Abstract:

Aiming at the characteristics of high stibium and bismuth content in lead anode mud，to overcome the disadvantage of analysis of silver by conventional AgCl gravimetry，several precipitation conditions for AgCl in tartaric acid-PbCl2-HNO3 system were investigated in this work.The results showed that AgCl can be precipitated completely when PbCl2 was used as coprecipitator，the concentration of tartaric acid was more than 15% in nitric acid solution and temperature was 70 ℃ for 30 min.This method eliminated the interference of copper，stibium and bismuth that exist with great quantity in lead anode mud.It was a rapid and accurate method，and the results was in accord with the fire assay’s.The proposed method was simple and low cost and suitable to determine silver whose content was more than 5% and coexisted in lead anode mud with high content of stibium and bismuth.

Key words: PbCl2, AgCl, coprecipitation, lead anode mud, silver, gravimetric method