Effect of Bi3+ Addition on Hydrogen Reduction of Acidic Cupric Sulfate Solution.

The reduction rate of cupric sulfate solution with hydrogen was catalytically enhanced by addition of 0.5g/l Bi3+. The catalytic effect of Bi3+was remarkable at high sulfuric acid concentration.Without Bi3+ addition, the reduction curves seem to be consisted of two segment, an initial stage with faster reduction rate and a later stage with very slow rate.After nucleation of copper, Cu2S is begun to form on copper surface, and when copper particles are covered with Cu2S, the reduction rate becomes very slow, and a long reaction time is required to complete the reduction.By addition of Bi3+, formation of Cu2S is supressed and also the reduction rate after nucleation is accelerated by addition of Bi3+.