use, even though not necessarily required.
available lime (ASTM definition) those constituents of a lime which enter into a desired reaction under the conditions of a specific method or process.
axial test of ball-mills, size analysis of feed at uniformly-spaced points along the length of the mill./td>
back-end (BE) the upper end of a rotary kiln at which the feed enters.
ball mill rotating vessel in which material is ground by cascading media.
balling (1) kiln operational problem in which the feed agglomerates into balls up to 2 m in diameter. (2) similar agglomeration of material in a ready-mix truck.
BaO barium oxide. Minor constituent of cement, 0-0.2%.
bar (obsolete) unit of pressure, equal to 100 kPa.
barite barytes, heavy spar, tiff, barium sulfate, BaSO4. Used as a high-density aggregate (dens 4480).
barium oxide BaO. Minor constituent of cement, 0-0.2%.
barium sulfate barite, barytes, heavy spar, tiff, BaSO4. Used as a high-density aggregate (dens 4480).
barrel (of cement) obsolete unit of cement mass. The barrel was the standard unit of cement output almost everwhere - except Britain, where the Imperial ton (2240 lb) was used - and continued in use in Germany (the fass) and the USA into the 20th century. There were many mass values considered standard, being typically the amount accommodated by a barrel of 4 cubit feet capacity. The standard fass was 170 kg. The "standard" barrel of cement last in use in the USA weighed 376 lb (170.5508 kg). The "barrel" of clinker was a smaller mass, being the amount that would make one barrel of cement.
barytes barite, heavy spar, tiff, barium sulfate, BaSO4. Used as a high-density aggregate (dens 4480).
basalt basic extrusive rock used as an aggregate, and as an abrasion-resistant duct lining.
BaSO4 barite, barytes, heavy spar, tiff, barium sulfate. Used as a high-density aggregate (dens 4480).
bassanite mineral consisting of calcium sulfate with varying degree of hydration due to variable numbers of water molecules filling channels in its crystal structure: CaSO4.nH2O or CŜHn, where n=0.05-0.7. Formed when gypsum is heated above 70ºC: on raising the temperature, n steadily decreases until at around 250ºC natural anhydrite (β-anhydrite, n=0) is formed. Forms at the higher end of the n-range are sometimes called "hemihydrate". Forms at the lower end of the n-range are sometimes called "γ-anhydrite" or "soluble anhydrite". Component of finished Portland cement, more soluble than gypsum.
Batchelor kiln elaborate form of chamber kiln, with double-decked drying chambers.
bauxite a soft mineral containing either gibbsite (Al(OH)3) or boehmite (AlO(OH)). A type of laterite.
bauxitic clay clay containing gibbsite or boehmite.
BCA Abbrev. - British Cement Association: industry association (UK) formed in 1987 by merger of the Cement Makers' Federation (CMF) and the Cement & Concrete Association (C&CA). Merged into the Mineral Products Association (MPA) in 2009.
BE abbrev., back-end: the upper end of a rotary kiln at which the feed enters.
BE O2 abbrev., back end gas oxygen content, usually expressed as % dry basis, by volume.
BEI abbrev., backscattered electron imaging.
beehive kiln form of bottle kiln of a characteristic beehive-shape.
belite the α- and β- polymorphs of dicalcium silicate, C2S, usually containing small amounts of substituents: principally alumina, iron oxide and magnesia. Hydrates slowly to form the strength-giving C-S-H.
bentonite expanding sodium montmorillonite clay used for thickening of slurries.
Bernoulli's Theorem for a fluid moving in a duct, the sum of the pressure energy, the potential energy and the kinetic energy is a constant at all points.
Besta feeder airlock feeder for introducing material into a pressurized system.
BET abbrev., back end (gas) temperature.
BET gas absorption Brünauer Emmett Teller method for assessing specific surface area. Gives higher value than air permeability, due to measurement of internal surfaces.
BGS abbrev., British Geological Survey.
bias the systematic component of the error of a test method: the mean deviation (positive or negative) from the true value.
bias (of a measuring instrument) (ISO definition) systematic error of the indication of a measuring instrument.
biaxial crystal crystal with two optic axes and three principal indices of refraction.
binary eutectic the minimum-melting-point mixture in a system of two components.
binding agent in XRF, a material added to a sample in order to improve the strength of a pressed pellet.
Bingham plastic a non-Newtonian fluid that behaves as a solid when under low stress, and a liquid under higher stress. Many solid/water pastes and slurries conform approximately to this model.
binomial distribution distribution function applicable to the frequency of binary (pass/fail) attributes in a small sample taken from a large population.
birefringence the difference between the greatest and the least index of refraction of an anisotropic crystal.
bituminous coal coal in which the content of volatile combustible matter is in the range 15-35% DMF.
black body a notional body that totally absorbs all incoming frequencies of radiation, reflecting none.
Blaine Raymond Leonard Blaine: researcher at NBS. Invented a technique for measuring fineness of cement in terms of specific surface.
Blaine apparatus apparatus for determination of the fineness of a powder in terms of specific surface. SI units of specific surface: m2/kg.
blastfurnace cement (European) cement containing 36-95% granulated blastfurnace slag in addition to clinker in its nucleus composition. EN 197 CEM III cement.
blastfurnace slag the molten material produced in an iron blastfurnace as a result of the reaction between the limestone flux and the siliceous and aluminous impurities in the iron ore. Extracted by periodically tapping off the molten layer from above the molten iron in the base of the furnace.
blast-furnace slag (ASTM definition) the nonmetallic product, consisting essentially of silicates and aluminosilicates of calcium and other bases, that is developed in a molten condition simultaneously with iron in a blast furnace.
blast-furnace slag cement, portland (ASTM) a hydraulic cement consisting of an intimately interground mixture of portland-cement clinker and granulated blastfurnace slag or an intimate and uniform blend of portland cement and fine granulated blastfurnace slag in which the amount of the slag constituent is between 25 and 70%. C 595 Type IS.
blastfurnace slag, air-cooled slag tapped from the furnace and allowed to cool slowly. Such slag is largely crystalline and has no latent hydraulic properties.
blastfurnace slag, crystalline blastfurnace slag that has crystallized during slow cooling.
blast-furnace slag, expanded (ASTM definition) the lightweight cellular material obtained by controlled processing of molten blast-furnace slag with water or water and other agents, such as steam or compressed air or both.
blastfurnace slag, foamed used as a light-weight aggregate.
blastfurnace slag, granulated To granulate slag, the molten slag is rapidly cooled, typically by immersion in water, as soon as it leaves the furnace. The cooling must be sufficiently rapid that crystallization can't take place, and a glass is formed.
blast-furnace slag, granulated (ASTM definition) the glassy granular mate­rial formed when molten blast-furnace slag is rapidly chilled, as by immersion in water.
blastfurnace slag, pelletized slag quenched with a limited amount of water, resulting in partial crystallization. Used in lower-quality slag cements.
bleaching in white cement manufacture, treating clinker leaving the kiln burning zone with an impinging reducing flame, causing conversion of Fe(III) to Fe(II).
bleeding of concrete the separation of clear water on the surface of concrete as a result of gravitational settlement of its solid particles.
bleed-water water that sometimes separates on the surface of concrete as a result of gravitational settlement of its solid particles.
blended hydraulic cement (ASTM definition) a hydraulic cement consisting of two or more inorganic constituents (at least one of which is not portland cement or portland cement clinker) which separately or in combination contribute to the strength­ gaining properties of the cement, (made with or without other constituents, processing additions and functional additions, by intergrinding or other blending).
blended hydraulic cement, trass cement produced by grinding portland cement clinker with 20-50% trass.
block cement (US) fine, rapid-hardening cement usually containing around 10% carbonate filler.
Blue Circle British-based international cement manufacturer
Blue Lias limestone argillaceous limestone used as a cement raw material from earliest times, in South Wales and southwest and central England, located at the base of the Jurassic.
boehmite AlO(OH): aluminium hydroxide. A soft mineral, constituent of some bauxites.
Bogue Robert Herman Bogue: researcher at the National Bureau of Standards, 1925-1955: devised a method of correlating the mineralogy of clinkers with their bulk chemistry.
Bogue calculations simultaneous equations relating the content of SiO2, Al2O3, Fe2O3 and CaO to the notional content of C3S, C2S, C3A and C4AF.
Bogue compounds the compounds C3S, C2S, C3A and C4AF. Quantities of these calculated from the bulk composition of a clinker assuming (mistakenly) that the clinker minerals have these idealized compositions.
Bogue equations equations based on the Bogue calculation for obtaining the notional content of C3S, C2S, C3A and C4AF.
bottle kiln intermittent kiln (20-30 tonnes/week) with primitive oval burning vessel, with a tapering upward extension to improve draught. Obsolete: much used in the early industry.
bottom ash large particles of partially fused ash that drop out of the gas stream by gravity in a pulverized-coal burning boiler. Finer particles carried in suspension by the gas are flyash (PFA).
Bragg's Law in X-ray diffraction, relates the angle of incidence of the diffracted ray to the perpendicular distance between crystal planes. sinθ=nλ/2d where λ is the X-ray wavelength and n is the reflection order.
bredigite inert, low-temperature silicate phase containing magnesia, C1.7M0.3S.
British cement brand name for hydraulic lime produced by Frost at Swanscombe, England, around 1810 onwards.
British Cement Association BCA: industry association (UK) formed in 1987 by merger of the Cement Makers' Federation (CMF) and the Cement & Concrete Association (C&CA). Merged into the Mineral Products Association (MPA) in 2009.
British thermal unit Btu, obsolete unit of heat energy, originally defined as the heat to raise 1 lb of water by 1ºF. Because the heat capacity of water varies with temperature, several different Btus may be encountered. Values vary from 1054 to 1060 J. Now used, ironically, only in the USA, where the value 1055.056 J is most commonly encountered, although the type used is rarely specified (or known) by the user.
brownmillerite mineral name for tetracalcium aluminoferrite solid solution series.
brucite mineral name for magnesium hydroxide, Mg(OH)2.
BSE abbrev., backscattered electron.
Btu British thermal unit, obsolete unit of heat energy.
building lime (ASTM definition) a lime whose chemical and physical characteristics and method of processing make it suitable for the ordinary or special construction uses of the product.
burner pipe (US) the pipe (or set of pipes) concentric with the kiln that passes through the kiln hood and conveys the fuel into the flame. Also called firing pipe (UK).
burning, double early cement manufacturing process in which limestone was burnt to lime, slaked, and mixed with clay slip, dried, and burnt a second time to clinker. Avoided the need to grind hard limestone.
burning zone the hottest part of a cement kiln in which the feed reaches sintering temperature.
burnt shale cement, portland (European) cement containing 6-35% burnt shale in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
butt strap a steel strap tying together the components of a butt joint, as in riveted kiln construction.
BZ abbrev., (kiln) burning zone
BZT abbrev., (kiln) burning zone temperature
C cement chemist's notation for lime, CaO.
Č cement chemist's notation for carbon dioxide, CO2.
C&CA abbrev., Cement and Concrete Association (UK).
C10S3Š3H hydroxyl ellestadite: common mid-kiln mineral in cement kilns
C12A7 dodecacalcium heptaaluminate. Highly reactive constituent of calcium aluminate cements. (Hypothetical anhydrous form).
C12A7H normal room-temperature form of dodecacalcium heptaaluminate; hydroxy groups are not lost until near the melting point. Mineral name Mayenite.
C20A13M3S3 Phase Q
C21S6A.CaCl2 alinite, Ca11Si3AlO18Cl. Major phase formed when chloride is added to rawmixes for the production of low-energy cements.
C2A dicalcium aluminate. Does not exist at ordinary pressures. Early texts applied this name to what is now known to be dodecacalcium heptaaluminate.
C2AS gehlenite, Ca2Al2SiO7. Calcium end-member of the melilite series: unreactive mineral found in calcium aluminate cements and air-cooled blastfurnace slags.
C2ASH8 strätlingite, (gehlenite hydrate), natural AFm mineral formed by hydration of some calcium aluminate cements and slag cements.
C2S called dicalcium silicate when pure. In real clinkers, the α- or β-form of the mineral is called belite, and usually contains small amounts of substituents: principally alumina, iron oxide and magnesia. Hydrates slowly to form the strength-giving C-S-H.
C2S3H2 gyrolite: one of a range of crystalline calcium silicate hydrates.
C2SH hillebrandite: one of a range of crystalline calcium silicate hydrates.
C2SH, α- α-dicalcium silicate hydrate.
C3A tricalcium aluminate, Ca3Al2O6. The most basic calcium aluminate, present in Portland cement clinker as an interstitial phase, crystallized from the melt. In real clinkers, it contains varying amounts of other oxides, particularly alkalis. The lower alkali form is cubic, and the higher alkali form is orthorhombic. Hydrates very rapidly in the absence of sulfate to form C3AH6, producing "flash set". In the presence of sulfate (~2%) the C3A is temporarily passivated due to the formation of an insoluble layer of ettringite.
C3A·3CaSO4·H32 ettringite, calcium sulfoaluminate hydrate, C63H32, prototype AFt phase, hydration product of cement that prevents flash set by passivating C3A. Late formation due to sulfate attack causes destructive expansion.
C3A·CaCl2·H10 Friedel's salt
C3MS2 merwinite, Ca3MgSi2O8,. Component of air-cooled blastfurnace slags.
C3S called tricalcium silicate when pure. In real clinkers, the mineral is called alite, and usually contains small amounts of substituents: principally alumina, iron oxide and magnesia. Hydrates rapidly to form the strength-giving C-S-H.
C3S2 tricalcium disilicate, Ca3Si2O7. Lower calcium silicate, not found in portland cement, mineral name rankinite.
C3S2·CaF2 calcium silicate fluoride, cuspidine
C3S2H3 afwillite: one of a range of crystalline calcium silicate hydrates.
C3S6H8 nekoite: one of a range of crystalline calcium silicate hydrates.
C3SŠČH15 thaumasite
C4A3Š kleinite, Klein's compound, calcium sulfoaluminate. Intermediate compound in cement kilns and component of ettringite cements. Mineral name Ye'elimite.
C4AF (approximately) the system of solid solutions that forms from the melt in Portland cement clinker, mineral name brownmillerite. Actual composition C4AnF2-n where n = 0 to 1.4 depending upon alumina ratio, plus substituted SiO2, MgO, TiO2, Mn2O3, ZnO etc.
C4AŜH12 "monosulfate", calcium monosulphoaluminate hydrate, prototype AFm phase, product of hydration of aluminates in the presence of restricted amounts of sulfate. Conversion of this to ettringite by excess sulfate causes destructive expansion.
C4S3H foshagite: one of a range of crystalline calcium silicate hydrates.
C5A3 pentacalcium trialuminate, conjectural and, in fact, non-existent calcium aluminate now known to be C12A7.
C5S2H calciochondrodite: one of a range of crystalline calcium silicate hydrates.
C5S2Š calcium sulfosilicate - mineral name ternesite, incorrectly called sulfospurrite. Low temperature intermediate in cement kilns.
C5S5H xonotlite: one of a range of crystalline calcium silicate hydrates.
C63H32 ettringite, calcium sulfoaluminate hydrate, C63H32, prototype AFt phase, hydration product of cement that prevents flash set by passivating C3A. Late formation due to sulfate attack causes destructive expansion.
C6S10H3 truscottite: one of a range of crystalline calcium silicate hydrates.
C6S2H3 tricalcium silicate hydrate: one of a range of crystalline calcium silicate hydrates.
CA calcium monoaluminate, CaAl2O4. Highly hydraulically reactive component of calcium aluminate cements.
Ca11Si3AlO18Cl alinite, C21S6A.CaCl2. Major phase formed when chloride is added to rawmixes for the production of low-energy cements.
CA2 calcium dialuminate, CaAl4O7. Relatively unreactive aluminate found in small quantities in calcium aluminate cements. Also occurs rarely in nature as grossite.
Ca2Al2SiO7 gehlenite, C2AS. Calcium end-member of the melilite series: unreactive mineral found in calcium aluminate cements and air-cooled blastfurnace slags.
Ca2K2(SO4)3 calcium langbeinite, calcium potassium sulfate, KC2Ŝ3. Common minor phase in portland cement clinker.
Ca3Al2O6 tricalcium aluminate, C3A. The most basic calcium aluminate, present in Portland cement clinker as an interstitial phase, crystallized from the melt. In real clinkers, it contains varying amounts of other oxides, particularly alkalis. The lower alkali form is cubic, and the higher alkali form is orthorhombic. Hydrates very rapidly in the absence of sulfate to form C3AH6, producing "flash set". In the presence of sulfate (~2%) the C3A is temporarily passivated due to the formation of an insoluble layer of ettringite.
Ca3MgSi2O8 merwinite, C3MS2. Component of air-cooled blastfurnace slags.
Ca3Si2O7 tricalcium disilicate, C3S2. Lower calcium silicate, not found in portland cement, mineral name rankinite.
Ca5(PO4)3F fluoroapatite, 3C3P.CaF2, common form of phosphate in raw materials.
Ca5(PO4)3OH apatite, 3C3P.Ca(OH)2, common form of phosphate in raw materials.
CA6 calcium hexa-aluminate, CaAl12O19. Unreactive mineral formed in high-alumina calcium aluminate cements. Also found rarely in nature as the mineral hibonite.
CaAl12O19 calcium hexa-aluminate, CA6. Unreactive mineral formed in high-alumina calcium aluminate cements. Also found rarely in nature as the mineral hibonite.
CaAl2O4 calcium monoaluminate, CA. Highly hydraulically reactive component of calcium aluminate cements.
CaAl4O7 calcium dialuminate, CA2. Relatively unreactive aluminate found in small quantities in calcium aluminate cements. Also occurs rarely in nature as grossite.
cabazite type of zeolite present in some pozzolans.
CAC abbrev., calcium aluminate cement.
CaF2 calcium fluoride: mineral name fluorite. Used as in mineralizer in cement manufacture.
CaFeSi2O6 mineral name hedenbergite. Salite pyroxene mineral found in igneous and metamorphic rocks.
cake, filter product of a slurry filtration process
calcareous (ASTM definition) originating from predominately calcium carbonate or one of its derivative forms.
Calcinator trade name for a slurry drying device consisting of a rotating cage filled with heat exchange bodies, through which the kiln exhaust gases pass, and into which slurry is sprayed. Manufactured by MIAG.
calcination strong heating of a substance to form oxide(s). Specifically, thermal decomposition of calcium carbonate, releasing carbon dioxide.
calciner a reactor in which calcium carbonate is thermally decomposed, usually in gas suspension.
calcining zone Intermediate zone of the kiln in which de-carbonation takes place, feed temperature 650-1050ºC
calciochondrodite C5S2H: one of a range of crystalline calcium silicate hydrates.
calcite the stable, naturally occurring polymorph of calcium carbonate. Main mineral in most cement rawmixes.
calcium potassium sulfate hydrate syngenite, K2Ca(SO4)2.H2O, KCŜ2H. Often responsible for pack-set in high-alkali cements.
calcium aluminate cement also known, inaccurately, as high-alumina cements. Cements with CA and C12A7 as their main active ingredients.
calcium aluminates a series of five different compounds of lime and alumina.
calcium aluminosulfate C4A3Š. Preferred term calcium sulfoaluminate.
calcium carbonate CaCO3, . Mineral forms calcite, aragonite, vaterite.
calcium chloride used as an accelerating admix in concrete and as a component in cements. In high doses (>0.2% of cement), causes corrosion of steel reinforcement.
calcium dialuminate CaAl4O7, CA2. Relatively unreactive aluminate found in small quantities in calcium aluminate cements. Also occurs rarely in nature as grossite.
calcium fluoride CaF2: mineral name fluorite. Used as in mineralizer in cement manufacture.
calcium formate used as a non-corrosive accelerator in concrete.
calcium hexa-aluminate CaAl12O19, CA6. Unreactive mineral formed in high-alumina calcium aluminate cements. Also found rarely in nature as the mineral hibonite.
calcium hydroxide Ca(OH)2, mineral name portlandite.
calcium langbeinite calcium potassium sulfate, Ca2K2(SO4)3, KC2Ŝ3. Common minor phase in portland cement clinker.
calcium monoaluminate CaAl2O4, CA. Highly hydraulically reactive component of calcium aluminate cements.
calcium monosulphoaluminate hydrate "monosulfate",C4AŜH12, prototype AFm phase, product of hydration of aluminates in the presence of restricted amounts of sulfate. Conversion of this to ettringite by excess sulfate causes destructive expansion.
calcium nitrite commonly used as a corrosion inhibitor in reinforced concrete.
calcium oxide lime, CaO, C. Major constituent of cement, 58-69%.
calcium potassium sulfate calcium langbeinite, Ca2K2(SO4)3, KC2Ŝ3. Common minor phase in portland cement clinker.
calcium stearate used as a waterproofing agent in concrete.
calcium sulfate (ASTM definition) as applied to cement manufacturing, a product composed essentially of calcium sulfate in any hydration state or states: anhydrite (CaSO4), gypsum (CaSO4.2H2O), and hemihydrate (CaSO4.0.5H2O).
calcium sulfate (mineralogical definition) exists in three mineral forms, depending on degree of hydration CaSO4.nH2O: natural anhydrite (n=0), bassanite (n=0.05-0.7) and gypsum (n=2).
calcium sulfate dihydrate CaSO4.2H2O, CŠH2, mineral name gypsum. Used for set control in cement manufacture.
calcium sulfate hemihydrate CaSO4.0.5H2O, CŠH0.5, representative formula of a range of compositions of bassanite with high water contents, formed when gypsum is heated above 70ºC. Loses water on heating, without change of mineral structure, forming "soluble anhydrite" (γ-anhydrite). Component of finished cement, more soluble than gypsum.
calcium sulfate, γ - or "soluble" anhydrite (CaSO4.nH2O where n=0.05-0.2. The low water-content form of bassanite, formed when gypsum or hemihydrate is heated above 150ºC. Metastable, gradually irreversibly converts to β-anhydrite ("insoluble" or "natural" anhydrite) at higher temperatures.
calcium sulfoaluminate kleinite, Klein's compound, C4A3Š. Intermediate compound in cement kilns and component of ettringite cements. Mineral name Ye'elimite.
calcium sulfosilicate C5S2Š, mineral name ternesite, sometimes incorrectly called sulfospurrite. Low temperature intermediate in cement kilns.
calcium titanium oxide CaTiO3, CT, mineral name perovskite. Main titanium mineral found in basic igneous rocks.
calibration (ISO definition) the set of operations which establish, under specified conditions, the relationship between values indicated by a measuring instrument or measuring system, or values represented by a material measure or a reference material, and the corresponding values of a quantity realized by a reference standard.
calorific value (CV) the amount of heat produced at constant volume when a fuel is burned, per unit mass of fuel. Units MJ/kg. In normal coals, the calorific value increases with carbon content and (much more) with hydrogen content, and diminishes with oxygen content. It therefore increases with rank up to the steam coal stage, after which loss of hydrogen causes it to decrease.
calorific value, gross (GCV) calorific value determined in conditions in which water produced by combustion is condensed to liquid. The standard laboratory method for liquid and solid fuels produces a gross value.
calorific value, nett (NCV) calorific value determined in conditions in which water produced by combustion remains in the gas phase. This is the normal condition of use of a fuel, and the nett value must be calculated from the gross value determined in the laboratory. NCV = GCV - 0.21829 H - 0.02443 M MJ/kg where H is % organic hydrogen content and M is % inherent moisture content. NCV can not be calculated if the hydrogen content is unknown.
Calorie (as a unit, Cal). Obsolete unit of heat energy, originally defined as the heat required to raise 1 g of water by 1ºC. Because the heat capacity of water varies with temperature, a number of different calories are encountered.
Calorie, 15ºC obsolete unit defined as the heat required to raise 1 g of water from 14.5ºC to 15.5ºC, equal to about 4.1855 J.
Calorie, IST International Steam Table calorie, obsolete unit commonly encountered in engineering texts, and defined as 4.1868 J.
Calorie, Thermochemical obsolete unit commonly encountered in thermodynamics texts, and defined as 4.1840 J. Used in calibration of fuel calorimeters, and therefore the most commonly encountered calorie in the cement industry.
CaMgSi2O6 CMS2, mineral name diopside. Salite pyroxene mineral common in igneous and metamorphic rocks.
cannibalistic crystal growth growth of large crystals in a melt with concurrent dissolution of smaller crystals, driven by a net reduction in the surface energy of the system.
cannon, air device for breaking silo blockages or preheater build-ups; air blaster.
CaO lime, calcium oxide, C. Major constituent of cement, 58-69%.
capability, process (SPC): the inherent natural variability of a process and its associated measuring system, after the effects of special causes have been eliminated.
caprock a stratum of rock near the top surface of a formation, typically formed by modification of the rock due to weathering.
carbonaceous rocks rocks containing coal-like minerals
carbonate aggregates refers mainly to calcite and dolomite aggregates.
carbonate titration assessment of acid-soluble carbonates in rawmix by treatment with standard acid followed by back-titration with standard alkali. Used as simple rawmix composition control technique.
carbonation reaction of concrete with atmospheric carbon dioxide
Carboniferous limestone limestone of the Pennines, Scotland, Ireland, Wales, much used in UK cement manufacture. Lower carboniferous age (=Mississippian, US)
carborundum silicon carbide, SiC. Used as an abrasion-resistant aggregate, and in some high-corrosion-resistance refractories.
