The Influence of Various Ions in the Bioleaching of Metal Sulphides

This study investigates the catalytic effect of various metallic ions, specifically Hg2+, Co2+, Ag+, Bi3+, and Cu2+, on the bioleaching of sphalerite and complex sulphide concentrates. Utilizing bacteria of the type Thiobacillus ferrooxidans that have been adapted to process sulphide concentrates, it was found that the presence of these cations significantly enhances the dissolution of copper from complex sulphides, with Ag+ and Hg2+ demonstrating the highest extraction efficiencies of 90% and 72.5%, respectively, compared to merely 26.5% recovery in the absence of a catalyst. Additionally, the microbiological dissolution of sphalerite is notably improved with the addition of Ag+ and Cu2+, achieving a zinc dissolution of 90%. The research further elucidates that increased amounts of Cu2+ correspond to a higher percentage of metal leached. The implications of these findings for the electrochemical dissolution processes of complex sulphides are discussed, highlighting the potential of using microorganisms in the extraction processes of the mining industry.