Abstract: A process for transporting a powder material, in which a device is fitted between a supply zone and a zone to be supplied, the device including at least one substantially horizontal conveyor which includes a lower duct and an upper duct being separated by a porous wall, the upper duct provided with a balancing column. The upper duct is filled with powder material and the lower duct is supplied with gas at a pressure that allows the potential fluidization of the powder material in the upper duct. The minimal bubbling speed, which corresponds to the maximum void fraction, is determined and the fluidization pressure is set to a value such that the fluidization speed of the gas is between 0.8 and 1.5 times the minimal bubbling speed, preferably between 0.9 and 1.3 times the minimal bubbling speed.

Abstract: A process making it possible to transport by potential fluidization, a powder material, in which a device is fitted between the supply zone, typically a storage zone for said powder material, and the zone to be supplied, said device including at least one substantially horizontal conveyor, called an “air chute”, which includes a lower duct designed for the circulation of a gas and an upper duct designed for the circulation of the powder material, said lower duct and said upper duct being separated by a porous wall that said gas can pass through, a process in which the upper duct is filled with said powder material and the lower duct is supplied with gas at a pressure that allows the potential fluidization of said powder material in said upper duct said upper duct being provided with at least one balancing column.

Abstract: A method for the production of aluminum from bauxites containing aluminum monohydate of the diaspore or boehmite type which may contain more than 1.5% by weight of calcium carbonates. The ore is digested by producing feeding a suspension produced from milled bauxite ore and concentrated aluminate liquor to a plant with a series of autoclaves and a series of regulators supplying tubular reheaters across the autoclaves with steam. The suspension first travels across the series of autoclaves, and on exiting, the digestion of the ore is practically complete, and the suspension then travels across the series of regulators. The condensation water from the steam coming from the regulator and feeding the reheater is collected in a purge pot. Within the series of regulators, the suspension is diluted on entering a regulator with the water coming from the condensation of the steam from one or several upstream regulators.

Abstract: Method for conveying a pulverulent material making it possible to divide said pulverulent material, from a single storage capacity (10), between several conveyors (50) with a controlled flow rate in each of said conveyors, characterized in that said storage capacity is linked to said conveyors by at least one aero-pipe (30) and in that a hyperdense fluidized meter (40), is connected to said aero-pipe, said hyperdense fluidized meter being intended to feed each of the conveyors.

Abstract: A method for the production of aluminum from bauxites containing aluminum monohydate of the diaspore or boehmite type which may contain more than 1.5% by weight of calcium carbonates. The ore is digested by the following steps: a1) a suspension, produced from the milled bauxite ore and the concentrated aluminate liquor is fed to a plant containing a series of n autoclaves and a series of m regulators supplying m tubular reheaters across m autoclaves with steam; a2) the suspension first travels across the series of autoclaves, and on exiting the last autoclave A, the digestion of the ore is practically complete and a3) the suspension then travels across the series of regulators, the condensation water from the steam V coming from the regulator D and feeding the reheater R is collected in a purge pot P. In at least one position in the series of regulators, the suspension is diluted on entering a regulator with the water coming from the condensation of the steam from one or several upstream regulators.

Abstract: Method for conveying a pulverulent material making it possible to divide said pulverulent material, from a single storage capacity (10), between several conveyors (50) with a controlled flow rate in each of said conveyors, characterised in that said storage capacity is linked to said conveyors by at least one aero-pipe (30) such as described in WO84 01560 and WO85 04676, and in that a hyperdense fluidised meter (40), such as the device described in EP 0 190 092, is connected to said aero-pipe, said hyperdense fluidised meter being intended to feed each of the conveyors.

Abstract: A solid mass for the recovery of mercury, comprising a solid mineral support or dispersant, essentially copper and sulphur at least partly in the form of copper sulfide is produced by the following stages:a) at least one copper compound other than a sulphide is incorporated into a solid mineral dispersant or carrier,b) the product obtained in stage (a) is calcined in order at least partly to convert the copper compound or compounds which it contains into copper oxide (CuO and/or Cu.sub.2 O),c) the product obtained in stage (b) or in stage (a) if there has not been a stage (b) is brought into contact with elementary sulphur,d) the product resulting from stage (c) referred to as the precursor, is subjected to a thermal treatment in a non-oxidizing atmosphere and accompanied by gas scavenging, to a temperature and for a sufficient time to allow the formation of sulphide of the metal(s) present.

Abstract: The invention relates to a pretreatment of a petrochemical or refining catalyst containing at least one metal in metallic or metallic oxide form, deposited on a support.The catalyst is impreganted by a solution or a suspension containing on the one hand a specific sulphur agent, e.g., diethanol disulfide and on the other an organic reducing agent, e.g., formic acid.

Abstract: The invention relates to an apparatus for purifying lithium, formed by a sealed enclosure comprising a heated upper portion 1 provided with a container 9 in which the molten lithium 11 is agitated and from which the impurities evaporate, and a cooled lower portion 13 provided with a condensation surface 17 and a pipe means 16 for producing a depression in the lower portion. The invention is used in the purification of lithium, and in particular, for separation of lithium from sodium and potassium impurities.

Abstract: The invention relates to a process for purifying lithium in which the lithium is melted in an inert atmosphere. The molten lithium is then maintained at a temperature of 400.degree. to 700.degree. C. under a pressure of less than 10 Pascal while agitating the molten lithium to renew its exposed surface. In this manner, impurities in the lithium are virtually exclusively vaporized, without giving rise to substantial evaporation of lithium. The vaporized impurities are then condensed at a temperature of less than 100.degree. C. and the purified lithium is recovered in molten form.