Flotation study of oxide zinc ore using cationic-anionic mixed collectors

A representative sample of zinc oxide from Dashteh Sefid mine was obtained and then mineral characterization studies were done. The results of mineralogical analysis showed that the main zinc-bearing minerals are smithsonite, hemimorphite and gangue minerals are quartz and dolomite. In the present paper, the effect of important factors including sodium sulfide, collector type (AC and AC/KAX), collector amount, sodium silicate, CMC dosage and frother type (MIBC and pine oil) were investigated. Design of experiment was carried out by the means of Design Expert 7 using Fractional Factorial 26–1. The results indicated that collector type, collector amount, CMC and frother dosage were the most effective factors controlling the zinc flotation recovery. For the zinc grade, it was found that all six parameters play a significant role. The maximum recovery and grade of zinc obtained 97.71% and 10.39% under the following optimum conditions: sodium sulfide, 5935.23 g/t; collector type, AC/KAX; collector amount, 654.09; sodium silicate, 300; CMC dosage, 600; frother type, MIBC. The result of two-stage cleaner flotation showed that zinc grade could be increased up to 16.2% with zinc recovery of 61.39%.