Multiple factors influencing high-purity indium electrolytic refining

The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer (GDMS). The effects of several factors such as the indium ion (In3+) concentration, the sodium chloride (NaCl) concentration, the current density, the gelatin concentration, the pH, and the electrode distance, were examined. Significant variations in impurity levels concerning gelatin concentration were observed. Both the gelatin and In3+ concentration were moderately positively correlated with the Pb content. The Sb concentration was associated positively with the NaCl concentration, while the Ti concentration had an adverse correlation with the NaCl concentration. The Bi element content was positively linked to the electrode distance. As the current density increased, Cu, Pb, and Bi impurities initially rose and then eventually declined. Notably, a critical current density of 45 A·m−2 was identified in this behavior. © 2024 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd