Abstract: In staged combustion, wherein fuel is fed into a furnace, and less than all of the gaseous oxidant needed to completely combust the fuel is fed with the fuel and combusted, providing uncombusted fuel, and the remaining portion of gaseous oxidant needed to combust the fuel is fed into the furnace through a second port, fuel is fed and combusted at the second port to heat the second port and lessen the tendency of deposits to form at the second port.

Abstract: A method of manufacture of Portland cement clinker is described in a dry process that captures the carbon dioxide emitted from the calcination of carbonate minerals, principally limestone. The process uses an indirectly heated, counter-flow reactor to pre-heat and calcine the cement meal to produce a separate calcined meal and carbon dioxide gas stream, with external heat being provided by the combustion of a secondary fuel stream with pre-heated air. This calcined meal is injected into the conventional rotary kiln, where the hot flue gas from combustion of the primary fuel with pre-heated air is used to fuse, react and sinter the powders to form granules of cement clinker. The clinker and carbon dioxide streams are cooled by the air pre-heaters.

Abstract: A process for decarbonation of particles of raw meal, to be burnt in a clinkering kiln at a cement plant, the process includes: a) decarbonation of particles of raw meal, in a fluidized bed heat exchanger, the particles being suspended in a rising carrier gas including carbon dioxide, the fluidized bed heat exchanger having a solid heat carrier circulating counter-current relative to the carrier gas, to provide an effluent gas including carbon dioxide and decarbonated raw meal; b) separating the effluent gas and the decarbonated raw meal c) separating the effluent gas into a first and second part; cooling the first part of the effluent gas and recycling to provide carrier gas, d) isolating the second part of effluent gas e) recovering and re-heating the heat carrier and recirculating to step (a).

Abstract: The present invention relates to a process for the production of a clinker with a high content of belite, said process comprising the following steps: (i) introducing a raw meal into a calcination chamber of a cement plant kiln; (ii) calcining the raw meal at a temperature of from 1150° C. to 1375° C.; (iii) measuring the weight per liter of the product of step (ii) and eliminating the product having a weight per liter strictly less than 650 g/liter; (iv) measuring the quantity of SO3 in the product of step (ii) and eliminating the product having a ratio of quantity of SO3 of the decarbonated raw meal/quantity of SO3 in the product of step (ii) less than or equal to 0.75 and greater than or equal to 1.2; (v) measuring the quantity of free lime (CaOl) in the product of step (ii) and eliminating the product having a quantity of free lime strictly greater than 1.5%, percentage by mass of free lime in the product of step (ii).

Abstract: A process for the production of cement which includes the calcination of calcium carbonate-containing raw meal in a calciner heated by combustion of a carbon-containing fuel with a gas including oxygen and from 0 to 80% by volume of carbon dioxide, and substantially free of nitrogen, and isolating the gas produced by combustion and calcination in the calciner.

Abstract: A process for producing a clinker with a high content of belite, includes (i) introducing a raw meal into a calcination chamber of a cement plant kiln; (ii) calcining the raw meal at a temperature of from 1150° C. to 1375° C.; (iii) measuring the weight per litre of the product of step (ii) and eliminating the product having a weight per litre strictly less than 650 g/litre; (iv) measuring the quantity of SO3 in the product of step (ii) and eliminating the product having a ratio of quantity of SO3 of the decarbonated raw meal/quantity of SO3 in the product of step (ii) less than or equal to 0.75 and greater than or equal to 1.2; (v) measuring the quantity of free lime (CaOl) in the product of step (ii) and eliminating the product having a quantity of free lime strictly greater than 1.5%, percentage by mass of free lime in the product of step (ii).

Abstract: The invention relates to a method and to apparatus for the production of a hydraulic binding agent from a plurality of raw material components (12a to 12e), wherein the raw material components are ground to a raw meal, the raw meal is burned to clinker in a combustion plant (2) and finally the clinker is ground together with further inter-grinding materials. Moreover, the mineralogical and/or chemical composition of the raw meal and/or the clinker is analyzed, at least two separate raw meal silos/clinker silos (4a to 4h, 5a to 5g) are provided in each case for the raw meal and/or the clinker and are filled with raw meal/clinker of different mineralogical and/or chemical composition. Furthermore the composition of the raw meal to be burned and/or of the clinker to be ground is fixed by controlled extraction as a function of the analysed composition of the raw meal/clinker from one or a plurality of raw meal silos/clinker silos.

