Electrochemical and Raman spectroscopic studies of the interaction of ethyl xanthate with Pd–Bi–Te

Previous mineralogical investigations (QemSCAN) performed on all effluent flotation streams of Mimosa mine indicated the presence of appreciable amounts of platinum group minerals (PGMs), which are not recovered. Most of the liberated PGMs in these streams belonged to the Pt–Pd–Bi–Te class, generally in excess of 70%, in all the samples investigated. In this work, electrochemical investigations and Raman spectroscopy have been employed to investigate the interaction of ethyl xanthate with Pd–Bi–Te. Raman spectroscopy has confirmed the co-presence of xanthate with dixanthogen indicating that xanthate retains its molecular integrity when it adsorbs on the surface of the Pd–Bi–Te. The result of this investigation has shown dixanthogen to be present on the mineral when its surface is anodically polarized. This suggests that the poor flotation recovery of the Pd–Bi–Te minerals from flotation feeds cannot be attributed to a lack of interaction of the collector with the surface.