Effect of electrochemical interactions among sulfide minerals and grinding medium on chalcopyrite flotation

The effect of galvanic interactions among sulfide minerals such as chalcopyrite, galena, and sphalerite in the presence and absence of a grinding ball material on the flotation recovery of chalcopyrite has been studied. X-ray photoelectron spectroscopy (ESCA) studies were carried out to identify the reaction products on the sulfide minerals after different apes of galvanic interactions. Galvanic contact with active minerals such as galena and sphalerite, either alone or together, significantly affected the floatability of chalcopyrite mineral, such an effect being more severely felt in the additional presence of a grinding medium as well as oxygen. Surface analysis studies revealed the presence of oxyhydroxide species of iron on all the sulfide mineral samples which were in prior contact with the grinding medium. The formation of such oxyhydroxide species of iron was found to be dependant on the relative electrochemical activity of the mineral. Probable electrochemical reaction mechanisms are discussed.