Abstract: A method for using waste heat from a cement producing plant, wherein heat of a process gas is used through a heat exchanger, which comprises a sequence of cyclones, for heating raw mix. A cement producing plant having at least one calcinator and at least one heat exchanger, which comprises a series of cyclones for heating raw mix. The process gas is removed at the outlet of the calcinator and/or at the gas-side outlet of the first cyclone in the heat exchanger in the direction of gas flow and, once the heat has been removed in a steam vessel, the cooled process gas is fed back into the second cyclone or third cyclone in the heat exchanger in the direction of gas flow. The heat taken from the process can be used for the further heating of unrecovered heat which can thereby be more efficiently converted into electrical energy.

Abstract: The method according to the invention for producing cement clinker comprises substantially the following method steps: raw cement material is preheated in a preheater, the preheated material is heated further in a calcining zone while admitting combustion air, and the material heated in this manner is fired in a kiln to form cement clinker, wherein a part of the waste gases developing in the kiln is used to preheat the raw cement material in the preheater, and another part is diverted, and is used in a heat exchanger to preheat the combustion air used in the calcining zone.

Abstract: A method for manufacturing a cement clinker includes a rotary furnace, a cyclone preheater receiving the fumes from said rotary furnace, an air blowing clinker cooler, and at least one heat exchanger, referred to as a first heat exchanger. The raw materials are preheated and decarbonated in said cyclone preheater. The clinker is cooled in said clinker cooler. A first portion of the hot air generated by said clinker cooler, or so-called secondary air, is directed to the rotary furnace to be used as combustion air. A second portion of the hot air generated, or so-called tertiary air, is directed and carried separately from the first portion to a place in the facility where fuel is burned. A third portion of hot air generated in said clinker cooler, or so-called excess air, is carried into at least said first heat exchanger for the purpose of recovering power to produce electricity.

Abstract: The present invention relates to a process of controlling crystal form of Alite in Portland cement clinker, wherein the said Portland cement clinker is thermally treated in order to change the crystal form of Alite in Portland cement clinker, so as to improve performance of resulting Portland cement clinker. The said process of present invention is easy and feasible.

Abstract: In a method for reducing the amount of chloride components in cement clinker kilns at least a portion of the chloride-containing gases is removed from the kiln chamber. The gases are guided into a condenser whereby the gas temperature is maintained at a value above the condensation temperature of the chloride components. The chloride components are then cooled on cooled condensation surfaces of the condenser to a value below the condensation temperature. The cleaned gases are removed from the condenser and preferably returned into the kiln chamber. The condensation surfaces are continuously or discontinuously cleaned, and the removed chloride crystals are taken out of the condenser.

Abstract: The invention is related to a method and an apparatus for producing cement clinker, in which the cement clinker is first of all burnt in a burning zone and then cooled in a cooling zone, wherein the cooling takes place at least partially by the delivery of fuel and steam, characterised in that in a first cooling phase the delivered fuel is mixed with the cement clinker and initially pyrolysed and the resulting pyrolysis products have a strong endothermic reaction with the steam, so that the cement clinker is quenched in such a way that at least 95%, preferably all, of the liquid phase contained therein is transformed into glass.

Abstract: Contaminated coal ash, for example flyash contaminated with carbon is introduced to hot clinker in a cooler downstream of a cement kiln; the carbon is combusted in the cooler to provide a cement clinker having an effective content of flyash free of carbon; this permits use of flyash contaminated with carbon without the need for separate special steps for carbon removal; volatile contaminants or contaminants having a volatile component, for example adsorbed ammonia are similarly removed in the cooler by volatilization.

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: Portland cement particles having the characteristics of slow hardening is oduced by a process of heat treating portland cement particles in the temperature range from 1500.degree. to 3000.degree. C. for from 0.5 to 10 seconds and cooling to obtain particles containing an amorphous, glassy shell as an outside layer.

Abstract: A method for producing portland clinker which includes the steps of calcining a mixture of raw materials, at 1,350.degree.-1.450.degree. C. in a reducing gaseous medium containing more than 80 mass % of carbon monoxide, said mixture containing 59.7-65.05 mass % of limestone, 32.83-39.07 mass % of phosphoric slag and 1.07-6.21 mass % of additional materials containing not less than 40 mass % of iron oxide. The calcined product is then subjected to forced cooling.