Effect of potential on characteristics of surface film on natural chalcopyrite

Electrochemical behavior of natural chalcopyrite in electrolyte solution containing 5×10−4 mol/L ethyl xanthate, and the effect of potential on the composition and characteristics of surface film were studied by cyclic voltammetry (CV), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The adsorption of xanthate (X−) occurred on the mineral surface at open-circuit potential (OCP). In the potential range from −0.11 to 0.2 V, the electrochemical reaction related to the formation of the hydrorphobic film of dixanthogen (X2) occurred on natural chalcopyrite surface. This surface film had high coverage and large thickness at the potential of 0 V, but it had low coverage and small thickness at the potentials of 0.1 V and 0.2 V. Electrochemical activation started to occur when the potential was higher than 0.2 V, and the film of X2 transformed to plenty of Cu(II) and Fe(III) oxygen-containing species which had the porous and loose characteristics.