Electrochemical behaviour of sulphide minerals under open circuit conditions

The following galvanic series increasing activity, holds in a 2.0 pH H2SO4 medium: pyrite, molybdenite, chalcopyrite, sphalerite, pyrrhotite, galena. Based on the combination potential values, the probable anodic (oxidation) reaction in a bimineral contact is predicted. When 2 sulfide minerals are in contact, the active mineral undergoes oxidation resulting in the formation of corroded surfaces as is observed by SEM. The galvanic current in a bimineral couple depends on the p.d. between the anode and the cathode