Etudes de la solubilisation du cuivre et cobalt contenu dans les anciens rejets de concentration des minerais de Tilwezembe à KZC

This study investigates the solubilization of copper and cobalt contained in historical tailings from the Tilwizembe ore, previously treated at the Kolwezi Concentrator (KZC) of Gécamines. The work aims to evaluate the potential of these tailings as a supplementary feed source for hydrometallurgical plants, notably the Shituru facilities. Leaching experiments were conducted on a representative tailings sample from KZC, assaying 1.17% Cu and 1.15% Co. Acid reductive leaching tests were performed by systematically varying key operating parameters: leaching time (30–120 min), pulp density (10–25% solids), temperature (25–60 °C), and sodium metabisulfite (SMBS) dosage (2–8 g) as reducing agent. The influence of each parameter on copper and cobalt dissolution yields was analyzed using standard hydrometallurgical evaluation criteria. Optimal conditions were obtained at 120 minutes of leaching, 60 °C, 15% solids, and 6 g SMBS, under which dissolution efficiencies of 84.8% for copper and 71.5% for cobalt were achieved. These results demonstrate that old Tilwizembe tailings constitute a technically viable secondary resource for Cu–Co recovery through acid reductive leaching, provided that operating conditions are appropriately optimized. The study contributes to the valorization of legacy tailings and supports the integration of such resources into existing metallurgical circuits to improve overall metal supply and resource efficiency.