Manganese recycling from zinc anode slime via SO2 reductive leaching in an integrated copper–zinc hydrometallurgical plant

Manganese is essential for zinc electrowinning but its recycling is challenging in oxide ore SX-EW circuits where P204 rejects Mn. This study proposes a novel manganese recycling strategy tailored for SX-EW streams involving the selective SO 2 reductive leaching of zinc anode slime followed by impurity removal. By controlling leaching pH at 5.0 with lime, Mn recovery > 92% while Fe, Ni, Co co-dissolution is suppressed to < 1%, 3%, 12% respectively. Residual impurities in the spent electrolyte are further removed by neutralization and DMDTC chelation. This integrated process effectively recovers manganese while simultaneously eliminating harmful impurities (Cu, Fe, Co, Ni), offering a sustainable solution for Mn management in complex oxide ore hydrometallurgy. The purified electrolyte enabled production of Grade #1 zinc with Pb < 0.005%.