BIOLEACHING OF SULFIDE COBALT-COPPER-NICKEL ORE USING THE STANDARD AND MODIFIED 9K MEDIA

Sciences, Petropavlovsk-Kamchatsky, e-mail: nigtc@nigtc.ru In the context of metal deficit for industry there is a need for the development of technologies for the efficient extraction of valuable components from mineral raw materials. Some of the metals in demand such as copper, nickel and cobalt are contained in sulfide copper-nickel ores the processing of which is complicated by the use of traditional chemical technologies. Biohydrometallurgy using the features of the energy metabolism of microorganisms in the catalysis of oxidative reactions is their alternative. The creation of certain conditions (for example, high temperature, the oxidizing activity of microorganisms, the chemical composition of solutions, the availability of oxidizing agents, etc.) affects the bioleaching of metal sulfides. It is believed that chloride ions can improve the kinetics of the dissolution of sulfide minerals in particular chalcopyrite. The paper presents the results of a comparative laboratory study of the bioleaching of sulfide cobalt-copper-nickel ore from the Shanuch deposit (Kamchatka Krai) which included the pyrrhotite-pentlandite-chalcopyrite association using a standard nutrient medium for microorganisms 9K and its modified version (9KCl) with replacement sulfate forms to chloride ones. It was shown that bioleaching made it possible to obtain solutions with a nickel concentration of 1,35 ± 0,19 and 1,24 ± 0,17 g/l, copper 0,074 ± 0,01 and 0,081 ± 0,01 g/l, cobalt 0,032 ± 0, 01 and 0,029 ± 0,01 g/l for 9K and 9KCl, respectively. Moreover, the recovery of metals in both cases did not exceed 30 % for nickel and cobalt. Copper deposition was observed. Taking into account the recognized positive effect of chloride ions in solution on the bioleaching of chalcopyrite no similar effect was found for polymetallic ore in the study. The standard nutrient medium 9K was optimal for the extraction of copper and other