A systematic review of gold extraction: Fundamentals, advancements, and challenges toward alternative lixiviants

• Published in: Journal of hazardous materials Vol. 440; p. 129778
• Main Authors: Liu, Zuo-wei, Guo, Xue-yi, Tian, Qing-hua, Zhang, Lei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-10-2022
• Subjects: Alternative lixiviants; Cleaner production; Cyanidation; Gold hydrometallurgy; Leaching; Gold hydrometallurgy; Alternative lixiviants; Leaching; Cyanidation; Cleaner production
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.129778

Since the birth of cyanidation, it has been dominant in the gold extraction industry. Recently, with the increasing awareness of environmental hazards and potential risks posed by the severe toxicity of cyanide, attempts to seek alternative lixiviants have arisen. Over the past three decades, a significant amount of literature has examined alternative lixiviants to cyanide for recovering gold, while few industrial applications have been reported due to various obstacles, such as toxicity, excessive consumption, or low leaching efficiency. These obstacles are progressively overcome in multiple ways, including process improvement, system optimization, use of co-intensifying systems, and development of additives. In this paper, related studies about alternative lixiviants and methods such as cyanide, thiosulfate, thiourea, thiocyanate, polysulfides, halides, and microbial leaching are summarized. The history, fundamentals, advancements, and challenges of alternative lixiviants are fully concluded to provide a reference for cleaner gold production. In addition, the comprehensive performance of lixiviants was evaluated according to a novel evaluation criterion proposed in terms of economy, efficiency, and environment.
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•The history and mechanisms of gold lixiviants in gold extraction were reviewed.•A novel evaluation criterion was proposed to evaluate the performance of lixiviants.•The current advances and progress of each lixiviant were summarized.•The challenges and prospects of each lixiviant were forecasted.