Patent ID: 7947108

Claim:
A method for removing copper and precious metal from a mineral material feed comprising copper and comprising precious metal locked in one or more sulfide mineral, the method comprising: pressure oxidizing the mineral material feed in particulate form slurried in an aqueous liquid to decompose at least a portion of the sulfide mineral, the pressure oxidizing comprising dissolving at least a majority of the copper of the mineral material feed into the aqueous liquid; recovering from the pressure oxidizing solid residue and acidic liquid effluent, the solid residue comprising at least a portion of the precious metal from the mineral material feed, the liquid effluent comprising in solution at least a majority of the copper of the mineral material feed; thiocyanate leaching at least a portion of the solid residue with an acidic thiocyanate leach solution to dissolve into the thiocyanate leach solution in the form of precious metal-hiocyanate complex at least a portion of the precious metal from the solid residue; and separating from the liquid effluent and recovering in a purified copper-containing product at least a majority of the copper dissolved in the liquid effluent; wherein feed of the thiocyanate leach solution to the thiocyanate leaching comprises dissolved ferric iron and a molar ratio of the dissolved ferric iron to the dissolved thiocyanate of at least 2.