Influence of mechanical activation on leaching kinetics of arsenopyrite

The influence of mechanical activation on the leaching kinetics of arsenopyrite was studied using a planetary centrifugal mill.It shows that mechanical activation can enhance the leaching process of arsenopyrite in a nitric-sulfate acidic solution.The leaching ratio within 20 min leaching time can increase from 2% to 80%～100%;10 and 20 minutes' activation can depress the apparent activation energy of leaching reaction from 54.5 kJ/mol to 39.0 kJ/mol and 34.0 kJ/mol,respectively.This means that the leaching reaction becomes little dependent on temperature,and arsenopyrite can change from refractory to flexible one;mechanical activation also increases the interplanar distance between crystal faces.The displacement of atoms from its equilibrium position indicates the increase in inner energy.