Selective depression of talc in chalcopyrite flotation by xanthan gum: Flotation response and adsorption mechanism

摘要

Being a common gangue mineral in many sulfide deposits, naturally hydrophobic talc needs to be depressed by adding depressants. In this paper, xanthan gum was introduced as a selective depressant for talc. The effect of xanthan gum on the flotation separation of chalcopyrite from talc has been studied, and the interaction me- chanism between xanthan gum and talc has been investigated. Micro -flotation results show that xanthan gum severely depresses talc flotation but barely affects chalcopyrite flotation at pH 8. In artificially mixed minerals flotation, a concentrate containing 31.87% Cu can be obtained at 90.03% Cu recovery from a feed of 16.94% Cu, indicating xanthan gum as a selective depressant. The effect of xanthan gum was also verified by the real ore flotation tests. The zeta potential measurements and adsorption measurements indicate that xanthan gum se- lectively adsorbs on talc surface. The results of XPS measurements and adsorption measurements illustrate that the adsorption of xanthan gum on talc surface occurs through physical interaction and hydrophobic interaction is considered as the main driving force. AFM images show that xanthan gum adsorbs on talc surface in a network structure with a layer thickness of 5.4 nm and coverage of 53.57%.