Exploring the influence of DMSA on thiosulphate leaching of gold ores

探讨DMSA对金矿石硫代硫酸盐浸出的影响

• 批准号: 444986-2012
• 负责人: Shepherd, Jeffrey
• 金额: $ 0.75万
• 依托单位: Laurentian University of Sudbury
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=535748
• 关键词: Exploring; influence; DMSA; thiosulphate; leaching

In the practice of extracting gold from ores, cyanide is the most common choice of leaching agent because of its selectivity for gold, excellent leaching kinetics, and ease of recovery from solution by adsorption onto coarse particles of activated carbon. However, cyanide is not suitable for extracting gold from carbonaceous ores and there is increasing environmental concern regarding it's toxicity. Because of these drawbacks, there is a need to identify less-toxic alternatives to cyanide that are appropriate for leaching gold from a wide variety of ores. In the search for an alternative to cyanide, thiosulphate has been identified as suitable candidate and shows good initial leaching kinetics for gold provided that ammonium hydroxide and copper sulphate are used as catalysts. However, the presence of these additives can hinder long-term leaching rates because they produce decomposition products that can adsorb on the gold surface and interfere with the leaching mechanism. Some recent studies have shown that adding controlled amounts of organic additives can provide a synergistic effect that improves the leaching rate of gold in thiosulphate systems. In the current research proposal, we will further study an improvement to gold leaching that we have observed when thiosulphate is mixed with small amounts of meso-2,3-dimercaptosuccinic acid (DMSA). The study will be performed in both laboratory controlled solutions as well as electrolytes that are industrially relevant to Barrick Gold corporation. The research may lead to the optimization of the amount of DMSA that should be added with thiosulphate for improved leaching in real ores. Moreover, the research will be performed by students who will learn the industrial practices of gold leaching and should result in personnel that are highly qualified in the metallurgical sector.

在从矿石中提取金的实践中，氰化物是最常用的浸出剂，因为它对金具有选择性、优异的浸出动力学，并且易于通过吸附在活性炭粗颗粒上从溶液中回收。然而，氰化物不适合从碳质矿石中提取金，并且其毒性越来越受到环境关注。由于这些缺点，需要找到适合从各种矿石中浸出金的毒性较小的氰化物替代品。在寻找氰化物替代品的过程中，硫代硫酸盐已被确定为合适的候选物，并且在使用氢氧化铵和硫酸铜作为催化剂的情况下，显示出良好的金初始浸出动力学。然而，这些添加剂的存在会阻碍长期浸出率，因为它们产生的分解产物会吸附在金表面并干扰浸出机制。最近的一些研究表明，添加控制量的有机添加剂可以提供协同效应，提高硫代硫酸盐系统中金的浸出率。在当前的研究计划中，我们将进一步研究当硫代硫酸盐与少量内消旋2,3-二巯基丁二酸（DMSA）混合时观察到的金浸出的改进。该研究将在实验室控制的溶液以及与巴里克黄金公司工业相关的电解质中进行。该研究可能会优化应与硫代硫酸盐一起添加的 DMSA 量，以改善实际矿石的浸出。此外，这项研究将由学生进行，他们将学习金浸出的工业实践，并应培养出冶金领域的高素质人才。