Bacteria-assisted Leaching of Arsenic-rich Gold Concentrate with Fe2(SO4)3 Solution
TAO Min-hui YANG Shao-bin ZHANG Guang-ji YUAN Qiu-hong CAO Jun-ya WANG Yue-hu HAN Bao-ling
College of resource and environment engineering, Liaoning Technical University College of resource and environment engineering, Liaoning Technical University Institute of Processing Engineering ，CAS Graduate University of Chinese Academy of Sciences Institute of Process Engineering, CAS Institute of Process Engineering, CAS Key Laboratory of Green Process Engineering, Institute of Process Engineering, Chinese Academy of Sciences
Abstract：Fe3+ solution leaching of an arsenic-rich gold concentrate has been studied by shake-flask tests. The effects of temperature, concentration of Fe3+ and high density of bacteria (separately Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Sulfobacillus sibiricu) have been investigated. Compared with bioleaching, Fe3+ solution chemical leaching leads to a higher dissolving rate of arsenic-rich gold concentrate. Higher temperature is favorable for the leaching, and the leaching rate of As is improved with increasing of temperature before reaching at 80. Fe3+ concentration has little effect on the leaching rate of As at the beginning of leaching, high Fe3+ concentration leads to high leaching rate of As when the concentration is lower than 40 g/L, but the leaching rate of As decreases when higher Fe3+ concentration is used due to the production of jarosite. In continuous operation, a higher leaching rate can be achieved under lower but constant Fe3+ concentration. In comparison with bioleaching experiments, increasing pulp density has an obviously negative effect on the bacteria, while the high density of bacteria can be helpful to relieve the effect, at the same time be better for Fe3+ solution chemical leaching for they can keep higher density of Fe3+ and lower S.
2010, Vol. 10 
