Abstract: A method of heating solids in a reactor to produce a heat-treated material, such as a cementitious, a supplementary cementitious, or a pozzolanic material, includes conveying the solids through the reactor from a feeding end to a discharge end so as to form a material bed extending from the feeding end to the discharge end; heating the solids during the conveying to at least 600° C. to transform the solids into the heat-treated material, wherein the heating includes applying radiative heating to the material bed from above and/or from the sides, wherein the radiative heating contributes at least 60% of the thermal energy needed for the heating, and wherein the material bed is mobilized during the conveying in order to renew the surface of the material bed that is exposed to the radiative heating.

Abstract: A method of calcining a raw material to obtain a cementitious material, includes providing a flow of raw material containing a metal carbonate, such as CaCO3 to a calcination system, introducing the flow of raw material into a first thermal reactor and at least partially decarbonating the raw material in the first thermal reactor by subjecting the raw material to a first heat treatment at a first temperature of at least 650° C. in order to obtain an at least partly decarbonated material and CO2, wherein the first thermal reactor is heated by electrical energy, and obtaining the cementitious material as a result of the first heat treatment.

Abstract: A method of producing clinker from cement raw meal, includes preheating cement raw meal in a preheater string, the preheater string including a plurality of preheater stages, pre-calcining preheated raw meal in a pre-calciner to obtain a pre-calcined product, introducing the pre-calcined product into a rotary kiln for calcining the pre-calcined product to obtain cement clinker, wherein a partial flow of at least partly preheated raw meal is diverted from the preheater string, introduced into a calcination device and at least partially decarbonated in the calcination device in order to obtain an at least partially decarbonated product and CO2, wherein the calcination device is heated by electrical energy, and wherein the at least partially decarbonated product is fed into the rotary kiln and the CO2 is drawn off from the calcination device.

Abstract: A method of processing exhaust gas containing CO2, such as exhaust gas from a cement production plant, includes burning fuel in the combustion reactor with the O2 content of the exhaust gas being used as an oxidizing agent, controlling the combustion in the combustion reactor so that the exhaust gas from the combustion reactor contains less than 10 vol.-% of oxygen and at least 80 vol.-% of a mixture of CO and CO2, and feeding the exhaust gas from the combustion reactor into a conversion reactor, in which the CO2 and optionally the CO contained in the exhaust gas is converted into a hydrocarbon fuel.

Abstract: In a process for utilizing organic waste materials, in particular cellulose-containing, moist, organic waste materials, in a clinker production process in which the waste materials are introduced as fuel and burnt in the clinker production process, the waste materials are brought into contact with the hot exhaust gases of the clinker production process and dried in a drying step flowing in parallel therewith before they are introduced into the clinker production process. The drying step is carried out in a drying reactor in which the moist waste materials are passed together with the hot exhaust gases through a series of concentrically arranged tubes, with multiple changes in flow direction about 180°, and the temperature of the hot exhaust gases is set to a maximum value of 400° C. by mixing in of ambient air and/or air from the clinker production process before the drying step.

Abstract: In a process for utilizing organic waste materials, in particular cellulose-containing, moist, organic waste materials, in a clinker production process in which the waste materials are introduced as fuel and burnt in the clinker production process, the waste materials are brought into contact with the hot exhaust gases of the clinker production process and dried in a drying step flowing in parallel therewith before they are introduced into the clinker production process. The drying step is carried out in a drying reactor in which the moist waste materials are passed together with the hot exhaust gases through a series of concentrically arranged tubes, with multiple changes in flow direction about 180°, and the temperature of the hot exhaust gases is set to a maximum value of 400° C. by mixing in of ambient air and/or air from the clinker production process before the drying step. (FIG.

Abstract: In a method for pretreating charges contaminated with carbon carriers such as, for instance, carbon-carrier-contaminated earths, soils, rocks or minerals having low calorific values for use in clinker kilns, the mentioned charges are introduced into a reactor (8) and heated or dried with gases. The heated gases are drawn off at temperatures below 1250° C., preferably between 700 and 900° C., and the heated or dried charge is separately discharged at temperatures between 500° C. and 1000° C., wherein the temperatures are set and maintained to stabilize the temperature distribution within the reactor (8) by controlling the supply of fresh air, the supply of water or water vapour, by controlling the feed rate of the charge and/or of process gases such as, e.g., tertiary air as well as, if required, by burning fuels. The gases drawn off from the reactor (8) are at least partially recirculated into the reactor (8) and/or supplied to a precalcining stage and/or a preheating stage of the clinker kiln (1).

Abstract: In a process for melting inorganic materials (7) in a rotary horizontal converter or a rotary kiln (1) by adding fuel (8), oxygen or oxygen-enriched gases (10) and the inorganic materials (7) to a liquid bath (5), solid fuel (8) is added in piece form. The oxygen or the oxygen-enriched gas (10) is blown at high velocity (v) onto the surface of the bath (5), reacts with the solid fuel (8) and releases heat in the course of this. By means of the process of the invention, high temperatures can be achieved with the use of inexpensive fuels.

Abstract: In a process for the thermal treatment of solid materials (3), in particular refuse, in which the solid materials (3) are burnt/gasified or pyrolized in a first step (5) with a lack of oxygen, and then, in an afterburning zone (14), the flue gases (6) from the first step (5) are mixed with an oxygen-containing gaseous medium (15) and are burnt with complete burn-off, the flue gases (6) emerging from the first step (5) are firstly actively homogenized in a mixing zone (7) with the addition of a gaseous oxygen-free or low-oxygen medium (8) before they are mixed with the oxygen-containing medium (15). Then, the homogenized flue-gas stream flows through a holding zone (13), in which it stays for at least 0.5 second, before, in an afterburning zone (14), the medium (15) which serves to ensure complete burn-off of the flue gas is added. The process according to the invention is distinguished by simple process steps and by a reduced level of pollutant emissions, in particular NOx, compared to the prior art.

Abstract: In a process for reprocessing slag and/or ash from the thermal treatment of refuse, the refuse (1) is pyrolyzed, gasified or partially combusted in a first process step, heavy-metal-containing slag and/or ash (8) having a comparatively high carbon content being formed. Said slag and/or ash (8) is then heated in a rotary kiln (6) to a temperature below the melting temperature of the slag and/or ash (8) in a second process step, the slag and/or ash (8), prior to its discharge from the rotary kiln (6), dwelling sufficiently long in the rotary kiln (6), that the heavy metals present therein are converted into their metallic form by reduction at the carbon endogenous to the slag and the readily volatile heavy metals are transferred to the gas phase and are discharged from the rotary kiln (6) together with the flue gas (9), and finally a slag (15) depleted in heavy metals being discharged from the rotary kiln (6).