CaSO4.0.5H2O calcium sulfate hemihydrate, CŜH0.5, representative formula of a range of compositions of bassanite with high water contents, formed when gypsum is heated above 70ºC. Loses water on heating, without change of mineral structure, forming "soluble anhydrite" (γ-anhydrite). Component of finished cement, more soluble than gypsum.
CaSO4.2H2O calcium sulfate dihydrate, CŜH2, mineral name gypsum. Used for set control in cement manufacture.
CaTiO3 calcium titanium oxide, CT, mineral name perovskite. Main titanium mineral found in basic igneous rocks.
causes, common (SPC): the irreducible normal distribution of variation events that lead to the inherent variability of a system.
causes, special (SPC): causes of measured variation in a process that consist of events outside the population of common causes leading to inherent variability.
causticisation obsolete process for converting sodium carbonate into sodium hydroxide by reacting with calcium hydroxide. Produced waste calcium carbonate which was historically used in cement manufacture.
CCRL abbrev., Cement and Concrete Reference Laboratory. Certifying agency for ASTM cement and concrete testing.
Celcon brand name, cellular concrete blocks using aluminium-powder foaming of sand/cement/lime paste.
cellular concrete (ASTM definition) a lightweight hydraulic-cement concrete having a homogeneous void or cell structure attained using gas-forming chemicals or foaming agents.
CEM I cement (European) cement containing only 0-5% minor additional constituents in addition to clinker in its nucleus composition. Portland cement.
CEM II cement (European) cement termed portland [component] cement where the [component] may be slag, silica fume, pozzolan, fly ash, burnt shale, limestone or a combination of these in amounts 6-35%.
CEM III cement (European) cement containing 36-95% granulated blastfurnace slag in addition to clinker in its nucleus composition. Blastfurnace cement.
CEM IV cement (European) cement containing 11-55% pozzolan in addition to clinker in its nucleus composition. Pozzolanic cement.
CEM V cement (European) cement containing 36-80% of both granulated blastfurnace slag and pozzolan, in addition to clinker in its nucleus composition. Composite cement.
Cement and Concrete Association (C&CA) UK industry research association, merged into the British Cement Association (BCA) in 1987, which in turn merged into the Mineral Products Association (MPA) in 2009.
cement chemist's notation expression of elemental oxides as single-letter symbols. Given in BOLD in this document. Also frequently encountered in texts on geochemistry.
SiO2S
Al2O3A
Fe2O3F
CaOC
MgOM
SO3Š
H2OH
CO2Č
Na2ON
K2OK
TiO2T
P2O5P
cement cooler device for cooling cement leaving the cement mill to an acceptable temperature.
Cement Makers' Federation CMF: industry association (UK). Merged with the Cement & Concrete Association in 1987 to form the British Cement Association (BCA), which in turn merged into the Mineral Products Association (MPA) in 2009.
cement mill (UK etc) mill in which clinker is ground to cement fineness. In US, finish mill. (US, obsolete) entire cement plant.
cement nucleus EN term for the all the components of a cement, excluding the calcium sulfate and additives.
cement plaster a soft mixture of lime and/or cement with sand and water for spreading on walls, ceilings, or other structures to form a smooth hard surface when cured.
cement rock limestone containing dispersed argillaceous mineral impurities in approximately the proportion needed for cement manufacture. Can be burned without grinding to produce a crude "natural" cement.
cement, aluminous alternative name for calcium aluminate cement.
cement, blastfurnace (European) cement containing 36-95% granulated blastfurnace slag in addition to clinker in its nucleus composition. EN 197 CEM III cement.
cement, blended hydraulic (ASTM definition) a hydraulic cement consisting of two or more inorganic constituents (at least one of which is not portland cement or portland cement clinker) which separately or in combination contribute to the strength­ gaining properties of the cement, (made with or without other constituents, processing additions and functional additions, by intergrinding or other blending).
cement, block (US) fine, rapid-hardening cement usually containing around 10% carbonate filler.
cement, British brand name for hydraulic lime produced by Frost at Swanscombe, England, around 1810 onwards.
cement, calcium aluminate also known, inaccurately, as high-alumina cements. Cements with CA and C12A7 as their main active mineral phases. Usually made by complete melting, and therefore also known by the Lafarge proprietary name "ciment fondu".
cement, coloured cement with inert pigments added.
cement, composite (European) cement containing 36-60% of both granulated blastfurnace slag and pozzolan, in addition to clinker in its nucleus composition. EN 197 CEM V cements.
cement, eisenportland German designation for portland blastfurnace slag cement containing 5-40% slag.
cement, erz early sulfate-resisting portland cement with a low (0.2-0.3) A/F ratio.
cement, expansive a hydraulic cement that forms a paste that increases in volume a controlled amount during the early hardening period occurring after setting.
cement, Ferrari early sulfate-resisting portland cement with a low (0.2-0.3) A/F ratio.
cement, flyash blended cement containing flyash (pfa) as a pozzolanic and/or workability-enhancing component.
cement, Frost's hydraulic lime produced by Frost at Swanscombe, England, around 1810 onwards.
cement, hochofen German designation for portland blastfurnace slag cement containing 41-85% slag.
cement, hydraulic (ASTM definition) a cement that sets and hardens by chemical interaction with water and that is capable of doing so under water.
cement, hydrophobic cement treated with a material rendering the particles hydrophobic, so that reaction with water does not begin until the surface material is worn off during mixing. Typically ~0.1% of fatty acid is interground.
cement, Keene's a cement consisting essentially of β-anhydrite, activated by inclusion of foreign ions, obtained by treating a pure gypsum plaster with a solutions of alum, then re-burning at 600°C, and grinding finely. Sets slowly and produces a harder product than hemihydrate.
cement, latent hydraulic substance that acts as a hydraulic cement when mixed with water and a minimal amount of some other substance that acts as a catalyst or activator: e.g. ground granulated blastfurnace slag (ggbs).
cement, low alkali cement supplied with a view to minimizing the risk of alkali/silica reaction. Specification maxima for equivalent alkalis range from 0.4 to 1.0%, but values of 0.6-0.7 are most common.
cement, magnesium oxychloride a cement produced by mixing magnesium chloride with freshly-burned magnesium oxide.
cement, masonry (ASTM definition) a hydraulic cement manufactured for use in mortars for masonry construction or in plasters, or both, which contains a plasticizing material and, possibly, other performance-enhancing addition(s).
cement, natural (ASTM definition) a hydraulic cement produced by calcining a naturally occurring argillaceous limestone at a temperature below the sintering point and then grinding to a fine powder.
cement, oil well cement used to seal the space between the well lining and the surrounding fractured rock. Special cement designed to make a pumpable paste under conditions of high temperature and pressure.
cement, portland (ASTM definition) a hydraulic cement produced by pulverizing portland-cement clinker, and usually containing calcium sulfate. ASTM C 150 Types I-V. (European) cement containing only 0-5% minor additional constituents in addition to clinker in its nucleus composition. EN 197 CEM I cement.
cement, portland blast-furnace slag (ASTM) a hydraulic cement consisting of an intimately interground mixture of portland-cement clinker and granulated blastfurnace slag or an intimate and uniform blend of portland cement and fine granulated blastfurnace slag in which the amount of the slag constituent is between 25 and 70%. C 595 Type IS.
cement, portland burnt shale (European) cement containing 6-35% burnt shale in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
cement, portland composite (European) cement containing 6-35% of multiple mineral cementitious components in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
cement, portland fly ash (European) cement containing 6-35% fly ash in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
cement, portland limestone (European) cement containing 6-35% limestone in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
cement, portland pozzolan (ASTM) blended cement containing 15-40% pozzolan in addition to clinker and calcium sulfate. C 595 Type IP. (European) cement containing 6-35% pozzolana in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
cement, portland silica fume (European) cement containing 6-10% silica fume in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
cement, portland slag (European) cement containing 6-35% granulated blastfurnace slag in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
cement, pozzolan modified portland (ASTM) blended cement containing 0-15% pozzolan in addition to clinker and calcium sulfate. ASTM C 595 Type I(PM).
cement, pozzolanic (European) cement containing 11-55% pozzolan in addition to clinker in its nucleus composition. EN 197 CEM IV cement.
cement, Roman 1) cement used by the Romans – consisted of lime and pozzolan. 2) brand name for a hydraulic lime invented by Parker, UK, 1796.
cement, self-stressing expansive cement used in self-stressing concrete.
cement, shrinkage-compensating form of expansive cement. Used in concrete, early expansion is produced sufficient to counteract later shrinkage, so avoiding the occurrence of tensile cracking.
cement, slag (ASTM) blended cement consisting of 70-100% granulated blastfurnace slag, plus clinker, calcium sulfate and/or hydrated lime. C 595 Type S.
cement, slag-modified portland (ASTM) an intimate and uniform blend of portland cement and granulated blastfurnace slag produced either by intergrinding or a combination of grinding and blending in which the slag constituent is less than 25% of the total, by mass. ASTM C 595 Type I(SM).
cement, soil cement used in soil stabilization, in which cement is blended into damp soil, and the mixture is roller compacted. The fine cement acts partly as an adhesive and partly as a grout.
cement, Sorel a kind of magnesium oxychloride cement.
cement, sulfate resisting portland portland cement that produces a concrete that is stable in contact with sulfate solutions. Aluminates are subject to expansive reaction with sulfate, and these are minimized in SRPC.
cement, sulfoaluminate cement containing kleinite (ye'elimite) as an active component, as in low-energy cements, expansive cements and ultra-high-early strength cements.
cement, supersulfated cement made from granulated blastfurnace slag (80-85%), calcium sulfate (10-15%) and portland cement (~5%). Gains strength mainly by formation of ettringite and C-S-H.
cement, ternary a composite or blended cement containing three cementitious components.
cement, trass cement produced by grinding portland cement clinker with 20-50% trass.
cement, white cement with low proportions of colouring elements in its composition: specifically, ultra-low-iron cement.
cementitious material, hydraulic (ASTM definition) an inorganic material or a mixture of inorganic materials which sets and develops strength by chemical reaction with water by formation of hydrates, and which is capable of doing so under water.
cements, lime pozzolan primitive cements consisting of mixtures of lime and pozzolan, that slowly develop strength by pozzolanic reaction.
cements, silica fume cements containing silica fume in amounts 3-20%. The silica fume reacts rapidly with the calcium hydroxide produced during cement hydration to produce enhanced strength at all ages.
CEMEX = Cementos Mexicanos: Mexican-based international cement manufacturer
CEN abbrev., Comité Européen de Normalisation. The European standards organization.
cenosphere mineral body in the form of a hollow egg-shell structure, formed by simultaneous rapid melting and out-gassing, forming a glassy bubble. Flyash (pfa) consists mainly of cenospheres.
centipoise cP (obsolete) unit of dynamic viscosity, =1 mPa.s
CETIC abbrev., Comité Européen Technical de l'Industrie Cimentière. European cement industry technical committee.
CGT abbrev., chain gas temperature: gas temperature downhill of kiln chained zone.
chabazite a pozzolanic zeolite.
chain curtains in kilns, heat exchange chains hung at one end from a circumferential hanging ring.
chain festoons in kilns, heat-exchange chains attached at both ends to a single circumferential hanging ring.
chain garlands in kilns, heat-exchange chains attached at each end to two axially displaced circumferential hanging rings.
chains, spiral in kilns, heat-exchange chains attached at one end to a helical hanging bar.
chalcedony amorphous silica mineral in sedimentary rocks, related to chert. In aggregates, subject to alkali attack.
chalk soft limestone with water content 10% or more. Major cement raw material in SE England, NW Europe and coastal eastern US.
chalk marl argillaceous chalk with 25-60% argillaceous material. Important raw material in S E England.
chamber kiln intermittent kiln (20-30 tonnes/week) with primitive oval burning vessel, from which the exhaust gases were drawn through a long horizontal chamber in which slurry was dried prior to transfer to the kiln vessel for burning. Obsolete: much used in the UK up to 1900.
chamosite a phyllosilicate mineral Fe5Al2Si3O10(OH)8, the iron end-member of the chlorite series. The magnesium end-member is clinochlore. It is used as an iron ore (56% Fe2O3 when pure), and is also found as a contaminant in kaolinitic clays.
characteristic radiation in XRF, the set of discrete frequencies of secondary radiation characteristic of a given element.
Chaux du Teil white chalky siliceous limestone containing ultra-fine silica, S W France. Historically used as a cement rock.
check standard (ISO definition) measuring equipment, product, or other objects serving to collect a data base for the control of a measurement process, by being measured by that process.
chemical lime (ASTM definition) a quicklime or hydrated lime whose chemical and physical characteristics and method of processing make it suitable for one or more of the many and varied chemical and industrial uses of the product.
chert mineral in sediments - mainly limestones – consisting of microcrystalline quartz with some hydrated silica.
china clay another name for kaolin
chi-squared distribution tests whether the observed frequencies in a distribution differ significantly from the frequencies that might be expected according to some assumed hypothesis.
chlorite a phyllosilicate mineral X5AS3H4, in which X is {MgO,FeO}. The magnesium end-member is clinochlore, and the iron end-member is chamosite. Other divalent ions can also substitute in X, as can monovalent ions in paired substitution with aluminium.
chloride trace ion in cement – has a powerful accelerating action but corrodes reinforcement at levels above 0.1%.
chondrodite a metamorphic mineral of the humite family.
chromic oxide chromium (III) oxide, Cr2O3, minor constituent of cement, 0.001-0.2%, limited due to the possible formation of Cr(VI). Used as a green pigment (viridian) in coloured cements.
chromium (III) oxide chromic oxide, Cr2O3, minor constituent of cement, 0.001-0.2%, limited due to the possible formation of Cr(VI). Used as a green pigment (viridian) in coloured cements.
chromium (VI) oxide chromium trioxide, CrO3, oxidized species constituting 5-50% of the chromium in cement. Major cause of allergic contact dermatitis, and minimized for that reason.
chromium trioxide chromium (VI) oxide, CrO3, oxidized species constituting 5-50% of the chromium in cement. Major cause of allergic contact dermatitis, and minimized for that reason.
chrysotile the most common asbestos mineral, a fibrous serpentine.
ciment fondu "melted cement", proprietary name for calcium aluminate cement used by its French originators.
ciment métallurgique sursulfaté Belgian name for supersulfated cement.
citric acid used as a retarder in reactive cements.
clay mineral consisting largely of aluminosilicate particles smaller than 1 μm, usually with a moisture content above 10%.
clay, burnt clay heated to around its temperature of dehydroxylation, used as a pozzolan.
clay, expanded mineral formed when certain laminar-structured clays are dehydroxylated. Used as a light-weight aggregate or as a pozzolan.
cleavage preferred direction of breakage in crystalline materials.
clinker a porous aggregation of mineral particles formed by sintering, the un-melted particles being cemented together by frozen melt.
clinker cooler device for cooling clinker leaving the kiln to near ambient temperature, and for recuperating the heat in the clinker. Various designs.
clinker, Portland cement a clinker, partially fused by pyroprocessing, consisting predominantly of crystalline hydraulic calcium silicates (ASTM definition). Alite is the defining mineral of the portland system.
clinkering the sintering process in a kiln, characterized by partial melting, agglomeration of finer particles, reduction in nodule porosity and rapid reaction between belite and free lime to form alite.
clinochlore a phyllosilicate mineral Mg5Al2Si3O10(OH)8 or M5AS3H4, the magnesium end-member of the chlorite series. The iron end-member is chamosite. Sometimes found as a contaminant in kaolinitic clays.
closed-circuit mill mill system in which the larger particles in the product are separated out in a classifier, and returned for further grinding.
closure plate lip at the end of a cylindrical vessel, such as a rotary kiln.
cluster, crystal (nest) in a material containing several phases, a non-random local concentration of crystals of one phase. In clinkers, typically caused by chemical inhomogeneity.
CMF abbrev., Cement Maker's Federation: industry association (UK). Merged with the Cement & Concrete Association in 1987 to form the British Cement Association (BCA), which in turn merged into the Mineral Products Association (MPA) in 2009.
CMS2 CaMgSi2O6, mineral name diopside. Salite pyroxene mineral common in igneous and metamorphic rocks.
coal solid fuel formed by progressive alteration of vegetable matter under anaerobic conditions by increased temperature and pressure. The coal's "rank" increases as alteration progresses.
coal, bituminous coal in which the content of volatile combustible matter is in the range 15-35% DMF.
coal, brown (lignite): coal in which the content of volatile combustible matter is greater than 45% DMF.
coal, standard (obsolete, UK) formalism for heat input to a kiln. 1 tonne standard coal = 29.288 GJ (gross) exactly.
coal, sub-bituminous coal in which the content of volatile combustible matter is in the range 35-45% DMF.
coarse aggregate (ASTM definition) aggregate predominantly retained on the 4.75-mm sieve.
coating in kilns, partially fused material that sticks to the refractory lining and protects it from heat and chemical attack.
cobalt blue cobalt (II) aluminate, Co(AlO2)2, used as a permanent pigment in blue coloured cements.
co-current heat exchanger heat exchanger in which two material flows exchange heat with each other while travelling in the same direction. e.g. suspension pre-heater riser.
coefficient of variation ratio of estimated standard deviation to population mean, usually expressed as a percentage.
coherent scattering (Rayleigh scattering): in XRF, primary X-ray photons scattered by the sample surface without change in wavelength.
cohort analysis method for elucidating non-linear relationships in a large population of data. The data set is sorted on the dependent variable, and divided into equal cohorts, and the mean values of dependent and independent variables in each cohort are plotted.
coke a carbonaceous solid produced from coal, petroleum or other materials by thermal decomposition with passage through a plastic state.
coke breeze the fine screenings from crushed coke, typically below 15 mm.
colliery waste shale/coal mixture sometimes used as a shale replacement in rawmix.
collimator a device for producing a parallel beam of radiation from a source radiating over a wide angle.
colorimetric analysis chemical analysis by development of coloured complexes in a solution of the sample, the colour-intensity of which is related to a specific element.
combinability a measure of the ease with which a raw-mix can be converted into a well-burned clinker.
combinability temperature the temperature at which the free lime is reduced to a fixed value (usually 2%) when a nodulized sample of rawmix is heated in a laboratory tube furnace. Typically 50-200ºC (can be much more) higher than that experienced in a production kiln.
Combine, The early, not-too-affectionate name for the Blue Circle Group.
combined moisture in non-fuel materials dried at 110ºC, moisture that may be released on heating to higher temperatures. May be crystallization water, or water formed on decomposition of hydroxylic minerals.
common causes (SPC): the irreducible normal distribution of variation events that lead to the inherent variability of a system.
common cements CEN term for hydraulic cements of various compositions, with long track-records in various parts of Europe, of which Portland cement is one. Defined in EN197.
compo archaic term for rawmix.
composite cement (European) cement containing 36-80% of both granulated blastfurnace slag and pozzolan, in addition to clinker in its nucleus composition. EN 197 CEM V cement.
composite cement, portland (European) cement containing 6-35% of multiple mineral cementitious components in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
composite sample sample gathered continuously, or in frequent small increments, that when blended represents the product of a specified process time period or batch.
compounds, Bogue the compounds C3S, C2S, C3A and C4AF. Quantities of these calculated from the bulk composition of a clinker assuming (mistakenly) that the clinker minerals have these idealized compositions.
compressive strength the measured maximum resistance of a specimen to axial loading. Unit MPa.
Compton scattering (incoherent scattering): in XRF, primary X-ray photons scattered by sample electrons with transfer of momentum. Loss of momentum causes a slight increase in wavelength.
concrete (ASTM definition) a composite material that consists essentially of a binding medium within which are embedded particles or fragments of aggregate; in hydraulic cement concrete, the binder is formed from a mixture of hydraulic cement and water.
concrete joints spaces between cast sections, or saw-cut spaces, designed to allow for expansion and contraction of concrete.
concrete, bleeding of the separation of clear water on the surface of concrete as a result of gravitational settlement of its solid particles.
concrete, cellular (ASTM definition) a lightweight hydraulic-cement concrete having a homogeneous void or cell structure attained using gas-forming chemicals or foaming agents.
concrete, fibre reinforced conventional concrete to which discontinuous discrete fibres are added during mixing. Fibres of steel, plastic, glass, wood etc add to the tensile strength of the matrix.
concrete, foamed same as cellular concrete.
concrete, fresh (ASTM definition) concrete which possesses enough of its original workability so that it can be placed and consolidated by the intended methods.
concrete, hydraulic-cement a composite material that consists essentially of a binding medium formed from a mixture of hydraulic cement and water, within which are embedded particles or fragments of aggregate.
concrete, mass concrete poured in large, thick sections.
concrete, no slump concrete with a slump of 6 mm or less, placed with high degrees of vibration.
concrete, no-fines (porous concrete) contains a narrowly graded coarse aggregate, little of no fine aggregate, and insufficient cement paste to fill the voids. Roller compaction leaves 20-35% voids content, allowing water to drain through.
concrete, polymer modified normal concrete to which a polymer or monomer is added during mixing. Increases strength, durability and abrasion resistance by eliminating voids.
concrete, porous (no-fines concrete) contains a narrowly graded coarse aggregate, little of no fine aggregate, and insufficient cement paste to fill the voids. Roller compaction leaves 20-35% voids content, allowing water to drain through.
concrete, precast concrete produced – often on a production-line basis-in standardized shapes and finishes, at a factory site remote from the final place of installation.
concrete, pre-stressed concrete in which the longitudinal reinforcement bars are maintained in high tension during the casting and curing process, and remain under tension in service. Ensures that all sections of the concrete matrix remain in compression under all design loading regimes.
concrete, recycled concrete in which some or all of the aggregate consists of crushed concrete.
concrete, refractory refractory made from a concrete mix, usually based on a calcium aluminate cement and refractory brick fragments.
concrete, reinforced concrete containing steel reinforcing bars designed in such a way that, when in service, most of the tensile stresses will be borne by the steel.
concrete, roller compacted lean, no-slump, almost dry concrete that is compacted by vibratory roller or plate compaction equipment.
concrete, self-stressing concrete containing an expansive cement with expansion sufficient to produce an appreciable permanent state of tension in its reinforcement.
condensed silica fume material produced by the re-oxidation of silicon monoxide, SiO, which is produced during various high-temperature reductive processes involving silica.
conductivity, thermal units W.m-1.K-1. Around 1 for concrete.
confirmation, metrological (ISO definition) set of operations required to ensure that an item of measuring equipment is in a state of compliance with requirements for its intended use.
conformity (quality systems): fulfilment of specific requirements.
connectivity the state or extent of being connected: as of silicate tetrahedra in a 3-dimensional lattice, or the pores in a concrete matrix.
consistency (ASTM definition) of fresh concrete, mortar or grout: the relative mobility or ability to flow.
consistency, normal (ASTM definition) a degree of plasticity of a hydraulic-cement paste that is appropriate for testing as measured by a stipulated method. The result of tests for normal consistency is reported as the mass of water required to achieve this plasticity divided by the mass of hydraulic cement, expressed as a percentage.
construction lime (ASTM definition) a lime whose chemical and physical characteristics and method of processing make it suitable for the ordinary or special construction uses of the product.
consumer risk (sampling) the risk that an inspection scheme will cause acceptance of a non-compliant lot.
continuous process a process – e.g. kiln or mill – in which feed is continuously introduced at one end, and product is continually withdrawn at the other.
control, quality (quality systems): operational techniques and activities that are used to fulfil requirements for quality.
controlled-fineness Portland cement generally refers to cement with surface area of 250-280 m2.kg-1, used in applications where removal of surplus water from the paste is desired, such as pipe spinning.
conventional true value of a quantity (ISO definition) value attributed to a particular quantity and accepted, sometimes by convention, as having an uncertainty appropriate for a given purpose.
conversion (of calcium aluminate cements pastes) the gradual transformation, with loss of strength, of initial hydrates (CAH10, C2AH8 and C3AH8) into C3AH6 and AH3.
cooler, cement device for cooling cement leaving the cement mill to an acceptable temperature.
cooler, clinker device for cooling clinker leaving the kiln to near ambient temperature, and for recuperating the heat in the clinker. Various designs.
cooler, grate clinker is moved over a perforated steel grate. Air is blown upward through the grates. Part of the air is used for combustion in the kiln.
cooler, planetary a set of tubes containing heat exchange devices similar to those in a rotary cooler, arranged around the circumference of a kiln at the outlet end. Also called a satellite cooler.
cooler, rotary inclined cylinder fitted with lifters. Clinker is cascaded through stream of air. The heated air is used for combustion in the kiln.
cooler, satellite a set of tubes containing heat exchange devices similar to those in a rotary cooler, arranged around the circumference of a kiln at the outlet end. Also called a satellite cooler.
cooler, Unax FLS version of the satellite cooler
corn syrup concentrated sugar solution used as a retarder in cements and in mortar and concrete mixes.
corona discharge ionized gas in a high electric field in which the voltage is maintained just below the breakdown (flash-over) voltage. Maintained in an electrostatic precipitator.
correction (ISO definition) the value which, added algebraically to the uncorrected result of a measurement, compensates for an assumed systematic error.
correction factor (ISO definition) numerical factor by which the uncorrected result of a measurement is multiplied to compensate for systematic error.
corrective in rawmix formulation, a minor component used to make a small adjustment to the composition.
corundum stable mineral form of aluminium oxide, Al2O3. Very hard.
counter, gas ionization device for counting photons by passing the radiation beam through an ionizable gas in an electric field between electrodes. Passage of a photon causes a cascade of ions to pass between the electrodes, producing a countable electric pulse.
counter, proportional gas a gas-ionization counter operated in the voltage range within which the pulse height is proportional to the photon energy.
counter, scintillation X-ray detector consisting of a phosphor that emits light when an X-ray photon passes through it, coupled with a photomultiplier to detect the resulting light pulse.
counter, sealed gas a type of proportional gas detector with a thick window, containing a gas sealed in for life. Used for detecting heavy-element X-rays.
counter-current heat exchanger heat exchanger in which two material flows exchange heat with each other while travelling in opposite directions. e.g. rotary kiln tube.
counting error in XRF, the component of error that derives solely from the randomness of counted photons. The SD on N counts is √N.
cP centipoise (obsolete) unit of dynamic viscosity, =1 mPa.s
3C3P.Ca(OH)2 apatite, Ca5(PO4)3OH, common form of phosphate in raw materials.
