Preparation of high-purity indium by electrorefining

The application of indium requires high purity indium as material, and the high purity indium has been prepared by electrorefining. The selection and preparation of electrolyte in electrorefining indium were investigated, and the effect of component of electrolytic solution on electrolytic refining was also studied. Compared with electrolyte of InCl3-HCl, electrolyte of In2（SO4）3-H2SO4 has higher stability and lower corrosivity, electrolytic solution can be heated at low temperature, and bath is open and simple, which makes operation more convenient. The results show that the voltage can be kept at 0.30.5 V, and the content of indium can exceed 99.999% when the content of indium（Ⅲ） ion and sodium chloride are 80120 g/L. The bench-scale test of electrolysis was carried out, and the product of indium reaches the national standard of 99.999% high purity indium.