Electrochemistry of Galena in Hight Alkaline Flotation

Electrochemical behaviour is studied of galena in collectorless or collector flotation system,especially in high alkalinity media(pH=12.8). It has been shown that at pH12.5 and E h0.17 V,S 0 and HPbO 2 - are oxidation products on the surface of galena, and the former is excessive due to the latter's dissolution. The excess sulfur has hydrophobic effect, which is advantageous to galena flotation. At the same time, sphalerite and pyrite are depressed due to their overoxidation.Diethyldithiocarbamate(DDTC) is the most suitable collector for galena and the suitable potential at which DDTC and galena react each other to form PbD 2 ranges from 0 to 0.2 V. Moreover, DDTC can depress the surface overoxidation of galena surface. Also,the study has shown that in the range of -0.9 to 0.6 V,the hydrophobic PbD 2 can be firmly adsorbed on the surface of galena.