Effect of Galvanic Interactions Between Grinding Media and Sulfide Minerals on Flotation Kinetics of Chalcopyrite

Although the flotation separation of sulfides and their electrochemical interactions have been examined in some investigations, study the direct relationship between the flotation kinetics of sulfides and their galvanic interactions during the process yet has not been addressed. To fill this gap, an extensive study was conducted to explore the effect of galvanic interactions for chalcopyrite and pyrite on their flotation kinetics when they are wetting ground by three different grinding media types (steel, chromium, and ceramic). Assessment of the flotation test results indicated that there was no galvanic interaction between the ceramic grinding balls and chalcopyrite. The galvanic interactions were mostly related to the grinding of chalcopyrite by steel balls. EDTA analysis showed that by increasing the amount of iron oxy/hydroxy and their precipitations on the surface of chalcopyrite, the recovery of chalcopyrite was decreased. Furthermore, increasing the pyrite content in the flotation of chalcopyrite increased the flotation rate constant and then decreased it. Flotation tests demonstrated that grinding chalcopyrite by ceramic media type, which has lower electrochemical activity in comparison with the other considered media, can be resulted in a higher flotation rate constant and ultimate recovery. Grinding the mixture of chalcopyrite and pyrite by steel or chromium media can show almost the same effect on the flotation rate constant and ultimate recovery. In general, the experimental results showed that by increasing the galvanic interaction, the flotation recovery and flotation kinetics were decreased.