Preparation of pure SbCl3 from lead anode slime bearing high antimony and low silver

A novel treatment process of lead anode slime bearing high antimony and low silver was developed by a potential-controlled chloridization leaching and continuous distillation. The experimental results show a high Sb³⁺ concentration, 489.2 g/L, in the leaching solution for two-stage countercurrent leaching process, and the leaching rates of Sb, Cu, Bi more than 99% when the potential is controlled at 450 mV. When the leaching solution is distillated and concentrated at 120 °C, almost all the silicon compound is evaporated into the concentration distillate and exists as amorphous hydrated silica. By the continuous distillation, high pure SbCl₃ could be prepared, and AsCl₃ is enriched in the distillate while metals Bi, Cu are enriched in the continuous distillation residue. As a result, the recovery rate of Sb is more than 95%.