| Based on the summary of the investigations on the leaching process ofindium, hard-zinc as well as the application of mechanical activation innon-ferrous metallurgy, kinetics of leaching indium from hard-zinc withhydrochloric acid with mechanically activation by stirring mill and planetarymill is studied. The subject investigated is hard-zinc, which has two differentpartcle size distribution. From the experiments, conclusions can be drawn asfollow:①Chemical activity was increased and reaction rate was improved afteractivated by stirring mill and planetary mill. For the hard-zinc with particle sizedistribution of 0.175～0.370 mm, after activated 30 minutes and 60 minutes bystirring mill, apparent activation energy was decreased from 24.51 kJ/mol to13.90 kJ/mol and 11.40 kJ/mol, respectively. The reaction order was decreasedfrom 0.39 to 0.36 and 0.22, respectively. After activated 1 hours and 2 hours byplanetary mill, apparent activation energy was decreased to 17.51 kJ/mol and 14.67 kJ/mol, respectively. The reaction rate was decreased to 0.28 and 0.26,respectively. For the other partical hard-zinc with particle size distribution of0.121～0.175 mm, after activated 1 hour by stirring mill and planetary millrespectively, apparent activation was decreased from 19.33 kJ/mol to 14.91kJ/mol and 18.01 kJ/mol, respectively. The reaction order was decreased from0.45 to 0.40 and 0.35, respectively.②The activation effect of stirring mill is better than the one of planetarymill under the same rotate speed, proportion of ball and material, and activationtime.③The partical size was decreased after activated by stirring mill andplanetary mill, which resulted in the apparent activation being decreased 7.28kJ/mol and 3.59 kJ/mol and reaction order 0.01 and 0.02.④Constrast the non-activated hard-zinc, activated hard-zinc can takeplace under lower temperature or in the process of mechanical activation.
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