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.

传统的提金方法是在氰化物(CN)溶液中浸金，然后在活性碳上回收金-氰化物络合物。最后，从活性碳中回收金，并将其提纯为高纯金。 氰化法提金是一种非常有效的方法，氰化法是一种高选择性的金浸出方法，但氰化法的毒性一直是困扰黄金工业的一大难题。CN是已知的毒性最大的物质之一，对人和动物都有极强的毒性。黄金行业多年来一直成功地使用CN，然而，每年都会有几起CN泄漏事故的报道。使用CN的另一个挑战是其在黄金提炼厂废水中的解毒成本。 通过开发不含CN的黄金提炼替代工艺，消除CN的使用一直是黄金行业的主要驱动力。到目前为止，加拿大黄金开采公司巴里克黄金公司是唯一一家开发和商业化了无CN黄金回收工艺的公司。该工艺以无毒的硫代硫酸钙为浸金介质，称为CATS法。然而，这一过程的一个重大挑战是硫代硫酸盐在浸金过程中的不稳定。这项研究的目的是了解硫代硫酸盐在浸出过程中氧化的根本原因，并开发解决这一挑战的方案。该项目成功完成后，CATS工艺的试剂成本将降至最低，该工艺可向其他加拿大和国际黄金公司销售，为Barrick Gold Corp和整个加拿大带来可观的收入。