Patent ID: 6451275
Filing Date: 2002-09-17
Classification: C22B,Y02P

Abstract:
A method for reducing cyanide consumption in mining processes to recover gold, silver or platinum group metals from a sulfur bearing ore body, comprising the steps of:providing an ore material containing gold, silver or platinum group metals and also containing at least one sulfur constituent selected from the group consisting of elemental sulfur and other sulfur compounds with oxidation states between a minus 2 state and a plus 6 state, and contacting said ore material with an aqueous medium containing sulfur dioxide gas, sulfite ions or bisulfite ions, in a manner to cause at least a portion of said constituents to be converted to species which are unreactive with cyanide and to form a solid phase containing the gold, silver or platinum group metals; and subjecting the solid phase to a cyanidation step to recover the gold, silver or platinum group metals therefrom.