National University of Science and Technology “MISiS”, Moscow, Russia:

B. E. Goryachev, Professor, Department of Mineral Processing and Technogenic Raw Materials
A. A. Nikolaev, Associate Professor, Department of Mineral Processing and Technogenic Raw Materials, e-mail: nikolaevopr@mail.ru
Kyaw Zay Ya, Postgraduate student, Department of Mineral Processing and Technogenic Raw Materials
A. A. Morgun, M. D. in Metallurgy, Department of Mineral Processing and Technogenic Raw Materials

The results of thermodynamic calculations for sphalerite surface acting with thiol collectors in alkaline solutions are presented. Potassium butyl xanthate and sodium dibutyl dithiophosphate were chosen as widely used collectors for flotation of copper-zinc and polymetallic ores. Interconnection of thiol collectors were analyzed with special attention to non-activated and activated by copper ions sphalerite. The hydrophilic/hydrophobic surface compounds that are formed on sphalerite surface at pH = 8–12 in the range of collector ions concentrations and oxidation-reduction potential were determined. It brings to better understanding the reasons for insufficient flotation of sphalerite in rough and differential flotation circuits, and improving metal recovery and concentrating grade. At the initial oxidation of sulphide sulpur to elemental state in slightly alkaline conditions there was now interactions of collector ions with non-activated sphalerite surface observed. The potentiometric studies of sphalerite electrode in slightly alkaline water solutions of thiol collectors were carried out. Copper sulphate solutions were used as activator reagents. It was established that the electrode potential of sphalerite electrode changed depending on the concentration of both xanthate and dithiophosphate ions. The results indicate that ions of both thiol collectors are potential-determining for sphalerite. The experimentally established functional connections for sphalerite electrode either unactivated or activated by copper ions, revealed that there were conditions for sphalerite interaction with dibutyldithiophosphate ions in spite of the absence in the literature of value for ion product of zinc dibutyldithiophosphate.

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