Surface sulfidization mechanism of cuprite and its response to xanthate adsorption and flotation performance

Abstract The flotation recovery of cuprite is unsatisfactory because of its natural hydrophilic surface, which decreases the flotation index of copper concentrate. One can modify the cuprite surface by sulfidization to create a hydrophobic surface that is more favorable for flotation. Therefore, it is necessary to reveal the surface sulfidization mechanism of cuprite to efficiently recover cuprite resources. In this work, we used Na2S to modify the cuprite surface and enhance the floatability of cuprite. Micro-flotation tests indicated that Na2S either enhanced or hindered the floatability of cuprite, depending on the quantity of Na2S. Analogously, surface adsorption measurements, zeta potential tests, and infrared spectroscopy analyses indicated that Na2S either enhanced or hindered the adsorption of xanthate on the cuprite surface, depending on the quantity of Na2S. X-ray photoelectron spectroscopy analyses and localized electrochemical impedance spectroscopy measurements indicated that more copper sulfide species formed on the cuprite surface in accordance with increasing Na2S concentration. Thus, an appropriate quantity of Na2S improves the flotation recovery of cuprite, whereas excessive Na2S lessens the flotation recovery of cuprite.