Alternative materials for engineered covers used to control acid mine drainage

用于控制酸性矿山排水的工程覆盖层的替代材料

• 批准号: RGPIN-2016-05667
• 负责人: Bussière, Bruno
• 金额: $ 4.37万
• 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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=646602
• 关键词: Alternative; materials; engineered; covers; used

One of the most serious environmental challenges facing the mining industry today is the reclamation of mine waste disposal areas, especially when they contain sulphide minerals that can produce acid mine drainage (AMD). The proposed research program seeks to improve cover technologies through the use of alternative materials as cover components, and is divided into two distinct projects: 1) assessment of paste rock as cover material; 2) assessment of bentonite based fine grained materials in engineered covers.****In Project 1, paste rocks with different waste rock to tailings ratios will be prepared, characterized, and tested. The performance of the paste rock mixtures will be compared, in terms of hydrogeological properties, with theoretical predictions made using Mixture theory. The results of large-scale column tests, in which paste rocks are used as cover material, will be compared with the results from existing field experimental cells. Both set-ups will be instrumented to measure unsaturated water movement and gas migration, and will allow for leachates to be recovered. Results obtained from the physical models (column tests and field experimental cells) will be compared with those from hydrogeochemical numerical models.****Bentonite-based fine-grained materials (soil-bentonite or geocomposite clay liner (GCL) are interesting options as cover materials when traditional fine-grained materials are not available near the mine site. Recent work performed by the candidate demonstrated that rock-bentonite mixtures are efficient in controlling oxygen migration over short periods, but are significantly influenced by freeze-thaw cycles. In Project 2, a detailed characterization of different soil bentonite mixtures will be performed in the lab. Based on the results of the characterizations, instrumented column tests in a temperature-controlled chamber will be performed to assess the performance of bentonite-based covers in controlling oxygen and water migration when exposed to freeze-thaw cycles. GCL will also be investigated in this project as a fine-grained layer used in engineered covers. The candidate has access to a mine site where GCL is used as an existing cover material. Laboratory tests (e.g., water and air permeability, microstructural characterization) on intact, post-freeze-thaw cycles, and in situ samples will be performed to evaluate the capacity of GCL to control fluid (water and gas) movement when installed at AMD-generating mine sites.****The proposed research program will provide new or improved techniques for the reclamation of AMD-generating mine waste disposal areas. The work will be performed by HQP, who will benefit from this training by becoming highly-valued specialists with the knowledge and ability to reduce the environmental impacts of mining, while supporting the industry's goal of sustainable exploitation of metal resources.******

当今采矿业面临的最严重的环境挑战之一是填海矿物废物处理区域，尤其是当它们含有可以产生酸性矿山排水（AMD）的硫化物矿物质（AMD）时。拟议的研究计划旨在通过使用替代材料作为覆盖组件来改善覆盖技术，并分为两个不同的项目：1）评估糊状岩石作为覆盖材料； 2）评估工程盖上的基于膨润土的细粒材料。从水文地质特性方面，将比较糊状岩石混合物的性能与使用混合理论做出的理论预测。将糊状岩石用作覆盖材料的大规模柱测试的结果将与现有实验细胞的结果进行比较。两种设置都将被仪器进行测量，以测量不饱和的水运动和气体迁移，并允许回收浸出物。将从物理模型（柱测试和现场实验单元）中获得的结果与水力地球化学数值模型的结果进行比较。****基于膨润土的细颗粒材料（土壤颗粒或地理碳酸盐或地理复合粘土衬里（GCL）是有趣的选择，作为覆盖材料，当材料不可用时，在群落附近进行了良好的循环。在项目2中，冻结周期的影响很大，在实验室的详细表征中，将在实验室中进行仪表室中的仪器测试。项目作为工程盖中使用的细粒层。候选人可以使用GCL用作现有的封面材料的矿场。实验室测试（例如，水和空气渗透性，微观结构表征）对完整的冻结周期和原位样品进行，以评估GCL在AMD生成的矿场上安装时GCL控制流体（水和天然气）运动的能力。这项工作将由HQP进行，HQP将通过成为高估的专家，从而通过知识和能力减少采矿的环境影响，同时支持该行业可持续利用金属资源的目标。**********