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 process for producing cement clinker, may involve preheating raw meal in a preheater, calcining the preheated raw meal in a calciner, and burning the preheated and calcined raw meal in a furnace to give cement clinker. The furnace may be supplied with a combustion gas having an oxygen content, and the temperature within the furnace is ascertained. The process may involve cooling the cement clinker in a cooler. The oxygen supply to the furnace is under closed-loop control as a function of the temperature ascertained within the furnace. The temperature ascertained is compared with a target value and, in the event of any variance of the temperature ascertained from the target value, the oxygen supply to the furnace and/or to the calciner is increased or decreased. The target value is adjusted depending on a particle size distribution and/or a lime standard.

A process for producing cement clinker, may involve preheating raw meal in a preheater, calcining the preheated raw meal in a calciner, and burning the preheated and calcined raw meal in a furnace to give cement clinker. The furnace may be supplied with a combustion gas having an oxygen content, and the temperature within the furnace is ascertained. The process may involve cooling the cement clinker in a cooler. The oxygen supply to the furnace is under closed-loop control as a function of the temperature ascertained within the furnace. The temperature ascertained is compared with a target value and, in the event of any variance of the temperature ascertained from the target value, the oxygen supply to the furnace and/or to the calciner is increased or decreased. The target value is adjusted depending on a particle size distribution and/or a lime standard.

High alumina cement is produced in a submerged combustion melter, cooled and ground.

The invention relates to a hydraulic binder consisting essentially in a hydraulically active amorphous calcium silicate phase, having in its constitution less than 20% in weight of a crystalline material. The said hydraulically active amorphous calcium silicate phase is a continuous matrix that may contain embedded fractions of crystalline material, being the overall C/S molar ratio of this hydraulic binder comprised between 0.8 and 1.25. The crystalline fraction of this material is essentially composed by wollastonite in both of its polymorphic structures, α and β. Furthermore, the invention relates to methods of producing the hydraulic binder by liquefying the raw materials, in a specified C/S molar ratio, followed by fast cooling to room temperature. Finally, the invention relates to a building material made by setting the binder or a mixture containing this binder with water and subsequent hardening. The invention enables the production of a hydraulic binder with a significant reduction of CO2 emissions, when compared to OPC clinker, by reducing the amount of limestone in the raw materials while obtaining competitive overall values of compressive strength of the hardened material.

The invention relates to a hydraulic binder consisting essentially in a hydraulically active amorphous calcium silicate phase, having in its constitution less than 20% in weight of a crystalline material. The said hydraulically active amorphous calcium silicate phase is a continuous matrix that may contain embedded fractions of crystalline material, being the overall C/S molar ratio of this hydraulic binder comprised between 0.8 and 1.25. The crystalline fraction of this material is essentially composed by wollastonite in both of its polymorphic structures, α and β. Furthermore, the invention relates to methods of producing the hydraulic binder by liquefying the raw materials, in a specified C/S molar ratio, followed by fast cooling to room temperature. Finally, the invention relates to a building material made by setting the binder or a mixture containing this binder with water and subsequent hardening. The invention enables the production of a hydraulic binder with a significant reduction of CO2 emissions, when compared to OPC clinker, by reducing the amount of limestone in the raw materials while obtaining competitive overall values of compressive strength of the hardened material.

Disclosed is a method for producing sintered material from organic raw materials, implemented in an apparatus comprising, a cyclone preheater, a rotary furnace and a grate cooler, and in which the raw materials are preheated in the cyclone preheater, the preheated material is calcined and sintered in the rotary furnace, and the calcined materials are cooled by blowing cooling air in the grate cooler, producing hot air. The hot air is separated into three upstream-to-downstream fractions, the three hot air fractions being at decreasing temperatures. The first air fraction acts as combustion air in at least the combustion zone of the rotary furnace and/or of the potential precalciner of the apparatus. The second air fraction is greater than the combustion air needs to produce energy. The third air fraction is directed at least in part to the combustion zone of the apparatus, providing combustion air with the first air fraction.

Disclosed is a method for producing sintered material from organic raw materials, implemented in an apparatus comprising, a cyclone preheater, a rotary furnace and a grate cooler, and in which the raw materials are preheated in the cyclone preheater, the preheated material is calcined and sintered in the rotary furnace, and the calcined materials are cooled by blowing cooling air in the grate cooler, producing hot air. The hot air is separated into three upstream-to-downstream fractions, the three hot air fractions being at decreasing temperatures. The first air fraction acts as combustion air in at least the combustion zone of the rotary furnace and/or of the potential precalciner of the apparatus. The second air fraction is greater than the combustion air needs to produce energy. The third air fraction is directed at least in part to the combustion zone of the apparatus, providing combustion air with the first air fraction.

The invention relates to a method for producing a supplementary cementitious material for use in a cement product or concrete, the method comprising the steps of activating clay to the supplementary cementitious material at between 600 to 1000 degree Celsius; treating the activated supplementary cementitious material under reduced conditions to form a reduced product and cooling the reduced product to 300-400 degrees Celsius by a quenching process under oxidizing conditions.

The invention relates to a method for producing a supplementary cementitious material for use in a cement product or concrete, the method comprising the steps of activating clay to the supplementary cementitious material at between 600 to 1000 degree Celsius; treating the activated supplementary cementitious material under reduced conditions to form a reduced product and cooling the reduced product to 300-400 degrees Celsius by a quenching process under oxidizing conditions.