Pretreatment and Extraction of Gold from Refractory Gold Ore in Acidic Conditions

As high-grade gold deposits are progressively depleted, the proportion of refractory gold ores in total reserves is continuously increasing, making gold recovery from refractory ores an inevitable trend in the future development of the gold industry. This study briefly analyzes the challenges faced during the leaching process of refractory gold ores under ambient conditions, and provides a detailed discussion on two acidic pretreatment technologies—pressure oxidation and bio-oxidation—as well as three acidic gold recovery technologies—thiosulfate leaching process, halogen leaching process, and thiocyanate leaching process. Additionally, this paper compares and analyzes the advantages and limitations of these acidic pretreatment and hydrometallurgical gold recovery technologies. The goal is to provide a comprehensive review of pretreatment technologies and leaching agents for refractory gold ores under acidic conditions (pH = 1–5), offering a reference for selecting appropriate treatment processes in the future, and to explore the potential development of acidic pretreatment and recovery technologies for refractory gold ores.