X-RAY PHOTOELECTRON SPECTROSCOPIC AND ELECTROCHEMICAL STUDIES OF THE INTERACTION OF XANTHATE WITH GALENA IN RELATION TO THE MECHANISM PROPOSED BY PAGE AND HAZELL

X-ray photoelectron spectroscopic (XPS) and electrochemical studies have been carried out on the interaction of galena with xanthate in the presence of oxygen in order to assess the conclusion reached by Page and Hazell (1989) that interaction only occurs after prior oxidation of the mineral surface. Electrochemical measurements of the rate of oxygen reduction on galena and a review of previously reported work on this process have shown, in contradiction to the claim of Page and Hazell, that oxygen reduction is sufficiently rapid to support the anodic oxidation of xanthate to give rise to monolayer coverage at time scales well within the range relevant to flotation. XPS investigations of fresh galena surfaces created by fracture under amyl or ethyl xanthate solutions in equilibrium with air confirm that xanthate interacts with the mineral surface. The initial xanthate monolayer has been found to have properties different from those of multilayer lead xanthate on lead or galena surfaces. © 1990.