The invention relates to a method and a system for obtaining a recyclable product from waste minerals by heating the mineral waste in a combustor by combusting waste fuel in a closed loop combustion process and treating the mineral waste with high levels of oxygen and/or carbon dioxide. A mixture of waste minerals for recycling and waste fuel for combustion is supplied to a combustor, also concentrated oxygen and recycled flue gas comprising carbon dioxide is supplied to the combustor for heating the mineral waste in an atmosphere of increased oxygen and carbon dioxide level to obtain a recyclable product from the waste minerals.

The invention relates to a method and a system for obtaining a recyclable product from waste minerals by heating the mineral waste in a combustor by combusting waste fuel in a closed loop combustion process and treating the mineral waste with high levels of oxygen and/or carbon dioxide. A mixture of waste minerals for recycling and waste fuel for combustion is supplied to a combustor, also concentrated oxygen and recycled flue gas comprising carbon dioxide is supplied to the combustor for heating the mineral waste in an atmosphere of increased oxygen and carbon dioxide level to obtain a recyclable product from the waste minerals.

System and method of low carbon emission production of cement include a conventional kiln, a precipitation reactor in material communications with the conventional kiln, an indirect heated kiln in material communications with the precipitation reactor, and a sequestration module in material communications with the indirect heated kiln and configured to sequester high purity carbon dioxide produced by the indirect heated kiln. The system may further comprise a compressor, in material communications with the indirect heated kiln and the sequestration module and the precipitation reactor, and configured to produce materialized carbon dioxide.

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 present disclosure provides an energy-efficient (low energy consumption), carbon enriched cement production system and a method for producing cement clinker. This system involves raw material preheating and precalcining system and sequentially connected kiln inlet chamber, rotary kiln and cooler, wherein the raw material preheating and precalcining system involves precalciner and preheater, and the cooler involves first cooling zone and second cooling zone. The first cooling zone includes first cooling partition and second cooling partition, wherein a mixture of pure oxygen and high-concentration CO.sub.2 flue gas entering the inlet of the first cooling partition, high-concentration CO.sub.2 flue gas entering the inlet of the second cooling partition, and air entering the inlet of the second cooling zone have solved the problems in existing cement kiln CO.sub.2 enrichment technology, i.e., extensive air leakage and high energy consumption between the first cooling zone and the second cooling zone.