Effects of pulp electrochemistry on PGE flotation in sulphide poor ores

This work gives a reader basic knowledge about mineralogy and mineral processing. Main focus of this work was on flotation process and pulp electrochemistry on flotation. Three different sulphide poor ores are examined on experimental part. Platinum and palladium were the noble metals, which were contained into studied ores. Electrochemistry of flotation of PGE minerals on sulphide poor ores has been examined only slightly. Bench scale flotation test was used in this study. Chalcopyrite, nickel-pentlandite, pyrite, platinum and pH electrodes were used to investigation of pulp electrochemistry during flotation tests. Effects of grinding media, carbon dioxide atmosphere in grinding and mixture of carbon dioxide and air as flotation gas to PGE flotation and electrochemistry of flotation were studied. Stainless steel grinding media created more oxidising pulp environment to flotation than mild steel grinding media. Concentrate quality improved also with stainless steel grinding media, but the recovery was remarkably poorer, than with mild steel grinding media. Carbon dioxide atmosphere in grinding created very reducing pulp environment, which caused very good concentrate quality. But the recovery was again poorer than with normal mild steel grinding media. Mixture of carbon dioxide and air as flotation gas improved PGE recovery with some ores, but not always. Effect of carbon dioxide to pulp electrochemistry was detected mainly via pH-value.