Leaching Behavior of Copper Sulfide Concentrate in Sulfate–Chloride Media With Hydrogen Peroxide and Ethylene Glycol

ABSTRACT The slow dissolution rate of copper sulfide minerals, particularly chalcopyrite, in sulfate‐based media is a significant challenge for efficient hydrometallurgical extraction. This study investigates the leaching behavior of Sungun Copper Concentrate (20.1% Cu) under sulfate‐chloride conditions, with the effects of sulfuric acid concentration, temperature, and chemical additives—namely chloride ions, hydrogen peroxide (H 2 O 2 ), and ethylene glycol. Experimental conditions included sulfuric acid concentrations of 0.5, 1, and 1.5 M, leaching temperatures of 21°C and 80°C. Temperature significantly enhanced the dissolution process, with copper recovery increasing from 12.1% at room temperature to 15.4% at 80°C. The introduction of 1 M sodium chloride induced a sulfate–chloride medium, disrupting the passivating sulfur layer on chalcopyrite, while hydrogen peroxide facilitated oxidation, achieving a copper recovery of 51.1%. At elevated temperatures, the rapid decomposition of hydrogen peroxide was stabilized with the addition of ethylene glycol, resulting in a further increase in copper recovery to 75.2%. The highest dissolution rate was achieved under optimized conditions of 1 M sulfuric acid, 1 M sodium chloride, 1 M hydrogen peroxide, 6 mL ethylene glycol, and 80°C. Kinetic analysis using the shrinking‐core model confirmed that the reaction was surface‐reaction‐controlled, with the apparent rate constant significantly enhanced by the presence of chloride ions and stabilized oxidants. These findings highlight the synergistic role of chloride ions and stabilized hydrogen peroxide in overcoming chalcopyrite passivation, improving leaching efficiency, and offering a sustainable approach for hydrometallurgical copper extraction.