Sulphuric acid leaching of zinc and copper from Nigerian complex sulphide ore in the presence of hydrogen peroxide

The lea ching of zinc and copper from Nigerian bulk sulphide ore with sulphuric acid in the presence of hydrogen peroxide was studied. The aim of the study was to investigate the effectiveness of hydrogen peroxide as an oxidant for the sulphuric acid leaching of zinc and copper from a complex sulphide ore. Distribution of elementals within the various particle sizes was initially determined by ICP-OES and XRF to provide a basis for explaining the dissolution process. The effects of concentration of hydrogen peroxide, particle size, stirring speed, and leaching time at a constant temperature of 298K were studied. There were variations in elemental and mineralogical composition within the different sizes. The concentrations of zinc and copper reduced as particle size decreased while silica, sulphur, iron and lead contents increased. Dissolution results showed that the leaching rate of copper was lower, than that of zinc. The highest recoveries of zinc and copper were obtained at a leaching time of 180 minutes, stirring speed of 160 rpm, particle size of 75 pm and a concentration of 1M H(2)SO4/1M H2O2. it was observed that the leaching rate of zinc and copper increased with increasing hydrogen peroxide concentration. increased stirring speed had a negative leaching effect as it promotes hydrogen peroxide decomposition.