Comprehensive recovery of zinc, iron and copper from copper slag by co-roasting with SO2-O2

In this study, a novel method to recover copper, zinc and iron from copper slag by SO2-O-2 roasting-leaching-magnetic separation was proposed. The effect of roasting experiment conditions were roasting temperature of 900 degrees C, holding time of 120 min, and phi(SO2) (The volume fraction of SO2 in the mixed gas of SO2 and O-2) of 90%. Under the leaching conditions of leaching temperature 80 degrees C, leaching time 1 h, liquid-solid ratio 14:1, and pH 7, 91.03% of copper and 85.04% of zinc can be recycled respectively. The iron in the leaching residue can be enriched and recovered by magnetic separation at a magnetic field strength of 3000 Gs for 40 min. The iron recovery rate is 85.88% with 53.86% of the iron grade in the concentrate. (C) 2022 Published by Elsevier B.V.