THE INVESTIGATION OF SULFIDE MINERAL FLOTATION REAGENT ADSORPTION USING RAMAN SPECTROSCOPY AND ELECTROCHEMISTRY

Abstract: The interaction of flotation reagents with metal and mineral surfaces have been studied with electrochemistry and Raman spectroscopy. Flotation reagents are used to selectively recover valuable minerals (typically particles about 10 microns in diameter) and to suppress the froth flotation of unwanted components by altering the hydrophobicity of the mineral surface. They are added to the mineral processing circuit and are pre-sent throughout the processing system. The predominant collectors used in the froth flotation proc-ess for sulfide minerals are alkyl dithiocarbonates (xanthates ROCS2) and similar thio compounds. The reagents adsorb onto mineral surfaces at sub-monolayer levels and can be “tailored ” by altering the R group. Xanthate-mineral interaction occurs by an electrochemical mechanism in which the anodic oxidation of the collector is coupled with the reduction of oxygen at the mineral surface. It has been shown electrochemically [1] that anodic oxidation of xanthate can result in chemisorption of a xanthate radical, and/or dimerization to form dixanthogen. SERS has enabled collection of direct chemical evidence of reagent interaction with copper, silver and gold surfaces under potential control. This data is directly comparable to the behavior of mineral particles in the flotation process, where the surface potential is controlled by a combination of oxygen concentra