Repurposing of mine tailings to maximize value recovery and reduce environmental impacts

重新利用尾矿以最大限度地回收价值并减少对环境的影响

• 批准号: RGPIN-2020-06352
• 负责人: Coudert, Lucie
• 金额: $ 1.89万
• 依托单位: Université du Québec en Abitibi-Témiscamingue
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741157
• 关键词: Repurposing; mine; tailings; maximize; value

The responsible management of solid waste, including mine tailings (MT), is one of the most significant challenges in the mining industry. By repurposing MT, metal(loid)s (potentially harmful or valuable) can be separated from the bulk material, thereby enhancing the recovery of valuable metals from mineral resources while converting problematic waste into "unreactive" materials. Moreover, the repurposing of MT represents a great opportunity to integrate the principle of circular economy in mining operations. Mineral separation (environmental desulfurization - ED) and metallurgical processes (chemical and biological) have been developed to remove deleterious and valuable metal(loid)s from MT. Current knowledge on the repurposing of MT, mainly focusing on the recovery of Au, Ni and Co, indicates that there is no "one-size-fits-all" approach, and little information related to the stability of final residues are available. The long-term objective of my research is to develop knowledge and methods to integrate MT repurposing into mining operations to reduce environmental impacts related to their management, while maximizing the recovery of valuable elements. This 5-year program strives to integrate the repurposing of MT containing high-technology metals (HTM - e.g. Co and Ni), precious metals (e.g Au) and/or problematic elements (e.g. As) through the development of (bio-)hydrometallurgical processes to maximize the value of extracted mineral resources while ensuring the stability of final residues. The specific objectives are: 1) evaluate the performance of hydrometallurgical processes and mechanisms involved during the repurposing of aged MT to recover Co and Ni; 2) assess the geochemical stability of final residues and its integration in decision-making for MT repurposing strategies and 3) compare the performance of (bio-)hydrometallurgical processes to recover precious metals from sulfide concentrate emerging from ED. The methodology used to reach these SO will comprise: i) detailed characterization (chemical, mineralogical), ii) (bio-)leaching tests, iii) leachate treatment to recover valuable elements and stabilize problematic metal(loid)s, ensuring the safety of final residues (solid and liquid), and iv) techno-economic analysis. The operating conditions of (bio-)leaching processes will be optimized using both parametric and statistical approaches to maximize the solubilization of valuable elements while ensuring the stability of final residues and reducing operating costs. This research program will provide a better understanding of the advantages and limitations of (bio-)hydrometallurgical processes with respect to the recovery of element of interest (e.g. Co, Ni, Au) from MT and sulfide concentrates from ED, while minimizing environmental impacts of final residues. The program will train undergraduate (4) and graduate (3) students, thus providing the Canadian mining industry and research community with much needed experts in this field.

包括尾矿 (MT) 在内的固体废物的负责任管理是采矿业最重大的挑战之一。通过重新利用尾矿，可以将金属（可能有害或有价值）从散装材料中分离出来。加强从矿产资源中回收有价值的金属，同时将有问题的废物转化为“非反应性”材料。此外，MT 的重新利用是将循环经济原理融入采矿作业中的绝佳机会。 ED）和冶金工艺（化学和生物）已被开发用于从 MT 中去除有害和有价值的金属（类）。目前关于 MT 重新利用的知识主要集中在金、镍和钴的回收上，这表明存在没有“一刀切”的方法，并且与最终残留物稳定性相关的信息很少。我研究的长期目标是开发知识和方法，将MT重新利用整合到采矿作业中，以减少对环境的影响。与他们有关的这个为期 5 年的计划致力于整合含有高科技金属（HTM - 例如 Co 和 Ni）、贵金属（例如 Au）和/或有问题元素（例如 As）的 MT 的再利用。 ）通过开发（生物）湿法冶金工艺，最大限度地提高提取的矿物资源的价值，同时确保最终残留物的稳定性，具体目标是：1）评估湿法冶金工艺的性能。以及旧 MT 回收 Co 和 Ni 过程中所涉及的机制；2) 评估最终残留物的地球化学稳定性及其在 MT 回收策略决策中的整合，以及 3) 比较回收（生物）湿法冶金工艺的性能从 ED 中提取的硫化物精矿中提取贵金属 用于获得这些 SO 的方法将包括：i) 详细表征（化学、矿物学），ii)（生物）浸出测试， iii) 渗滤液处理以回收有价值的元素并稳定有问题的金属（类），确保最终残留物（固体和液体）的安全，以及 iv) 优化（生物）浸出工艺的操作条件。使用参数和统计方法最大限度地提高有价值元素的溶解度，同时确保最终残留物的稳定性并降低运营成本。该研究计划将更好地了解（生物）湿法冶金工艺在回收方面的优势和局限性。该计划将培训本科生 (4) 和研究生 (3)，从而为加拿大采矿业和研究社区，拥有该领域急需的专家。