Thermodynamics of Indium Dissolution in Molten CaO-based Slags
The solubility of indium in the CaO-SiO2-Al2O3 slag was measured by a thermochemical equilibration technique. The dissolution mechanism of indium into the CaO-SiO2-Al2O3 slag at 1773 K under reducing atmosphere was elucidated. The indium solubility increases in calcium silicate based flux and decreases in calcium aluminate based flux with increasing oxygen partial pressure. Also, it decreases by increasing the basicity of slag, followed by an increase with increasing basicity of slag, indicating that indium dissolution mechanism changes according to the basicity of slag. Therefore, a dissolution mechanism of indium can be constructed as following equation;In(s)+1/4O2(g)=(In+)+1/2(O2-)(in high silica region) In(s)+1/2(O2-)=(In-)+1/4O2(g)(in low silica region) The enthalpy change of indium dissolution reaction is negative, indicating that the dissolution is an exothermic reaction. The solubility of indium is strongly dependent on the content of silica. The activity coefficient, and thus the excess free energy of In2O linearly decreases with increasing silica content, indicating that the In2O is believed to behave as a weak basic oxide in high silica region. Therefore, it is recommended to use suitable flux which corresponds to the CaO-Al2O3-20wt％ SiO2 in order to minimize the indium loss during pyrometallurgical processing of In-containing materials.
Indium Solubility Basicity Dissolution mechanism CaO-SiO2-Al2O3 slag
Kyu Yeol KO Joo Hyun PARK
School of Materials Science and Engineering, University of Ulsan, Ulsan 680-749, Korea
国际会议
Ninth International Conference on Molten Slags,Fluxes and Salts(第九届国际熔渣、溶剂与熔盐学术会议 MOLTEN12)
北京
英文
1-12
2012-05-27（万方平台首次上网日期，不代表论文的发表时间）