The cementation of lead from ammoniacal ammonium sulphate solution

Due to increasingly stringent SO2 emissions legislation, there have been numerous research efforts to find a hydrometallurgical replacement for lead-acid battery smelter recycling operations. One promising possibility is the use of ammoniacal ammonium sulphate (AAS) solution to dissolve the lead sulphate found in used battery pastes. This paper examines the possibility of recovering metallic Pb from AAS solution via cementation, using Ni powder as the reductant. The highest recovery rates were achieved with high (17 mol/l) ammonium hydroxide and moderate (2 mol/l) ammonium sulphate concentrations. Below 135 degrees C, reaction kinetics are rate-controlling and above 135 degrees C, diffusion is rate-controlling. (C) 1998 Elsevier Science B.V.