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 method of grinding a mineral material (10) containing at least calcium impurities implemented in a plant (1) including a grinder (2) and a granulometric selection device, referred to as a selector device (3), able to separate the materials into two fractions. The method includes the following steps: grinding the mineral material by material bed compression with the grinder to obtain a ground material, separating the ground material into a fine fraction and a coarse fraction with the selector device, returning the coarse fraction (13) to the grinder (2) for a further grinding step. At least part of the ground material is subjected to sorting intended to separate the metal impurities from the mineral materials. A plant as it stands, and the method and installation will find a particular use for producing hydraulic binders such as cement.

Abstract: A hydrodynamic bearing for supporting a hollow cylinder that may be deformable in the radial direction, driven in a rotational movement about its axis, the diameter being greater than or equal to one meter, the bearing essentially consisting of a bushing and a bushing support, and in which the bushing, notably of constant thickness, extends over a portion of cylinder of axis ?, having a guide surface, intended to follow the exterior surface of the cylinder via a film of lubricant, and a surface secured to the bushing support. The bushing support has, if appropriate locally, at least in the region of an intermediate zone of the bearing, cross-section-reducing elements allowing elastic deformation of the bearing so as to limit the maximum value of the guide forces over the bushing. The bearing is useful in supporting and guiding a rotating hollow grinder subjected to unevenly distributed forces during rotation.

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.

Abstract: Method for cooling granular solid materials from a continuous curing facility having at least one area for burning a fuel to cure granular materials, wherein the curing of the granular materials, then the cooling of the cured granular materials is carried out in two consecutive steps, a first cooling step in a first cooler and a second cooling step in a second cooler, the method including: providing a cold air source for cooling the granular materials, the cold air source directly supplying air to the second cooler by blowing, and the air heated by the cured granular materials being used during the cooling as combustion gas for the burning area. All gases generated by the first and second coolers are routed to the burning area for use as a combustion gas, and the amount of cold air blown to the second cooler is adjusted to cover the air combustion needs.

Abstract: A method for producing cement clinker in a plant that includes: a first cyclone preheater and a second cyclone preheater for preheating first and second portions of a raw material, respectively; a precalcinator using a combustion gas for burning a fuel, the fumes released by the precalcinator being directed to the second cyclone preheater; a rotary furnace provided with a fuel burner, the fumes released by the rotary furnace being directed to the first cyclone preheater; and a clinker cooler that blows cooling air across the clinker at the outlet of the rotary furnace. According to the method, the precalcinator combustion gas contains between 90 and 100 vol % of oxygen. The precalcinator may consist of a fluidized bed, the fluidization gas being the combustion gas. The invention also relates to a plant as such.

Abstract: A device for the selective granulometric separation of solid powdery materials using centrifugal action, capable of separating materials into a fine material fraction and a coarse material fraction, includes: a housing, a cylindrical rotor rotatable, relative to the housing, about a vertical axis inside the housing and provided with blades evenly distributed on the periphery of an upper outlet opening through which a stream of gas, laden with particles having a size lower than a predetermined particle size, is drawn, a set of vertical adjustable vanes evenly distributed about the rotor along the generatrices of a virtual cylinder and directing the gas stream towards the rotor, elements for feeding the particles between the vanes and the rotor, collecting unit lower than the rotor for collecting the unfed particles having fallen and having a size larger than the predetermined particle size.

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: 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. According to the invention, the flue gases produced by the rotary furnace are separated from the gases from the preheater so as not to mix them, the precalcination reactor is fed with an oxygen-rich gas and a portion of the gases leaving the cyclone preheater is recycled into said precalcination reactor, or even into the preheater so as to obtain a flux suitable for suspending matter in the preheater. The non-recycled other portion of the gases, rich in carbon dioxide, is adapted for the purpose of limiting the amount of CO2 discharged, by means such as sequestration means.

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.