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.

A rotary kiln includes a stationary fuel nozzle and a perforated flame holder positioned within an inclined rotating shell. The flame holder includes a plurality of perforations that collectively confine a combustion reaction of the burner to the flame holder to shift most heat transfer from the combustion reaction from radiation heat transfer to convective heat transfer.

An installation for thermal treatment of free-floating raw material, in particular cement raw meal and/or mineral products, may include a riser line through which hot gases can flow. The riser line has at least one fuel inlet for introducing fuel into the riser line. The riser line has at least one raw meal inlet for introducing raw meal into the riser line, which raw meal inlet is arranged upstream of the fuel inlet in a flow direction of gas inside the riser line. Further, a method for thermal treatment of free-floating raw material may involve introducing fuel via a fuel inlet into a riser line for guiding hot gases and introducing raw meal into the riser line. The raw meal is introduced into the riser line upstream of the fuel inlet in the flow direction.

Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods makes use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

The present invention provides a method and system for manufacturing cement wherein ground particles of cement and calcium sulfate are subjected to infrared sensors, laser sensors, or both, so that emanated, irradiated, transmitted, and/or absorbed energy having wavelengths principally within the range of 700 nanometers to 1 millimeter can be monitored and compared to stored data previously obtained from ground cement and sulfate particles and preferably correlated with stored strength, calorimetric, or other data values, such that adjustments can be made to the mill processing conditions, such as the form or amounts of calcium sulfate (e.g., gypsum, plaster, anhydride), or cement additive levels. The strength and other properties of cement can be thus adjusted, and its quality can be more uniform.

A method for processing material that contains cement rock may involve comminuting the material in a first comminuting device, feeding the material to a reactor in which the material is mixed with an aqueous liquid and CO.sub.2 and in which a mixing movement of the material is generated, and removing the material from the reactor and subdividing the material into at least two fractions by way of a classifying device. The temperature and the pressure in the reactor are maintained such that the pressure exceeds atmospheric pressure and such that the temperature is greater than 100° C. The method may further involve removing a withdrawal stream of the aqueous liquid from the reactor and separating and discharging suspended particles of the material from the withdrawal stream.

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.

A manufacturing process of a concrete product includes: (1) extracting calcium from solids as portlandite; (2) forming a cementitious slurry including the portlandite; (3) shaping the cementitious slurry into a structural component; and (4) exposing the structural component to carbon dioxide sourced from a flue gas stream, thereby forming the concrete product.

An environmentally friendly cement comprises (1) an active filler comprising waste materials composed of a thermal insulation wool and a waste thereof; (2) an inert filler comprising metakaolin and an aggregate optionally selected from cement, fine sand, gravel, waste to be solidified, and organic resin; and (3) an aqueous solution of sodium metasilicate as an alkaline compound. A method for producing the environmentally friendly cement comprises mixing ingredients (1) and (3) and ingredients (2) and (3) respectively to obtain a slurry A and a slurry B respectively; mixing the slurry A and B; and hardening the final slurry, whereby elements silicon and aluminum in the ingredient (1) are dissolved out in the basic solution of the ingredient (3), and a closed framework structure is formed by bonding silica and alumina as tetrahedrons. The environmentally friendly cement has excellent fire tolerance, heat insulation, acid and alkaline resistance, and mechanical properties.