Abstract: In one aspect the present invention provides a method of recovering gold from each of at least two different refractory gold-bearing sulfidic mineral materials. A first mineral material is subjected to biooxidation pretreatment to release gold locked within sulfide minerals. The biooxidation produces an acidic biooxidation liquor effluent that contains significant dissolved iron in the ferric form. All or a portion of the biooxidation liquor effluent is used as an acidic treatment liquid to treat the second mineral material, which contains acid-consuming minerals. During the treatment, acid-consuming minerals react with the acidic solution, raising solution pH and resulting in reduced solubility and precipitation of dissolved iron and other metals. Also during the treating, sulfides in the second mineral material or oxidized, thereby releasing gold for subsequent recovery.

Abstract: In one aspect the present invention provides a method of recovering gold from each of at least two different refractory gold-bearing sulfidic mineral materials. A first mineral material is subjected to biooxidation pretreatment to release gold locked within sulfide minerals. The biooxidation produces an acidic biooxidation liquor effluent that contains significant dissolved iron in the ferric form. All or a portion of the biooxidation liquor effluent is used as an acidic treatment liquid to treat the second mineral material, which contains acid-consuming minerals. During the treatment, acid-consuming minerals react with the acidic solution, raising solution pH and resulting in reduced solubility and precipitation of dissolved iron and other metals. Also during the treating, sulfides in the second mineral material or oxidized, thereby releasing gold for subsequent recovery.