US 7,488,370 B2
	Reducing cyanide consumption in gold recovery from finely ground sulphide ores and concentrates
Michael M Hourn, Carindale (Australia); Rodrigo U Ventura, Sunnybank (Australia); John A Willis, Sherwood (Australia); and David Winborne, Mitchelton (Australia)
Assigned to Xstrata Queensland Ltd., Brisbane, Queensland (Australia)
Appl. No. 10/533,317 PCT Filed Oct. 22, 2003, PCT No. PCT/AU03/01400 § 371(c)(1), (2), (4) Date Feb. 08, 2006, PCT Pub. No. WO2004/042094, PCT Pub. Date May 21, 2004.
Claims priority of application No. 2002952490 (AU), filed on Nov. 06, 2002.
Prior Publication US 2006/0185475 A1, Aug. 24, 2006
Int. Cl. C22B 3/04 (2006.01)

U.S. Cl. 75—743  [75/744; 75/735; 75/737; 75/733]

10 Claims

1. A process for extracting a metal from a refractory material containing the metal, the process comprising fine grinding the material, subjecting the ground material to a leaching step carried out at 1 atmosphere or less in the presence of an alkaline material and an oxidizing agent, adjusting the leaching step to produce partially oxidized material, wherein the amount of oxidation of the partially oxidized material is between 9%-20%, and subjecting the partially oxidized material to a cyanide extraction step to recover the metal.