The effect of various parameters on the Jarosite formation in bioleaching of Sarcheshmeh copper mine sulfide ores

Jarosite is one of the limiting factors for recovery of copper from copper sulfide minerals. This study aimed to evaluate the influence of concentration of ferrous sulfate, pH and temperature on the jarosite formation during the sulfide ore bioleaching of Sarcheshmeh copper mine. In this study, samples were collected from the depot crushing heap bioleaching site of Sarcheshmeh Copper Mine. The bioleaching experiments were performed in 500 ml flasks, containing 10% solids of sulfide ore  (w/v), pulp (200 ml), the 9K culture medium, bacteriainoculation (10% v/v of Acidithiobacillus ferrooxidans). The flask were shaked at 130 rpm throughout incubation. Our results showed that increase in pH and concentration of ferrous sulfate facilitate rate of ferric iron precipitation. Maximum precipitation rate of ferric was achieved in 50 g/l of sulfate concentration, temperature 32 ° C and pH 2/2. According to XRD and FTIR analysis of Bioleaching residue, the produced ferric precipitations are often potassium and ammonium jarosite. With regard to the optimal conditions in this study in terms of pH, temperature and concentration of ferrous sulfate it is possible to regulate Jarosite formation through bioleaching process and to increase the production of copper efficiency from copper sulfide ores.