Potential control flotation of galena in strong alkaline media

Abstract

The electrochemical oxidation of galena in collectorless and collector flotation systems, particularly in strong alkaline media, was studied. The results show that, with pH value higher than 12.5 and potentials below 0.17 V, the oxidation products of galena are elemental sulfur and HPbO₂⁻. Elemental sulfur was present on the mineral surface in excess of oxidized lead species due to dissolution of HPbO₂⁻, which is beneficial to the flotation of galena. Under the same conditions, sphalerite and pyrite were depressed as a result of significant surface oxidation. Diethyldithiocarbamate (DDTC) was found to be the most suitable collector for galena flotation in strongly alkaline media. The very potential produced hydrophobic PbD₂—the surface reaction product of DDTC with galena, is 0 to 0.2 V. Meantime DDTC can depress the surface over-oxidation of galena. Investigations also indicate that, in the range of − 0.9 V to 0.6 V, hydrophobic PbD₂ can be firmly adsorbed on galena.

Keywords

galena / potential control flotation / collector

References

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