A Raman Spectroscopic Investigation of Pyrite Oxidation and Flotation Reagent Interaction

Abstract

The oxidation of pyrite and the interaction of flotation collectors, xanthate and hydroxamate, with the pyrite surface were investigated via normal- and surface-enhanced Raman scattering (SERS) techniques. SERS was facilitated via vapour deposition of a discontinuous gold island film or through the application of silver colloids to the pyrite surface. The oxidation of pyrite produced a Raman-inactive solid phase, in addition to octasulfur. 442 nm irradiation could induce the formation of polymeric sulfur from the pyrite oxidation product. Dixanthogen was the major species present on pyrite conditioned with xanthate solutions under oxidizing conditions, although a bound xanthate species was also evident, particularly at reducing potentials. The interaction of hydroxamate with pyrite under oxidizing conditions produced a ferric hydroxamate compound