3C3P.CaF2 fluoroapatite, Ca5(PO4)3F, common form of phosphate in raw materials.
CrO3 chromium (VI) oxide, chromium trioxide, oxidized species constituting 5-50% of the chromium in cement. Major cause of allergic contact dermatitis, and minimized for that reason.
Cr2O3 chromium (III) oxide, chromic oxide, minor constituent of cement, 0.001-0.2%, limited due to the possible formation of Cr(VI). Used as a green pigment (viridian) in coloured cements.
cracking, D- (ASTM definition) in concrete, a series of cracks near to and roughly parallel to features such as joints, edges and structural cracks.
cracking, map web of inter-connected surface cracks. Symptom of alkali/silica reaction.
creep long-term plastic deformation of concrete under load.
CRH abbrev. Cement Roadstone Holdings plc: Ireland-based international cement manufacturing company.
cristobalite high-temperature polymorph of silica, SiO2.
critical speed the speed of a rotating cylinder at which the centripedal force at the top equals the gravitational force, so that the contents cease to tumble or cascade. Ball mills are typically made to rotate at 70-80% of critical speed. N (rpm) = 42.29/√D where D is the diameter (m) inside the lining.
cross-current heat exchanger heat exchanger in which two material flows exchange heat with each other while travelling at right angles to one another. e.g. grate cooler.
cruciform lifter/heat exchanger of cross-shaped cross section in a kiln or rotary cooler.
crushed quicklime (ASTM definition) quicklime 64 mm and smaller
crusher/drier a crusher, usually of hammer variety, swept with hot air so that material can be simultaneously comminuted and dried.
cryolite sodium hexafluoroaluminate, Na3AlF6: used as a flux in aluminium manufacture, and as a mineralizer in cement manufacture.
crystal any solid material in which the component atoms are arranged in a definite pattern and whose surface regularity reflects its internal symmetry.
crystal defect a localized departure from isotropy in a crystal structure. Chemical reaction of a crystal proceeds from the points of emergence of defects on the surface, so that defectiveness profoundly affects reactivity.
crystal, anhedral mineral crystal with faces deformed to fit the space in the surrounding matrix – indicative of late formation in a freezing melt.
crystal, euhedral mineral crystal with faces well-formed in its normal crystalline habit – indicative of early formation in a freezing melt.
crystal, subhedral mineral crystal with faces partially deformed by the surrounding matrix – indicative of formation at an intermediate stage in a freezing melt, or very rapid growth.
crystalline material material in which regular, repeated structure (on the molecular scale) is evident in at least one dimension.
crystallography the study and detailed description of the three-dimensional atomic-scale structure of crystals.
CS2H2 okenite: one of a range of crystalline calcium silicate hydrates.
CS2H2 Z-phase: one of a range of crystalline calcium silicate hydrates.
CSA (1) abbrev., calcium sulfoaluminate: (2) abbrev., Canadian Standards Association
C-S-Hphase the generalized term for the nearly-amorphous hydrates formed when alite and belite react with water. Compositions vary widely around a typical C3S2H3.
C-S-H (I) low-calcium semi-crystalline form of C-S-H which is a structurally imperfect form of 1.4 nm tobermorite. Composition varies around C5S5H6.
C-S-H (II) high-calcium semi-crystalline form of C-S-H which is a structurally imperfect form of jennite. Composition varies around C9S5H11.
CŜH0.5 calcium sulfate hemihydrate, CaSO4.0.5H2O, representative formula of a range of compositions of bassanite with high water contents, formed when gypsum is heated above 70ºC. Loses water on heating, without change of mineral structure, forming "soluble anhydrite" (γ-anhydrite). Component of finished cement, more soluble than gypsum.
CŜH2 calcium sulfate dihydrate, CaSO4.2H2O, mineral name gypsum. Used for set control in cement manufacture.
CT calcium titanium oxide, CaTiO3, mineral name perovskite. Main titanium mineral found in basic igneous rocks.
curing the process of development of the mature physical properties of paste, mortar or concrete.
curing membrane a film, usually an organic material sprayed on, deposited on the surface of concrete after setting is complete, designed to reduce water loss and/or solar gain.
curling the tendency of flat concrete on grade to become concave, due to differential shrinkage of the exposed surface.
curtains, chain in kilns, heat exchange chains hung at one end from a circumferential hanging ring.
cuspidine calcium silicate fluoride, C3S2CaF2.
customer (quality systems): recipient of a product provided by the supplier.
CV (1) abbrev., coefficient of variation. (2) abbrev., calorific value.
cyclone a conical vessel in which solids are centrifugally separated out from a fluid. The suspension enters tangentially at the wide end of the cone and forms a vortex: solids pass out at the narrow end, and clean fluid leaves via the vortex finder, on the centre line of the wide end.
CZ abbrev., calcining zone. Intermediate zone of the kiln in which de-carbonation takes place, feed temperature 650-1050ºC.
DAF basis dry, ash-free basis. Reporting format for fuel analyses in which the constituents are expressed as a percentage of the fuel mass after notional removal of total moisture and ash.
dam ring in a cylindrical reactor, kiln, cooler, etc, a circumferential barrier designed to slow the movement of solids and provide a deeper bed.
damper a variable restriction in a duct used for control of flow.
damp-proofers hydrophobic agents applied to the surface of work to reduce water permeation.
Davis preheater preheater in which kiln gas is passed through an annular bed of nodules, movement of the nodule bed being achieved by eccentric movement of the annulus.
DAWN equation A rule-of-thumb equation for power drawn by a ball mill. P = 0.2846 D A W N, where P (kW) is the power drawn (excluding drivetrain and motor losses); D is the diameter inside lining in metres; A = 1.073 - α (the fractional volume loading); W = mass of charge in tonnes; N = rotation speed in rpm. Power can be calculated for individual chambers or for the entire mill. A better value of A is given by A = 1.249 - 1.19 α0.75.
D-cracking (ASTM definition) in concrete, a series of cracks near to and roughly parallel to features such as joints, edges and structural cracks.
DCS abbrev., distributed control system.
dead burned dolomite (ASTM definition) dolomitic limestone that has been heated with or without additives to a temperature sufficiently high and for a long enough time to decompose the carbonate structure so as to form calcium oxide and periclase in a matrix that provides resistance to subsequent hydration and recombination with carbon dioxide.
dead time in XRF, the time of recovery of a gas ionization detector following generation of a pulse, during which it is unable to count further incoming photons.
dead time correction in XRF, mathematical correction made to the count-rate from a detector to allow for counts missed during dead time.
dead-burning a term applied to burning of lime, cement, gypsum, etc, meaning burning at excessive temperature, resulting in an un-reactive product, due mainly to excessive crystal growth.
de-aerators agents used in small doses to remove entrained air from a mix. Typically tributylphosphate, dibutyl phthalate, polydimethylsiloxane.
decrepitation thermal decomposition or phase change of a mineral accompanied by violent breakage of the crystals.
DEF abbrev., delayed ettringite formation.
defect, crystal a localized departure from isotropy in a crystal structure. Chemical reaction of a crystal proceeds from the points of emergence of defects on the surface, so that defectiveness profoundly affects reactivity.
deicer scaling surface damage to concrete caused by the action of deicing salt. Avoided mainly by preparing dense, impermeable concrete.
delayed ettringite formation the formation of ettringite from the original cement components in a concrete after the period of strength growth, generally accompanied by destructive expansion. An effect of high-temperature curing, in which the normal early formation of ettringite is suppressed due to its instability at temperatures above 70ºC.
dellaite natural calcium silicate hydrate C6S3H.
dendritic crystals crystals that grow in a branching, tree-like pattern.
dense phase conveying pneumatic conveying with a high solids/air ratio.
dependability (quality systems): availability performance and its influencing factors: reliability performance, maintainability performance and maintenance-support performance.
design review (quality systems): documented, comprehensive, and systematic examination of a design to evaluate its capability to fulfil the requirements for quality, identify problems, if any, and propose the development of solutions.
detector in XRF, a device for measuring secondary X-rays, usually of the gas-ionization counter type.
detector, gas flow a type of proportional gas detector with a very thin window, continuously swept with gas from an external cylinder. Used for detecting light-element X-rays.
detector, gas ionization device for counting photons by passing the radiation beam through an ionizable gas in an electric field between electrodes. Passage of a photon causes a cascade of ions to pass between the electrodes, producing a countable electric pulse.
detector, proportional gas a gas-ionization counter operated in the voltage range within which the pulse height is proportional to the photon energy.
detector, scintillation X-ray detector consisting of a phosphor that emits light when an X-ray photon passes through it, coupled with a photomultiplier to detect the resulting light pulse.
detector, sealed gas a type of proportional gas detector with a thick window, containing a gas sealed in for life. Used for detecting heavy-element X-rays.
deviation permit (quality systems): written authorization to depart from the originally specified requirements for a product prior to its production.
devitrification reversion of a glass to a crystalline form.
dew-point the temperature at which the partial pressure of water in a sample of air becomes equal to its saturated vapour pressure.
diabase hard intrusive basic igneous rock containing calcium-rich plagioclase and pyroxene, used as an aggregate. Also called dolerite.
diaspore HAlO2: hydrogen aluminium oxide. Very hard mineral, occurring with corundum. Not a hydroxide. Easily distinguished from the isomeric boehmite (AlO.OH - a soft mineral found in bauxite).
diatomaceous earth a sediment formed from the microscopic siliceous skeletal structures of diatoms. Sometimes used as a pozzolan.
dibutyl phthalate agent used to de-aerate mortar/concrete mixes.
dicalcium ferrite Ca2Fe2O5, C2F, end member of the ferrite solid solution series.
dicalcium silicate the name for pure C2S. In real clinkers, the α- or β-form of the mineral is called belite, and usually contains small amounts of substituents: principally alumina, iron oxide and magnesia. Hydrates slowly to form the strength-giving C-S-H.
differential thermal analysis measurement of the changes in enthalpy (sensible heat, endotherms and exotherms) of a material as a function of temperature. Some phases can be quantitatively estimated from the intensity of their identified endotherms/exotherms.
diffraction phenomena produced by the spreading of waves around and past obstacles of comparable size to the wavelength.
di-hydrated lime (ASTM definition) dolomitic lime which has been hydrated under greater than atmospheric pressure and contains less than 8 % unhydrated oxides.
diopside CaMgSi2O6, CMS2. Salite pyroxene mineral common in igneous and metamorphic rocks.
diorite dark-coloured granular igneous rock used as an aggregate.
dioxin, 1,4- trivial name of 3,6-dioxacyclohexa-1,4-diene.
Dioxins colloquial generic term for substituted dibenzo-1,4-dioxins. Normally refers to chlorine-substituted forms.
disagglomerator device for breaking up the compressed cake of particles produced by a high-pressure roll press.
dispersion efficiency the ability of a spectrometer to separate closely-spaced spectral lines. A function of grating (crystal) dispersion power, degree of collimation and line width.
distribution, chi-squared tests whether the observed frequencies in a distribution differ significantly from the frequencies that might be expected according to some assumed hypothesis.
DMF basis dry, mineral-matter free basis. Reporting format for fuel analyses in which the constituents are expressed as a percentage of the fuel mass after notional removal of total moisture and ash-producing minerals.
dodecacalcium heptaaluminate C12A7(H), highly reactive constituent of calcium aluminate cements: mineral name mayenite.
dolerite hard intrusive basic igneous rock containing calcium-rich plagioclase and pyroxene, used as an aggregate. Also called diabase.
dolomite mineral: CaMg(CO3)2. Harder than calcite. The main magnesium-bearing mineral in most limestones.
dolomite, dead burned (ASTM definition) dolomitic limestone that has been heated with or without additives to a temperature sufficiently high and for a long enough time to decompose the carbonate structure so as to form calcium oxide and periclase in a matrix that provides resistance to subsequent hydration and recombination with carbon dioxide.
dolomitic lime (ASTM definition) indicates the presence of 35 to 46 % magnesium carbonate (MgCO3) in the limestone from which the material was formed.
dolomitic limestone (ASTM definition) limestone containing from 35 to 46 % magnesium carbonate (MgCO3).
dolomitization the conversion of a calcitic limestone to dolomite by contact with magnesium-bearing waters, sea water.
dolostone geologist's term for a rock mainly consisting of, or cemented by, dolomite.
Dopol preheater Polysius twin-string suspension preheater with common mixing chamber.
double burning early cement manufacturing process in which limestone was burnt to lime, slaked, and mixed with clay slip, dried, and burnt a second time to clinker. Avoided the need to grind hard limestone.
double-hydrated lime (ASTM definition) dolomitic lime which has been hydrated under greater than atmospheric pressure and contains less than 8 % unhydrated oxides.
drier, spray- device for removing the water from a solution or slurry, by spraying it into a hot gas-stream.
drift (ISO definition) the slow variation with time of a metrological characteristic of a measuring instrument.
Dry basis Reporting format for material analyses in which the constituents are expressed as a percentage of the mass of material after drying, typically at 105-110ºC.
dry process process in which a dry rawmix is prepared and fed as a powder to the kiln system.
Dry, ash-free basis DAF basis. Reporting format for fuel analyses in which the constituents are expressed as a percentage of the fuel mass after notional removal of total moisture and ash.
Dry, mineral-matter free basis DMF basis. Reporting format for fuel analyses in which the constituents are expressed as a percentage of the fuel mass after notional removal of total moisture and ash-producing minerals.
drying shrinkage shrinkage that occurs in concrete when the free water in its structure evaporates after curing.
DSC abbrev., differential scanning calorimetry.
d-spacing the perpendicular distance between crystal planes associated with an X-ray diffraction line.
DTA abbrev., differential thermal analysis.
dust, cement kiln (CKD) solid material leaving a kiln system in suspension in the exhaust gas stream.
dusting degradation of mineral crystals to fine powder due to polymorphic phase changes. Commonly refers to the effect of β - γ inversion of belite.
dyke tabular intrusion of igneous rock steeply inclined to the bedding of the enclosing rock.
dynamic viscosity the rate of change of strain with stress, at stress levels above the yield stress, in Bingham plastics.
early stiffening (ASTM definition) rapid loss of plasticity or rapid development of rigidity in freshly mixed hydraulic cement paste, mortar, or concrete.
Eddystone lighthouse construction project during which John Smeaton first demonstrated the principals of hydraulic lime manufacture. Off the coast of Devon, England.
EDTA abbrev., ethylene diamine tetraacetic acid
efflorescence a thin film of powdery material on the surface of mortar or concrete, resulting from crystallization of salts from pore liquid exposed to the air.
eisenportlandzement German designation for portland blastfurnace slag cement containing 5-40% slag.
elasticity property by virtue of which a body resists and recovers from deformation produced by force.
electron microprobe analysis, scanning chemical analysis using the secondary X-rays generated by the electron beam in an electron microscope. Allows semi-quantitative analysis of areas as small as 0.5 μm, giving unambiguous identification of minerals in the micrograph, and indicating the impurity-chemistry of major phases.
electron microscopy, scanning microscopy that builds an image by scanning the sample with a very fine beam of electrons, and measuring the electrons scattered.
electron probe micro-analysis chemical analysis using the secondary X-rays generated by the electron beam in an electron microscope. Allows semi-quantitative analysis of areas as small as 0.5 μm, giving unambiguous identification of minerals in the micrograph, and indicating the impurity-chemistry of major phases.
electrostatic precipitator (EP), device for removing suspended solids from a gas stream, by passing the gas through a corona discharge. Particles become charged, and are attracted to, and adhere to, electrodes from which they are periodically removed by vibration.
elevated-temperature curing curing for rapid strength development for high productivity in pre-cast work. The rate of strength development roughly doubles for every 20ºC temperature rise.
elevator, bucket vertical conveyor consisting of buckets on a chain or belt.
ellestadite Ca10(SiO4)3(SO4)3{OH,F}. Continuous solid solution series ranging from hydroxyellestadite to fluoroellestadite, which also forms a continuous solid solution series with apatite. Common intermediate material in cement kilns.
ELNES abbrev., electron energy loss near-edge structure.
elutriator obsolete method of particle size analysis using air separation.
empirical corrections in XRF, matrix corrections calculated from the intensities in a calibration sample set. Inferior to fundamental parameters unless the set of samples is very large and the precision is very good.
EN abbrev., Europäische Norm – European Standard. Standard produced by CEN.
endothermic reaction chemical reaction in which enthalpy is absorbed.
enhancement effect in XRF, matrix effect in which the intensity of fluorescence for an element is increased as a result of absorption of secondary radiation from other (generally heavier) elements in addition to absorption of primary radiation. The effect varies with the concentration of the interfering elements.
enstatite MgSiO3, MS, deleterious mineral found in some raw materials. End member of the orthopyroxenes – a solid solution series with ferrosilite, FeSiO3.
entity (quality systems): item which can be individually described and considered.
entrained air void a space in cement paste typically between 10 and 1000 μm in diameter and spherical or nearly so.
entrapped air void a space in cement paste characteristically 1 mm or more in width and irregular in shape.
EP abbrev., electrostatic precipitator.
epitaxy crystallization of a substance on the surface of a crystal of another substance, the morphology being governed by that of the substrate.
EPMA abbrev., electron probe microanalysis.
equivalent alkalies.  (ASTM definition) in hydraulic cement, total combined sodium and potassium oxides, expressed as a percentage, calculated from the analysis, by means of the formula Na2Oeq = % Na2O + 0.658 % K2O.
error of measurement, absolute (ISO definition) the result of a measurement minus the true value of the measurand.
erzzement early sulfate-resisting portland cement with a low (0.2-0.3) A/F ratio.
ESCA abbrev., electron spectroscopy for chemical analysis
escape peak in XRF, separate, lower-intensity pulse produced by a proportional gas detector resulting from fluorescence of the gas stimulated by the secondary radiation being measured.
ESR abbrev., electron-spin resonance
etchant liquid or gas used for etching.
etching superficial chemical attack on a solid surface by a liquid or gaseous agent. Used in reflective microscopy as a means of distinguishing different phases.
ettringite calcium sulfoaluminate hydrate, C63H32, prototype AFt phase, hydration product of cement that prevents flash set by passivating C3A. Late formation due to sulfate attack causes destructive expansion.
ettringite, delayed formation the formation of ettringite from the original cement components in a concrete after the period of strength growth, generally accompanied by destructive expansion. An effect of high-temperature curing, in which the normal early formation of ettringite is suppressed due to its instability at temperatures above 70ºC.
euhedral crystal mineral crystal with faces well-formed in its normal crystalline habit – indicative of early formation in a freezing melt.
eutectic in a system of two or more substances, the mixture that has the lowest melting temperature in the composition range.
eutectic temperature the temperature of melting of a eutectic.
eutectic, binary the minimum-melting-point mixture in a system of two components.
eutectic, ternary the minimum-melting-point mixture in a system of three components.
evaporable water water in cement paste not tied up in hydrates.
evaporite rock formed of salts crystallized under salt-lake conditions.
evidence, objective (quality systems): information which can be proved true, based on facts obtained through observation, measurement or test.
exothermic reaction chemical reaction in which enthalpy is released.
expanded blast-furnace slag (ASTM definition) the lightweight cellular material obtained by controlled processing of molten blast-furnace slag with water or water and other agents, such as steam or compressed air or both.
expansion test, autoclave ASTM test method (C 151) for soundness of cement
expansion test, Le Chatelier EN test method for soundness of cement.
expansion, delayed ettringite the formation of ettringite from the original cement components in a concrete after the period of strength growth, generally accompanied by destructive expansion. An effect of high-temperature curing, in which the normal early formation of ettringite is suppressed due to its instability at temperatures above 70ºC.
expansion, restrained expansion of a mortar- or concrete matrix resulting in elastic stretching of embedded reinforcement.
expansion, sulfate also caused sulfate unsoundness. Cements expand destructively at late ages if the amount of sulfate present is greater than that needed to convert aluminates to monosulfate.
expansive hydraulic cement (ASTM definition) a hydraulic cement that forms a paste when mixed with water, and increases in volume a controlled amount during the early hardening period occurring after setting.
exposed aggregate finish concrete in which the cement paste is removed from the surface by grinding, hammering, etching etc, to expose aggregate surfaces.
external sulfate attack production of ettringite from monosulfate at late age causing disruptive expansion, as a result of attack by sulfate permeating the concrete from the external environment. Typically results from contact with sulfate-bearing groundwater or sea water.
extinction loss of transmission of polarized light through a crystal when its polarizing plane is orthogonal to the plane of the light.
extrusive rocks igneous rocks that have formed by solidification of magma on the surface, at or near atmospheric pressure.
F cement chemist's notation for  iron (III) oxide, Fe2O3
falling alternative term for dusting
false set (ASTM definition) early stiffening with little evolution of heat, which can be dispelled by further mixing without the addition of water.
fayalite iron (II) orthosilicate, Fe2SiO4. End member of the olivine solid-solution series.
FeCO3 iron (II) carbonate, mineral name siderite. Forms solid solutions with calcium carbonate.
Fe2O3 iron oxide, iron (III) oxide, ferric oxide, F. Major constituent of cement, 0.2-5%. From the Latin ferrum.
Fe2SiO4 iron (II) orthosilicate. End member of the olivine solid-solution series. Mineral name fayalite.
Fe3O4 magnetite, iron (II,III) oxide. Occurs in some iron ores and as the major component of millscale. Used as a cement raw material and as a high-density aggregate (dens 5200).
feldspar a series of minerals of general formula AT4O8, in which A is sodium, potassium or calcium, and T is aluminium and silicon, in amounts required to preserve charge neutrality. The most common minerals in the Earth's crust.
feldspar, alkali member of the solid solution series NaxK1-xAlSi3O8, end-members albite and orthoclase.
feldspar, plagioclase member of the solid solution series NaxCa1-xAl2-xSi2+xO8, end-members albite and anorthite.
Ferrari cement early sulfate-resisting portland cement with a low (0.2-0.3) A/F ratio.
ferric oxide iron oxide, iron (III) oxide, F. Major constituent of cement, 0.2-5%. From the Latin ferrum.
ferrite (phase) the system of solid solutions usually termed tetracalcium aluminoferrite (C4AF) that forms from the melt in Portland cement clinker, mineral name brownmillerite. Actual composition C4AnF2-n where n = 0 to 1.4 depending upon alumina ratio, plus substituted SiO2, MgO, TiO2, Mn2O3, ZnO etc.
ferrocement reinforced concrete composed of closely-spaced layers of continuous relatively thin mesh or wire embedded in mortar, constructed by hand plastering, shotcreting, etc, to produce a shell casting usually less than 25 mm in thickness.
ferrosilite FeSiO3, mineral found in some raw materials. Theoretical end-member of the orthopyroxenes, a solid solution series with enstatite, MgSiO3.
ferrous oxide iron (II) oxide.
FeSiO3 ferrosilite, mineral found in some raw materials. Theoretical end-member of the orthopyroxenes, a solid solution series with enstatite, MgSiO3.
festoons, chain in kilns, heat-exchange chains attached at both ends to a single circumferential hanging ring.
FGD abbrev., flue-gas de-sulfurization.
