Leaching Kinetics of Zinc Sulfide Concentrate with Air-oxidation and Sulfuric Acid

A study on the oxidative leaching kinetics of zinc sulfide concentrate was carried out.The effects of the granularity of zinc sulfide concentrate,acidity,reaction temperature,catalyst quantity,leaching time on the comprehensive leaching ratio were determined.Under the optimal conditions,the comprehensive leaching rate of zinc may reach 98%.The leaching reaction is a typical oxido-reduction and the results show that the leaching process can be simulate with a shrinking core model.The leaching ratio is mixed controlled by the diffusion and reaction of chemistry.An empirical equation for the leaching kinetics is established,which is 1-(1-α)1/3= 8.07×10-7D-1-0.470.14exp(-11072/RT)t+B.It provides the theoretical basis for oxidative leaching zinc sulfide concentrate with air and sulfuric acid.The activation energy is 11.0727 kJ/mol calculated according to the Arrhenius equation.