Cement clinker

Cement clinker Cement-composites Cement copper Cemented carbide... 

A second form of limestone is finely pulverized limestone for masonry cement. This form is achieved by intergrinding roughly equal parts of limestone and cement clinker in a bad mill to which an air-entraining agent is added. 

Pordand cement clinker is formed by the reactions of calcium oxide and acidic components to give C S, C2S, C A, and a ferrite phase approximating... 

The theoretical energy requirement for the burning of Portiand cement clinker can be calculated from the heat requirements and energy recovery from the various stages of the process. Knowledge of the specific heats of the various phases, and the heats of decomposition, transformation, and reaction then permits calculation of the net theoretical energy requirement of 1760 kj (420 kcal) for 1 kg of clinker from 1.55 kg of dry CaCO and kaolin (see Clays) (8). 

Phases Formed in Pordand Cements. Most clinker compounds take up small amounts of other components to form soHd solutions (11). Best known of these phases is the C S soHd solution called aHte. Phases that may occur Hi Portiand cement clinker are given Hi Table 1. In addition, a variety of minor phases may occur Hi Portiand cement clinker when certain minor elements are present Hi quantities above that which can be dissolved Hi other phases. Under reducHig conditions Hi the kiln, reduced phases, such as ferrous oxide [1345-25-17, FeO, and calcium sulfide [20548-54-3] CaS, maybe formed. 

Table 2. Properties of the More Common Phases in Portland Cement Clinker ...

Fig. 4. Photomiciogiaph of polished and etched sections of Poidand cement clinkers. The C A appears as dark interstitial material, the C AF as light...

Portiand cement clinker structures (18,19) vary considerably with composition, particle size of raw materials, and burning conditions, resulting in variations of clinker porosity, crystallite sizes and forms, and aggregations of crystallites. Alite sizes range up to about 80 p.m or even larger, most being 15—40 )J.m. 

Raw Material Proportions. The three main considerations in proportioning raw materials for cement clinker are the potential compound composition the percentage of Hquid phase at clinkering temperatures and the bumabiUty of the raw mix, ie, the relative ease, in terms of temperature, time, and fuel requirements, of combining the oxides into good quaUty clinker. The ratios of the oxides are related to clinker composition and bumabiUty. For example, as the CaO content of the mix is increased, more C S can be formed, but certain limits cannot be exceeded under normal burning conditions. The lime saturation factor (LSF) is a measure of the amount of CaO that can be combined (20) ... 

The potential compound composition of a cement or cement clinker can be calculated from the oxide analyses of any given raw materials mixture, or from the oxide analyses of the cement clinker or finished cement. The simplest and most widely used method is the Bogue calculation (23). The ASTM C150 (24) calculation is somewhat modified. 

Burning changes raw mix chemically into cement clinker. Note four-stage preheater, flash furnaces, and shorter kiln. 

ASTM C845 Type E-I (K) expansive cement manufactured ia the United States usually depends on aluminate and sulfate phases that result ia more ettriagite formation duriag hydration than ia normal Portland cements. Type K contains an anhydrous calcium sulfoaluminate, C A SI. This cement can be made either by iategraHy burning to produce the desired phase composition, or by intergrinding a special component with ordinary Portland cement clinkers and calcium sulfate. 

Oil well cements (78) are usually made from Pordand cement clinker and may also be blended cements. The American Petroleum Institute Specification for Materials and Testing for Well Cements API Specification 10) (78) includes requirements for nine classes of oil well cements. They are specially produced for cementing the steel casing of gas and oil wells to the walls of the bore-hole and to seal porous formations (79). Under these high temperature and pressure conditions ordinary Pordand cements would not dow propedy and would set prematurely. Oil well cements are more coarsely ground than normal, and contain special retarding admixtures. 

Finisli-Grinding of Cement Clinker Typically the hot clinker is first cooled and then ground in a compartment mill in closed circuit with an air classifier. To crush the chukers, balls as large as 5 in may be needed in the first compartment. A roll press added before the ball mill can reduce clinkers to a fine size, ana thus reduce the load on the ball mills. The main reasons for adding a roll press has been to increase capacity of the plant, and lower cost. 

Sintering 2 to 50 High to very high Up to 100 ton/hr Strongest bonding Ferrous non-ferrous ores, cement clinker, minerals, ceramics... 

Cement clinker 75-80 D285 suspension types 20-.35 A26KY... 

S. Hundebol. Method and plant for manufacturing cement clinker. Patent WO 9429231, 1994. 

Aliphatic solvents, alkyllithium compounds and, 14 250-251 Aliphatic sulfonates, 26 145 Aliquot samples, 13 413-415 analysis of, 13 416 Aliskren, 5 158 Alitame, 12 42 24 232 Alite, phase in Portland cement clinker, 5 471, 472t, 473t Alitretinoin, 25 790 Alizarin, color of, 7 331 Alizarin derivatives, 9 337 Alizarin pure Blue B, 4 361t Alkadienes, metathesis of, 26 923 Alkali/alkaline-earth cation recognition,... 

Alkali aluminate (5-calcium disilicate monosulfate), phase in Portland cement clinker, 5 472t Alkali aluminate (8-calcium disodium trialuminate), phase in Portland cement clinker, 5 472t Alkali belite, phase in Portland cement clinker, 5 472t Alkali blue toners, 14 318 Alkali borate glasses, 12 572, 573, 584 Alkali catalysed pad-dry-bake procedure, 9 485... 

U.S. imports for consumption, 4 528t Calcium(II), concentration formation constant of chelates, 5 717t 12-Calcium-7-aluminate, phase in Portland cement clinker, 5 472t Calcium absorption, 26 292 Calcium addition, in silicon production, 22 505-506... 

Calcium aluminate chloride, phase in Portland cement clinker, 5 472t Calcium aluminate fluoride, phase in Portland cement clinker, 5 472t Calcium aluminoferrite, phase in Portland cement clinker, 5 472t Calcium aluminoferrite hydrate, 5 477t Calcium—aluminum alloys, 4 530 Calcium amalgam, 22 773 Calcium ammonium nitrate, 2 724 Calcium analysis, of water, 26 37 Calcium A zeolite, separation of hydrocarbons by, 16 823 Calcium—barium—silicon alloy, 22 519 Calcium-bearing manganese silicon,... 

Calcium cyanamid process, for ammonia synthesis, 11 114, 115 Calcium cyanide, 8 194-197 Calcium cyanide diammoniate, 8 195 Calcium dichromate, molecular formula, properties, and uses, 6 561t 5-Calcium disilicate monosulfate, phase in Portland cement clinker, 5 472t 5-Calcium disilicate monocarbonate, phase in Portland cement clinker, 5 472t Calcium disilicide, 4 530 8-Calcium disodium trialuminate, phase in Portland cement clinker, 5 472t Calcium doping, 23 842-844 Calcium P-alumina, 2 406t Calcium ethylenediaminetetraacetate, 7 596t... 

Dibutylstibinic acid, 3 73 Dibutyltin diacetate, 24 823 Dibutyltin dilaurate, 24 823 Dicadmium triantimonide, 4 510 Dicalcium alumino monosilicate, phase in Portland cement clinker, 5 472t Dicalcium ferrite, phase in Portland cement clinker, 5 472t Dicalcium hexaborate pentahydrate,... 

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