FGD gypsum impure gypsum formed by treating SOx-bearing exhaust gases with limestone or lime.
fibre reinforced concrete conventional concrete to which discontinuous discrete fibres are added during mixing. Fibres of steel, plastic, glass, wood etc add to the tensile strength of the matrix.
filler (in cement) an inert mineral addition that functions without substantial chemical reaction. Particularly limestone, that functions by densifying the paste.
filter cake semi-solid product of a slurry filtration process
filter cloth the filter medium used in slurry filtration.
filtrate the clear fluid separated out during a filtration process.
filtration separation of solids from a suspension in a fluid by passage through a porous medium.
final setting time the time taken by a paste of initial normal (standard) consistency to reach a state where the surface is not easily indented, this condition being defined in terms of a penetrometer test.
fine aggregate (ASTM definition) aggregate passing the 9.5-mm sieve and almost entirely passing the 4.75-mm sieve and predominantly retained on the 75 μm sieve.
fineness in cement manufacture, an expression of the degree of grinding, in terms of sieve residue, mean particle size or specific surface.
finish mill (US) mill in which clinker is ground to cement fineness. In UK sometimes, cement mill.
finishing the processes of producing a presentable and durable surface on the exposed face of a concrete casting, by floating, edging, jointing, troweling, brooming etc.
finishing hydrated lime (ASTM definition) hydrated lime suitable for use in the finish coat of plaster.
finishing quicklime (ASTM definition) quicklime suitable (after slaking to a lime putty) for use in the finish coat of plaster.
firing pipe (UK) the pipe (or set of pipes) concentric with the kiln that passes through the kiln hood and conveys the fuel into the flame. Also called burner pipe (US).
fixed carbon in coal, coke and bituminous materials, the solid residue other than ash, that is left after removal of the volatile matter.
flame zone of incandescent gas in which self-sustaining combustion takes place.
flame photometry analysis by measuring the intensity of characteristic UV/visible emission spectra produced when a solution of analyte is introduced into a flame.
flash set (ASTM definition) early stiffening with evolution of considerable heat, which cannot be dispelled by further mixing without the addition of water.
flint a microcrystalline form of silica, commonly taking the form of 20-200 mm nodules, sometimes found in chalk. In SE England, major component of sea-dredged aggregate.
fluid, Newtonian a fluid in which the shear rate is proportional to the stress applied.
flume sloped trough for conveying slurry downhill.
fluorescence emission of radiation of lower energy resulting from absorption of radiation of higher energy. Emission persists only while the incoming radiation is absorbed.
fluorescence test crude test for assessment of latent hydraulic activity in slag, by noting colours produced by different particles in UV light.
fluorescent yield the proportion of absorbed incident energy that is re-emitted as secondary (fluorescent) radiation, the remainder being lost in scattering and Auger emission. Rises with increasing atomic number.
fluorine minor component of cement, 0.01-0.25%.
fluorite mineral form of calcium fluoride, CaF2. Used as in mineralizer in cement manufacture.
fluoroapatite Ca5(PO4)3F, 3C3P.CaF2, common form of phosphate in raw materials.
fluorspar mineral calcium fluoride, CaF2, in massive crystalline form: fluorite. Used as in mineralizer in cement manufacture.
flush sudden uncontrolled increase in material flow-rate. In kilns, sudden movement of fine, under-burned material through the burning zone due to loss of damming effect following loss of build-up or reduction in burning zone liquid.
fluxing lime (ASTM definition) a term referring to quicklime used as an agent in the manufacture of steel or glass.
fluxstone (ASTM definition) a term referring to limestone (high-calcium, magnesian, or dolomitic) used as an agent in the manufacture of iron and steel or glass.
fly ash cement, portland (European) cement containing 6-35% fly ash in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
flyash pulverized fuel ash (US). Produced as fine powder when pulverized coal is burned in a power station, and captured in the exhaust dust-control equipment. UK: pfa
flyash, Class C flyash with both pozzolanic and cementitious properties. Commonly has between 10 and 30% CaO.
flyash, Class F flyash with pozzolanic properties, but no cementitious properties. Commonly has less than 10% CaO.
foamed concrete same as cellular concrete.
foamed slag lightweight aggregate made by simultaneous freezing and aeration of molten slag using compressed air.
fog room (ASTM definition) a moist room in which the humidity is controlled by atomization of water.
Folax FLS reciprocating grate cooler brand name.
fondu cement informal term for calcium aluminate cement, based on its Lafarge proprietary name.
forsterite magnesium orthosilicate, Mg2SiO4, M2S. End member of the olivine solid-solution series.
foshagite C4S3H: one of a range of crystalline calcium silicate hydrates.
foundry sand silica sand containing minor amounts of binders for making refractory moulds for metal casting. Used material is sometimes used as a cement rawmix component.
free lime lime that remains as uncombined oxide (or hydroxide) in a clinker or cement. Combined lime is present in silicates, aluminates, ferrites and salt phases.
free moisture (fuels) the difference between the total moisture and the inherent moisture. Roughly equivalent to the moisture loss of an as-received fuel on ambient-air-drying.
free moisture (non-fuel materials) the moisture lost when a sample is dried to constant mass at 110ºC.
freeze-thaw damage damage to concrete caused by repeated expansive freezing of absorbed water. Avoided mainly by use of air-entrainment, which provides space for expansive crystallization.
fresh concrete (ASTM definition) concrete which possesses enough of its original workability so that it can be placed and consolidated by the intended methods.
front end the lower, hot end of a rotary kiln from which the clinker leaves.
Frost's cement hydraulic lime produced by Frost at Swanscombe, England, around 1810 onwards.
fundamental parameters in XRF, matrix corrections calculated from first principles, based upon tube characteristics, geometry and known elemental physics. Also know as theoretical corrections.
furan trivial name of oxacyclopentadiene.
furans colloquial generic term for substituted dibenzofurans. Normally refers to chlorine-substituted forms.
furnace bottom ash large particles of partially fused ash that drop out of the gas stream by gravity in a pulverized-coal burning boiler. Finer particles carried in suspension by the gas are flyash (PFA).
gage (sic) length (ASTM definition) in cement testing, the nominal length between the innermost ends of metal studs that are moulded into a test specimen with the axis of the stud in each end of the test specimen coincident with the longitudinal axis of the test specimen and with each other.
gap-graded aggregates aggregate in which some intermediate size range is missing.
garlands, chain in kilns, heat-exchange chains attached at each end to two axially displaced circumferential hanging rings.
garnet series of minerals of general formula A3B2(SiO4)3 in which A is usually divalent and B is usually trivalent. All have extensive solid-solution series.
garnets, pyralspite series of garnets of general formula A3Al2(SiO4)3 in which A is divalent, typically Mg (pyrope), Fe(II) (almandine) or Mn(II) (spessartine).
gas ionization counter/detector device for counting photons by passing the radiation beam through an ionizable gas in an electric field between electrodes. Passage of a photon causes a cascade of ions to pass between the electrodes, producing a countable electric pulse.
gas proportional counter/detector a gas-ionization counter operated in the voltage range within which the pulse height is proportional to the photon energy.
GCV abbrev., gross calorific value.
gehlenite Ca2Al2SiO7, C2AS. Calcium end-member of the melilite series: unreactive mineral found in calcium aluminate cements and air-cooled blastfurnace slags.
gehlenite hydrate strätlingite, C2ASH8, natural AFm mineral formed by hydration of some calcium aluminate cements and slag cements.
gel, alkali-silica gel formed when alkalis from the cement react with active silica in the aggregate. imbibation of water into the gel causes disruptive expansion.
geotechnical grouts grouts injected into a soil or rock formation to change the physical characteristics of the formation. Mainly for strengthening and stabilization.
Gepol Polysius version of shaft preheater.
ggbs abbrev., ground granulated blastfurnace slag
Gibbs' phase rule F=C+2-P, where F is the number of degrees of freedom of a system, C is the number of components, and P is the number of phases present.
gibbsite Al(OH)3: aluminium tri-hydroxide. A soft mineral, constituent of some bauxites.
Gilmore setting time form of setting time determination using two needle penetrometers. Obsolescent.
glass a solid with no regular crystalline structure, typically formed by supercooling a melt until its increased viscosity prevents crystallization.
glass bead material dissolved in molten glass and cast into a flat disc for analysis by XRF.
glauconite granular hydrous mica clay mineral, general formula K2M4-2xAxF2+xS16-2xH4, where x=0.4 to 1.2.
glycol an organic compound with multiple hydroxy groups on adjacent carbon atoms. Many glycols form complexes with lime.
gneiss coarse-grained, non-layered metamorphic rock, generally resulting from alteration of igneous rocks.
goethite hydrogen iron (III) oxide, α-FeHO2: mineral with similar structure to diaspore but much softer. Constituent of laterite iron ores and ochres.
GPC abbrev., gel permeation chromatography.
grab sample (US) a sample taken essentially instantaneously from a process stream, with no attempt at averaging over time. In UK, "spot" sample.
grade (quality systems): category or rank given to entities having the same functional use but different requirements for quality.
granite coarse- or medium-grained intrusive igneous rock that is rich in quartz and feldspar. The most common plutonic rock of the Earth's crust, forming by the cooling of magma (silicate melt) at depth.
granular quicklime (ASTM definition) quicklime 6.4 mm and smaller.
granulated blastfurnace slag To granulate slag, the molten slag is rapidly cooled, typically by immersion in water, as soon as it leaves the furnace. The cooling must be sufficiently rapid that crystallization can't take place, and a glass is formed.
granulated blast-furnace slag (ASTM definition) the glassy granular material formed when molten blast-furnace slag is rapidly chilled, as by immersion in water.
granulometry, laser technique for measuring particle size distribution, by analyzing the diffraction pattern produced when a laser beam is passed through a suspension of the solid.
grate cooler clinker is moved over a perforated steel grate. Air is blown upward through the grates. Part of the air is used for combustion in the kiln.
gravel (ASTM definition) coarse aggregate resulting from natural disintegration and abrasion of rock or processing of weakly bound conglomerate.
greywacke sedimentary rock consisting of gritty particles of igneous and metamorphic rock minerals, in an argillaceous matrix. Some forms are subject to alkali-silica reaction.
grinding aid a substance added in small quantities to process material being ground, in order to make the grinding process more efficient. Usually work by preventing re-agglomeration caused by the re-welding of freshly broken surfaces.
gross calorific value (GCV) calorific value determined in conditions in which water produced by combustion is condensed to liquid. The standard laboratory method for liquid and solid fuels produces a gross value.
grossite rare natural mineral form of calcium dialuminate, CaAl4O7, CA2.
grossular end-member ugrandite garnet of formula C3AS3.
ground granulated blastfurnace slag (ggbs). Cementitious material produced by drying and grinding granulated blastfurnace slag.
ground quicklime (ASTM definition) quicklime 6.4 mm and smaller.
grout a thin slurry of sufficiently low viscosity to allow it to penetrate into narrow cracks and voids.
grouts, geotechnical grouts injected into a soil or rock formation to change the physical characteristics of the formation. Mainly for strengthening and stabilization.
Gunite a mortar or concrete mix with low water content that is placed by blasting onto a surface with compressed air.
gunmix a dry mortar or concrete mix that forms Gunite when mixed with water.
gunning applying a Gunite concrete.
gypsum mineral form of calcium sulfate dihydrate, CaSO4.2H2O, CŜH2. Used for set control in cement manufacture.
gypsum plaster a hard white substance made by the addition of water to powdered and partly dehydrated gypsum, used for holding broken bones in place and making sculptures and casts.
gypsum, FGD impure gypsum formed by treating SOx-bearing exhaust gases with limestone or lime.
gyrolite C2S3H2: one of a range of crystalline calcium silicate hydrates.
H cement chemist's notation for water, H2O.
hafnium chelates used in combination with organic polymers to render grouts thixotropic.
halite mineral name for sodium chloride, NaCl.
hardness the relative ability of substances to abrade or indent one another.
hausmanite mineral form of manganese (II,III) oxide, Mn3O4: isomorphous with magnetite.
heat balance assessment of the heat flow in a process, typically a kiln system, in association with a mass balance. The first law of thermodynamics requires that the heat inputs to a closed system should equal the heat outputs.
heat capacity the rate of increase of the enthalpy of a substance with temperature, at a specified temperature. Units: J.kg-1.K-1.
heat exchanger, co-current heat exchanger in which two material flows exchange heat with each other while travelling in the same direction. e.g. suspension pre-heater riser.
heat exchanger, counter-current heat exchanger in which two material flows exchange heat with each other while travelling in opposite directions. e.g. rotary kiln tube.
heat exchanger, cross-current heat exchanger in which two material flows exchange heat with each other while travelling at right angles to one another. e.g. grate cooler.
heat, sensible heat possessed by a system by virtue only of its temperature, neglecting heat associated with phase changes.
heating value, lower obsolete term for Nett Calorific Value.
heating value, upper obsolete term for Gross Calorific Value.
heavy spar barite, barytes, tiff, barium sulfate, BaSO4. Used as a high-density aggregate (dens 4480).
heavyweight aggregate (ASTM definition) aggregate of high density such as barite, magnetite, limonite, iron or steel.
hedenbergite CaFeSi2O6. Salite pyroxene mineral found in igneous and metamorphic rocks.
HeidelbergCement German-based international cement manufacturer
hematite mineral form of iron (III) oxide, Fe2O3. Present in red iron ores.
hemihydrate colloquial name for calcium sulfate hemihydrate, CaSO4.0.5H2O, CŜH0.5.
heterogeneity defect in clinker, resulting in zones of different chemical and mineralogical composition within the nodule, all of which deviate from the desired mineralogy. Caused by poor rawmix blending and/or poor mixing or segregation in the kiln system.
hexagonal crystal system system characterized by one unique axis of threefold or sixfold symmetry that is perpendicular and unequal to three lateral and equal axes, the latter mutually intersecting at an angle of 120º.
hibonite natural form of calcium hexa-aluminate, CaAl12O19, CA6, with a wide range of ionic substitutions.
high alumina cement common misnomer for calcium aluminate cement.
high pressure roll press roll crusher that achieves high-efficiency fine grinding of material by fracturing particles under ultra-high stress.
high-calcium lime (ASTM definition) indicates the presence of 0 to 5 % magnesium carbonate (MgCO3) in the limestone from which the material was formed.
high-calcium limestone (ASTM definition) a limestone containing from 0 to 5 % MgCO3.
high-grading in quarrying, a malpractice consisting of extracting material of excessively high quality, so that concentration of lower quality material in the remaining reserve eventually renders it unusable.
high-range water reducer (superplasticizing admixture): water-reducing admixture, the air-entraining and retarding characteristics of which have been minimized, so that high doses, and major reductions in concrete water/cement ratio are possible.
hillebrandite C2SH: one of a range of crystalline calcium silicate hydrates.
hochofenzement German designation for portland blastfurnace slag cement containing 41-85% slag.
Hoffman kiln obsolete kind of semi-continuous static kiln used for burning bricks, but also used to make cement clinker, using briquetted rawmix.
Holcim Swiss-based international cement manufacturer
hood (rotary kiln) the static enclosure through which the fuel and combustion air are passed into the hot end of a rotary kiln, and through which the progress of clinkering can be monitored.
Hooke's Law within the elastic limit of a body, the ratio of the stress applied to the strain produced is a constant.
hornblende subgroup of amphibole minerals that are calcium-rich and monoclinic in crystal structure, generalized formula NxC4M2x+y-6A16-x-ySyH2, where x=0 to 1 and y=12 to 14.
horse power obsolete unit of power: 1 HP = 745.7 W.
humite a family of layered metamorphic rocks found at the contact of acid plutonic rocks with limestones. General formula M5S2H.
hydrated lime (ASTM definition) a dry powder obtained by treating quicklime with water enough to satisfy its chemical affinity for water under the conditions of its hydration. It consists essentially of calcium hydroxide or a mixture of calcium hydroxide and magnesium oxide or magnesium hydroxide, or both.
hydrated lime, finishing (ASTM definition) hydrated lime suitable for use in the finish coat of plaster.
hydrated lime, hydraulic (ASTM definition) the hydrated dry cementitious product obtained by calcining a limestone containing silica and alumina to a temperature short of incipient fusion so as to form sufficient free lime (CaO) to permit hydration, and at the same time, leaving unhydrated sufficient calcium silicates to give a dry powder meeting hydraulic property requirements.
hydrated lime, mason's (ASTM definition) hydrated lime suitable for use for masonry purposes.
hydration (ASTM definition) the chemical reaction between hydraulic cement and water forming new compounds most of which have strength-producing properties.
hydraulic related to water. Specifically, for cements etc, able to set and gain strength under water.
hydraulic cement (ASTM definition) a cement that sets and hardens by chemical interaction with water and that is capable of doing so under water.
hydraulic cement, air-entraining (ASTM definition) hydraulic cement containing an air entraining addition in such amount as to cause the product to entrain air in mortar within specified limits.
hydraulic cement, blended (ASTM definition) a hydraulic cement consisting of two or more inorganic constituents (at least one of which is not portland cement or portland cement clinker) which separately or in combination contribute to the strength­ gaining properties of the cement, (made with or without other constituents, processing additions and functional additions, by intergrinding or other blending).
hydraulic cement, expansive (ASTM definition) a hydraulic cement that forms a paste when mixed with water, and increases in volume a controlled amount during the early hardening period occurring after setting.
hydraulic cementitious material (ASTM definition) an inorganic material or a mixture of inorganic materials which sets and develops strength by chemical reaction with water by formation of hydrates, and which is capable of doing so under water.
hydraulic cements, latent substance that acts as a hydraulic cement when mixed with water and a minimal amount of some other substance that acts as a catalyst or activator: e.g. ground granulated blastfurnace slag (ggbs).
hydraulic hydrated lime (ASTM definition) the hydrated dry cementitious product obtained by calcining a limestone containing silica and alumina to a temperature short of incipient fusion so as to form sufficient free lime (CaO) to permit hydration, and at the same time, leaving unhydrated sufficient calcium silicates to give a dry powder meeting hydraulic property requirements.
hydraulic material, latent material that acts as a hydraulic cement if mixed with water and a minimal amount of some other substance that serves as a catalyst or activator. Particularly ground granulated blastfurnace slag.
hydraulic modulus the ratio (C+M+A)/S, used as a gauge of granulated blastfurnace slag quality.
hydraulic-cement concrete a composite material that consists essentially of a binding medium formed from a mixture of hydraulic cement and water, within which are embedded particles or fragments of aggregate.
hydrogarnet phases extensive set of solid solution minerals of general formula A3B2(SiO4)3-x(OH)4x, in which A is usually divalent and B is usually trivalent.
hydrogen iron (III) oxide goethite, FeHO2: mineral with similar structure to diaspore but much softer. Constituent of laterite iron ores and ochres.
hydrogrossular solid solution series of general formula C3AS3-xH2x. The most hydrated form (x=3) is a hydration product of calcium aluminates.
hydrophobic cement cement treated with a material rendering the particles hydrophobic, so that reaction with water does not begin until the surface material is worn off during mixing. Typically ~0.1% of fatty acid is interground.
hydrophobing agents usually long-chain fatty acids that form a thin film on the surface of each cement particle, with the aliphatic chain outermost. Silicones are also used on the surface of finished concrete.
ICMA abbrev., International Cement Microscopy Association.
id abbrev., internal diameter
idiomorphic crystal mineral crystal with faces well-formed in its normal crystalline habit – indicative of early formation in a freezing melt.
IEEE abbrev., Institute of Electrical and Electronic Engineers
igneous rocks rocks that have formed as a result of solidification of a molten magma.
ignition in chemical analysis, the process of heating a material to constant mass at a high temperature.
ignition loss LoI, the % loss in weight of a sample when ignited to constant mass at a prescribed temperature (for cement, 950ºC in ASTM, 975ºC in EN).
illite sheet-structured clay mineral group of general formula AlSi2O5(OH), AS4H. e.g. pyrophyllite.
ilmenite iron titanium oxide, FeTiO3. Found in some clays, particularly kaolins.
image analysis automated method for quantifying phases in a micrograph.
imbibation the process whereby water is drawn into an expanding hydrate system from an outside reservoir, thus supplying both volume and hydration capacity. Important in alkali-silica reaction, sulfate attack and expansive concretes.
impedance spectroscopy, AC technique used for examining the structure of cement pastes.
imperial ton ton of 2240 lb, = 1.0160470 metric tonnes: obsolete. Also known as long ton.
incoherent scattering (Compton scattering): in XRF, primary X-ray photons scattered by sample electrons with transfer of momentum. Loss of momentum causes a slight increase in wavelength.
indium antimonide InSb, used as a dispersion crystal in XRF. The [111] plane has a d-spacing of 0.3740 nm.
induction furnace furnace in which heat is produced in the conductive walls of the furnace, or its conductive charge, by application of a high frequency alternating electric field.
induction period period of hydration of cement during which the cement particles are coated with protective layers and the paste remains fluid, usually between 5 minutes and 3 hours. Followed by the acceleratory period.
influence quantity (ISO definition) a quantity which is not the subject of the measurement but which influences the value of the measurand or the indication of the measuring instrument.
inherent moisture in solid fuels, the moisture loss obtained by heating to constant mass at 105ºC a sample that has first been brought to equilibrium with air at 30ºC and 96% humidity. Roughly equivalent to the moisture content of the air-dry fuel. In normal coals, the inherent moisture content diminishes with increasing rank.
initial setting time the time taken by a paste of initial normal (standard) consistency to reach a state where rigidity is just starting to become apparent, this condition being defined in terms of a penetrometer test. Marks (roughly) the start of the acceleratory period of hydration.
InSb indium antimonide, used as a dispersion crystal in XRF. The [111] plane has a d-spacing of 0.3740 nm.
insoluble anhydrite or β-anhydrite, natural anhydrite: the most stable polymorph. Occurs naturally, or obtained by heating other calcium sulfate forms to around 700ºC.
inspection (quality systems): activity such as measuring, examining, testing, or gauging one or more characteristics of an entity and comparing the results with specified requirements in order to establish whether conformity is achieved for each characteristic.
insufflation in cement kilns, the process of blowing fine materials (other than fuel) into the front end of the kiln.
interburden in a quarry, waste rock lying between seams of the rock to be extracted.
inter-element correction in XRF, mathematical correction of an element's X-ray intensity for the effects of absorption and enhancement by other elements in the sample.
intermittent kiln kiln in which the materials are loaded in, burned, then emptied out, in a batch process. Obsolete.
internal sulfate attack production of ettringite from monosulfate at late age causing disruptive expansion, as a result of attack by sulfate present in excess in the concrete. Typically results from suppressed early ettringite formation, e.g. by hot curing (DEF).
internals fittings, castings, linings etc inside a kiln or mill
international measurement standard (ISO definition) a standard recognized by an international agreement to serve internationally as the basis for fixing the value of all other standards of the quantity concerned.
interstice (silo) a small silo occupying the space between four large silos in a square arrangement.
interstitial material in Portland cement clinkers, the material between the silicate crystals that results from freezing of the melt. Consists mainly of aluminate and ferrite.
intrusive rocks igneous rocks that have formed by penetration and subsequent solidification of magma among subterranean rocks, under pressure.
invariant point a point in a phase diagram in which the system has zero degrees of freedom.
iron (II) carbonate FeCO3, mineral name siderite. Forms solid solutions with calcium carbonate.
iron (II) disulfide FeS2. Polymorphs pyrite and marcasite - the most common sulfur minerals in the Earth's crust.
iron (II) orthosilicate Fe2SiO4. End member of the olivine solid-solution series. Mineral name fayalite.
iron (II) oxide ferrous oxide: present in small quantities in clinker that has been subjected to a reducing environment. Enters the clinker phases as a magnesia replacement.
iron (II) sulfate cement additive, used with the intention to reduce the amount of soluble hexavalent chromium in the cement.
iron (II,III) oxide magnetite, Fe3O4. Occurs in some iron ores and as the major component of millscale. Used as a cement raw material and as a high-density aggregate (dens 5200).
iron (III) oxide iron oxide, Fe2O3, F. Major constituent of cement, 0.2-5%.
iron oxide usual term for iron (III) oxide, Fe2O3, F. Major constituent of cement, 0.2-5%.
iron pyrites Iron (II) Disulfide FeS2.
ISO abbrev., International Standards Organization
ISO 9000 the international standard for Quality Systems.
isometric crystal cubic crystal.
isothermal condition a condition of a system in which it undergoes change in heat content or pressure without change in temperature.
isotropic material material whose physical properties do not vary with direction.
Italcementi Italian-based international cement manufacturer
IUGS abbrev., International Union of Geological Sciences.
IUPAC abbrev., International Union of Pure and Applied Chemistry.
jetting method for clearing buildup in kiln systems, using high-pressure water.
Johnson, Isaac Charles (1811-1911) Pioneer of cement manufacture. Claimed to have invented "modern" Portland cement. This claim is not accepted today.
joints, concrete spaces between cast sections, or saw-cut spaces, designed to allow for expansion and contraction of concrete.
jolting table device for compacting mortar prisms in the EN 196 strength test.
K cement chemist's notation for potash, potassium oxide, K2O, from Latin kalium.
K2Ca(SO4)2.H2O syngenite, calcium  potassium sulfate hydrate, KCŜ2H. Often responsible for pack-set in high-alkali cements.
K2O potash, potassium oxide, K. Minor constituent of cement, 0.05-1.5%. K is from the Latin, kalium.
K2SO4 potassium sulfate, , mineral name arcanite. Minor phase in portland cement clinker.
KA3S6H2 a potassium mica, e.g. muscovite.
KAlSi2O6 orthoclase, KAS4. The most common feldspar, and second most common mineral (after quartz) in the earth's crust.
kames glacial formations often used as aggregate sources.
kaolin cohesive clay containing kaolinite as its principal component. Low-iron forms are used as a raw material for white cement manufacture.
kaolin, calcined product consisting of meta-kaolinite if calcined at a low temperature, or mullite if calcined at a higher temperature.
kaolinite aluminium silicate hydrate, Al2Si2O5(OH)4, S2AH2. The most common clay mineral, present in most clays and shales. Forms by decomposition of feldspars.
