BIOLEACHING OF COPPER SULPHIDES FLOTATION CONCENTRATE USING CONSORPTIUM OF MESOPHILES AND TERMOPHILES MICROORGANISMS

摘要

The use of mixed cultures of acidophilus microorganisms that act in different temperature ranges, aims at speeding up the digestion of chalcopyrite, highly refractory sulphide mineral, the major mineral in the flotation concentrate of Caraiba Mining Co., with an attractive processing cost. The concentrate under consideration contains mainly chalcopyrite (CuFeS_2) and bornite (Cu_5FeS_4) with contents of, approximately, 70 and 30%, respectively. It was observed in this study, the performance of consortium of mesophiles, moderate and extreme thermophile microorganisms, in the oxidation of the aforementioned sulphides minerals, evaluating operational parameters such as pH of the leaching solution, the reaction temperature and redox potential, with consequent extraction of 80% of the concentrate copper content within 60 days of bioleaching. Such high copper extraction was achieved in column bioleaching tests.