Process for recovering metals from solution through solvent extraction and pyrometallurgical reduction

摘要

Solvent extraction is used for selective recovery of a dissolved metal such as copper from an aqueous solution of metals by means of an organic liquid, immiscible with the aqueous solution and selective for the metal of interest. The metal is extracted from the organic liquid by means of another aqueous stripping solution. The metal values are sufficiently concentrated in the aqueous stripping solution to get continuous precipitation of a metal salt in a substantially pure form. The metal salt is separated, rinsed, and dried to form an intermediate product. Preferably, the metal salt is a sulfate which is then dehydrated and thermally decomposed to form metal oxide and sulfur dioxide. The metal oxide may be also considered as an intermediate product. It is also desirable to pyrometallurgically reduce the metal oxide until pure metal powder is obtained, or it may be cast into ingots.