Optimization of the Bioleaching process Applicable forCopper Recovery from the Ores Using a Mix culture ofSulfobacillus Acidophilus and SulfobacillusThermosulfidooxidans

The purpose of this study is to optimize the bioleaching process in which sulfur oxidizing microorganisms, Sulfobacillus Acidophilus and Sulfobacillus Thermosulfidooxidans, are used for recovery of copper from the low grade ores of Sarcheshmeh, Kerman, Iran.Plackett-Burman and Box-Behnken methods were used as the design of experiment (DOE) methods according to the number of factors and their related levels. Plackett-Burman was the first method for achieving the most effective factors between twelve parameters and Box-Behnken was used in final optimization for determination the best process conditions according to four factors chosen as a result ofthe first set of experiments. DOE and analysis of variance (ANOVA) showed that the best optimum conditions for bioleachingprocess by a mix culture of Sulfobacillus Acidophilus and Sulfobacillus Thermosulfidooxidans are pH 2, a temperature of 50°C, FeSO4.7H2O concentration of 80 g/l and MgSO4.7H2O concentration of 0.12 g/l.