Biomineral Processing for Extraction of Metal Values from Ores/Concentrates/Wastes

Lean copper ore (-0.3-0.4% Cu) of Malanjkhand Copper Project (MCP) is a granite rock with copper as chalco-pyrite in the quartz veins. XRD identification of the ore showed chalcopyrite, pyrite and silica as major phases and bornite being the minor phase. The wild strains of Acidi-thiobacillus ferrooxidans (Tf) isolated from source mine water in 9K+ medium were used for bioleaching. On bench scale with non-adapted Tf isolate, maximum (72%) Cu biodissolution was found at 2.0 pH, 5%PD using <50um particles at 35oC temperature in 40 days. Whereas, using Tf isolate adapted on 5%(w/v) ore at 2.0pH and 25oC, copper biorecovery rose to 75% under same conditions.