Effect of activated carbon on the bioleaching of chalcopyrite concentrate

The effect of the addition of activated carbon on the bioleaching of chalcopyrite concentrate, which contained pyrite, sphalerite and galena as sulfide gangue minerals, has been investigated using Thiobacillus ferrooxidans. The addition of activated carbon accelerated the dissolution of copper from the chalcopyrite concentrate. The recovery of copper increased with increase in the amount of activated carbon and with decrease in particle size of activated carbon. In the chemical control, activated carbon also enhanced the dissolution rate of copper and zinc from the chalcopyrite concentrate. These results indicated that the enhanced rate of leaching could be attributed to the galvanic interactions between activated carbon and chalcopyrite or sphalerite. The presence of Thiobacillus ferrooxidans could accelerate the galvanic interactions. (C) 1998 Elsevier Science B.V. All rights reserved.