An electrochemical investigation of chalcopyrite paste electrode in the presence of Acidithiobacillus ferrooxidans
The electrochemical behaviors of chalcopyrite paste electrode obtained from the Dexing Copper Mine were investigated by Chronoamperometry and electrochemical impedance spectroscopy ( EIS) measurement in the presence of Acidithiobacillus ferrooxidans. The bioleaching residue of chalcopyrite was also analysed by X-ray diffraction ( XRD). The XRD experiment showed that CuS, S , Fe2O3 and jarosite were the products of chalcopyrite in bioleaching. The Chronoamperometry and electrochemical impedance spectroscopy results indicated that the chalcopyrite electrode had different features in different applied DC potentials. From these results, the variation with the applied DC potentials of charge transfer electrical resistance of the reaction product, the double layer capacitance and other characteristic parameters were considered. An equivalent circuit has been considered for the analysis of the EIS spectra of the chalcopyrite electrode. The fitting of EIS experimental data along with the XRD and Chronoamperometry results validated the proposed mechanism. The proposed mechanism showed that the products of chalcopyrite were CuS, Fe2+ and S° below 0. 500 V. While they were CuS, Fe2O3 and S° above 0. 500 V. The Fe2O3 layer hindered the diffusion of reaction reagents and products to or from the mineral substrate surface. At 600 mV, the breach of non-porous Fe2O3 layer occurred. These results improved our understanding on the bioleaching mechanism of chalcopyrite.
chalcopyrite Acidithiobacillus .electrode oxidation
Alin Li Songtao Huang Jiankang Wen Biao Wu Minglin Wu
National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, No. 2 Xinjiekouwai Street, 100088, Beijing, China
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
238-243
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）