Behavior and Study of the Kinetics Aspects of Hydrothermal Leaching Conducted on Thermal Activated Products of Complex Polymetallic Secondary Sulfide Concentrate

The utilization of complex polymetallic secondary sulfide concentrate (CPSSC) is challenging due to its unique structure and composition. This study aims to investigate the effects of thermal activation and hydrothermal leaching on CPSSC to enhance copper extraction. Initially, CPSSC was subjected to roasting, followed by hydrothermal leaching under oxygen pressure with water. Characterization of the mineral phase structure and morphology of the activated products and leached residues was performed using XRD and SEM-EDS. The results indicated that optimal conditions for hydrothermal leaching of the roasting activated CPSSC include leaching temperatures of 185°C, oxygen partial pressure of 0.6 MPa, liquid-to-solid ratio of 12.5:1, and stirring rate of 600 r/min. Under these conditions, the transfer of iron and lead occurred predominantly, remaining in the leached residue as iron oxide and lead sulfate, while the copper leaching rate reached 95.73%. Kinetic analysis revealed that the copper extraction process follows a chemical reaction control model, with activation energy determined to be 41.98 kJ/mol via the Arrhenius equation.