Kinetics of Copper Removal from Sulfidized Molybdenite Concentrates by Pressure Leaching

Molybdenite concentrates produced from porphyry copper deposits often contain copper as an impurity, necessitating purification for high-grade output. This study aims to explore a new method for copper elimination from molybdenite concentrates with chalcopyrite. The methodology involves the sulfidation of the molybdenite concentrate followed by pressure leaching in sulfuric acid-oxygen media. Results demonstrate that copper can be effectively dissolved from sulfidized molybdenite concentrates at low temperatures (373 K to 423 K) and low oxygen pressures, achieving a final copper content of less than 0.2 pct, suitable for market standards. The study reveals that both temperature and oxygen partial pressure significantly influence copper dissolution. Kinetic analysis through the shrinking core model indicates that the copper dissolution process is controlled by surface chemistry, with an activation energy of 51 kJ/mol in the specified temperature range. Additionally, the dissolution rate is determined to be zero-order in relation to hydrogen ion concentration and first-order with respect to oxygen partial pressure.