KAP abbrev., potassium acid phthalate, HOCO.C6H4.COOK, used as a dispersion crystal in XRF. The [1010] plane has a d-spacing of 1.325 nm.
KAS4 orthoclase, KAlSi2O6. The most common feldspar, and second most common mineral (after quartz) in the earth's crust.
KC2Ŝ3 calcium langbeinite, calcium potassium sulfate, Ca2K2(SO4)3. Common minor phase in portland cement clinker.
kCal kilocalorie. Obsolete: unit of energy. Can be Thermochemical, IST, "15-degree" and various others.
kCal(IST) International Steam Table kilocalorie: obsolete unit of energy, = 4.1868 kJ. Mainly used by process engineers.
kCal (Thermochemical) Thermochemical kilocalorie: obsolete unit of energy, = 4.1840 kJ. Used in laboratory work, thermodynamics, and the measurement of fuel calorific value.
kCal/kg kilocalories per kilogram. Obsolete unit of heat consumption, = 4.1840 kJ/kg
KCl KCl. Mineral name sylvite. Important volatile intermediate in kiln reactions.
KCŜ2H syngenite, calcium  potassium sulfate hydrate, K2Ca(SO4)2.H2O. Often responsible for pack-set in high-alkali cements.
Keene's cement a cement consisting essentially of β-anhydrite, activated by inclusion of foreign ions, obtained by treating a pure gypsum plaster with a solutions of alum, then re-burning at 600°C, and grinding finely. Sets slowly and produces a harder product than hemihydrate.
kg kilogram: SI unit of mass.
kgf kilogram-force: unit of force, = 9.806 N
kiln alignment adjusting rollers to ensure that the centers of all the kiln tyres are co-linear.
kiln hood the static enclosure through which the fuel and combustion air are passed into the hot end of a rotary kiln, and through which the progress of clinkering can be monitored.
kiln liquid liquid that forms due to partial melting of the clinker in the hottest part of the kiln.
kiln zone region of the kiln in which a specific set of reactions or transformations take place. Normally defined in terms of feed temperature range.
kiln, beehive form of bottle kiln of a characteristic beehive-shape.
kiln, bottle intermittent kiln (10-30 tonnes/week) with primitive oval burning vessel, with a tapering upward extension to improve draught. Obsolete: much used in the early industry.
kiln, chamber intermittent kiln (10-30 tonnes/week) with primitive oval burning vessel, from which the exhaust gases were drawn through a long horizontal chamber in which slurry was dried prior to transfer to the kiln vessel for burning. Obsolete: much used in the UK up to 1900.
kiln, Hoffman obsolete kind of semi-continuous static kiln used for burning bricks, but also used to make cement clinker, using briquetted rawmix.
kiln, intermittent kiln (such as bottle kiln or chamber kiln) in which the materials are loaded in, burned, then emptied out, in a batch process. Obsolete.
kiln, shaft type of low-technology continuous kiln in which briquetted rawmix and fuel are loaded into the top of a vertical shaft through which an up-draught of air is drawn. As material passes downward, calcination, clinkering and cooling successively take place, and clinker is withdrawn from the bottom, with output in the range 20-100 tpd.
kiln, static non-rotary kiln: could be intermittent (e.g. bottle kiln), semi-continuous (e.g. Hoffman kiln), or continuous (shaft kiln).
kleinite Klein's compound, calcium sulfoaluminate, ye’elimite, C4A3Š. Intermediate compound in cement kilns and component of ettringite cements.
Klein's compound kleinite, calcium sulfoaluminate, ye’elimite, C4A3Š. Intermediate compound in cement kilns and component of ettringite cements.
KM6AS6H2 a magnesium mica, e.g. phlogopite.
KOSH reagent KOH and sucrose reagent. Used for selectively dissolving aluminates and ferrites.
potassium sulfate, K2SO4, mineral name arcanite. Minor phase in portland cement clinker.
kW kilowatt: SI unit of power
kyanite metamorphic high-pressure mineral, AS.
Lafarge French-based international cement manufacturer
laitance (ASTM definition) a layer of weak material derived from cementitious material and aggregate fines either: 1) carried by bleeding to the surface or to internal cavities of freshly placed concrete, or 2) separated from the concrete and deposited on the concrete surface or in internal cavities during placement of concrete under water.
large lump quicklime (ASTM definition) quicklime 200 mm and smaller
larnite natural β-C2S or belite. Named after Larne, Northern Ireland.
laser granulometry technique for measuring particle size distribution, by analyzing the diffraction pattern produced when a laser beam is passed through a suspension of the solid.
late expansion expansion of a mortar after the main period of strength development.
latent hydraulic material material that acts as a hydraulic cement if mixed with water and a minimal amount of some other substance that serves as a catalyst or activator. Particularly ground granulated blastfurnace slag.
laterite soft, clay-like mineral containing hydroxides of aluminium and iron.
Latin square arrangement for experimental design to obtain coefficients in multi-dimensional equations, avoiding co-variance of the dependent variables, from the minimum number of samples. Also called magic square.
launder sloped trough for conveying slurry downhill.
LB lithium metaborate, LiBO2, used as a low-atomic-number flux for the production of glass beads for XRF analysis of acidic materials.
LB2 lithium tetraborate, Li2B4O7, used as a low-atomic-number flux for the production of glass beads for XRF analysis of basic materials.
LCF abbrev., lime combination factor.
LCL abbrev., lower control limit.
Le Chatelier expansion test EN test method for soundness of cement.
Lea and Nurse method absolute method for determination of air-permeability specific surface, to which all other methods are traceable.
Lehigh limestone a cement rock much used in early American natural- and portland cement manufacture. Lehigh valley, eastern Pennsylvania.
length change (ASTM definition) in cement testing, an increase or decrease in linear dimension due to causes other than applied load, usually measured along the longitudinal axis of a test specimen and expressed as a percentage of a gage length.
lepidocrocite iron (III) oxide hydroxide, γ-FeO.OH: soft mineral with similar structure to boehmite. Constituent of laterite iron ores and ochres.
Lepol grate, double pass Lepol grate divided into two chambers, in which the kiln gases exhausted from the first chamber, are passed through the bed a second time in the second chamber before going to exhaust.
Lepol grate, single pass Lepol grate in which the kiln gases go to exhaust after one pass through the feed bed.
Lepol process abbrev., Lellep-Polysius, semi-dry or semi-wet cross-current preheater process in which nodules of rawmix are carried on a moving chain grate, and heated by kiln gases passing downward through the feed bed and grate. Dried and partially calcined nodules are then discharged into the rotary kiln.
Li2B4O7 lithium tetraborate, LB2, used as a low-atomic-number flux for the production of glass beads for XRF analysis of basic materials.
LiBO2 lithium metaborate, LB, used as a low-atomic-number flux for the production of glass beads for XRF analysis of acidic materials.
LiF lithium fluoride, most commonly used dispersion crystal in XRF. The [200] plane has d-spacing of 0.2014 nm, for the [220] plane it is 0.1424 nm and for the [420] plane it is 0.0901 nm.
lifter form of heat exchanger in a kiln or rotary cooler designed to lift the feed and cascade it through the gas stream.
lightweight aggregate (ASTM definition) aggregate of low density used to produce lightweight concrete, including: pumice, scoria, volcanic cinders, tuff and diatomite; expanded or sintered clay, shale, slate, diatomaceous shale, perlite, vermiculite or slag; and end products of coal or coke combustion.
lignin complex hydroxyaromatic polymer that constitutes 25-35% of the structure of wood. Removed chemically from wood to leave cellulose for paper making, usually by treatment with sulfur dioxide and alkalis, which dissolves it as lignosulfonate.
lignite (brown coal): coal in which the content of volatile combustible matter is greater than 45% DMF.
lignosulfonate product from the removal of lignin during papermaking. Acts as a deflocculant, and is used as a water-reducer in cement rawmix and in concrete: commonly contaminated with sugars due to cellulose hydrolysis during manufacture.
lime the mineral name of calcium oxide. Cubic, sodium chloride structure. Also the common name of calcium oxide (CaO, C) as an analyte; major constituent of cement, 58-69%.
lime (ASTM definition) a general term which includes the various chemical and physical forms of quicklime, hydrated lime, and hydraulic lime. It may be high-calcium, magnesian, or dolomitic. The chemical forms of calcium oxide (CaO), calcium hydroxide (Ca(OH)2), magnesium oxide (MgO), or magnesium hy­droxide (Mg(OH)2) alone or in combination may be produced either primarily or as a by-product of materials other than limestone, for example, Ca(OH)2 formed by acetylene generation from calcium carbide (CaC2), water treatment sludges, etc.
lime mortar (ASTM definition) a lime putty mixed with an aggregate, suitable for masonry purposes.
lime pozzolan cements primitive cements consisting of mixtures of lime and pozzolan, that slowly develop strength by pozzolanic reaction.
lime putty (ASTM definition) the product obtained by slaking quicklime with water according to the directions of the manufacturer or by mixing hydrated lime and water to a desired consistency.
lime saturation factor (LSF) the ratio of the amount of lime actually present in a mix or clinker to that theoretically needed to react with the more acidic oxides. Values over 100% indicate excess lime, so that formation of free lime is inevitable.
lime, agricultural (ag-lime) either ground quicklime or hydrated lime whose calcium and magnesium content is capable of neutralizing soil acidity.
lime, air-slaked (ASTM definition) the product containing various proportions of the oxides, hydroxides, and carbonates of calcium and magnesium which results from the exposure of quicklime to the air in sufficient quantity to show physical signs of hydration.
lime, available (ASTM definition) those constituents of a lime which enter into a desired reaction under the conditions of a specific method or process.
lime, building (ASTM definition) a lime whose chemical and physical characteristics and method of processing make it suitable for the ordinary or special construction uses of the product.
lime, chemical (ASTM definition) a quicklime or hydrated lime whose chemical and physical characteristics and method of processing make it suitable for one or more of the many and varied chemical and industrial uses of the product.
lime, construction (ASTM definition) a lime whose chemical and physical characteristics and method of processing make it suitable for the ordinary or special construction uses of the product.
lime, di-hydrated (ASTM definition) dolomitic lime which has been hydrated under greater than atmospheric pres­sure and contains less than 8 % unhydrated oxides.
lime, dolomitic (ASTM definition) indicates the presence of 35 to 46 % magnesium carbonate (MgCO3) in the limestone from which the material was formed.
lime, double-hydrated (ASTM definition) dolomitic lime which has been hydrated under greater than atmospheric pres­sure and contains less than 8 % unhydrated oxides.
lime, fluxing (ASTM definition) a term referring to quicklime used as an agent in the manufacture of steel or glass.
lime, free lime that remains as uncombined oxide (or hydroxide) in a clinker a cement. Combined lime is present in silicates, aluminates, ferrites and salt phases.
lime, high-calcium (ASTM definition) indicates the presence of 0 to 5 % magnesium carbonate (MgCO3) in the limestone from which the material was formed.
lime, hydrated (ASTM definition) a dry powder obtained by treating quicklime with water enough to satisfy its chemical affinity for water under the conditions of its hydration. It consists essentially of calcium hydroxide or a mixture of calcium hydroxide and magnesium oxide or magnesium hydroxide, or both.
lime, hydraulic hydrated (ASTM definition) the hydrated dry cementitious product obtained by calcining a limestone containing silica and alumina to a temperature short of incipient fusion so as to form sufficient free lime (CaO) to permit hydration, and at the same time, leaving unhydrated sufficient calcium silicates to give a dry powder meeting hydraulic property requirements.
lime, magnesian (ASTM definition) indicates the presence of 5 to 35 % magnesium carbonate (MgCO3) in the limestone from which the material was formed.
lime, mono-hydrated (ASTM definition) dolomitic lime which has been hy­drated at atmospheric pressure and contains more than 8 % unhydrated oxides.
lime, pulverized (ASTM definition) quicklime substantially all passing a 850­-μm sieve.
lime, refractory (ASTM definition) lime (usually of a dolomitic type) that has been extremely hard burned so that it will possess little or no tendency for conversion of the oxides to hydroxides.
lime, spray (ASTM definition) a hydrated lime of such fineness that at least 95 % of the particles will pass a 45­-μm sieve.
limestone (ASTM definition) an initially sedimentary rock consisting chiefly of calcium carbonate or of the carbonates of calcium and magnesium. Limestone may be of high calcium, magnesian, or dolomitic.
limestone cement, portland (European) cement containing 6-35% limestone in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
limestone, Aberthaw Blue Lias limestone selected by Smeaton for hydraulic lime manufacture for the Eddystone Lighthouse, 1756.
limestone, agricultural (ASTM definition) ground or pulverized limestone whose calcium and magnesium content is capable of neutralizing soil acidity.
limestone, Blue Lias argillaceous limestone used as a cement raw material from earliest times, in South Wales and central England.
limestone, Carboniferous limestone of the Pennines, Scotland, Ireland, Wales, much used in UK cement manufacture. Lower carboniferous age (=Mississippian, US).
limestone, dolomitic (ASTM definition) limestone containing from 35 to 46 % magnesium carbonate (MgCO3).
limestone, high-calcium (ASTM definition) a limestone containing from 0 to 5 % MgCO3.
limestone, Lehigh a cement rock much used in early American natural- and portland cement manufacture. Lehigh valley, eastern Pennsylvania.
limestone, magnesian (ASTM definition) a limestone containing from 5 to 35 % MgCO3.
limestone, oolitic limestone consisting mainly of small spherical "fish-roe" crystal growths.
liming material (ASTM definition) a general term which includes the various chemical and physical forms of lime, limestone, mollusc shells, marl, and slag whose calcium and magnesium compounds are capable of neutralizing acidity.
limits of permissible error of a measuring instrument (ISO definition) the extreme values of an error permitted by specifications, regulations, etc. for a given measuring instrument.
limonite a yellow-coloured laterite containing principally goethite and/or lepidocrocite. Used as a cement rawmix component, and as a heavy aggregate (dens 4200). In the natural finely-divided form (ochre) used as a yellow or orange cement pigment.
LIMS abbrev., Laboratory Information Management System.
liquid, kiln liquid that forms due to partial melting of the clinker in the hottest part of the kiln.
litre-weight test method of assessing the degree of burning of a clinker, by measuring bulk density of a single size-range of nodules. Hotter or longer burning produces liquid that progressively eliminates voids, leading to increased bulk density.
lithium fluoride LiF, used as a dispersion crystal in XRF.
lithium metaborate LiBO2, LB, used as a low-atomic-number flux for the production of glass beads for XRF analysis of acidic materials.
lithium tetraborate Li2B4O7, LB2, used as a low-atomic-number flux for the production of glass beads for XRF analysis of basic materials.
LoI loss on ignition, the % loss in weight of a sample when ignited to constant mass at a prescribed temperature (for cement, 950ºC in ASTM, 975ºC in EN).
long ton ton of 2240 lb, = 1.0160470 metric tonnes: obsolete. Also known as imperial ton.
loop, quality (quality systems): conceptual model of interacting activities that influence quality as well as the losses incurred when satisfactory quality is not achieved.
Los Angeles abrasion value a measure of the abrasion resistance of large aggregate. Sized aggregate is rotated in a drum with steel balls, and the weight loss is measured.
loss on ignition LoI, the % loss in weight of a sample when ignited to constant mass at a prescribed temperature (for cement, 950ºC in ASTM, 975ºC in EN).
low alkali cement cement supplied with a view to minimizing the risk of alkali/silica reaction. Specification maxima for equivalent alkalis range from 0.4 to 1.0%, but values of 0.6-0.7 are most common.
lower heating value obsolete term for Nett Calorific Value.
LSF abbrev., lime saturation factor.
M cement chemist's notation for magnesia, MgO.
m/s meters per second: SI unit of velocity.
m2 square meters: SI unit of area.
m2/kg square meters per kilogram: SI unit of specific surface area.
M2S magnesium orthosilicate, Mg2SiO4. End member of the olivine solid-solution series. Mineral name forsterite.
m3 cubic meters: SI unit of volume.
mag-chrome (magnesia-chrome). High temperature refractory material.
magic square arrangement for experimental design to obtain coefficients in multi-dimensional equations, avoiding co-variance of the dependent variables, from the minimum number of samples. Also called Latin square.
magnesia magnesium oxide, MgO, M. Major constituent of cement, 0.4-5%. Mineral name, periclase.
magnesia (ASTM definition) the chemical compound magnesium oxide (MgO).
magnesia-chrome (mag-chrome). High temperature refractory material.
magnesian lime (ASTM definition) indicates the presence of 5 to 35 % magnesium carbonate (MgCO3) in the limestone from which the material was formed.
magnesian limestone (ASTM definition) a limestone containing from 5 to 35 % MgCO3
magnesite mineral form of magnesium carbonate, MgCO3.
magnesium carbonate mineral name magnesite, MgCO3.
magnesium fluorosilicate used as a surface treatment for concrete to protect from aggressive agents.
magnesium hydroxide mineral name brucite, Mg(OH)2.
magnesium orthosilicate magnesium orthosilicate. End member of the olivine solid-solution series. Mineral name forsterite.
magnesium oxide magnesia, MgO, M. Major constituent of cement, 0.4-5%. Mineral name, periclase.
magnesium oxychloride cement a cement produced by mixing magnesium chloride solution with freshly-burned magnesium oxide.
magnetite iron (II,III) oxide, Fe3O4. Occurs in some iron ores and as the major component of millscale. Used as a cement raw material and as a high-density aggregate (dens 5200).
management, quality (quality systems): all activities of the overall management function that determine the quality policy, objectives and responsibilities, and implement them by means such as quality planning, quality control, and quality improvement within the quality system.
Management, Top (quality systems): the highest echelon of an organization, from which quality policy emanates and by whom commitment to the quality policy is explicitly expressed.
manganese (III) oxide manganic oxide, Mn2O3, . Minor constituent of cement, 0.01-1%.
manganese (II) carbonate MnCO3, mineral name rhodocrosite. Forms solid solutions with calcium carbonate.
manganic oxide manganese (III) oxide, Mn2O3, . Minor constituent of cement, 0.01-1%.
manufactured sand (ASTM definition) fine aggregate produced by crushing rock, gravel, iron blastfurnace slag, or hydraulic cement concrete.
map cracking web of inter-connected surface cracks. Symptom of alkali/silica reaction.
marble a metamorphic modification of limestone, containing calcite and dolomite plus small quantities of high-temperature minerals.
marcasite polymorph of iron (II) disulfide, FeS2, a minor constituent of many rocks.
marine sediments rocks that have formed by the deposition of suspended mineral fragments under sea water.
marl fine-grained, soft rock containing 40-80% calcium carbonate, the remainder being mostly clay minerals.
masonry cement (ASTM definition) a hydraulic cement manufactured for use in mortars for masonry construction or in plasters, or both, which contains a plasticizing material and, possibly, other performance-enhancing addition(s).
masonry cement, Type M ASTM masonry cement for high-strength applications. Typically contains 15-25% filler.
masonry cement, Type N ASTM masonry cement for low-strength applications. Typically contains 50-60% filler.
masonry cement, Type S ASTM masonry cement for medium-strength applications. Typically contains 30-45% filler.
mason's hydrated lime (ASTM definition) hydrated lime suitable for use for masonry purposes.
mason's quicklime (ASTM definition) quicklime suitable (after slaking to a lime putty) for use for masonry purposes.
mass absorption coefficient the relative rate of attenuation of X-rays per unit mass of absorbing medium. Varies with composition of medium and wavelength of incident X-rays.
mass balance assessment of the mass flow in a process, typically a kiln system. The law of conservation of mass requires that the mass inputs to a closed system should equal the mass outputs.
mass concrete concrete poured in large, thick sections.
matrix correction in XRF, mathematical correction of an element's X-ray intensity for the effects of absorption and enhancement by other elements in the sample.
matrix effect in XRF, an inter-element interference caused by passage of the primary and/or secondary radiations through the matrix of atoms that constitutes the sample.
maturity in concrete, the extent to which some property, particularly strength, has progressed towards its limiting value.
mayenite rare mineral form of dodecacalcium heptaaluminate C12A7(H)
MBM meat and bone meal: the dried and ground residue of waste meat and carcass rendering, after most of the fat has been pressed out. Used as a fuel.
meal the product of a mill.
measurand (ISO definition) a quantity subjected to measurement.
measurement (ISO definition) the set of operations having the object of determining the value of a quantity.
measurement standard (ISO definition) a material measure, measuring instrument, reference material or system intended to define, realize, conserve or reproduce a unit or one or more values of a quantity in order to transmit them to other measuring instruments by comparison.
measurement standard, international (ISO definition) a standard recognized by an international agreement to serve internationally as the basis for fixing the value of all other standards of the quantity concerned.
measurement standard, national (ISO definition) a standard recognized by an official national decision to serve, in a country, as the basis for fixing the value of all other standards of the quantity concerned.
measuring equipment (ISO definition) all of the measuring instruments, measurement standards, reference materials, auxiliary apparatus and instructions that are necessary to carry out a measurement. This term includes measuring equipment used in the course of testing and inspection, as well as that used in calibration.
measuring instrument (ISO definition) a device intended to make a measurement, alone or in conjunction with measuring instrument.
meat and bone meal (MBM): the dried and ground residue of waste meat and carcass rendering, after most of the fat has been pressed out. Used as a fuel.
melilite solid-solution series of general formula Ca2Al2-2x,MgxSix+1O7: found in air-cooled blastfurnace slag.
membrane, curing a film, usually an organic material sprayed on, deposited on the surface of concrete after setting is complete, designed to reduce water loss and/or solar gain.
merwinite Ca3MgSi2O8, C3MS2. Component of air-cooled blastfurnace slags.
metakaolin artificial pozzolan obtained by controlled heating of kaolin. Ultra-reactive: has similar properties to silica fume.
metakaolinite obtained by controlled heating of kaolinite until de-hydroxylation is almost complete.
metaquartzite quartzite in which the matrix is formed by recrystallization of silica under high temperature and pressure.
metric ton(ne) 1000 kg, =1.1023112 short tons or 0.9842064 long tons
metrological confirmation (ISO definition) set of operations required to ensure that an item of measuring equipment is in a state of compliance with requirements for its intended use.
Mg2SiO4 magnesium orthosilicate, M2S. End member of the olivine solid-solution series. Mineral name forsterite.
MgO magnesia, magnesium oxide, M. Major constituent of cement, 0.4-5%. Mineral name, periclase.
MgSiO3 enstatite, MS, deleterious mineral found in some raw materials. End member of the orthopyroxenes – a solid solution series with ferrosilite, FeSiO3.
mica a wide range of layer-structured aluminosilicate minerals.
micron commonly used misnomer for micrometer (μm).
microsilica alternative name for silica fume.
milk of lime (ASTM definition) a suspension of hydrated lime (or slaked quicklime) in water in such proportions as to resemble milk in appearance.
mill, closed-circuit mill in which the larger particles in the product are separated out in a classifier, and returned for further grinding.
mill, roller syn: vertical spindle mill, VSM: material is ground under heavy rollers in a stream of air: mainly for raw grinding.
mill, rough first stage washmill for grinding to around 10 mm.
mill, wash mill for autogenous wet-grinding of soft materials. Solid material and water are fed to an open bowl in which they are agitated by rotating harrows until fine enough to pass out through grids around the circumference of the bowl.
mill, wet a mill that grinds material with water, producing a slurry.
millscale black iron oxide, mainly Fe3O4, that forms on the surface of steel plate, strip, wire etc., during hot processing, and is subsequently detached as flakes. Used as a cement rawmix component.
mineral additions minerals other than clinker and gypsum present in appreciable amounts in composite cements. These include pozzolans, latent hydraulic materials and fillers.
mineral matter in fuel, the inorganic constituents in their natural state. When heated, this forms the ash.
Mineral Products Association MPA: UK industry association formed in 2009 by the merger of the Quarry Products Association, the British Cement Association and The Concrete Centre.
mineralizer a material added to rawmix to catalyze the production of silicates, typically allowing processing to be accomplished at a lower temperature.
MIP abbrev., mercury intrusion porosimetry.
Mn2O3 manganese (III) oxide, manganic oxide, . Minor constituent of cement, 0.01-1%.
MnCO3 manganese (II) carbonate, mineral name rhodocrosite. Forms solid solutions with calcium carbonate.
