Abstract:Electrostatic separation is one of the mineral processing methods based on mineral conductivity. This method has some significant problems such as being sensitive to humidity, high middling product, and impurity of non-conductive minerals. In this study, a new pretreatment method was proposed for the separation of zircon from quartz before electrostatic separation to solve these disadvantages. In this regard, two stages of pretreatment were applied which involved using collector of sodium dodecyl sulfate (SDS) for adjusting wettability of the zircon surface and spraying electrolyte aqueous solution to increase conductivity of the quartz surface. The effects of important parameters including pH, collector concentration, conditioning time, and concentration and type of electrolyte on the process efficiency were evaluated. The results showed that the optimal conditions of high-tension electrical separation were pH of 4, SDS concentration of 1×10^-4 mol/L, conditioning time of 4 min and NaCl as an electrolyte with concentration of 4.27 mol/L. Separation efficiency of 95.12% was achieved in optimum conditions. This pretreatment method can be successfully used before high-tension electrical separation to separate the conductive or non-conductive minerals with various compositions.

Key words: zircon; quartz; collector; electrolyte aqueous solution; conductivity; high-tension electrical separation; surface treatment