Raman spectroscopy characterization of some Cu, Fe and Zn sulfides and their relevant surface chemical species for flotation

Raman spectroscopy as a high-resolution characterization technique was used to analyze various pure metal sulfides immersed in water, namely pyrite (FeS2), chalcopyrite (CuFeS2), sphalerite (ZnS), marmatite (Zn1-XFeXS) and galena (PbS). The Raman characterization was undertaken in situ with the minerals immersed in water. Characteristic Raman spectrum that shows the vibrational modes of the atomic bonds in the mineral crystal structure is reported. This spectroscopic technique revealed that marmatite particles are composed of micro-size, perhaps nano-size, zones with different Fe and Zn content. With the intensity of the Fe-S and Zn-S Raman signals, the iron content of the zones was quantified. The copper ion up-take by marmatite particles was studied through this technique. It was found that the up-take of copper ions on the marmatite zones depended on their Fe content. Copper ion up-take occurred more preferentially on the zones of low Fe content than on those of high Fe content. The adsorption of the collector propyl xanthate on pyrite and chalcopyrite was also assessed by Raman spectroscopy. The Raman spectrum revealed that dixanthogen formed on the surface of these sulfides.