Mohs' scale arbitrary scale of mineral hardness, ranging from 1 (talc) to 10 (diamond).
moist room (ASTM definition) an enclosed room for storage and curing of paste, mortar, and concrete specimens in which temperature and high relative humidity can be controlled within specified limits.
moisture, free (fuels) the difference between the total moisture and the inherent moisture. Roughly equivalent to the moisture loss of an as-received fuel on ambient-air-drying.
moisture, free (non-fuel materials) the moisture lost when a sample is dried to constant mass at 110ºC.
moisture, inherent in solid fuels, the moisture loss obtained by heating to constant mass at 105ºC a sample that has first been brought to equilibrium with air at 30ºC and 96% humidity. Roughly equivalent to the moisture of the air-dry fuel, it consists (mainly) of water loosely held within the structure of the coal, held by hydrogen bonding. Increases as rank is reduced.
molasses raw sugar used as a retarder in cements and in mortar and concrete mixes
moler an impure diatomaceous earth used in Denmark as a pozzolan.
monocalcium silicate CS: has two polymorphs: wollastonite (β-) and pseudowollastonite (α-), the former being the more stable at room temperature.
monoclinic crystal system system characterized by a single, twofold axis of symmetry, a single plane of symmetry, or a combination of the two: three unequal axes, only two of which are perpendicular.
mono-hydrated lime (ASTM definition) dolomitic lime which has been hydrated at atmospheric pressure and contains more than 8 % unhydrated oxides.
monolithic refractory refractory formed in place in the form of a single casting.
monosulfate colloquial name for calcium monosulphoaluminate hydrate, C4AŜH12, prototype AFm phase, product of hydration of aluminates in the presence of restricted amounts of sulfate. Conversion of this to ettringite by excess sulfate causes destructive expansion.
montmorillonite expanding layer-clay mineral producing gels with water, of general formula AlSi2O5(OH).nH2O. Present in bentonite.
mortar (ASTM definition) a mixture of finely divided hydraulic cementitious material, fine aggregate, and water in either the un-hardened or hardened state; hydraulic mortar.
mortar strength test compressive strength test for cement: (Europe: EN 196) 3 sand: 1 cement: 0.5 water mechanically compacted into 40x40x160 mm prisms. (N America: ASTM C 109) 2.75 sand: 1 cement: 0.475 water hand-tamped into 50 mm cubes.
mortar, lime (ASTM definition) a lime putty mixed with an aggregate, suitable for masonry purposes.
MPA Abbrev. - Mineral Products Association: UK industry association formed in 2009 by the merger of the Quarry Products Association, the British Cement Association and The Concrete Centre.
MS enstatite, MgSiO3, deleterious mineral found in some raw materials. End member of the orthopyroxenes – a solid solution series with ferrosilite, FeSiO3.
mullite aluminium silicate mineral A3S2. Constituent of refractories and ceramics.
multi-laboratory precision the ability of a test to yield a consistent value, when performed by different operators at different locations. Reproducibility.
multi-layer crystal In XRF, a matrix of thick low-atomic-number layers and thin high-atomic number layers, typically formed by vacuum evaporation, that functions as a diffraction crystal of very large d-spacing, for selection of long-wave-length X-rays.
muscovite a potassium mica, approximately KA3S6H2.
Mylar polyethylene terephthalate: used as ultra-thin film in windows in XRF work.
N cement chemist's notation for soda, sodium oxide, Na2O.
Na2O soda, sodium oxide, N. Minor constituent of cement, 0.02-0.8%.
Na2SO4 sodium sulfate, mineral name thenardite.
Na3AlF6 cryolite, sodium hexafluoroaluminate: used as a flux in aluminium manufacture, and as a mineralizer in cement manufacture.
NA3S6H2 a sodium mica, e.g. paragonite.
national measurement standard (ISO definition) a standard recognized by an official national decision to serve, in a country, as the basis for fixing the value of all other standards of the quantity concerned.
natural anhydrite or β-anhydrite, "insoluble" anhydrite: the most stable polymorph. Occurs naturally, or obtained by heating other calcium sulfate forms to around 700ºC.
natural cement (ASTM definition) a hydraulic cement produced by calcining a naturally occurring argillaceous limestone at a temperature below the sintering point and then grinding to a fine powder.
natural pozzolan a natural mineral that reacts with lime to form strength-giving hydrates. Can be a sediment containing ultra-fine silica or silicates, or volcanic material containing reactive glass.
NCV abbrev., nett calorific value.
nekoite C3S6H8: one of a range of crystalline calcium silicate hydrates.
nest, crystal (cluster) in a material containing several phases, a non-random local concentration of crystals of one phase. In clinkers, typically caused by chemical inhomogeneity.
nett calorific value (NCV) calorific value determined in conditions in which water produced by combustion remains in the gas phase. This is the normal condition of use of a fuel, and the nett value must be calculated from the gross value determined in the laboratory.
neutron activation analysis, prompt gamma (PGNAA) method for analysis of entire process streams without sampling or preparation, by passing thermal neutrons through the material, and measuring the resulting gamma ray spectrum.
Newtonian fluid a fluid in which the shear rate is proportional to the stress applied.
NIST abbrev., National Institute of Standards and Technology. US national reference laboratory, successor to the National Bureau of Standards (NBS).
NMR abbrev., nuclear magnetic resonance.
no slump concrete concrete with a slump of 6 mm or less, placed with high degrees of vibration.
no-fines concrete (porous concrete) contains a narrowly graded coarse aggregate, little or no fine aggregate, and insufficient cement paste to fill the voids. Roller compaction leaves 20-35% voids content, allowing water to drain through.
normal consistency (ASTM definition) a degree of plasticity of a hydraulic-cement paste that is appropriate for testing as measured by a stipulated method. The result of tests for normal consistency is reported as the mass of water required to achieve this plasticity divided by the mass of hydraulic cement, expressed as a percentage.
normal distribution distribution function applicable to the magnitude of random errors in a measurement system.
nose ring the lower tip of a rotary kiln, through which the clinker passes out into the cooler.
nose ring casting high-temperature steel casting designed to retain the refractory in the kiln nose-ring.
NOx the combined oxides of nitrogen (N2O, NO, NO2), expressed as nitric oxide (NO).
NPL abbrev., National Physical Laboratory. UK national reference laboratory.
NRMCA abbrev., National Ready-Mix Concrete Association (US).
nuclear magnetic resonance analysis technique in which certain atomic nuclei are made to resonate (by radio frequency radiation) between energy levels induced by an external magnetic field. Provides information on the electronic environment of the atoms.
nucleus, cement EN term for the all the components of a cement, excluding the calcium sulfate and additives.
objective evidence (quality systems): information which can be proved true, based on facts obtained through observation, measurement or test.
ochres impure natural iron hydroxides (limonite), colour from yellow to orange depending on the oxidation state and degree of hydration. Used as pigments in coloured cements.
oil well cement cement used to seal the space between the well lining and the surrounding fractured rock. Special cement designed to make a pumpable paste under conditions of high temperature and pressure.
okenite CS2H2: one of a range of crystalline calcium silicate hydrates.
olivine series of minerals of which the forsterite/fayalite series is the parent. γ-C2S is an olivine.
on-grade concrete concrete cast on, and attached to, the natural ground surface.
oolitic limestone limestone consisting mainly of small spherical "fish-roe" crystal growths.
opal microcrystalline silica mineral, subject to alkali/silica reaction when used as an aggregate.
OPC abbrev., ordinary portland cement (UK), equivalent to portland cement Type I (US).
orthoclase KAlSi2O6, KAS4. The most common feldspar, and second most common mineral (after quartz) in the earth's crust. Potassium end-member of the alkali feldspar series. Common potassium-bearing constituent of clays and shales.
orthopyroxenes simple pyroxene minerals of idealized formula Mg1-xFexSiO3, x varying from 0 (enstatite) to ~1 (ferrosilite). Found in ultrabasic igneous rocks.
orthoquartzite quartzite in which the matrix is formed by precipitation of silica from interstitial water in sediments.
orthorhombic crystal system system characterized by three unequal, mutually perpendicular axes.
ovality defect of rotary kilns - the tendency of the kiln to deviate slightly from a perfectly circular cross-section by sagging under its own weight, mainly in the vicinity of the tyre.
overburden in a quarry, the waste material overlying the rock to be extracted.
overburden ratio the ratio of overburden moved to desired product quarried. Key parameter in quarry economics.
P cement chemist's notation for phosphorus pentoxide, P2O5.
P10 gas in XRF, term for 90% argon + 10% methane used as a detector gas in gas-flow detectors.
P2O5 phosphorus pentoxide, P. Minor constituent of cement 0.02-0.8%.
pack set the reduction of flowability of cement powder and formation of lumps associated with storage under pressure and/or vibration.
palygorskite swelling clay, typically M2AS8H.24H2O. Alternatively attapulgite.
paragonite a sodium mica, approximately NA3S6H2.
parawollastonite the 2M-polytype of β-CS.
Parker's Roman cement brand name for a hydraulic lime invented by Parker, UK, 1796.
particle size distribution the proportions (usually by mass) of the particles of a solid material in each of a set of defined size ranges.
passing, % the amount of material below a certain size: i.e. the amount going through a sieve.
paste, cement (ASTM definition) an un-hardened or hardened mixture of finely divided hydraulic cementitious material and water.
PE abbrev., penta-erythritol: C(CH2OH)4, used as a dispersion crystal in XRF. The [002] plane has a d-spacing of 0.4371 nm.
pebble quicklime (ASTM definition) quicklime 64 mm and smaller
pellet, pressed finely-ground material pressed under a load of several tons into a circular disc, for analysis by XRF.
pelletized blastfurnace slag slag quenched with a limited amount of water, resulting in partial crystallization. Used in lower-quality slag cements.
penetrometer a device for measuring the rigidity of a solid, by penetration with a needle of fixed dimensions. Measured either by determination of the depth of penetration under a fixed applied force, or by determination of the force required for a fixed depth of penetration.
pentacalcium trialuminate C5A3, conjectural and, in fact, non-existent calcium aluminate now known to be C12A7.
penta-erythritol (PE): C(CH2OH)4, used as a dispersion crystal in XRF. The [002] plane has a d-spacing of 0.4371 nm.
pentasodium tripolyphosphate used as a slurry deflocculant.
percent passing the amount of material below a certain size: i.e. the amount going through a sieve.
percent retained the amount of material above a certain size: i.e. the amount retained on a sieve.
periclase the mineral name of magnesium oxide. Cubic, sodium chloride structure.
peritectic mixture a minimum-melting point mixture of solid phases in which at least one phase decomposes on melting.
peritectic point the temperature at which a peritectic mixture melts.
perovskite calcium titanium oxide, CaTiO3, CT. Main titanium mineral found in basic igneous rocks.
petcoke petroleum coke: solid fuel resulting from pyrolysis of the residues from petroleum refining and cracking.
pfa abbrev., pulverized fuel ash (UK). Produced as fine powder when pulverized coal is burned in a power station, and captured in the exhaust dust-control equipment. US: flyash
PGNAA abbrev., Prompt Gamma Neutron Activation Analysis. Method for analysis of entire process streams without sampling or preparation, by passing thermal neutrons through the material, and measuring the resulting gamma ray spectrum.
pH "puissance d'hydrogène": the logarithm (base 10) of the molar hydrogen ion concentration in a solution. A measure of acidity/alkalinity. Acids have pH 3 or less. Alkalis have pH 11 or more.
phase rule, Gibbs' F=C+2-P, where F is the number of degrees of freedom of a system, C is the number of components, and P is the number of phases present.
phenolphthalein test test for carbonation performed on a concrete cross-section. Un-carbonated paste gives a pink colour due to calcium hydroxide present: carbonated paste is neutral and therefore colourless.
phlogopite a magnesium mica, approximately KM6AS6H2.
phosphogypsum gypsum formed as a by-product when phosphate rock is treated with sulfuric acid in order to release phosphoric acid.
phosphorus pentoxide P2O5, P. Minor constituent of cement 0.02-0.8%.
photometry, flame analysis by measuring the intensity of characteristic UV/visible emission spectra produced when a solution of analyte is introduced into a flame.
PID controller abbrev., proportional + integral + differential controller.
pigments for cement pigments specially selected for strong colour, resistance to alkalis and to oxidation, and lack of deleterious reaction with setting cement.
pipette sedimentation method the Andreason pipette.
pipette, Andreason obsolete gravimetric sedimentation method for measuring particle size distribution of fine powders.
plagioclase feldspar member of the solid solution series NaxCa1-xAl2-xSi2+xO8, end-members anorthite (x=0) and albite (x=1).
plan, quality (quality systems): document setting out the specific quality practices, resources and sequence of activities relevant to a particular product, project, or contract.
planetary cooler a set of tubes containing heat exchange devices similar to those in a rotary cooler, arranged around the circumference of a kiln at the outlet end. Also called a satellite or integral cooler.
planning, quality (quality systems): activities that establish the objectives and requirements for quality and for the application of quality system elements.
plaster a plastic mixture of solid cementing material and water for spreading on walls, ceilings, or other structures to form a smooth hard surface when dried.
plaster of Paris plastering material consisting mainly of calcium sulfate hemihydrate.
plaster, cement a soft mixture of lime and/or cement with sand and water for spreading on walls, ceilings, or other structures to form a smooth hard surface when cured.
plaster, gypsum a hard white substance made by the addition of water to powdered and partly dehydrated gypsum, used for holding broken bones in place and making sculptures and casts.
plastic, Bingham a non-Newtonian fluid that behaves as a solid when under low stress, and a liquid under higher stress. Many solid/water pastes and slurries conform approximately to this model.
PLC abbrev., programmable logic controller.
pleochroism, crystal absorption of different light frequencies, and therefore display of different colours, along different crystal axes.
pleochroite roughly C40A25M7S7. Fibrous natural mineral also found in calcium aluminate cements.
plerosphere cenosphere containing smaller cenospheres. Common in good-quality flyash.
plombierite natural calcium silicate hydrate similar to C-S-H.
point counting the technique of quantitative mineralogical analysis by microscopy. The mineral at each of several thousand regularly-spaced points on a micrograph is identified, and the quantity of each mineral is assessed from the total number of occurrences and its density.
Poisson distribution distribution function applicable to the frequency of random events in a continuum.
policy, quality (quality systems): overall intentions and direction of an organization with regard to quality, as formally expressed by Top Management.
polished section flat cross-section of mineral material polished to a sub-micron surface finish, for use in reflected-light petrographic microscopy.
polydimethylsiloxane silicone agent used to de-aerate mortar/concrete mixes.
polyethylene terephthalate (Mylar): used as ultra-thin film in windows in XRF work. Also the most common plastic used in packaging.
polymer modified concrete normal concrete to which a polymer or monomer is added during mixing. Increases strength, durability and abrasion resistance by eliminating voids.
polymorph one of a set of substances that have the same chemical formula, but differing crystal structure.
Polysius Krupp Polysius: Cement making equipment supplier.
polytype any of a number of forms of a crystalline substance which differ only in one of the dimensions of the unit cell.
pore solution the aqueous solution between the solid particles in a cement paste through which ions migrate during the hydration process. The process is strongly affected at each stage by the ion concentrations present.
porous concrete (no-fines concrete) contains a narrowly graded coarse aggregate, little of no fine aggregate, and insufficient cement paste to fill the voids. Roller compaction leaves 20-35% voids content, allowing water to drain through.
portland blast-furnace slag cement (ASTM) a hydraulic cement consisting of an intimately interground mixture of portland-cement clinker and granulated blastfurnace slag or an intimate and uniform blend of portland cement and fine granulated blastfurnace slag in which the amount of the slag constituent is between 25 and 70%. C 595 Type IS.
portland burnt shale cement (European) cement containing 6-35% burnt shale in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
portland cement (ASTM definition) a hydraulic cement produced by pulverizing portland-cement clinker, and usually containing calcium sulfate. ASTM C 150 Types I-V. (European) cement containing only 0-5% minor additional constituents in addition to clinker in its nucleus composition. EN 197 CEM I cement.
Portland Cement Association USA association of manufacturers.
portland cement clinker (ASTM definition) a clinker, partially fused by pyroprocessing, consisting predominantly of crystalline hydraulic calcium silicates (ASTM definition). Alite is the defining mineral of the portland system.
portland cement, air-entraining portland cement produced by introducing an air-entaining agent at the grinding stage.
Portland cement, controlled fineness generally refers to cement with surface area of 250-280 m2.kg-1, used in applications where removal of surplus water from the paste is desired, such as pipe spinning.
portland cement, hydrophobic cement treated with a material rendering the particles hydrophobic, so that reaction with water does not begin until the surface material is worn off during mixing. Typically ~0.1% of fatty acid is interground.
portland cement, pozzolan modified (ASTM) blended cement containing 0-15% pozzolan in addition to clinker and calcium sulfate. ASTM C 595 Type I(PM).
portland cement, slag-modified (ASTM) an intimate and uniform blend of portland cement and granulated blastfurnace slag produced either by intergrinding or a combination of grinding and blending in which the slag constituent is less than 25% of the total, by mass. ASTM C 595 Type I(SM).
portland cement, sulfate resisting portland cement that produces a concrete that is stable in contact with sulfate solutions. Aluminates are subject to expansive reaction with sulfate, and these are minimized in SRPC.
portland composite cement (European) cement containing 6-35% of multiple mineral cementitious components in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
portland fly ash cement (European) cement containing 6-35% fly ash in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
portland lime cement mixture of Portland cement and lime, used in masonry mortar.
portland limestone cement (European) cement containing 6-35% limestone in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
portland pozzolan cement (ASTM) blended cement containing 15-40% pozzolan in addition to clinker and calcium sulfate. C 595 Type IP. (European) cement containing 6-35% pozzolana in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
portland pozzolan cement (ASTM definition) a hydraulic cement consisting of an intimate and uniform blend of portland cement or portland blast-furnace slag cement and fine pozzolan produced by intergrinding portland cement clinker and pozzolan, by blending portland cement or portland blastfurnace slag cement and finely divided pozzolan, or a combination of intergrinding and blending, in which the amount of the pozzolan constituent is within specified limits.
portland silica fume cement (European) cement containing 6-10% silica fume in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
portland slag cement (European) cement containing 6-35% granulated blastfurnace slag in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
Portland stone building stone obtained from the Isle of Portland off the coast of Dorset – the only high-class building zone available in S E England, and much used in London. Portland cement got its name from a supposed resemblance to this stone when set.
portlandite mineral form of calcium hydroxide, Ca(OH)2.
potash potassium oxide, K2O, K. Minor constituent of cement, 0.05-1.5%.
potassium chloride KCl. Mineral name sylvite. Important volatile intermediate in kiln reactions.
potassium oxide potash, K2O, K. Minor constituent of cement, 0.05-1.5%.
potassium sulfate K2SO4, , mineral name arcanite. Minor phase in portland cement clinker.
pozzolan (ASTM definition) a siliceous or siliceous and aluminous material, which in itself possesses little or no cementitious value but which will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form cementitious hydrates.
pozzolan cement, portland (ASTM) blended cement containing 15-40% pozzolan in addition to clinker and calcium sulfate. C 595 Type IP.
pozzolan modified portland cement (ASTM) blended cement containing 0-15% pozzolan in addition to clinker and calcium sulfate. ASTM C 595 Type I(PM).
pozzolan, artificial pozzolan that has been produced by thermal decomposition of aluminosilicates (e.g. burnt shale), or as a byproduct of other high-temperature processes (e.g. silica fume).
pozzolan, highly reactive pozzolan containing amorphous silica particles substantially below 100 nm, such as silica fume and rice-husk ash.
pozzolan, natural a natural mineral that reacts with lime to form strength-giving hydrates. Can be a sediment containing ultra-fine silica or silicates, or volcanic material containing reactive glass.
pozzolana or pozzolan: material containing reactive, fine silica capable of reacting with lime to produce hydraulic activity.
pozzolana cement, portland (European) cement containing 6-35% pozzolana in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
pozzolanic activity hydraulic hydration reactions between lime and the mainly siliceous active constituents in a pozzolan.
pozzolanic cement (European) cement containing 11-55% pozzolan in addition to clinker in its nucleus composition. EN 197 CEM IV cement.
Pozzuoli town near Naples, Italy, from which pozzolans derive their name.
PPCC abbrev., polymer portland cement concrete.
precalciner modification of a preheater in which virtually total calcination of the rawmix is achieved, supplied with heat both by the kiln exhaust and by additional injections of fuel.
precast concrete concrete produced – often on a production-line basis-in standardized shapes and finishes, at a factory site remote from the final place of installation.
precipitation the process of causing a suspended solid to separate out from a suspension in a liquid or gas.
precipitator, electrostatic (EP), device for removing suspended solids from a gas stream, by passing the gas through a corona discharge. Particles become charged, and are attracted to, and adhere to, electrodes from which they are periodically removed by vibration.
precision the ability of a test to yield a consistent value – not necessarily the true value. Encompasses both repeatability and reproducibility.
precision (ISO definition) the closeness of agreement between independent test results under stipulated conditions.
precision, multi-laboratory the ability of a test to yield a consistent value, when performed by different operators at different locations. Reproducibility.
precision, single-operator the ability of a test to yield a consistent value, when performed by one operator on one set of apparatus. Repeatability.
preheater a heat-exchange device designed to raise the temperature of rawmix, with partial calcination, by bringing it into intimate contact with kiln exhaust gas before passing it into the rotary kiln for clinkering.
preheater, Davis preheater in which kiln gas is passed through an annular bed of nodules, movement of the nodule bed being achieved by eccentric movement of the annulus.
Prepol Polysius precalciner brand name
Prepol-AS Polysius precalciner design, with air-separate design.
Prepol-AT Polysius precalciner design, with air-through design.
pressed pellet finely-ground material pressed under a load of several tons into a flat circular disc, for analysis by XRF.
pre-stressed concrete concrete in which the longitudinal reinforcement bars are maintained in high tension during the casting and curing process, and remain under tension in service. Ensures that all sections of the concrete matrix remain in compression under all design loading regimes.
primary air combustion air that is used to propel the fuel into the flame. Specifically, the air emerging from the firing pipe into the kiln.
procedure (quality systems): specified way to perform an activity.
process (quality systems): set of interrelated resources and activities which transform inputs into outputs.
process capability (SPC): the inherent natural variability of a process and its associated measuring system, after the effects of special causes have been eliminated.
processed sewage pellets (PSP) sewage filter cake, dried and pelletised, for use as a fuel.
producer risk (sampling) the risk that an inspection scheme will cause rejection of a compliant lot.
product (quality systems): results of activities or processes.
prompt gamma neutron activation analysis (PGNAA) method for analysis of entire process streams without sampling or preparation, by passing thermal neutrons through the material, and measuring the resulting gamma ray spectrum.
proportional counter/detector, gas a gas-ionization counter operated in the voltage range within which the pulse height is proportional to the photon energy.
proportional gas counter a gas-ionization counter operated in the voltage range within which the pulse height is proportional to the photon energy.
proximate analysis of fuels the determination of moisture (free and inherent), volatile matter, ash and fixed carbon (by difference).
PSD abbrev., particle size distribution.
pseudo-crystal In XRF, a matrix of thick low-atomic-number layers and thin high-atomic number layers, typically formed by vacuum evaporation, that functions as a diffraction crystal of very large d-spacing, for selection of long-wave-length X-rays.
pseudomorph mineral with the external crystal form of one mineral and the internal chemistry of another.
pseudowollastonite unstable natural polymorph of monocalcium silicate, β-CS
psi pounds (force) per square inch. Unit of pressure or stress (obsolete).
PSP abbrev., processed sewage pellets.
pulse height selection in XRF, electronic removal of pulses from a detector not associated with the incoming secondary X-rays.
pulverized fuel ash (PFA) produced as fine powder when pulverized coal is burned in a power station, and captured in the exhaust dust-control equipment. (US: flyash).
pulverized lime (ASTM definition) quicklime substantially all passing a 850­-μm sieve.
putty, lime (ASTM definition) the product obtained by slaking quicklime with water according to the directions of the manufacturer or by mixing hydrated lime and water to a desired consistency.
pyralspite garnets series of garnets of general formula A3Al2(SiO4)3 in which A is divalent, typically Mg (pyrope), Fe(II) (almandine) or Mn(II) (spessartine).
pyrite usually means iron pyrites
pyrope end-member pyralspite garnet of formula M3AS3.
pyrophyllite AlSi2O5(OH), S4AH, typical phyllite clay mineral.
pyroprocessing processes involving material temperatures above 500ºC, such as calciners and kilns.
pyroxenes chain metasilicate minerals common in igneous and metamorphic rocks. Idealized formula Mg2-x-yFexCaySi2O6, where y varies from 0 (orthopyroxenes) to 1 (salites), and x varies from 0 to (2-y).
pyrrhotite defect iron (II) sulfide, typically Fe0.98S, found in some low-silica igneous rocks.
