Patent ID: 6423117
Filing Date: 2002-07-23
Classification: C22B,Y02P

Abstract:
A process for extracting at least one valuable metal from starting material comprising a plurality of metallic compounds including (i) said at least one valuable metal and/or compound thereof, (ii) oxide of at least one other metal and (iii) sulphide of the same or different other metal,which process includes treating the starting material with a first liquid leaching agent at a pH of less than 4.0 containing (iv) acid and sodium chloride and, subsequently with a second liquid leaching agent containing (v) a source of cyanide ions, so as to solubilize said valuable metals(s), and whereby liquor at a pH of less than 4.0 obtained from the treatment with said second leaching agent which contains said solubilized valuable metals(s) is caused to contact valuable metal-retaining means wherein said valuable metal(s) is (are) retained.