Hydrometallurgical Treatment of Lead Concentrates for the Recovery of Valuable Metals

Abstract

Metals play a critical role in electricity, industrialization, and medicine, but their effective recovery from ores while removing impurities remains a challenge. This thesis, titled ’Hydrometallurgical Treatment of Lead Concentrates for the Recovery and Separation of Valuable Metals, tends to focus on the selective leaching of PbS concentrate to recover valuable metals and associated metals. Two different sets of experiments were performed under different conditions of temperature, acid concentration. The first experiment utilized a pressured autoclave system, and different concentrations of oxygen were employed during this experiment. The second set of experiments was performed using a glass reactor to investigate the dissolution behavior of PbS-rich solid residues under various nitric acid conditions. The effects of temperature, leaching time, and reagent concentration on leaching efficiency were assessed. We used ICP-OES and XRD to analyze the leachates and solid residue collected as samples, respectively. From the results of the experiments conducted in the autoclave, metals such as Iron (Fe) and Calcium (Ca) showed the best leaching efficiencies, reaching up to 85% for Iron and 62% for Calcium. Bismuth showed moderate leaching efficiency between 35% and over 70% while lead (Pb) did not dissolve as its leaching efficiency was <0.05%. The results from the glass reactor show better leaching efficiencies for Pb (39%), Bi(73%), and Ag(88%). XRD analysis confirmed the transformation of PbS into 𝑃𝑏𝑆𝑂4. These results demonstrate the potential of hydrometallurgical processes in recovering valuable metals, especially under appropriate temperature and oxidant conditions.