GB666869A - Improvements relating to the distillation of metals - Google Patents

Abstract

A process for distilling a normally non-volatile metal from a metal-bearing material comprises contacting the material with the vapour phase of the halide of a volatile substance at a temperature and pressure at which occurs an endothermic reaction resulting in the formation of the vapour of the stable halide of the normally non-volatile metal and the vapour of the volatile substance, and converting the resultant vapour mixture into the normally non-volatile metal and the halide of the volatile substance by the reaction of the vapour of the volatile substance with the vapour of the halide of the normally non-volatile metal, whereby the normally non-volatile metal condenses. The volatile substance may be a metal or a non-metal, or a volatile, stable or unstable, lower halide. In the latter case the normally non-volatile metal to be distilled is contacted by a higher halide of a metal or non-metal, which higher halide need not be volatile, resulting in the formation of the vapour of the normal halide of the normally non-volatile metal and the vapour of the lower halide of the metal or non-metal. The conversion of the resultant vapour mixture may be brought about by cooling or absorption of the normally non-volatile metal whereby the metal condenses as absorbate. In the former case, the vapour which is brought into contact with the metal bearing material is preferably in the unsaturated state so that the halide of the volatile substance and the normally non-volatile metal condense separately. The method may be used for separating, e.g. baryllium and vanadium from impurities, such as oxides or carbides, or for obtaining non-volatile metals from alloys, or intermetallic compounds, e.g. ferro-manganese, ferro-vanadium, ferro-chromium, ferro-titanium, ferro-molybdenum, and ferro-tungsten. Specification 620,071 is referred to.