Preparation of high-purity antimony oxychloride from high-arsenic refined bismuth dust

Preparation of high-purity antimony oxychloride from high-arsenic refined bismuth dust in a process of hydrochloric acid leaching, antimony powder reduction, hydrolysis, hydrochloric acid dissolution, impurity removal, hydrolysis was studied. In the process of leaching with hydrochloric acid, the leaching rates of Sb, As, Bi and Pb are 99.50%, 92.79%, 95.12% and 85.34% when the ratio of hydrochloric acid solutions to refined bismuth dust is 3:1, reaction time is 4 h, reaction temperature is 80°C, the content of hydrochloric acid is 1.2 times of its theoretical content. Sb5+ is reduced to Sb3+ by adding antimony powder into the hydrochloric acid leaching solution, which is then hydrolyzed. The hydrolysis rate of Sb3+ arrives at 98.25% when the reaction temperature is 20°C, reaction time is 1 h, and the ratio of water to SbCl3 solution is 10:1. After the hydrolysate is dissolved by hydrochloric acid solutions and the impurity is removed after 1 h by means of adding agent, the solution is hydrolyzed and the products is obtained by means of filtration, washing and drying. The content of Sb in the products arrives at 75.71% and the impurity contents of As, Pb, Bi are 0.0819%, 0.0392% and 0.1187%, respectively. The product is rhombohedral particles with the advantages of uniform size and its chemical formula is Sb4O5Cl2.