QCX FLS brand name for their LIMS package: "Quality Control by X-ray".
quality (quality systems): totality of characteristics of an entity that bear on its ability to satisfy stated and implied needs.
quality assurance (quality systems): all the planned and systematic activities implemented within the quality system, and demonstrated as needed, to provide adequate confidence that an entity will fulfil requirements for quality.
quality audit (ISO definition) a systematic and independent examination to determine whether quality activities and related results comply with planned arrangements and whether these arrangements are implemented effectively and are suitable to achieve objectives.
quality control (quality systems): operational techniques and activities that are used to fulfil requirements for quality.
quality loop/spiral (quality systems): conceptual model of interacting activities that influence quality as well as the losses incurred when satisfactory quality is not achieved.
quality management (quality systems): all activities of the overall management function that determine the quality policy, objectives and responsibilities, and implement them by means such as quality planning, quality control, and quality improvement within the quality system.
quality plan (quality systems): document setting out the specific quality practices, resources and sequence of activities relevant to a particular product, project, or contract.
quality planning (quality systems): activities that establish the objectives and requirements for quality and for the application of quality system elements.
quality policy (quality systems): overall intentions and direction of an organization with regard to quality, as formally expressed by Top Management.
quality review (ISO definition) a formal evaluation by top management of the status and adequacy of the quality system in relation to quality policy and new objectives resulting from changing circumstances.
quality surveillance (quality systems): continual monitoring and verification of the status of an entity and analysis of records to ensure that specified requirements are being fulfilled.
quality system organizational structure, procedures, processes, and resources needed to implement quality management.
quality system review (ISO definition) a formal evaluation by top management of the status and adequacy of the quality system in relation to quality policy and new objectives resulting from changing circumstances.
quantitative X-ray diffraction analysis (QXRD) method of determining the amounts of different crystalline phases in a solid by measuring selected peak areas and comparing with calibration standards.
quarrying, selective managing the operation of a quarry to avoid undesirable materials.
quartz usual stable polymorph of silica, SiO2.
quartzite a modified sandstone consisting of mainly of quartz grains embedded in a fine silica matrix. May be either sedimentary (orthoquartzite) or metamorphic (metaquartzite).
quenching sudden cooling of a hot material, usually in order to preserve high temperature phases in a meta-stable condition. In white cement manufacture, cooling clinker with water as soon as it leaves the kiln burning zone.
quick set alternative term for flash set.
quicklime (ASTM definition) a calcined limestone, the major part of which is calcium oxide or calcium oxide in association with mag­nesium oxide, capable of slaking with water.
quicklime, crushed (ASTM definition) quicklime 64 mm and smaller
quicklime, finishing (ASTM definition) quicklime suitable (after slaking to a lime putty) for use in the finish coat of plaster.
quicklime, granular (ASTM definition) quicklime 6.4 mm and smaller.
quicklime, ground (ASTM definition) quicklime 6.4 mm and smaller.
quicklime, large lump (ASTM definition) quicklime 200 mm and smaller
quicklime, mason's (ASTM definition) quicklime suitable (after slaking to a lime putty) for use for masonry purposes.
quicklime, pebble (ASTM definition) quicklime 64 mm and smaller
quicklime, run-of-kiln (ASTM definition) quicklime as drawn or discharged from a kiln.
quicklime, screened (ASTM definition) quicklime 6.4 mm and smaller.
QXDA abbrev., quantitative X-ray diffraction analysis.
QXRD abbrev., quantitative X-ray diffraction analysis. Method of determining the amounts of different crystalline phases in a solid by measuring selected peak areas and comparing with calibration standards.
R cement chemist's notation for R2O3, equal to alumina+iron oxide, Al2O3+ Fe2O3.
R2O3 equal to alumina+iron oxide, Al2O3+ Fe2O3. Cement chemist's notation R.
rammix monolithic refractory material, supplied as a doughy paste, rammed into place before firing.
rank (of coal) the degree of geological alteration, resulting in progressive reduction in the fuel's oxygen content, and a corresponding reduction in the volatile matter and inherent moisture content.
rankinite mineral name of tricalcium disilicate, Ca3Si2O7, C3S2. Lower calcium silicate, not found in portland cement.
rat holing The tendency for granular material in a silo to flow towards the extraction point in a narrow column above the extraction point, the remainder of the silo contents remaining static, or "dead".
raw feed (kilns) = rawmix.
raw meal rawmix produced in a dry process raw mill (European usage).
rawmix a ground mixture of raw material components, produced by the raw mill.
Rayleigh scattering (coherent scattering): in XRF, primary X-ray photons scattered by the sample surface without change in wavelength.
RbAP abbrev., rubidium acid phthalate, HOCO.C6H4.COORb, used as a dispersion crystal in XRF. The [1010] plane has a d-spacing of 1.305 nm.
RCC abbrev., roller compacted concrete.
ready-mixed concrete concrete mixed at a central batching plant, then delivered by road to the point of placement in a plastic condition, using a mixer truck. Accounts for the majority of cement use in most developed countries.
recovered liquid fuel (RLF or secondary liquid fuel SLF): combustible liquids, such as waste lubricants, waste solvents, cooking oil, paint, varnish, ink and other liquid organics, prepared for use as a fuel.
recuperation in cement kilns, the extraction and re-use of heat in exhaust gases, or in the clinker.
Recupol early Polysius grate cooler, using a moving chain grate.
recycled concrete concrete in which some or all of the aggregate consists of crushed concrete.
reference conditions (ISO definition) conditions of use for a measuring instrument prescribed for performance testing, or to ensure valid intercomparison of results of measurements.
reference intensity ratio the intensity of the main peak in the X-ray diffraction pattern of a pure crystal phase, expressed as a ratio to a common external standard.
reference material (ISO definition) a material or substance one or more properties of which are sufficiently well established to be used for the calibration of an apparatus, the assessment of a measurement method, or for assigning values to materials.
refractoriness the tendency of a mineral to remain chemically and physically unaffected by high temperatures.
refractory a mineral composition, or brick or casting made from that composition, that can be used as a high-temperature-resistant lining for a reaction vessel.
refractory concrete refractory made from a concrete mix, usually based on a calcium aluminate cement and refractory brick fragments.
refractory lime (ASTM definition) lime (usually of a dolomitic type) that has been extremely hard burned so that it will possess little or no tendency for conversion of the oxides to hydroxides.
reinforced concrete concrete containing steel reinforcing bars designed in such a way that, when in service, most of the tensile stresses will be borne by the steel.
repeatability the ability of a test to yield a consistent value, when performed by one operator on one set of apparatus. May be assessed as single-operator precision.
reproducibility the ability of a test to yield a consistent value, when performed by different operators at different locations. May be assessed as multi-laboratory precision.
resolution (of an indicating device) (ISO definition) a quantitative expression of the ability of an indicating device to permit distinguishing meaningfully between immediately adjacent values of the quantity indicated.
restrained expansion expansion of a mortar- or concrete matrix resulting in elastic stretching of embedded reinforcement.
retained, % the amount of material above a certain size: i.e. the amount retained on a sieve.
retarder substance that slows down a reaction, specifically the setting of cement.
retarding admixture (ASTM definition) admixture that retards the setting of concrete.
retrofit modification of an obsolescent technology to more modern specifications.
reversion conversion of a metastable solid phase into a more stable one, typically involving complete re-organization of the crystal structure.
review, design (quality systems): documented, comprehensive, and systematic examination of a design to evaluate its capability to fulfil the requirements for quality, identify problems, if any, and propose the development of solutions.
RH(P)C abbrev., rapid hardening (portland) cement (UK), equivalent to an inferior portland cement Type III (US).
rheology the study of the dynamics of flow of a fluid.
rhodocrosite mineral name for manganese (II) carbonate, MnCO3.
rice husk ash used as a pozzolan due to its high content of active silica.
riddlings fine solid materials that leak through the holes in a grate.
riding ring (of kiln) alternative name for kiln tyre.
Rigden apparatus apparatus for measuring specific surface by air permeability.
riser a duct in which a stream of gas rises vertically
risk, consumer (sampling) the risk that an inspection scheme will cause acceptance of a non-compliant lot.
risk, producer (sampling) the risk that an inspection scheme will cause rejection of a compliant lot.
RLF abbrev., recovered liquid fuel.
roll press, high pressure roll crusher that achieves high-efficiency fine grinding of material by fracturing particles under ultra-high stress.
roller compacted concrete lean, no-slump, almost dry concrete that is compacted by vibratory roller or plate compaction equipment.
roller mill syn: vertical spindle mill, VSM: material is ground under heavy rollers in a stream of air: mainly for raw grinding.
rollers the flat-faced wheels on which a kiln or mill tyre rides, or grinding elements in a roller mill.
rolling SD a measure of current variability obtained by calculating the SD of the last n samples each time a new sample is measured.
Roman cement 1) cement used by the Romans – consisted of lime and pozzolan. 2) brand name for a hydraulic lime invented by Parker, UK, 1796. It was made exclusively by calcining calcareous septaria found in some clays, and this is how the term is understood in Britain and North America. During the nineteenth century, ersatz imitations of the cement were made from marl in some parts of central Europe, and in those areas the term is applied to these today.
Rosin-Rammler distribution a mathematical model for particle size distributions, given by: where Rx is the % retained at size x, xc is a characteristic size, and S is the "slope".
Rosin-Rammler slope slope in the Rosin Rammler particle size distribution: increased slope indicates an increasingly narrow distribution, with fewer small and large particles, and more medium-sized particles.
rotary cooler inclined cylinder fitted with lifters. Clinker is cascaded through stream of air. The heated air is used for combustion in the kiln.
rotary kiln a continuous kiln consisting of an inclined cylinder, through which materials pass in the downhill direction, while being heated by a counter-current of hot combustion gases.
rough mill first stage washmill for grinding to around 10 mm.
run-of-kiln quicklime (ASTM definition) quicklime as drawn or discharged from a kiln.
S cement chemist's notation for silica, SiO2.
Š cement chemist's notation for sulfur trioxide, SO3.
S/R abbrev., ratio of SiO2 (S) to R2O3 (R). Silica Ratio: Silica modulus
S2AH2 Al2Si2O5(OH)4, kaolinite: the most common clay mineral.
S4AH AlSi2O5(OH), pyrophyllite, etc: typical phyllite clay mineral.
Sacrofano earth weathered diatomite sediment used as a pozzolan (Italy).
salicylic acid/methanol reagent (SAM reagent), used for selective dissolution of calcium silicate phases, leaving aluminates and ferrites, etc.
salites simple pyroxene minerals of idealized formula Mg1-xFexCaSi2O6, x varying from 0 (diopside) to 1 (hedenbergite). Common in igneous and metamorphic rocks.
SAM reagent abbrev., salicylic acid/methanol reagent. Used for selective dissolution of calcium silicate phases, leaving aluminates and ferrites, etc.
sample a portion drawn from a process stream, the study of which is intended to lead to statistical estimates of the attributes of the whole process stream.
sample, composite sample gathered continuously, or in frequent small increments, that when blended represents the product of a specified process time period or batch.
sample, grab (US) a sample taken essentially instantaneously from a process stream, with no attempt at averaging over time. In UK, "spot" sample.
sample, spot (UK) a sample taken essentially instantaneously from a process stream, with no attempt at averaging over time. In US, "grab" sample.
sampler device for withdrawing a sample of material from a process stream.
sampler, auto a sampler designed to withdraw a sample from a process stream continuously, or intermittently at pre-determined times, automatically.
sand lime brick brick made from fine sand with 10% lime added, autoclaved with steam. Hydrothermally-formed C-S-H binds the particles.
sand, manufactured (ASTM definition) fine aggregate produced by crushing rock, gravel, iron blastfurnace slag, or hydraulic cement concrete.
sandstone sedimentary rock consisting mainly of quartz grains embedded in a fine matrix of clay- or carbonate minerals.
sanidine high-temperature feldspar, metastable polymorph of KAS6.
santorin earth a natural pozzolan from the Aegean island of Santorini.
satellite cooler a set of tubes containing heat exchange devices similar to those in a rotary cooler, arranged around the circumference of a kiln at the outlet end. Also called a planetary cooler.
scanning electron microprobe analysis chemical analysis using the secondary X-rays generated by the electron beam in an electron microscope. Allows semi-quantitative analysis of areas as small as 0.5 μm, giving unambiguous identification of minerals in the micrograph, and indicating the impurity-chemistry of major phases.
scanning electron microscopy microscopy that builds an image by scanning the sample with a very fine beam of electrons, and measuring the electrons scattered.
scattering, Compton (incoherent) in XRF, primary X-ray photons scattered by sample electrons with transfer of momentum. Loss of momentum causes a slight increase in wavelength.
scattering, Rayleigh (coherent) in XRF, primary X-ray photons scattered by the sample surface without change in wavelength.
schist coarse-grained, layered metamorphic rock, generally resulting from alteration of sediments. Sometimes used as a rawmix component.
scintillation counter/detector X-ray detector consisting of a phosphor that emits light when an X-ray photon passes through it, coupled with a photomultiplier to detect the resulting light pulse.
scoops in kilns, devices for introducing dust, etc at some intermediate point in the kiln tube.
scoria foam-like volcanic glass, used as a pozzolan.
screened quicklime (ASTM definition) quicklime 6.4 mm and smaller.
SD abbrev., standard deviation.
sealed gas counter/detector a type of proportional gas detector with a thick window, containing a gas sealed in for life. Used for detecting heavy-element X-rays.
secondary air the combustion air that is supplied to a flame from the airstream surrounding the primary jet. Specifically, this is the hot air entering a kiln from the cooler.
secondary ettringite ettringite formed late in the life of concrete, as a result of infiltration of aluminium or sulfate ions.
secondary liquid fuel (SLF or recovered liquid fuel RLF): combustible liquids, such as waste lubricants, waste solvents, cooking oil, paint, varnish, ink and other liquid organics, prepared for use as a fuel.
secondary X-rays in XRF spectroscopy, X-rays re-emitted by an irradiated sample.
Sedigraph sedimentation method of particle size analysis in which a powder is dispersed in liquid, and the PSD is inferred from the rate of settling, measured by X-ray absorption.
sedigraph, X-ray device for measuring particle size distribution of a solid by measuring the attenuation of X-rays passing through a partly settled suspension of the solid in a liquid.
sedimentary rocks rocks that have formed by the deposition of suspended mineral fragments on a land surface or under water.
sedimentation analysis method of particle size analysis in which a powder is dispersed in liquid or air, and the PSD is inferred from the rate of settling, measured gravimetrically (Andreason), by light absorption (Wagner), or by X-ray absorption (Sedigraph).
segregation (concrete practice: ASTM definition) the unintentional separation of the constituents of concrete or particles of aggregate, causing a lack of uniformity in their distribution.
segregation (cement manufacture) the tendency of a blended mixture of raw materials to separate into its components during post-blending handling.
selective quarrying managing the operation of a quarry to avoid undesirable materials.
self-stressing concrete concrete containing an expansive cement with expansion sufficient to produce an appreciable permanent state of tension in its reinforcement.
SEM abbrev., scanning electron microscope, or scanning electron microprobe analysis.
semi-anthracite coal in which the content of volatile combustible matter is in the range 8-15% DMF. Called steam coal in the UK.
semi-dry process process in which a dry rawmix is first prepared, then this is nodulized with water addition prior to introduction into the kiln system.
semi-wet process process in which a slurry rawmix is first prepared, then this is pressed to a cake and crumbled or nodulized prior to introduction into the kiln system.
sensible heat heat possessed by a system by virtue only of its temperature, neglecting heat associated with phase changes.
serpentine series of laminar metamorphic rocks, of general formula MSH.
set, false (ASTM definition) early stiffening with little evolution of heat, which can be dispelled by further mixing without the addition of water.
set, flash (ASTM definition) early stiffening with evolution of considerable heat, which cannot be dispelled by further mixing without the addition of water.
set, pack the reduction of flowability of cement powder and formation of lumps associated with storage under pressure and/or vibration.
setting (ASTM definition) the process, due to chemical reactions, occurring after the addition of mixing water, that results in a gradual development of rigidity of a cementitious mixture.
setting time the time taken by a paste of initial normal (standard) consistency to reach a defined degree of rigidity. The rigidity is usually measured by some form of penetrometer.
setting time, concrete determined by penetrometer on mortar extracted from the concrete by sieving.
setting time, final the time taken by a paste of initial normal (standard) consistency to reach a state where the surface is not easily indented, this condition being defined in terms of a penetrometer test.
setting time, Gilmore form of setting time determination using two needle penetrometers. Obsolescent.
setting time, initial the time taken by a paste of initial normal (standard) consistency to reach a state where rigidity is just starting to become apparent, this condition being defined in terms of a penetrometer test. Marks (roughly) the start of the acceleratory period of hydration.
setting time, Vicat form of setting time determination using a needle penetrometer.
sewage sludge separated flocculated solids sometimes used as a fuel and/or rawmix component.
SF abbrev., suspension furnace: type of precalciner.
shaft kiln type of low-technology continuous kiln in which briquetted rawmix and fuel are loaded into the top of a vertical shaft through which an up-draught of air is drawn. As material passes downward, calcination, clinkering and cooling successively take place, and clinker is withdrawn from the bottom, with output in the range 20-100 tpd.
shaft preheater counter-current heat exchanger with kiln gases ascending and feed descending under gravity. Constrictions in the shaft induce turbulent mixing.
shale argillaceous rock of medium hardness with a distinct laminar structure.
shells sea shells, mostly composed of aragonite, are sometimes used as a cement rawmix component.
short ton US ton of 2000 lb, = 0.9071848 metric tonnes: obsolete. Also known as colonial ton.
shot hole hole drilled for placing blasting explosives.
shotcrete low-water-content mortar or concrete that is pneumatically projected onto a surface at high velocity. Typically used for depositing thin layers on curved surfaces.
shrinkage defect of concrete in which, if the concrete is not free to move, tensile cracking takes place.
shrinkage cracking cracking in concrete that occurs when restrained concrete is subject to tensile forces exceeding its tensile strength, as a result of shrinkage.
shrinkage, drying shrinkage that occurs in concrete when the free water in its structure evaporates after curing.
shrinkage-compensating cement form of expansive cement. Used in concrete, early expansion is produced sufficient to counteract later shrinkage, so avoiding the occurrence of tensile cracking.
SI Système Internationale d'Unités: the international system of units used by all standards bodies.
SiC carborundum, silicon carbide. Used as an abrasion-resistant aggregate, and in some high-corrosion-resistance refractories.
siderite mineral name for iron (II) carbonate, FeCO3. An iron ore, 69% Fe2O3 when pure.
sieve analysis determination of the particle size distribution of a solid material, by shaking on sieves with successively smaller openings.
silex flint-like mineral, but usually lacking flint's nodular form.
silica silicon dioxide, SiO2, S. Major constituent of cement, 18-26%.
silica fume cement, portland (European) cement containing 6-10% silica fume in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
silica fume cements cements containing silica fume in amounts 3-20%. The silica fume reacts rapidly with the calcium hydroxide produced during cement hydration to produce enhanced strength at all ages.
silica fume, condensed material produced by the re-oxidation of silicon monoxide, SiO, which is produced during various high-temperature reductive processes involving silica.
silicon carbide carborundum, SiC. Used as an abrasion-resistant aggregate, and in some high-corrosion-resistance refractories.
silicon dioxide silica, SiO2, S. Major constituent of cement, 18-26%.
silicosis form of pneumoconiosis caused by exposure to air-borne respirable ultra-fine silica.
silicosulfate calcium sulfosilicate, C5S2Š, mineral name ternesite, sometimes incorrectly called sulfospurrite. Low temperature intermediate in cement kilns.
sill tabular intrusion of igneous rock nearly parallel to the bedding of the enclosing rock.
sillimanite high-pressure aluminium silicate mineral AS.
SIMS abbrev., secondary ion mass spectroscopy.
single-operator precision the ability of a test to yield a consistent value, when performed by one operator on one set of apparatus. Repeatability.
sintering Heating to a temperature at which part, but not all, of a mixture melts.
SiO2 silica, silicon dioxide, S. Major constituent of cement, 18-26%.
slag a material produced in the purification of metals, in the form of a molten phase immiscible with the metal, that preferentially dissolves impurities. Quenched iron blastfurnace slag is used as a component in some cements.
slag cement (ASTM) blended cement consisting of 70-100% granulated blastfurnace slag, plus clinker, calcium sulfate and/or hydrated lime. C 595 Type S.
slag cement (ASTM definition) a hydraulic cement consisting mostly of an intimate and uniform blend of ground, granulated blast­furnace slag and, one or both of portland cement or hydrated lime, in which the amount of the slag constituent is within specified limits.
slag cement, portland (European) cement containing 6-35% granulated blastfurnace slag in addition to clinker in its nucleus composition. A variety of EN 197 CEM II cement.
slag modified portland cement (ASTM) an intimate and uniform blend of portland cement and granulated blastfurnace slag produced either by intergrinding or a combination of grinding and blending in which the slag constituent is less than 25% of the total, by mass. ASTM C 595 Type I(SM).
slag, blastfurnace the molten material produced in an iron blastfurnace as a result of the reaction between the limestone flux and the siliceous and aluminous impurities in the iron ore. Extracted by periodically tapping off the molten layer from above the molten iron in the base of the furnace.
slag, blast-furnace (ASTM definition) the nonmetallic product, consisting essentially of silicates and aluminosilicates of calcium and other bases, that is developed in a molten condition simultaneously with iron in a blast furnace.
slag, granulated blast-furnace (ASTM definition) the glassy granular mate­rial formed when molten blast-furnace slag is rapidly chilled, as by immersion in water.
slag, pelletized blastfurnace slag quenched with a limited amount of water, resulting in partial crystallization. Used in lower-quality slag cements.
slag, steel slag produced in a steel furnace, sometimes used as a cement rawmix component. Contains a wide range of heavy metals, particularly chromium.
slag-modified portland cement (ASTM definition) an intimate and uniform blend of portland cement and granulated blastfurnace slag produced either by intergrinding or a combination of grinding and blending in which the slag constituent is less than 25% of the total, by mass.
slate metamorphic rock with lamellar structure produced by subjection of argillaceous rocks to intense shear forces. Sometimes used a cement raw material.
SLF abbrev., secondary liquid fuel.
slate, expanded light-weight aggregate formed by careful calcination of fragments of slate.
slump a measure of concrete workability in which concrete is placed in an open-bottomed conical mould, leveled off, and the mould withdrawn. The slump value is the vertical distance through which the top of the pile of concrete sinks.
slump loss the tendency of concrete to become less workable during the first hour after mixing. Usually given as the ratio of slump at a given time to slump when first mixed.
slurry Thick suspension of a solid in a liquid. Specifically, thick suspension of ground cement raw materials in water.
slurrying Milling a solid with liquid to produce a slurry.
Smeaton, John English civil engineer. First established (1756) that the hydraulic nature of limes increases with the clay content of the limestone from which they are made.
smectite soft, layered, expanding clay mineral series.
SO3 sulfur trioxide, Š. Major constituent of cement, 1.5-7%.
soda sodium oxide, Na2O, N. Minor constituent of cement, 0.02-0.8%.
sodalite a feldspathoid mineral N3A3S6.2NaCl, found in basic igneous rocks.
sodium aluminium fluoride sodium hexafluoroaluminate
sodium chloride mineral name halite, NaCl.
sodium hexafluoroaluminate cryolite, Na3AlF6: used as a flux in aluminium manufacture, and as a mineralizer in cement manufacture.
sodium oxide soda, Na2O, N. Minor constituent of cement, 0.02-0.8%.
sodium silicate used as a surface treatment for concrete to protect from aggressive agents.
sodium sulfate Na2SO4, mineral name thenardite.
soil cement cement used in soil stabilization, in which cement is blended into damp soil, and the mixture is roller compacted. The fine cement acts partly as an adhesive and partly as a grout.
solid solution a crystalline solid having a continuously variable composition over a certain range, characterized by a crystal lattice in which the identity of atoms or ions in a given location in the structure may vary in a random manner.
solid solution series the continuous sequence of substances with compositions intermediate between two distinct mineral phases, called end members. Physical properties of the series vary continuously with composition.
soluble anhydrite or γ-anhydrite. Form of bassanite with low water content (CaSO4.nH2O where n=0.05-0.2). Formed when gypsum or hemihydrate is heated above 150ºC. Metastable, gradually irreversibly converts to β-anhydrite ("insoluble" anhydrite) at higher temperatures. More soluble than gypsum.
solution series, solid the continuous sequence of substances with compositions intermediate between two distinct mineral phases, called end members. Physical properties of the series vary continuously with composition.
solution, solid a crystalline solid having a continuously variable composition over a certain range, characterized by a crystal lattice in which the identity of atoms or ions in a given location in the structure may vary in a random manner.
sonic sound intensity used as a control parameter in ball mills, coolers, etc.
Sorel cement a kind of magnesium oxychloride cement.
soundness the ability of a cement to confer dimensional stability upon concrete throughout its lifetime.
SOx total of all sulfur oxides, usually expressed as SO2.
SP abbrev., suspension preheater
SPn abbrev., suspension preheater of n stages
space group the fundamental symmetry classification of a crystal.
SPC abbrev., statistical process control.
special causes (SPC): causes of measured variation in a process that consist of events outside the population of common causes leading to inherent variability.
specific gravity (obsolete) density expressed as a ratio to the density of water at some fixed temperature. Density preferred.
specific heat obsolete term for heat capacity.
specific surface US preferred term for specific surface area.
specific surface area the total surface area of all the particles in a solid, per unit mass: SI unit – m2.kg-1. Values depend upon the method of measurement employed.
specification (ASTM definition) an explicit set of requirements to be satisfied by a material, product, system or service.
specified measuring range (ISO definition) the set of values for a measurand for which the error of a measuring instrument is intended to lie within specified limits.
spectroscopy, electron, for chemical analysis (ESCA)
spectroscopy, X-ray fluorescence (XRF): analysis by measurement of the characteristic secondary X-rays emitted by each element in a sample irradiated with white X-rays.
spessartine end-member pyralspite garnet of formula Mn3Al2(SiO4)3.
spinel magnesium aluminate, MgAl2O4, MA. Component of some refractories.
spiral chains in kilns, heat-exchange chains attached at one end to a helical hanging bar.
spiral, quality (quality systems): conceptual model of interacting activities that influence quality as well as the losses incurred when satisfactory quality is not achieved.
splash box device for dispersing feed into the gas stream in a riser duct of a suspension preheater.
spot sample (UK) a sample taken essentially instantaneously from a process stream, with no attempt at averaging over time. In US, "grab" sample.
spray lime (ASTM definition) a hydrated lime of such fineness that at least 95 % of the particles will pass a 45 μm sieve.
spray-drier device for removing the water from a solution or slurry, by spraying it into a hot gas-stream.
spurrite calcium silicocarbonate, Ca5(SiO4)2CO3: common constituent of kiln build-up.