Abstract: In the method according to the invention for operating a cement plant, the raw meal is preheated in a preheating zone, the preheated material is precalcined in a calcining zone and the precalcined material is finally sintered in a sintering zone. The cement plant is operated in such a manner that the precalcined material which is supplied to the sintering zone has an SO3 concentration of at least 5.5% by mass and a CaSO4 proportion of at least 75%, preferably 90%, of the total salt content.

Abstract: In order to create a process for the economical production of cement clinker in a cement clinker production line with a raw meal preheater, a precalcination stage, a rotary tubular kiln and a clinker cooler, in which the total oxygen excess required for all firing points, i.e., the ratio of total oxygen to total fuel, also designated as &lgr; value, is to lie as low as possible, it is proposed according to the invention, to continuously measure the content of CO and/or (unburned) hydrocarbons and/or other combustion products in the exhaust gas path of the precalcination stage and, in dependence on this measurement value, to perform a regulating intervention on the amount of an oxidation agent and/or catalyst to be injected into the precalcination stage.

Abstract: Cement clinker is produced using high sulfur fuels by combusting high sulfur fuel within a kiln. The feed material is introduced at an inlet of preheater of the kiln and is sintered by the combusting fuel to form sintered material. The sintered material is cooled to form cement clinker. The production of the sintered material is controlled by measuring the sulfur content in the cement clinker and using that measurement to control the concentration of oxygen at the reaction and sintering zone of the kiln.

Abstract: In order to create a process for the economical production of cement clinker in a cement clinker production line with a raw meal preheater, a precalcination stage, a rotary tubular kiln and a clinker cooler, in which the total oxygen excess required for all firing points, i.e., the ratio of total oxygen to total fuel, also designated as &lgr; value, is to lie as low as possible, it is proposed according to the invention, to continuously measure the content of CO and/or (unburned) hydrocarbons and/or other combustion products in the exhaust gas path of the precalcination stage and, in dependence on this measurement value, to perform a regulating intervention on the amount of an oxidation agent and/or catalyst to be injected into the precalcination stage.

Abstract: A method for the continuous treatment of particulate material, such as cement raw meal, in an apparatus comprising a stationary reactor (6) configured as a conical spouted bed, to which the material is fed and treated in a suspended bed by means of gas which, via a centrally arranged gas inlet (21), is injected at the bottom of the reactor (6) and flows upwards through the reactor (6), and wherefrom the material is discharged via an opening (21) at the bottom of the reactor (6).

Abstract: The properties of cement matrices are improved by one or more of the three processes, which can be performed individually, sequentially, or in any desired combination. In each instance a supercritical fluid is or includes a solvent for one of two (or more) reactants such as a monomer and a polymer initiator. The resulting mixture is infused into the matrix under supercritical conditions. The other reactant is placed into the matrix; for example, by incorporating it in the wet cement paste prior to curing. When the mixture is infused into the matrix, the reactants react and change the cement matrix in predictable, desired ways. The solvent itself may or may not be supercritical, and if it is not, it is mixed with a supercritical fluid, which might or might not be another solvent. In this manner, the inside of the matrix may be coated and/or sealed with a polymer, for example, or the entire cement matrix may be rendered relatively flexible and ductile.

Abstract: The invention relates to a method for manufacturing cement clinker whereby the raw meal is initially subjected to preparatory processing, e.g. by comminution, homogenization and/or drying, and, eventually, nodulized and burned, with the nodulization process itself taking place in a stationary burning reactor. By the method according to the invention a sulphatic compound is added to the raw meal in a sufficient quantity before introducing the raw meal into the stationary burning reactor or directly into the stationary reactor, e.g. through the combustion air or together with the fuel. The sulphatic compound may be selected among all types of sulphates which will not affect the properties of the finished cement. It is particularly advantageous to use calcium sulphate, either naturally occurring or industrial by-products and regular waste materials, e.g. used absorbent from dry exhaust gas desulphurization.

