Electrochemical effects of mineral-mineral interactions on the flotation of chalcopyrite and sphalerite

The role of mineral-mineral interactions on the flotation of chalcopyrite and sphalerite has been discussed with respect to different sulphide mineral combinations involving chalcopyrite, galena and sphalerite. Rest potential, combination potential and galvanic current measurements were made to understand the electrochemical behaviour of the above sulphide minerals when present individually and in different combinations. Galvanic interactions between a noble mineral such as chalcopyrite and active minerals such as galena and sphalerite significantly affect the floatability of the noble mineral, the effect on the active mineral being minimal. The deleterious effect of ageing of a single sulphide mineral, especially in the presence of oxygen, on its floatability could be minimized if it is present in galvanic combinations in a flotation medium. ESCA studies were carried out to identify the reaction products on the sulphide minerals after different types of mineral-mineral interactions. Probable electrochemical reaction mechanisms are outlined.