SURFACE CHEMISTRY OF THE LOCKED PARTICLES FOR SULPHIDE MINERALS

The electrochemical methods have been used in flotation of sulphide minerals by utilizing the semiconductor properties of the minerals. Electrochemistry is one of the tools that can be preferred to identify problems in flotation systems faster and to achieve more effective flotation results. In this study, some of the electrochemical methods such as open circuit potential (OCP), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used to determine the galvanic interactions between locked and liberated sulphide particles. As it was assumed that the surface area of the sulphide minerals effects the flotation characteristics, some mineral electrodes were prepared to simulate this phenomenon. For this purpose, a three-electrode system was set up to investigate the electrochemical responses of galena-pyrite (0.52 cm²), pure galena (0.20 cm²) and pure pyrite (0.18 cm²) minerals. The tests were carried out in a buffer solution at pH 9.2. The changes of the surface chemistry of the minerals, with (10^-4 M NaEX) and without collector, were also examined. During the process, charge transitions between the minerals were occurred due to the galvanic interactions regardless of the surface area and changed the flotation behavior of these minerals by reducing and oxidizing each other.