Stability of gold-thiosulphate complexes during gold-thiosulphate leaching process

金-硫代硫酸盐浸出过程中金-硫代硫酸盐络合物的稳定性

• 批准号: 522968-2017
• 负责人: Ghahreman, Ahmad
• 金额: $ 7.99万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=697749
• 关键词: Stability; gold; thiosulphate; complexes; during

The conventional method for gold extraction is to leach gold in a cyanide (CN) solution and the recover the gold-cyanide complex on activated carbon. Finally the gold can be recovered from the activated carbon and refined as highly pure gold. Although the gold extraction with CN (i.e. CN process) is a very efficient process and CN is known to be a highly selective leaching for gold, the toxicity of CN has always been a challenge for the gold industry. CN is one of the most toxic materials known and is extremely toxic for human and animals. The gold industry has been successfully using CN for many years, nonetheless, several accidents of CN spills are reported every year. Another challenge with the use of CN is the cost of its detoxification in the waste waters of the gold extraction plants. To eliminate the use of CN has been a major drive in the gold industry, via development of alternative CN-free processes for gold extraction. Thus far, Barrick Gold Corp., a Canadian gold mining company, is the only company which has developed and commercialized a CN-free process for gold recovery. The process is called CaTS process which uses non-toxic calcium thiosulphate as the gold leaching media. However one significant challenge with this process is the instability of thiosulphate during the gold leaching process. The objective of this study is to understand the fundamental reason behind the thiosulphate oxidation during the leaching process, and develop a solution for this challenge. After successful completion of the project, the reagent cost of the CaTS process will be minimized and the process can be marketed to other Canadian and international gold companies, generating significant revenues for Barrick Gold Corp, and Canada in general.

黄金提取的常规方法是将黄金浸入氰化物（CN）溶液中，并在活性炭上恢复金氰化物络合物。最后，可以从活性碳中回收黄金，并以高度纯金的形式进行精制。 尽管使用CN的黄金提取（即CN过程）是一个非常有效的过程，并且CN是对黄金的高度选择性浸出，但CN的毒性一直是黄金行业的挑战。 CN是已知最有毒的材料之一，对人和动物具有极高的毒性。黄金行业已经成功使用了CN多年了，尽管如此，每年都有几次CN溢出事故。使用CN的另一个挑战是其在黄金提取厂的废水中排毒的成本。 消除CN的使用一直是黄金行业的主要推动力，它通过开发无CN的替代品黄金提取过程。到目前为止，加拿大黄金矿业公司Barrick Gold Corp.是唯一开发并将其商业化的无CN恢复流程进行商业化的公司。该过程称为CATS工艺，该过程使用硫代硫酸钙作为黄金浸出培养基。然而，这一过程的一个重大挑战是在黄金浸出过程中硫代硫酸盐的不稳定性。这项研究的目的是了解浸出过程中硫代硫酸盐氧化背后的基本原因，并为这项挑战开发解决方案。成功完成该项目后，将最大程度地减少猫流程的试剂成本，并可以向其他加拿大和国际黄金公司销售该过程，从而为Barrick Gold Corp和加拿大总体上获得可观的收入。