Abstract: The invention relates to the preparation of a material mixture consisting of a plurality of mineral raw material components which are delivered individually proportioned, are ground and homogenised, wherein samples are periodically analysed and determined ACTUAL values are compared with predetermined DESIRED values in order if appropriate to carry out corrective control interventions on the proportioning of raw material components by way of a laboratory computer. In relatively short time periods evaluations of the material samples and re-homogenisation of the ground mixture can be carried out very reliably with relatively low expenditure on construction if the material samples are analysed on the spot by means of a rapid analysis arrangement and the determined ACTUAL values from this analysis are passed to the laboratory computer, the homogenisation being carried out in a mixing zone with relatively small receiving capacity which is separated from the storage zone.

Abstract: A method and apparatus for controlling the temperature in a kiln in which cement clinker is manufactured. The temperature is controlled by controlling the fuel rate to the kiln. The fuel rate is adjusted according to a calculation that is made of the sulphur evaporation in the kiln, thereby obtaining a measure of the instantaneous temperature in the burning zone. The evaporation factor is calculated on the basis of measurements of the sulphur content in the cyclone material which passes to the kiln or a measurement of the sulphur content in the exit gases out of the kiln.

Abstract: A sintering method of cement clinkers in which preheated cement raw material powder is granulated and sintered in a fluidized bed granulating and sintering furnace, and granulated and sintered clinkers are introduced into a cooling device, for manufacturing high-quality cement clinkers by use of a single fluidized bed-granulating and sintering furnace efficiently with a small heat loss, wherein clinkers are discharged from the fluidized bed granulating and sintering furnace through a clinker dropping hole which is provided in a fluidizing gas distributor of the furnace or in a radial direction extending from the gas distributor, an opening area of the clinker dropping hole is regulated by a gate portion to maintain the differential pressure in a fluidized bed within a predetermined range, air for classifying and cooling the clinkers is blown into a discharge chute connected to the clinker dropping hole, the amount of the blown air is regulated to make the flow velocity of the air blowing from the clinker drop

Abstract: A source of free lime is introduced into a cooling zone of a cement kiln in an amount to elevate the free lime content to a content of 0.6 to 2.0%, by weight. This addition is made without altering the normal or standard process operating parameters of the kiln for cement clinker production. The free lime content of 0.6 to 2.0%, by weight, provides advantageous characteristics in cement produced with the cement clinker.

Abstract: A design optimization process used to determine the proportions of sand, cement, coarse aggregate, water, fly ash, water reducers, air entraining agents and fillers needed to produce a concrete mixture that has desired strength and slump properties and a minimal cost. The optimization process comprises a combination of models that accurately reflect the properties of a concrete mixture based on the properties of its individual components. The process is further capable of optimizing the durability of the cementitious mixture and of accurately calculating the expected yield of the mixture.

Abstract: The present invention is directed to a method and apparatus for controlling the kiln gas stream in a conventional long wet or dry process cement kiln. A portion of the kiln gas stream can be withdrawn from the rotary kiln vessel at a point upstream, relative to kiln gas flow of the chain system in the mineral drying zone. Alternatively, or in conjunction with bypass formation, the apparatus can be used to add tertiary air to the kiln gas stream to promote combustion efficiency downstream of the clinkering zone. Use of the present apparatus to form a kiln gas bypass stream enhances operating efficiencies of long kilns by reducing dust loss, by facilitating isolation of high alkali by-product streams, by reducing alkali content of collected kiln dust, by increasing energy efficiency of long kiln operation, and by allowing greater overall control in the cement manufacturing process.

Abstract: Admixtures for spray concrete or mortar which contain silicic acid sol or consist of it, are used for the processing of spray concrete or mortar according to the dry or the wet method. Said admixtures lead to a clear reduction of dust formation and of rebound. With the processing of spray concrete or mortar the addition of the inventive admixtures takes place preferably during the spraying, for example at the spray nozzle.

Abstract: Flowability improving agent comprising a combination of(A) a sulphonated melamine-formaldehyde resin, a sulphonated melamine-urea-formaldehyde resin or a sulphonated naphthalene-formaldehyde resin and(B) a compound of the general formulaAr O--[R.sub.1 ].sub.n --R.sub.2.