Study on vacuum carbothermic reduction kinetics of hemimorphite catalyzed by calcium fluoride

The kinetics of the vacuum carbothermic reduction of hemimorphite was studied with CaF2 as catalysis in the temperature range of 1273-1423 K. The results showed that the zinc reduction rate could be enhanced by increasing the adding weight of CaF2, initial moles ratio of C/Zntotal or the reaction temperature. And the zinc reduction rate would decrease with the increasing of either the average particles size of hemimorphitethe or the system pressure when it was higher than 20 kPa. It could be inferred that the reduction reaction was controlled by the surface reaction with the activation energy of 164.82 kJ/mol by solid-solid reaction model.