The device for pre-heating cement raw meal for the cement clinker production comprises at least one heat exchanger line for charging cement raw meal in countercurrent flow to the hot gases drawn through the heat exchanger line and a supporting structure (19) for the at least one heat exchanger line, wherein the heat exchanger line comprises a plurality of heat exchangers (8, 9, 10) which are interconnected and through which flow can pass consecutively. The supporting structure (19) comprises stands (20) which jointly form a triangular outline (21) and serve to transfer load into at least one foundation.

The device for pre-heating cement raw meal for the cement clinker production comprises at least one heat exchanger line for charging cement raw meal in countercurrent flow to the hot gases drawn through the heat exchanger line and a supporting structure (19) for the at least one heat exchanger line, wherein the heat exchanger line comprises a plurality of heat exchangers (8, 9, 10) which are interconnected and through which flow can pass consecutively. The supporting structure (19) comprises stands (20) which jointly form a triangular outline (21) and serve to transfer load into at least one foundation.

A method of processing exhaust gas from a cement plant, the cement plant including one or several raw meal mills for milling a cement raw meal, one or several preheater strings, each having a plurality of preheater stages, and a rotary kiln, wherein the one or several preheater strings are for preheating the cement raw meal in counter-current flow with an exhaust gas from the rotary kiln. The method includes extracting the exhaust gas from a second highest or highest stage of at least one of the preheater string(s), cooling the exhaust gas to a temperature of <250 C., dedusting the exhaust gas, introducing the cooled and dedusted exhaust gas into a carbon capture installation, in which CO.sub.2 is separated from the exhaust gas for obtaining a CO.sub.2 lean gas, wherein the exhaust gas, when being introduced into the carbon capture installation, has a CO.sub.2-content of >25 vol.-%.

The invention provides a powder-gas heat exchanger for exchanging heat between a powder stream and a gas stream in counter-current flow comprising a powder stream mass flow rate substantially equal to a gas stream mass flow rate in a vertical shaft heat exchanger. A hot gas stream may be adapted for use in heating a cool solids stream, or a cool gas stream may be adapted for use in cooling a hot solids stream.

The present invention relates to a rotary kiln for burning carbonate-containing material, in particular limestone or dolomite, including a rotary tube having an inlet end for feeding the material to be burned and an outlet end for discharging the burnt material, and a burner unit arranged in the region of the outlet end, the rotary tube having an inlet zone at its inlet end and an outlet zone at its outlet end, a preheating zone and a combustion zone being arranged between the inlet zone and outlet zone in the direction of transport of the material. The rotary kiln is characterized according to the invention in that at least one projection is arranged in the outlet zone of the rotary tube, the at least one projection having a contour tapering in the direction of rotation of the rotary tube. The present invention further relates to a method for burning carbonate-containing material, in particular limestone or dolomite.

A method of producing sulfur concrete using precipitated salts. The method comprises obtaining precipitated salts from a salt solution, which comprises: mixing the salt solution with calcium oxide to form a basic suspension; treating the basic suspension using carbon dioxide to cause salts to precipitate from the salt solution; and separating the precipitated salts out from the treated basic suspension to produce a treated salt solution. The method also comprises forming the sulfur concrete, which comprises mixing elemental sulfur with a modifying agent to form a sulfur-containing polymer; pre-heating aggregates comprising at least the precipitated salts; and mixing the aggregates with the sulfur-containing polymer to form the sulfur concrete.

A method for manufacturing cement clinker includes the steps: preheating a raw meal in a first preheater using kiln off-gas to provide a partially preheated raw meal, preheating the partially preheated raw meal in a second preheater to provide preheated raw meal, precalcination of the pre-heated raw meal in a calciner being a circulating fluidized bed reactor by burning fuel with oxygen and recirculated calciner exhaust gas instead of air to provide a precalcined raw meal wherein at least 2 mbar overpressure are adjusted in the calciner, transferring the precalcined raw meal to a rotary kiln for sintering to provide the cement clinker, cooling the cement clinker, and capturing carbon dioxide from a calciner exhaust gas in a carbon dioxide purification unit.

The invention provides a powder-gas heat exchanger for exchanging heat between a powder stream and a gas stream in counter-current flow comprising a powder stream mass flow rate substantially equal to a gas stream mass flow rate in a vertical shaft heat exchanger. A hot gas stream may be adapted for use in heating a cool solids stream, or a cool gas stream may be adapted for use in cooling a hot solids stream.

A cement clinker producing system, capable of providing a gas containing a carbon dioxide gas at a high concentration by increasing a carbon dioxide gas concentration for a part of an exhaust gas, includes a cyclone preheater to preheat a cement clinker raw material, a rotary kiln to burn the preheated cement clinker raw material so as to provide cement clinker, a calcination furnace to promote decarbonation of the cement clinker raw material, a clinker cooler to cool the cement clinker, a kiln exhaust-gas discharge passages to discharge an exhaust gas generated in the rotary kiln, a combustion-supporting gas supply device to supply a combustion-supporting gas having a higher oxygen concentration than air, a combustion-supporting gas supply passage to guide the combustion-supporting gas to the calcination furnace, and a calcination furnace exhaust-gas discharge passage to discharge a carbon dioxide gas-containing exhaust gas generated in the calcination furnace.

A method of producing sulfur concrete using precipitated salts. The method comprises obtaining precipitated salts from a salt solution, which comprises: mixing the salt solution with calcium oxide to form a basic suspension; treating the basic suspension using carbon dioxide to cause salts to precipitate from the salt solution; and separating the precipitated salts out from the treated basic suspension to produce a treated salt solution. The method also comprises forming the sulfur concrete, which comprises mixing elemental sulfur with a modifying agent to form a sulfur-containing polymer; pre-heating aggregates comprising at least the precipitated salts; and mixing the aggregates with the sulfur-containing polymer to form the sulfur concrete.