A system for the calcination of powder materials comprising a plurality of vertical reactor tubes in which a falling powder is heated about a heating zone by radiation from the externally heated walls of the reactor tubes, in which the calcination process of the powder may be a reaction which liberates a gas, or induces a phase change; wherein the average velocity of the particles of falling powder during its transit through the reactor tubes is 1.0 m/s or less; the powder material flux for each tube is preferably in the range of 0.5-1 kg m-2 s-1, and wherein the length of the heating zone is in the range of 10 to 35 m.

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 make 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 application relates to a process for the purification of waste materials or industrial by-products, the process comprising the steps of: a) Preparing a composition (C) by blending or mixing waste materials or industrial by-products comprising chlorine (B) with one or more materials comprising heavy metals (HM) b) Reacting (B) and (HM) by thermal treatment of (C) c) Separating evaporated heavy metal chloride compounds (HMCC) d) Obtaining a solid material after the thermal treatment step.

A method of producing a synthetic carbonated mineral component in a cement manufacturing plant, includes providing a carbonatable substance from an external source, introducing the carbonatable substance into an exhaust gas installation of the cement manufacturing plant for contacting the carbonatable substance with CO.sub.2 enriched exhaust gas, carbonating the carbonatable substance by reacting the carbonatable substance with CO.sub.2 contained in the CO.sub.2 enriched exhaust gas, thereby obtaining the synthetic carbonated mineral component, and removing the synthetic carbonated mineral component from the exhaust gas installation.

In various embodiments, a process is described for the preparation of a concrete mixture in a Ready-mix or for an installation. A quantity of amorphous silica is added with an average particle size in the range of from about 1 to about 55 nanometers and/or wherein the surface area of the particles of the amorphous silica is in the range of from about 300 to about 900 m2/g. The amorphous silica may be added in colloidal form or otherwise, and is added at a particular stage to ensure efficacy.

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.

A method for operating a plant for producing cement clinker from raw meal having, as viewed in the materials flow direction, at least one calciner for deacidifying the raw meal, and at least one rotary kiln for sintering the deacidified raw meal to form cement clinker. The deacidified raw meal, after passing through the calciner, flows via a cyclone preheating stage into the rotary kiln. Exhaust gases are guided from the rotary kiln into a reactor, arranged between the rotary kiln and the calciner, with fuel being fed into the reactor superstoichiometrically in relation to the dwell time of the exhaust gases in the reactor, so that carbon dioxide in the exhaust gases is reduced to form carbon monoxide. The carbon monoxide is used as a reducing agent for nitrogen oxides, which are chemically reduced in the reactor independently of the short dwell time in the calciner.

A process for producing a syngas containing CO and H.sub.2 from a stream of light hydrocarbons and from combustion flue gases from a cement clinker production unit comprising at least one calcining kiln (300), and a means for discharging the combustion flue gases (500) from the calcining kiln to the outside of said unit, said process comprising the following steps: at least some of the combustion flue gases (70) obtained in said clinker production unit are collected upstream of said means for discharging the combustion flue gases (500); a reaction stream (113) comprising a stream of light hydrocarbons (110) containing methane and the combustion flue gases (70) is prepared; said reaction stream (113) is sent to a tri-reforming reactor (1009) to obtain a syngas (114).

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 make 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.

A system and a method for generating carbon nanotube (CNT)-reinforced cementitious materials are provided. An exemplary method includes capturing carbon dioxide formed in while calcining cementitious precursors, converting the carbon dioxide to hydrocarbons, producing CNTs on the calcined cementitious precursors from the hydrocarbons, and forming CNT-reinforced, cementitious materials from the calcined cementitious precursors comprising the CNTs.