Abstract: The invention relates to a process for manufacturing cement clinker in a plant having a cyclone preheater, a precalcination reactor, a rotary furnace and a clinker cooler. In the process, the flue gases from the furnace are conducted to the precalcination reactor, or even to the cyclone preheater. According to the invention, the precalcination reactor is fed with an oxygen-rich gas, the nitrogen content of which is less than 30%, constituting the sole oxygen source for said reactor, and a portion leaving the cyclone preheater is recycled into the plant so as to obtain a suitable flux necessary for suspending matter in said preheater, while the other portion, rich in carbon dioxide, is adapted for the purpose of a treatment for limiting the amount of carbon dioxide discharged into the atmosphere, such as particularly sequestration.

Abstract: A method for manufacturing a cement clinker includes a rotary furnace, a cyclone preheater receiving the fumes from said rotary furnace, an air blowing clinker cooler, and at least one heat exchanger, referred to as a first heat exchanger. The raw materials are preheated and decarbonated in said cyclone preheater. The clinker is cooled in said clinker cooler. A first portion of the hot air generated by said clinker cooler, or so-called secondary air, is directed to the rotary furnace to be used as combustion air. A second portion of the hot air generated, or so-called tertiary air, is directed and carried separately from the first portion to a place in the facility where fuel is burned. A third portion of hot air generated in said clinker cooler, or so-called excess air, is carried into at least said first heat exchanger for the purpose of recovering power to produce electricity.

Abstract: A grain size and/or pulverulent-matter drying apparatus for the treatment of suspended mineral particles, at least 90% in weight of which have a size less than 60 mm, primarily includes a substantially vertical gas pipe with an ascending flow provided with a gas inlet, a lower opening and an upper opening between which a supply opening is also provided for insertion of matter. A portion of the matter, or so-called “fines”, can escape with the gas through the upper opening due to the bearing capacity of the ascending flow, while another coarser portion of the matter is not carried away by the gas and falls into the lower opening. The apparatus also has a device for creating turbulence, which favors the separation of the different grain sizes and the suspension of matter, provided at the internal wall of the pipe and located between the lower opening and the supply opening.