Leaching of Copper from Malachite with Methane-sulfonic Acid

The process of leaching copper from malachite using methane-sulfonic acid (MSA) as an organic leaching reagent was investigated in this study. The effects of acid concentration, reaction temperature, particle size, and stirring speed on the copper leaching fraction were determined. Results indicated that leaching reagent concentration and reaction temperature exerted significant effects on copper extraction, whereas particle size and stirring speed exerted a relatively minor effect on the leaching rate. The kinetics of the dissolution process followed the shrinking core model, and a new kinetic model was found suitable to represent the rate-controlling step. The apparent activation energy of this process was determined to be 24.48 kJ/mol, and a semi-empirical rate equation was obtained to describe the process.