Patent ID: 7018593
Filing Date: 2006-03-28
Classification: C22B,Y02P,Y10S

Abstract:
1. A method of recovering base metal from a tailings dump which contains bacteria which are capable of oxidizing sulphide minerals in the dump, the method including the steps of: (a) aerating a surface layer of the dump by agitating or mechanically loosening the surface layer; (b) providing conditions favourable for oxidation of sulphide minerals by the bacteria: (c) allowing oxidation of the sulphide minerals by the bacteria to take place for a controlled period resulting in an oxidised surface layer; (d) removing the oxidised surface layer after the controlled period and adding water thereto to form a slurry wherein the slurry is directed to at least one tank in which agitation of the slurry takes place; (e) separating the slurry into solids and a solution; and (f) recovering base metal from the solution using solvent extraction or ion exchange techniques.