New disposal techniques for reactive mine wastes to improve stability and facilitate site reclamation upon closure

反应性矿山废物的新处置技术可提高稳定性并促进关闭后的场地复垦

• 批准号: RGPIN-2020-05638
• 负责人: Aubertin, Michel
• 金额: $ 3.13万
• 依托单位: École Polytechnique de Montréal
• 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=740697
• 关键词: New; disposal; techniques; reactive; mine

The complex challenges raised for the safe management of large quantities of reactive mine wastes require innovative approaches to address various geo-environmental concerns and ensure the geotechnical and hydrogeochemical stability of the disposal sites. Recent work has shown that waste rock inclusions (WRI) placed along selected paths within tailings impoundment can be used to improve their stability and performance by accelerating drainage and consolidation and providing reinforcement. This innovative technique, initially proposed by the Applicant (and collaborators), has been applied efficiently on a large scale at the Canadian Malartic gold mine site (western QC, Canada) for over 7 years. The successful field application of this technique has also raised additional questions that have not yet been addressed (or even considered), including the effect of WRI on the degree of saturation of adjacent tailings, their influence on oxygen ingress and generation of acid mine drainage (AMD) from sulphide minerals, and  how these may impact the reclamation work upon site closure. These issues will be investigated through the proposed Discovery Grant program (Project A). The disposal of reactive waste rock in piles exposed to natural conditions is another critical issue for mining operations, as these may become a major source of contaminated waters. Preliminary laboratory and field work has shown that it is possible to control the generation of contaminated seepage waters in piles by limiting surface infiltration with the addition of flow control layers (FCL) on the top and inside the pile. These layers are placed during pile construction on the surface of each bench (and lift) to limit infiltration and deep percolation toward the reactive core of the pile. Laboratory tests on physical models, numerical simulations and a recently built large scale experimental waste rock pile at the Tio mine (RTFT, Eastern QC) have shown that this technique has a great potential. But the studies also revealed other key aspects that need to be looked at more closely, including three-dimensional effects, localized water flow in the coarse-grained waste rock below the FCL, and ways to define optimum conditions to maximize the efficiency of FCL in terms of material properties and layer thickness, inclination, and vertical position in the pile. These aspects will also be investigated  through the proposed Discovery Grant research program (Project B).

大量活性矿山废物的安全管理面临着复杂的挑战，需要创新的方法来解决各种地质环境问题，并确保处置场的岩土工程和水文地球化学稳定性。最近的工作表明，沿线放置的岩石废物夹杂物（WRI）。尾矿库内选定的路径可用于通过加速排水和固结以及提供加固来提高其稳定性和性能。这种创新技术最初由申请人（和合作者）提出，已在加拿大大规模有效应用。 Malartic 金矿现场（加拿大 QC 西部）超过 7 年的成功现场应用也引发了尚未解决（或什至考虑）的其他问题，包括 WRI 对饱和度的影响。邻近尾矿的影响、它们对硫化物矿物的氧气进入和酸性矿山排水 (AMD) 的影响，以及这些问题如何影响场地关闭后的复垦工作，这些问题将通过拟议的发现资助计划（项目 A）进行调查。的暴露在自然条件下的废石堆中的反应性废石是采矿作业的另一个关键问题，因为这些废石可能成为污染水的主要来源，初步实验室和现场工作表明，可以通过以下方法控制废石堆中污染渗水的产生。通过在桩的顶部和内部添加流量控制层 (FCL) 来限制表面渗透。这些层在桩施工期间放置在每个长凳（和升降机）的表面上，以限制向反应核心的渗透和深层渗透。堆实验室。对物理模型、数值模拟和最近在 Tio 矿山建造的大型实验废石堆（RTFT，Eastern QC）的测试表明，这项技术具有巨大的潜力，但研究还揭示了其他需要关注的关键方面。更仔细地，包括三维效应、FCL 下方粗粒废石中的局部水流，以及定义最佳条件的方法，以最大限度地提高 FCL 在材料特性和层厚度、倾斜度和垂直位置方面的效率这些方面都会。也可以通过拟议的发现资助研究计划（项目 B）进行调查。