Material separation

Abstract

A metal or alloy, present in material containing another metal or alloy having a higher melting point, can be recovered by heating the material in conditions preventing oxidation of the lower melting point metal or alloy, vaporizing this metal or alloy and depositing it on at least one collective surface. The initial heating may be performed in a controlled atmosphere at around atmospheric pressure, e.g. up to the melting point of the lower melting metal or alloy, whereafter the pressure can be reduced and heating continued to effect the vaporization. Apparatus for use in such a process comprises a heating chamber, means for heating the material in said chamber, means for producing higher and lower pressure conditions in said chamber, and condenser means in said chamber or arranged to be put into communication with the chamber in conjunction with the production of said lower pressure condition for the deposition of vaporized lower melting point metal or alloy on said condenser means. The invention may be applied to recovery of tin and lead from tin plate scrap, and more generally to recovery of lower melting point metals and alloys, e.g. zinc, lead or copper, from scrap and refuse.

Dependencies are inferred from the claim text.