Recovery of iron from lead-zinc metallurgical slags by bath smelting

Abstract

The recovery of iron from iron sinking slag and lead smelter slag was investigated by desulfurization-reduction bath smelting. The effects of lead smelter slag (LSS) to iron sinking slag (ISS) mass ratio and temperature were investigated in desulfurization experiments. The X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses show that the optimum conditions are LSS:ISS of 3:7 and temperature of 1350°C. The composition of desulfurization products is mainly ZnFe2O4, and the desulfurization rate of 99.66% is obtained under optimum conditions. The thermogravimetric (TG) and differential scanning calorimeter (DSC) analyses demonstrate that reductant is necessary for decomposition and reduction of zinc ferrite in desulfurization product. The effects of reductant, temperature and feeding modes on iron enrichment were investigated in reduction experiments. The scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) determination show that the iron content of reduction product is up to 99.36% under optimum conditions of coke as reductant, reduction temperature of 1450°C and the feeding mode of premixing.