Patent ID: 7514050

Claim:
A method for processing iron-containing, sulfidic mineral materials comprising gold contained in sulfide minerals, the method comprising: biooxidizing first said mineral material in the presence of biooxidation liquor, the biooxidizing comprising: (i) decomposing at least a portion of the sulfide minerals of the first said mineral material through microbial action, thereby releasing first gold from the sulfide minerals of the first said mineral material; and (ii) generating acidic effluent of the biooxidation liquor having a pH of smaller than pH 2.5 and comprising dissolved ferric iron; treating second said mineral material, which is different than the first said mineral material, with treating liquid, the second said mineral material comprising acid-consuming mineral content, and feed of the treating liquid supplied to the treating comprising at least a portion of the effluent of the biooxidation liquor and having a pH of smaller than pH 2.5, the treating comprising: (i) decomposing at least a portion of the sulfide minerals of the second said mineral material, thereby releasing second gold from the sulfide minerals of the second said mineral material; (ii) reacting acid of the treating liquid with the acid-consuming mineral content of the second said mineral material, thereby at least partially neutralizing the acid; and (iii) precipitating iron from the treating liquid; (iv) removing from the treating a treated effluent of the treating liquid, the treated effluent having a pH that is higher than the pH of the feed of the treating liquid; after the biooxidizing, leaching solid residue of the biooxidizing with a first leach solution and dissolving at least a portion of the first gold into the first leach solution; and discontinuing the treating when the pH of the treated effluent is greater than pH 3.5 and after the discontinuing of the treating, leaching solid residue of the treating with a second leach solution and dissolving from the solid residue of the treating at least a portion of the second gold into the second leach solution.