This Small Business Innovation Research Phase 1 project is designed to develop a biooxidation process module for low grade rhenium-bearing molybdenum ores and concentrates. Molybdenite (MoS2) and chalcopyrite (CuFeS2) are sulfides of molybdenum and copper, respectively. Rhenium (Re) is a rare metal that can substitute for molybdenum in the molybdenite crystal lattice and for which molybdenite is the only significant mineral source. These minerals frequently coexist in a given porphyry copper ore-body. Currently, rhenium, of high value and with current and potential industrial applications, cannot be recovered unless the molybdenite is roasted. This process in itself is extremely capital intensive and results in SO2 production and other environmental impacts. Here, a novel process is proposed which is highly selective for sequential metal release. We describe a process module for biooxidizing copper sulfide contaminated molybdenite concentrates and selectively mobilizing copper or molybdenum and rhenium. This process is designed to be integrated into a pre-existing chalcopyrite leach circuit or as an independent biooxidation facility and will utilize molybdenite originating from porphyry copper deposits. Variability in the grade of feed stocks should not be problematic. The total annual domestic market is estimated at $60-200 million.
