Removal of Pb and Ag in preparation of high purity Bi2O3 from silver-zinc slag.

A Bi2O3 solution was obtained by leaching silver-zinc slag with an HCl-NaClO3-NaCl solution. Pb2+ and Ag+ concentrations in the BiCl3 solution were up to 1 371 mg/l and 46.1 mg/l, respectively. Pb2+ and Ag+ in the solution were removed using silver-zinc slag and NaI, respectively. Pb2+ and Ag+ concentrations were reduced to about 1 mg/l under the following conditions: ratio of BiC13 solution to silver-zinc slag = 10:1, initial pH 0.3- 0.4, agitation speed 1 000 rev/min, the reaction time no more than 15 minutes and the amount of NaI added 1.2-1.4 times the theoretical amount. High-purity Bi2O3 was prepared from the deleaded and desilvered BiCl3 solution by hydrolysis and conversion.
A Bi2O3 solution was obtained by leaching silver-zinc slag with an HCl-NaClO3-NaCl solution. Pb2+ and Ag+ concentrations in the BiCl3 solution were up to 1 371 mg/l and 46.1 mg/l, respectively. Pb2+ and Ag+ in the solution were removed using silver-zinc slag and NaI, respectively. Pb2+ and Ag+ concentrations were reduced to about 1 mg/l under the following conditions: ratio of BiC13 solution to silver-zinc slag = 10:1, initial pH 0.3- 0.4, agitation speed 1 000 rev/min, the reaction time no more than 15 minutes and the amount of NaI added 1.2-1.4 times the theoretical amount. High-purity Bi2O3 was prepared from the deleaded and desilvered BiCl3 solution by hydrolysis and conversion.