Abstract
Reduction of zinc silicate concentrate by carbon was carried out at 950-1150 deg C for periods up to 3 h under nitrogen atmosphere with and without additives. The maximum extent of reduction amounts to 91% at 1100 deg C for 2 h in presence of 2% K sub 2 CO sub 3 . The collected zinc metal from the condensation of the volatilized zinc has a purity of 98.8%. The reaction mechanism was postulated and advocated by chemical and physical analysis. The reduction process under isothermal conditions fit the diffusion model [1-(1-x) exp 1/3 ] exp 3/2 and chemical reaction model 1-(1-x) exp 1/3 up to 80 and 70% reduction extents in absence and presence of K sub 2 CO sub 3 respectively. The activation energies was found to be 76 and 43 kcal.mole exp -1 for the two models respectively.