Thermodynamic properties of bioleaching liquid mixtures with and without mesophilic bacteria at different temperatures
来源期刊：Rare Metals2007年第6期
论文作者：LIU Meilin, RUAN Renman, WEN Jiankang, and WANG Dianzuo National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Non-Ferrous Metals, Beijing , China
文章页码：528 - 535
摘 要：In this work,low-grade copper sulfide mine has been treated by the bioleaching process using native cultures of Acidithiobacillus ferrooxidans. The bioleaching experiments were carried out in shake flasks at pH 2.0, 180 r·min-1 and 30°C for mesophilic bacteria. The conductivity of copper bioleaching liquid was determined by the electric conductivity method at temperatures ranging from 298 K to 313 K. The ionic activity coefficients were estimated using Debye-Hcker and Osager-Falkenlagen equations. Meanwhile, the effects of temperature and concentration on the mean ionic activity coefficients were discussed. The relative partial molar free energies, enthalpies and entropies of copper leaching solution at above experimental temperatures were calculated. The behaviors of change of relative partial molar quantities were discussed on the basis of electrolytic solution theory. Simultaneously, the thermodynamic characters of bioleaching solution with and without mesophilic bacteria were compared. The existence of mesophilic bacteria changed the Fe3+/Fe2+ ratio, which resulted in the difference of ionic interaction. The experimental data show that the determination of the thermodynamic properties during the bioleaching processes should be important.
LIU Meilin, RUAN Renman, WEN Jiankang, and WANG Dianzuo National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Non-Ferrous Metals, Beijing 100088, China
摘 要：In this work,low-grade copper sulfide mine has been treated by the bioleaching process using native cultures of Acidithiobacillus ferrooxidans. The bioleaching experiments were carried out in shake flasks at pH 2.0, 180 r·min-1 and 30°C for mesophilic bacteria. The conductivity of copper bioleaching liquid was determined by the electric conductivity method at temperatures ranging from 298 K to 313 K. The ionic activity coefficients were estimated using Debye-Hcker and Osager-Falkenlagen equations. Meanwhile, the effects of temperature and concentration on the mean ionic activity coefficients were discussed. The relative partial molar free energies, enthalpies and entropies of copper leaching solution at above experimental temperatures were calculated. The behaviors of change of relative partial molar quantities were discussed on the basis of electrolytic solution theory. Simultaneously, the thermodynamic characters of bioleaching solution with and without mesophilic bacteria were compared. The existence of mesophilic bacteria changed the Fe3+/Fe2+ ratio, which resulted in the difference of ionic interaction. The experimental data show that the determination of the thermodynamic properties during the bioleaching processes should be important.
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