Process for manufacturing cement clinker in a plant, and cement clinker manufacturing plant as such

A method for manufacturing a cement clinker in a facility comprising:

• a cyclone preheater for preheating the raw matter;
• a precalcination reactor, fitted with one or more burners, for providing heat to the cyclone preheater;
• a rotary furnace, fitted with a burner fed with fuel;
• a clinker cooler with blown-air cooling, at the exit from said rotary furnace, generating hot gas;
• a method wherein:
• the raw matter is preheated and decarbonated in said cyclone preheater and/or said precalcination reactor;
• the clinker coming out of the furnace is cooled in said clinker cooler;
• characterised in that:
• the fumes generated by the rotary furnace and the gases from the preheater are separated so that said fumes and said gases from the preheater are not mixed together,
• the precalcination reactor is fed with an oxygen-rich gases whose nitrogen content is lower than 30%, forming the single oxygen source of said reactor;
• a portion of the gases from said cyclone preheater is recycled in said precalcination reactor, possibly said cyclone preheater, so as to obtain an adequate flux necessary for suspending matter in said preheater, while the other portion of the carbon dioxide-rich gases from said cyclone preheater is adapted in the perspective of a treatment for limiting the amounts of carbon dioxide discharged into the atmosphere, such as for example, sequestration.