GB686037A - Method of and apparatus for producing aluminium - Google Patents

Abstract

686,037. Extracting or refining aluminium. VEREINIGTE ALUMINIUMWERKE AKT.-GES. July 20, 1950 [Oct. 1, 1948; Oct. 1, 1948], No. 18206/50. Class 82(i) A method of refining or producing aluminium from aluminiferous raw materials by treating the materials with aluminium halide vapour and separating the abs o bed aluminium from the vapour by cooling, characterized in that the reaction gas is circulated without the aid of mechanical means by effecting the absorption of aluminium in known manner at a heated zone and separation of the aluminium from the circulating gas at one or more cooling surfaces maintained at a lower temperature than the heated zone, and preferably cooled by a cooling medium, which separating surface or surfaces is or are located at a higher level than the heated zone. Apparatus for carrying out the reaction comprises a tower-like reaction and separation vessel which is closed at the bottom by a heatable trough to hold the molten aluminiferous material and is cooled in the upper parts and has, internally, beneath the cooling zone, a horizontal ring adapted to receive pure aluminium running down the walls. In the modification shown in Fig. 2 the separating surface is formed by a number of internally cooled bodies 13, 13<SP>1</SP> projecting into the space containing the gaseous compounds formed by the reaction, which are so designed as to have a temperature field having the highest possible temperature gradient in their vicinity. These projecting bodies may be of cylindrical or conical form. A receiving vessel 14 is situated immediately below the cooled bodies to collect molten aluminium dripping from the said bodies and to shield these bodies from direct heat radiation from the heated zone. The receiving vessel projects to the outside of the tower to permit withdrawal of molten aluminium. To maintain gas pressure within the tower the apparatus may communicate with a heated reservoir vessel for aluminium trichloride which is filled with a salt melt adapted to dissolve the aluminium trichloride, e.g. a melt of halides of alkali and/or alkaline earth metals. Specification 582,579 is referred to.