Activation of quartz flotation by Cu2+, Ni2+ in the sodium ethylxanthogenate (EX) system

Abstract

During the flotation of metal sulfide minerals, due to the interference of unavoidable ions, the quartz also partially floats in some cases. The research on the mechanism of quartz being activated and floating up is still insufficient. In this study, the influence of unavoidable ions Cu2+ and Ni2+ on the floatation of quartz was studied by micro-flotation experiments, adsorption detection, zeta potential measurement, solution composition calculation, infrared spectroscopy (FT-IR) analysis, X-ray photoelectron spectroscopy (XPS) analysis, and atomic force microscopy (AFM) observation. This provides a theoretical reference for further understanding the mechanism of sodium ethylxanthogenate and quartz surface, as well as the development of new quartz depressant. The results of flotation showed that after activation by Cu2+(1×10-4 mol/L) and Ni2+(5×10-5 mol/L), quartz was captured by sodium ethylxanthogenate (EX:1.4×10-4 mol/L) under alkaline conditions, while the best recoveries were 80% and 43%, respectively. The results of adsorption measurement and Zeta potential measurement showed that the precipitation rate of Cu2+ was greater than that of Ni2+ under alkaline conditions. In addition, both Cu2+ and Ni2+ were electrostatically adsorbed on the quartz surface and changed the Zeta potential of quartz. The solution composition calculation further showed that Cu(OH)+, Cu(OH)2(s), and Ni(OH)+, Ni(OH)2(s) were the main components in the solution under alkaline conditions. FT-IR analysis, XPS analysis, and AFM observations revealed that Cu species and Ni species were adsorbed on O atoms on the quartz surface, providing active sites for EX adsorption.