GB582579A - Improvements relating to the production or refining of aluminium - Google Patents

Abstract

A process for producing or refining aluminium comprises reacting heated aluminium-bearing materials with a halide brought to the vapour-phase previous to the reaction, for instance a low-boiling or subliming halide such as aluminium chloride. The aluminium volatilises under the formation of aluminium-halogen compound vapours from which the aluminium is recovered. The aluminium may be brought into reaction in a finely-divided condition, e.g., powder or drops. The halide vapour should not be saturated under the condition of reaction. This may be effected by employing a temperature of reaction higher than the temperature of evaporation of the halide. The reaction may be carried out under reduced pressure and/or in the presence of hydrogen or other gas inert to aluminium. At least two halide condensers may be used and employed alternately as condenser and evaporator whereby the same amount of halide is repeatedly used for reaction without discontinuing the distillation. If the temperature of the zone in which the aluminium is condensed is kept between the condensation temperature of aluminium and that of the halide, the halide is kept in the vapour phase in the reaction chamber or in circulation through it. The halide may be condensed separately from the aluminium, and the heat of condensation of the aluminium may be utilised to evaporate and/or preheat halide required for further reaction.