Selective flotation of Cu-Mo sulfides using xanthan gum as a novel depressant

•Selective flotation of chalcopyrite and molybdenite was achieved by XG.•XG mainly adsorbed on molybdenite surface other than that of chalcopyrite.•XG was more environment friendly compared to conventional copper depressant. Molybdenite and chalcopyrite is generally separated through the selective depression of chalcopyrite using potentially toxic depressants such as sodium sulfide and cyanides. In this work, xanthan gum (XG), a polymer polysaccharide, was investigated as a potential molybdenite depressant in copper-molybdenum sulfides separation. Single mineral flotation tests indicated that molybdenite could be effectively depressed by XG, while chalcopyrite was slightly affected. The artificial mixed minerals flotation tests proved that molybdenite and chalcopyrite could be selectively separated with the addition of XG. The adsorption mechanism was studied through zeta potential and infrared spectroscopy measurements. The results revealed that XG mainly adsorbed on molybdenite surfaces other than chalcopyrite. In a word, the experiments results illustrated that XG could be applied as a promising depressant in the selective flotation separation of molybdenite and chalcopyrite, which has the advantage of environment compatibility over conventional copper depressants.