<Contribution>Electrolytic Refining of Lead by Sulfamate Bath

R. Piontelli and F.C. Mathers stated that lead was electrolytically refined in the Sulfamate bath. We studied conditions of electrolysis, addition agents and the separation of tin in comparison with the Betts process, and found that it was suitable to operate with the bath containing Pb in 80 g/l, acid in 50～100g/l, and to choose as addition agents, 0.01% β-naphthol and 0.01% glue. We also discovered that in the sulfamate bath a better deposits could be produced than in the case of Betts process by treating with a low grade anode, but the separation of tin was not accomplished so well as Piontelli advocated. We obtained the consumption rate of power, addition agents, and acid in operating 20T/M pilot plant. The results of these experiments lead us to believe that the sulfamate method can be compared favorably with Betts process when the sulfamic acid can be easily obtained