Acid leaching behavior of sulfide and oxide minerals determined by electrochemical polarization measurements

Potentiostatic anodic and cathodic polarization curves have been obtained for numerous sulfide and oxide minerals in 1N sulfuric and hydrochloric at ambient temperature and 90°C. Polarization curves are compared in this paper for varius minerals to show the effects of acid composition and temperature on predicted leaching rates. Predictions generally agree with published experience for both oxidizing and reducing conditions. Polarization curves combined for various mineral pairs show practical effect of galvanic interactions as a function of acid type, temperature, and relative surface area. Applications and limitations of the method are discussed.