A process and device separate off a volatile component from the off-gases in cement clinker production. Raw materials for cement clinker production are passed through a preheater with heat exchange with the off-gases and are then burnt in a rotary kiln. Owing to the heating in the preheater, the volatile component bound in the raw materials is vaporized and separated off. A first raw material stream having a relatively high concentration of the volatile component is applied to a first line of the preheater and a second raw material stream having a lower concentration of the volatile component is applied to a second line. The volatile component is separated off from the first substream of the off-gases. The first raw material stream heated to a temperature of at least 250 C. with the first substream of the off gases in the first line is combined with the second raw material stream.

A process and device separate off a volatile component from the off-gases in cement clinker production. Raw materials for cement clinker production are passed through a preheater with heat exchange with the off-gases and are then burnt in a rotary kiln. Owing to the heating in the preheater, the volatile component bound in the raw materials is vaporized and separated off. A first raw material stream having a relatively high concentration of the volatile component is applied to a first line of the preheater and a second raw material stream having a lower concentration of the volatile component is applied to a second line. The volatile component is separated off from the first substream of the off-gases. The first raw material stream heated to a temperature of at least 250 C. with the first substream of the off gases in the first line is combined with the second raw material stream.

A process and device separate off a volatile component from the off-gases in cement clinker production. Raw materials for cement clinker production are passed through a preheater with heat exchange with the off-gases and are then burnt in a rotary kiln. Owing to the heating in the preheater, the volatile component bound in the raw materials is vaporized and separated off. A first raw material stream having a relatively high concentration of the volatile component is applied to a first line of the preheater and a second raw material stream having a lower concentration of the volatile component is applied to a second line. The volatile component is separated off from the first substream of the off-gases. The first raw material stream heated to a temperature of at least 250 C. with the first substream of the off gases in the first line is combined with the second raw material stream.

To produce cement clinker by baking of raw meal in a kiln, use is conventionally made of a raw meal preheater in which the heat of the flue gas emerging from the kiln is transferred to the raw meal. In order to remove impurities which accumulate in circulation between the kiln and the raw meal preheater, a part of the flue gas is extracted from the kiln, bypassing the raw meal preheater. The heat generated during the baking of cement clinker can be used particularly efficiently if the flue gases extracted and diverted past the raw meal preheater are used in a boiler to generate hot steam which can subsequently be expanded in a turbine.

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.

There is provided a cement plant including a chlorine bypass apparatus capable of efficiently reducing the chlorine concentration in a cement kiln due to exhaust gas extraction by a small amount, by preventing calciner exhaust gas low in chlorine concentration from contamination and extracting a part of kiln exhaust gas high in chlorine concentration. In the invention, a baffle wall 20 which protrudes, on a lower face 16a of an exhaust duct 16 of a calciner connected to the pipe inclination part 14 of an exhaust gas pipe 9 rising from a kiln inlet part 2 of a cement kiln 1, toward a pipe inclination part 14 side at an inclination angle within a range of 20 to 60 relative to the horizontal plane, and a spacing between a lower end edge 20a of the baffle wall and an opposite wall plane 14a of the pipe inclination part is configured such that an average flow rate of the exhaust gas between the both falls within a range of 15 to 35 m/s.

A cement manufacturing plant includes a raw meal mill, at least one preheater string, a clinker furnace and a clinker cooler including a first section and a second section, wherein a preheater exhaust gas recirculation device is provided for recirculating exhaust gas leaving the at least one preheater string into the first section of the clinker cooler, and wherein the cement plant is configured for switching between an air operation mode and an oxyfuel operation mode, includes a first switching device for connecting either a source of air or a source of oxygen rich gas to a burning zone of the clinker furnace burner, and a second switching device for either establishing or separating a connection of the preheater exhaust gas recirculation means to the first section of the clinker cooler.

Providing a cement production apparatus in which raw material is supplied into a duct with being dispersed uniformly so that heat-exchanging efficiency is improved by even preheating and clogging and the like are prevented, so that stable operation can be carried out. Between cyclones at an upper stage and a cyclone at a lower stage disposed below cyclones at an upper stage, a duct 21 is provided to introduce exhaust gas to the cyclones at the upper stage with distributing after flowing upward from the cyclone at the lower stage; at a lower position than a distribution part 23 of the duct 21, a material-supplying pipe 22 is connected for supplying cement raw material; at a connected part of the material-supplying pipe 22 to the duct 21, a material-guiding chute 24 on which the cement raw material is supplied from the material-supplying pipe 22 and which drops it into the duct 21 is provided with protruding into the duct 21; and the material-guiding chute 24 is formed to have a flat upper surface and to be expandable by sliding so that insertion depth of a tip end 24a from an inner-wall surface 21b of the duct 21 is 0.15 to 0.5 times of an inner diameter of the duct 21.

A method for treating exhaust gas in an exhaust gas treatment device of a system may involve withdrawing exhaust gas from a processing device for mechanically and/or thermally processing an inorganic material of the system. The material to be fed to the processing device may be preheated by heat exchange with the exhaust gas. Further, a temperature of the exhaust gas entering the exhaust gas treatment device may be adjusted by adapting the exchange of heat between the exhaust gas and the inorganic material. In some examples, the exhaust gas treatment device may comprise an oxidation catalytic converter and/or a reduction catalytic converter.

A method and device for the combined manufacturing of cement clinker and calcined clay, in a cement manufacturing line by the steps: providing, preheating and precalcining a cement raw meal in a preheater and calciner section, sintering the precalcined cement raw meal in a rotary kiln and cooling the resulting cement clinker with a counter current air stream in a clinker cooler, and in a clay manufacturing line by the steps: providing and preheating a clay raw material in a heat exchange section, and calcining the preheated clay raw material suspended in gas in a flash calciner. Hot air from the cooler is divided into a first combustion air stream for sintering the cement raw meal and a second combustion air stream for calcining the clay raw material. Exhaust gas from calcining clay raw material is fed into the calcination of the preheated cement raw meal.