Effect of copper and iron ions on the sulphidizing floatation of copper in copper smelting slag

Abstract

This study investigates the influence of Na2S, CuSO4 and FeCl3 on sulphidizing floatation of copper in copper smelting slag. The results show that copper has a good floatability, independent of the addition of Na2S and Cu2 + ions, while Fe3+ inhibits the floatation. In the pH range between 2 and 4, in conditions with Na2S and Cu2 + ions addition, the recovery rate of metal copper rapidly increased and maintained the high level. But the inhibition effect of Fe3+ was enhanced with the increasing of the concentration. Further analysis shows that the Cu2+ and Fe3+ both enhance the surface potential, but with addition of Na2S, Fe3+ and Cu2+ get an opposite effect. Sodium sulfide would formed polysulfide, Monosulfides and polysulfides on solid surface. The addition of Cu2+ would not increase the adsorption amount of S2p on Cu surface and Fe3+ would not only oxidized sulfur ions thus reduce the adsorption and change the valence state of sulfur, but also oxidized metallic copper.