Effects of Different Grinding Media and Milling Conditions on the Flotation Performance of a Copper-Pyrite Ore

Abstract

Different milling conditions, such as wet or dry, and use of different grinding media have a great impact on the flotation performance of sulphide minerals. In the present study, the effects of wet and dry grinding and the use of different grinding media, such as mild steel (MS) and stainless steel (SS), were investigated on a Cu-sulphide ore. The samples were ground as dry and wet with both grinding media, to a P80 value of −75 µm, and then flotation was carried out under the same conditions. The obtained data from flotation were evaluated in terms of solid/water recovery, chalcopyrite/pyrite recovery and separation efficiency. The effects of different milling conditions were discussed with the measured chemical parameters such as redox potential and dissolved oxygen level together with the flotation rate of chalcopyrite. The redox potential of the dry ground ore, irrespective of the type of milling media, was measured considerably higher than the wet grinding conditions. With SS media flotation, the rate of Cu was high for dry grinding, resulting in a higher selective concentrate in terms of grade. However, Cu recovery was lower due to the instability of the froth structure. Separation efficiency pointed out that the best flotation performance could be obtained using a wet grinding condition with MS balls.