SR Silica Ratio: Silica modulus
SR(P)C abbrev., sulfate resisting (portland) cement (UK), equivalent (roughly) to portland cement Type V (US).
SrCO3 strontium carbonate, mineral name strontianite.
SrO strontium oxide, strontia. Minor constituent of cement, 0.01-0.4%.
stability (ISO definition) the ability of a measuring instrument to maintain constant its metrological characteristics.
standard coal (obsolete, UK) formalism for heat input to a kiln. 1 tonne standard coal = 29.288 GJ (gross) exactly.
standard practice (ASTM definition) a definitive set of instructions for performing one or more specific operations that does not produce a test result.
standard test method (ASTM definition) a definitive procedure that produces a test result.
standard, check (ISO definition) measuring equipment, product, or other objects serving to collect a data base for the control of a measurement process, by being measured by that process.
static kiln non-rotary kiln: could be intermittent (e.g. bottle kiln), semi-continuous (e.g. Hoffman kiln), or continuous (shaft kiln).
steel ring sample finely ground material pressed under a load of several tons into a 40-mm diameter steel ring for analysis by XRF.
steel slag slag produced in a steel furnace, sometimes used as a cement rawmix component. Contains a wide range of heavy metals. Use in cement manufacture requires a detailed knowledge of the metals present and of the risks associated with their addition.
Stefan-Boltzmann Law the energy radiated in unit time by a black body is given by E=k(T4-T04) where T is the absolute temperature of the body, T0 is the temperature of the surroundings and k is a constant.
STEM abbrev., scanning transmission electron microscopy.
stemming material used to pack a shot-hole above the explosive charge.
stiffening, early  (ASTM definition) rapid loss of plasticity or rapid development of rigidity in freshly mixed hydraulic cement paste, mortar, or concrete.
Stokes' Law the terminal velocity of a spherical body of radius r and density ρ1, falling under gravity through a viscous medium of dynamic viscosity η and density ρ2 is given by v = 2 g r212)/(9 η). A key equation in understanding the entrainment of solid particles in gas streams.
stpd abbrev., short tons per day
strain the relative change in dimensions of a body when a stress is applied. Dimensionless.
strätlingite (gehlenite hydrate), C2ASH8, natural AFm mineral formed by hydration of some calcium aluminate cements and slag cements.
strength retrogression decline in strength of mortar or concrete at later ages.
strength test, accelerated strength test performed at controlled elevated temperature.
stress, yield in a Bingham plastic, the minimum stress required before flow begins. SI unit: Pa
strontia strontium oxide, SrO. Minor constituent of cement, 0.01-0.4%.
strontianite mineral name for strontium carbonate, SrCO3.
strontium carbonate SrCO3, mineral name strontianite.
strontium oxide strontia, SrO. Minor constituent of cement, 0.01-0.4%.
strontium silicates series of silicates with similar hydraulic properties to those of calcium.
stucco fine plaster used for coating wall surfaces or moulding into architectural decorations.
subaerial sediments rocks that have formed by the deposition of wind-blown mineral fragments on a land surface.
sub-bituminous coal coal in which the content of volatile combustible matter is in the range 35-45% DMF.
subhedral crystal mineral crystal with faces partially deformed by the surrounding matrix – indicative of formation at an intermediate stage in a freezing melt, or very rapid growth.
sulfate attack destruction of concrete by the action of sulfate ions, either from within the concrete (internal) or from the surrounding environment (external). Typically occurs by expansive conversion of monosulfate to ettringite.
sulfate attack, external production of ettringite from monosulfate at late age causing disruptive expansion, as a result of attack by sulfate permeating the concrete from the external environment. Typically results from contact with sulfate-bearing groundwater or sea water.
sulfate attack, internal production of ettringite from monosulfate at late age causing disruptive expansion, as a result of attack by sulfate present in excess in the concrete. Typically results from suppressed early ettringite formation, e.g. by hot curing (DEF).
sulfate expansion also caused sulfate unsoundness. Cements expand destructively by ettringite crystal growth at late ages if the amount of sulfate present is greater than that needed to convert aluminates to monosulfate.
sulfate plant mud a calcium carbonate by-product resulting from the reaction of ammonium carbonate and calcium sulfate to form ammonium sulfate fertiliser. Historically used in cement manufacture.
sulfate resistance ability of a cement to resist the effects of external sulfate attack on concrete. Achieved by minimizing C3A content or by using slag as a component.
sulfate resisting portland cement portland cement that produces a concrete that is stable in contact with sulfate solutions. Aluminates are subject to expansive reaction with sulfate, and these are minimized in SRPC.
sulfate unsoundness also called sulfate expansion. Cements expand destructively at late ages if the amount of sulfate present is greater than that needed to convert aluminates to monosulfate.
sulfathüttenzement German name for supersulfated cement.
sulfoaluminate cement cement containing kleinite as an active component, as in low-energy cements, expansive cements and ultra-high-early strength cements.
sulfoaluminate cement non-Portland cement containing calcium sulfoaluminate, C4A3Š, as an active component.
sulfospurrite incorrect name for C5S2Š, calcium sulfosilicate (ternesite). Low temperature intermediate in cement kilns. It is not related to spurrite (C5S2Č).
sulfur trioxide SO3, Š. Major constituent of cement, 1.5-7%.
super-P abbrev., superplasticizing admixture.
superplasticizing admixture (high-range water reducer): water-reducing admixture, the air-entraining and retarding characteristics of which have been minimized, so that high doses, and major reductions in concrete water/cement ratio are possible.
supersulfated cement cement made from granulated blastfurnace slag (80-85%), calcium sulfate (10-15%) and portland cement (~5%). Gains strength mainly by formation of ettringite and C-S-H.
surface area, specific the total surface area of all the particles in a solid, per unit mass: SI unit – m2.kg-1. Values depend upon the method of measurement employed.
surkhi burned kaolinitic clay consisting of impure metakaolinite: used for centuries as a pozzolan in India
surveillance, quality (quality systems): continual monitoring and verification of the status of an entity and analysis of records to ensure that specified requirements are being fulfilled.
sylvite mineral name for potassium chloride, KCl. Important volatile intermediate in kiln reactions.
syngenite calcium potassium sulfate hydrate, K2Ca(SO4)2.H2O, KCŜ2H. Often responsible for pack-set in high-alkali cements.
system, quality organizational structure, procedures, processes, and resources needed to implement quality management.
T cement chemist's notation for titania, titanium dioxide, TiO2.
TA duct abbrev., tertiary air duct
talc basic magnesium silicate M3S4H.
t-distribution tests whether a sample is representative of the population from which it is drawn.
TEM abbrev., transmission electron microscopy.
terminology standard (ASTM definition) a document comprising definitions of terms; explanations of symbols, abbreviations, or acronyms.
ternary cement a composite or blended cement containing three cementitious components.
ternary eutectic the minimum-melting-point mixture in a system of three components.
ternesite mineral name of C5S2Š, calcium sulfosilicate, sometimes incorrectly called sulfospurrite. Low temperature intermediate in cement kilns. It is not related to spurrite (C5S2Č).
terrazzo decorative concrete made using medium-fine aggregate that is ground and polished after hardening to produce a surface that has cross-sections of both paste and aggregate.
tertiary air supplemental hot air from the cooler used to support combustion in the calciner vessel of a precalciner.
tertiary air duct (TA duct) duct through which tertiary air passes from the cooler to the calciner vessel.
tetracalcium aluminoferrite approximately C4AF , the system of solid solutions that forms from the melt in Portland cement clinker, mineral name brownmillerite. Actual composition C4AnF2-n where n = 0 to 1.4 depending upon alumina ratio, plus substituted SiO2, MgO, TiO2, Mn2O3, ZnO etc.
tetragonal crystal system system characterized by a fourfold rotation or rotary inversion axis of symmetry: three axes, two of which are equal, are mutually perpendicular.
thallium acid phthalate (TlAP): HOCO.C6H4.COOTl, used as a dispersion crystal in XRF.
thaumasite modified AFt phase similar to ettringite, of formula C3SŜČH15. Forms in cold, wet conditions in association with sulfate attack and fine carbonates.
thenardite mineral name of sodium sulfate, Na2SO4.
theoretical corrections in XRF, matrix corrections calculated from first principles, based upon tube characteristics, geometry and known elemental physics. Also know as fundamental parameters.
thermal analysis, differential measurement of the changes in enthalpy (sensible heat, endotherms and exotherms) of a material as a function of temperature. Some phases can be quantitatively estimated from the intensity of their identified endotherms/exotherms.
thermal conductivity units W.m-1.K-1. Around 1 for concrete.
thixotropy the property of becoming less viscous when subjected to an applied stress. Viscosity gradually recovers when the stress is removed.
tiff barite, barytes, heavy spar, barium sulfate, BaSO4. Used as a high-density aggregate (dens 4480).
tilleyite natural calcium silicate carbonate C5S2Č2.
TiO2 titania, titanium dioxide, T. Minor constituent of cement, 0.05-0.5%.
titania titanium dioxide, TiO2, T. Minor constituent of cement, 0.05-0.5%.
titanium chelates used in combination with organic polymers to render grouts thixotropic.
titanium dioxide titania, TiO2, T. Minor constituent of cement, 0.05-0.5%.
TlAP abbrev., thallium (I) acid phthalate, HOCO.C6H4.COOTl, used as a dispersion crystal in XRF. The [1010] plane has a d-spacing of 1.295 nm.
tobermorite natural layered calcium silicate hydrate mineral, approximately C10S11H10, related to C-S-H. The layer spacing varies with the degree of hydration, yielding 1.1 nm and 1.4 nm forms.
tobermorite, 1.1 nm tobermorite close to the natural mineral in form, approximately C10S11H10. Found in pastes of autoclaved concrete, and when the 1.4 nm form is heated above 55ºC.
tobermorite, 1.4 nm tobermorite close to C-S-H(I) in form, approximately C10S11H18.
ton, imperial UK ton of 2240 lb (Av), = 1.0160468 metric tonnes = 1.1199998 short tons: used in the UK until 1972.
ton(ne), metric 1000 kg, = 0.9842066 imperial tons = 1.1023112 short tons.
ton, short or colonial ton: US ton of 2000 lb (US), = 0.9071849 metric tonnes = 0.8928573 imperial tons: used only in the USA.
Top Management (quality systems): the highest echelon of an organization, from which quality policy emanates and by whom commitment to the quality policy is explicitly expressed.
Total Quality Management operational philosophy for entire organizations, involving concepts such as Customer Satisfaction, Zero Defects, Continuous Improvement, etc.
TQM abbrev., Total Quality Management
traceability (quality systems): ability to trace the history, application, or location of an entity by means of recorded identifications. (of equipment): the trail of documentation linking the calibration of a measuring system to a primary national or international standard. (of measurement: the property of the result of a measurement whereby it can be related to appropriate measurement standards, generally international or national standards, through an unbroken chain of comparisons.
trail, audit (quality systems): an quality auditing process in which the documentary history of an entity's movement through the quality system is examined and verified.
trap rock common name for hard igneous rock used as aggregate, sometimes dolerite, sometimes basalt.
trass glassy volcanic tuff used as a pozzolan in Germany.
trass cement cement produced by grinding portland cement clinker with 20-50% trass.
tributyl phosphate (n-C4H9)3PO4. Used to de-aerate mortar/concrete mixes.
tricalcium aluminate C3A, Ca3Al2O6. The most basic calcium aluminate, present in Portland cement clinker as an interstitial phase, crystallized from the melt. In real clinkers, it contains varying amounts of other oxides, particularly alkalis. The lower alkali form is cubic, and the higher alkali form is orthorhombic. Hydrates very rapidly in the absence of sulfate to form C3AH6, producing "flash set". In the presence of sulfate (~2%) the C3A is temporarily passivated due to the formation of an insoluble layer of ettringite.
tricalcium disilicate Ca3Si2O7, C3S2. Lower calcium silicate, not found in portland cement, mineral name rankinite.
tricalcium silicate the name for pure C3S. In real clinkers, the mineral is called alite, and usually contains small amounts of substituents: principally alumina, iron oxide and magnesia. Hydrates rapidly to form the strength-giving C-S-H.
tricalcium silicate hydrate C6S2H3: one of a range of crystalline calcium silicate hydrates.
tridymite the silica polymorph stable between 870 and 1470ºC.
triethanolamine common cement grinding aid component. When used as the acetate, also functions as an accelerator.
trigonal crystal system system in which all axes are unequal, and all angles differ from 90º.
true value of a quantity, conventional (ISO definition) value attributed to a particular quantity and accepted, sometimes by convention, as having an uncertainty appropriate for a given purpose.
truscottite C6S10H3: one of a range of crystalline calcium silicate hydrates.
turbidimeter a photometer designed for measurement of the light absorption of a turbid suspension, to determine the concentration of suspended material present.
Type I portland cement (US) general purpose portland cement.
Type I(PM) blended cement (ASTM) blended cement containing 0-15% pozzolan in addition to clinker and calcium sulfate. Pozzolan modified portland cement.
Type I(SM) blended cement (ASTM) an intimate and uniform blend of portland cement and granulated blastfurnace slag produced either by intergrinding or a combination of grinding and blending in which the slag constituent is less than 25% of the total, by mass. Slag-modified portland cement.
Type I/II portland cement (US) general purpose portland cement meeting both Type I and Type II specifications.
Type II portland cement (US) general purpose portland cement with moderate sulfate resistance.
Type III portland cement (US) rapid hardening portland cement.
Type IP blended cement (ASTM) blended cement containing 15-40% pozzolan in addition to clinker and calcium sulfate. Portland pozzolan cement.
Type IS blended cement (ASTM) a hydraulic cement consisting of an intimately interground mixture of portland-cement clinker and granulated blastfurnace slag or an intimate and uniform blend of portland cement and fine granulated blastfurnace slag in which the amount of the slag constituent is between 25 and 70%. Portland blast-furnace slag cement.
Type IV portland cement (US) portland cement with low heat of hydration.
Type M masonry cement ASTM masonry cement for high-strength applications. Typically contains 15-25% filler.
Type N masonry cement ASTM masonry cement for low-strength applications. Typically contains 50-60% filler.
Type S blended cement (ASTM) blended cement consisting of 70-100% granulated blastfurnace slag, plus clinker, calcium sulfate and/or hydrated lime. Slag cement.
Type S masonry cement ASTM masonry cement for medium-strength applications. Typically contains 30-45% filler.
Type V portland cement (US) portland cement with high sulfate resistance.
UCL abbrev., upper control limit.
ugrandite garnets series of garnets of general formula Ca3B2(SiO4)3 in which B is trivalent, typically Al (grossular), Fe(III) (andradite) or Cr(III) (uvarovite).
ultimate analysis of fuels the determination of carbon, hydrogen, sulfur, nitrogen and ash, plus occasionally some other elements. Oxygen may be estimated (inaccurately) by difference.
Unax cooler FLS version of the satellite cooler
uncertainty of measurement (ISO definition) result of the evaluation aimed at characterizing the range within which the true value of a measurand is estimated to lie, generally with a given likelihood.
unit cell the smallest repeating structural unit in a crystal lattice.
unsoundness of cement tendency of the cement to cause late expansion of the concrete, potentially causing failure.
unsoundness, sulfate also caused sulfate expansion. Cements expand destructively at late ages if the amount of sulfate present is greater than that needed to convert aluminates to monosulfate.
upper heating value obsolete term for Gross Calorific Value.
USGS abbrev., United States Geological Survey.
uvarovite end-member ugrandite garnet of formula Ca3Cr2(SiO4)3.
variance (statistics) the square of the standard deviation.
variation, coefficient of ratio of estimated standard deviation to population mean, usually expressed as a percentage.
vaterite rare metastable polymorph of calcium carbonate.
VCM (coal testing): abbrev., volatile combustible matter.
VDZ German Cement Works Association
verification (quality systems): confirmation by examination and provision of objective evidence that specified requirements have been fulfilled. (of equipment): pass/fail test to confirm that a measuring system produces correct data when used to measure an accepted standard material or test-piece. As distinct from calibration.
vermiculite clay related to montmorillonite that expands about 20-flod when heated rapidly to 300ºC. The expanded form is used as a light-weight aggregate.
vertical kiln syn: shaft kiln: static kiln in which feed in briquette- or lump-form passes down a shaft while hot combustion gases percolate up through the column of material. Can be intermittent or continuous.
vertical spindle mill VSM: syn: roller mill, VSM: material is ground under heavy rollers in a stream of air: used for rawmix, fuel and cement grinding.
vertumnite C2ASH8
vibrating table device sometimes used as an alternative to the jolting table for compaction of mortar prisms in the EN 196 strength test.
Vicat needle needle of 1-mm diameter circular section (Europe) or 1-mm square section (ASTM) with a total mass of 300 g, for determination of initial and final setting times.
Vicat setting time form of setting time determination using a needle penetrometer.
Vinsol resin pine oil resin used as an air entraining agent in cements and concrete.
viridian chromium (III) oxide, chromic oxide, Cr2O3, used as a pigment in green coloured cements.
VM (coal testing): abbrev., volatile matter.
void spacing factor average maximum distance from any point in cement paste to the edge of the nearest air void. A measure of the effectiveness of entrained air for freeze-thaw protection – should be less than 0.2 mm for good performance.
volatile (combustible) matter of fuels, those products, exclusive of moisture, given off when a sample is heated at a defined coking temperature, with limited access of air. In normal coals, the volatiles are a mixture of hydrogen, methane, carbon monoxide, hydrogen sulfide, ammonia, etc. The volatile matter content diminishes with increasing rank.
volatile circulation the cycle of volatilization (in zones of high-temperature feed) and condensation (in zones of lower-temperature gas) resulting in a relatively high concentrations of volatiles between these zones. Plays a vital role in reducing kiln operating temperature.
volatiles in kilns, those components of the mix capable of volatilizing at burning zone temperature. Mainly SO3, Na2O, K2O and Cl.
vortex finder the outlet duct that projects axially into a cyclone, and conveys out clean fluid.
VSM abbrev., vertical spindle mill: roller mill
Wagner turbidimeter device for measurement of particle size distribution and specific surface by sedimentation (obsolete). The light transmission of a settling suspension of cement is measured.
waiver (quality systems): written authorization to use or release a product which does not conform to the specified requirements.
washmill mill for autogenous wet-grinding of soft materials. Solid material and water are fed to an open bowl in which they are agitated by rotating harrows until fine enough to pass out through grids around the circumference of the bowl.
water reducer, high-range (superplasticizing admixture): water-reducing admixture, the air-entraining and retarding characteristics of which have been minimized, so that high doses, and major reductions in concrete water/cement ratio are possible.
water-reducing admixture (ASTM definition) admixture that either increases the slump of freshly mixed mortar or concrete without increasing the water content, or that maintains the slump with a reduced amount of water, due to factors other than air entrainment.
water-resisting admixture admixture used to reduce the water-penetrability of concrete. May be either a densifier that eliminates inter-connected voids, or a hydrophobic agent.
wet process process in which rawmix is prepared as a slurry and is fed to the kiln system in that form.
wg abbrev., water gauge (i.e pressure expressed as the equivalent head of water).
whinstone intrusive volcanic rock, northern England. Used as aggregate.
white cement cement with low proportions of colouring elements in its composition: specifically, ultra-low-iron cement.
white wash (ASTM definition) a combination of hydrated lime (or slaked quicklime), water, and other materials to be used as a paint-like coating.
white X-rays X-rays with a broad continuous spectrum of wavelengths.
whitlockite rare natural mineral form of calcium phosphate, Ca3(PO4)2, C3P.
wollastonite stable natural polymorph of monocalcium silicate, β-CS
wool, blastfurnace slag fibres of blastfurnace slag glass, used as an insulating material.
workability the ease of placing, consolidating and finishing freshly mixed concrete. Usually measured in terms of concrete slump.
works Obsolete term for cement Plant (UK etc)
wrecking removing brickwork from kiln (US)
wüstite mineral form of iron (II) oxide: defect sodium chloride structure, typically Fe0.95O.
XANES Abbrev., X-ray absorption near-edge spectroscopy.
xenomorphic crystal mineral crystal with no faces, deformed to fit the space in the surrounding matrix – indicative of late formation in a freezing melt.
xonotlite C5S5H: one of a range of crystalline calcium silicate hydrates.
X-ray electromagnetic radiation with wavelength in the range 15 pm to 5 nm.
X-ray analysis analysis using X-ray excitation of the sample. Typically X-ray emission or X-ray fluorescence spectroscopy.
X-ray diffraction analytical technique for identifying and quantifying the crystalline species in a solid matrix. In the cement industry, X-ray powder diffraction is usually used.
X-ray fluorescence spectrometry (XRF): analysis by measurement of the characteristic secondary X-rays emitted by each element in a sample irradiated with white X-rays.
X-ray microanalysis chemical analysis using the secondary X-rays generated by the electron beam in an electron microscope. Allows semi-quantitative analysis of areas as small as 0.5 μm, giving unambiguous identification of minerals in the micrograph, and indicating the impurity-chemistry of major phases.
X-ray powder diffraction XRD analysis in which the finely-ground sample is examined in the form of a flat-surfaced compact, the crystals present producing diffraction lines at discrete angles of incidence to the sample surface. The angles characterize the crystal identity, and the line intensities indicate the amount of that mineral present.
X-ray sedigraph device for measuring particle size distribution of a solid by measuring the attenuation of X-rays passing through a partly settled suspension of the solid in a liquid.
X-rays, secondary in XRF spectrometry, X-rays re-emitted by an irradiated sample.
X-rays, white X-rays with a broad continuous spectrum of wavelengths.
XRD abbrev., X-ray diffraction.
XRF Abbrev., X-ray fluorescence.
ye’elimite The naturally-occurring mineral form of calcium sulfoaluminate C4A3Š.
yield stress in a Bingham plastic, the minimum stress required before flow begins. SI unit: Pa.
yield, fluorescent the proportion of absorbed incident energy that is re-emitted as secondary (fluorescent) radiation, the remainder being lost in scattering and Auger emission. Rises with increasing atomic number.
Young's Modulus in a compressed elastic solid, the ratio of the longitudinal force per cross-sectional area to the change in length per unit length. SI unit: Pa.
zeolites cage-structured alkali aluminosilicate hydrates. The main reactive ingredients of classical natural pozzolans.
zeta potential electrical potential difference between a particle, with its coupled surrounding liquid layers, and the bulk of the liquid. Raising zeta potential causes a dispersion to deflocculate, as in the action of superplasticizers.
zinc fluorosilicate used as a surface treatment for concrete to protect from aggressive agents.
zinc oxide minor constituent of portland cement clinker in the range 0-0.10%.
zinc phosphate cement chemical cement system using reaction of phosphoric acid with zinc oxide.
zinc salts act as a retarder in mortar/concrete mixes.
zirconia used for manufacture of hard, heavy, low-wear grinding media where metal contamination must be avoided.
zirconium chelates used in combination with organic polymers to render grouts thixotropic.
zone, kiln region of the kiln in which a specific set of reactions or transformations take place. Normally defined in terms of feed temperature range.
zoned crystals crystals, typically of solid-solution phases, in which the composition of the core is markedly different from that of the exterior. Caused by changing composition of the melt as crystallization takes place.
Z-phase CS2H2: one of a range of crystalline calcium silicate hydrates.
zur Strassen equation equation used to calculate theoretical heat of formation of portland cement clinker - obsolete
χ2 distribution tests whether the observed frequencies in a distribution differ significantly from the frequencies that might be expected according to some assumed hypothesis.

I first compiled this as a means of remaining sane and out of trouble during the ghastly, acrimonious and morale-sapping last days of Blue Circle. The original Word file has been rather crudely parsed into HTML, and although I have scanned it for transcription errors, some may remain. I am delighted to receive notification of these, or of the no doubt numerous factual errors and illiteracies, by email. Also suggestions for additions and clarification. Lists of thousands of errors are perfectly acceptable! Most of the references to Blue Circle politics have been removed, but a few may still be recognizable.

Insofar as the glossary has any purpose at all, it was intended to be a tool for students of cement technology, allowing them to break through the barrier of jargon that the technological self-elected elite raises in order to protect its exclusivity.

As for the accuracy of this glossary, in general it does not represent "generally accepted" knowledge - it is mere expert opinion. For "consensus opinion" (bearing in mind that most people that contribute to a consensus know nothing whatever about the subject) or "the Democracy of the Ignorant", I recommend Wikipedia.

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© Dylan Moore 2011: commenced 04/10/2011: last edit 08/08/16.