Surface potential and wettability of enargite in potassium amyl xanthate solution

The voltammetric, ultraviolet techniques and contact angle measurements were used to investigate the oxidation of xanthate and the reduction of dixanthogen on synthetic and natural enargite electrodes which were kept under a fixed potential. The effect of applied potential on the enargite electrode surface in potassium amyl xanthate (PAX) solutions at pH 10 and 7 was investigated by contact angle measurement after the electrodes were conditioned for 10 min. The effect of PAX concentration on enargite floatable potential range was also studied. The hydrophobic film on the enargite surface was extracted using hexane and examined by ultraviolet spectroscopy. The results indicate that the hydrophobic film on the enargite surface in PAX solution was dixanthogen, and it began to form on the enargite electrode surface in 7×10−4 M PAX solution from −0.2 V vs. Standard Calomel Electrode at pH 10 and from −0.275 V vs. Standard Calomel Electrode at pH 7. The floatable potential range of enargite was 60–70 mV narrower in 7×10−5 M PAX solution than in 7×10−4 M PAX solution. The potential needed to reduce dixanthogen on enargite surface was as low as −0.6 V vs. Standard Calomel Electrode.