Direct Reduction of Zinc Sulfide

The direct reduction of ZnS by C and CaO and catalystic effect of Na2CO3, Na2SO4 and Fe2O3 were studied by the thermogravimetry and measurement of the generated CO and CO2 in the temperature range 900-1100°C. The mechanism of the direct reduction was investigated by thermodynamic data and characterizing the residues at various conditions of the direct reduction by x-Ray diffraction and XMA.The overall reaction of direct reduction is represented by the equation (1).ZnS+CaO+C=ZnO+CaS+CO...(1)It is conside-red that the equation (1) is divided into the following three elementary reactions and the equation (2) is the ratedetermining reaction of direct reduction.ZnS+CaO=ZnO+CaS...(2)ZnO+C=Zn+CO...(3)ZnO+CO=Zn+CO2...(4)The small amount of addition of Na2CO3, Na2SO4 and Fe2O3 (about 1 wt%) to samples of direct reduction is very effective for activating the direct reduction due to accelerating the equation (2).