Recovery of Copper from the Slag of Khatoonabad Flash Smelting Furnace by Flotation Method

Copper loss in the slag of Khatoonabad flash smelting furnace is estimated to be about 1–3 %. At present, the electric slag cleaning furnace is used for the recovery of copper from slag. However, due to low recovery efficiency of electric furnace along with high consumption of electrical energy and water, selection of a method to enable minimum energy consumption and maximum recovery of copper seems to be essential. Therefore, the aim of this study was to investigate the possibility of copper recovery from this slag using flotation method, and to determine the effective parameters involved in the process. Based on the experiments conducted, the best results were obtained for pH 11.5, 60 g/t Z11 and R407 collectors with a weighing ratio of 3–2, 40 g/t of MIBC and A65 frothers with an equal weighting ratio and grinding time of 45 min. Under these conditions, the copper concentrate grade and recovery were 19 and 91.1 % in the rougher step, 27.4 and 96.3 % in the cleaner step, and 32 and 93 % in the recleaner step, respectively. © 2013, The Institution of Engineers (India).