Dissolution of mechanically activated sphalerite in the wet and dry milling conditions

The aim of this work has been to examine the effect of intensive ball milling of sphalerite in the wet and dry modes on the microstructural changes and the subsequent effect on its dissolution rate. Sample characterization showed that the BET surface area and the amorphization degree were obtained to 18.2 m(2)/g and 78.92% in the wet mode and 7.72 m(2)/g and 90.35% in the dry mode milling after 180 min, respectively. The maximum extraction of Zn obtained 23.7, 67.12 and 85% in the unmilled, wet and dry milled samples, respectively. The ratio of kinetic rate constant has been increased by 37 and 67 times, respectively. Also, the activation energy was decreased with increasing of milling time. Selectivity of sphalerite leaching versus surface area was obtained higher than that of the wet milling. Leaching experiments indicated that structural disordering had a drastic effect on the reactivity of mechanically activated sphalerite. (C) 2021 Elsevier B.V. All rights reserved.