Recovery of manganese and zinc from waste Zn–C cell powder: Characterization and leaching

Abstract

A large number of waste Zn–C cells (Haquebrand) were broken down and collected as agglomerated powder. This powder was sun-dried, dry-ground and sieved down to 300mesh size and stored. The sample was analysed and found to contain (35.4±0.2)% Mn, (11.0±0.1)% Zn and ∼2.5% Fe as major metallic constituents. The phases, ZnMn2O4 and Zn(ClO4)2·2H2O or MnO(OH) were identified in the hot water washed sample. The material was found to be leached effectively by a 2mol/L sulfuric acid solution containing glucose (2g/L). However, the dissolution was dependent on (S/L) ratio; and the stage-wise leaching was not fruitful for Mn-dissolution. On leaching 5g of powder (<53μm) with a 250mL of 0.5g glucose containing 2mol/L sulfuric acid solution (S/L=20g/L), at 100°C and 300rpm for 1h, a solution containing (7.08±0.10)g/L Mn2+, (2.20±0.06) Zn2+ and ∼0.40g/L Fe3+ was recovered corresponding to cent percent dissolutions of Zn and Mn and 80% dissolution of Fe.