The influence of various ions in the bioleaching of metal sulphides

The catalytic effect of various metallic ions (Hg 2+, Co 2+, Ag +, Bi 3+ and Cu 2+) in the bioleaching of a sphalerite concentrate and complex sulphide concentrate was studied. Bacteria of the type Thiobacillus ferro-oxidans adapted to sulphide concentrates were used. The cations studied increase the copper dissolution from complex sulphides, with Ag + and Hg 2+ prominent with an extraction efficiency of 90% and 72.5%, respectively, compared with a 26.5% recovery in the absence of a catalyst. The microbiological dissolution of the sphalerite improves considerably with the addition of Ag + and Cu 2+ as catalysts, with zinc dissolution of 90% Furthermore, it is shown that additional amounts of Cu 2+ increase the percentage of metal leached. The influence of catalytic ions in electrochemical processes of dissolution of complex sulphides is discussed.