Properties and Geotechnical Behaviour of Cemented Tailings Backfills with Additive-Enhanced Performance under Different Thermal and Mechanical Loading Conditions

不同热力和机械荷载条件下添加剂增强胶结尾矿充填物的性能和岩土工程行为

• 批准号: RGPIN-2018-04411
• 负责人: Fall, Mamadou
• 金额: $ 3.79万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=749465
• 关键词: Properties; Geotechnical; Behaviour; Cemented; Tailings

Canada is one of the largest mining nations in the world. However, this industry is associated with the production of a large quantity of solid waste, especially tailings. The sustainable management of tailings is a great challenge for Canada. One of the most successful and innovative tailings management strategies is the development of cemented paste backfill technology (CPB, a mix of tailings, water and binder). The key functions of CPB, a vital component of underground mine operations, are the mechanical stabilization of underground mine openings, and the maximization of safe and economic ore recovery. In addition, the maximum underground disposal of tailings represents significant environmental benefits. The key performance characteristics of any type of CPB include: mechanical stability under static loading conditions, mechanical stability at the early ages under dynamic loading conditions (liquefaction potential), flowability and cost. One of the key priorities in CPB technology is the development of new types of CPBs that have high mechanical stability with a shorter curing time (increase mine productivity), and improved and/or excellent flowability at an acceptable cost. To achieve this goal, the mining industry and mine backfill engineers have been placing strong emphasis on the use of novel types of additives (chemical admixtures, nanoparticles) in CPB in recent years to develop new types of CPB. However, many previous attempts to develop these new types of CPBs and their field applications have produced disappointing results or failed due the lack of a sufficient and basic understanding of the behaviour and performance of CPBs that contain such additives as well as due to the lack of consideration of the coupled thermo-mechanical (TM) loading conditions to which these CPBs are subjected in the field. The lack of consideration given to these coupled TM processes has long been defended on the basis that it is difficult to do so. However, this does not mean that these issues are not essential. Innovative thinking is needed to face these challenges and thus address this deficiency in technology. Therefore, novel methods and tools for studying the response (e..g, mechanical stability, liquefaction potential) of these new types of CPBs: (CH-CPB or CPB with chemical admixtures; nano-CPB or CPB that contains nanoparticles) to TM loads in static and dynamic loading conditions as well as for assessing the flowability of these types of CPBs under various thermal conditions in mines, and for preparing optimal backfill recipes are identified and proposed in this research program. These tools and a thorough understanding of the behaviour and performance of these new types of CPBs under various field TM loading conditions are imperative and essential for economic reasons, mine worker safety and the development of economically and environmentally sustainable mining strategies.

加拿大是世界上最大的矿业国家之一。然而，该行业与大量固体废物，特别是尾矿的生产有关。尾矿的可持续管理对加拿大来说是一个巨大的挑战。最成功和创新的尾矿管理战略之一是开发胶结膏体回填技术（CPB，尾矿、水和粘合剂的混合物）。CPB是地下采矿作业的重要组成部分，其关键功能是地下采矿开口的机械稳定，以及安全和经济的矿石回收率的最大化。此外，最大限度地将尾矿埋在地下，具有重大的环境效益。任何类型的CPB的关键性能特征包括：静态负载条件下的机械稳定性，动态负载条件下早期的机械稳定性（液化潜力），流动性和成本。CPB技术的关键优先事项之一是开发具有高机械稳定性和较短固化时间（提高矿山生产率）以及以可接受的成本改善和/或优异流动性的新型CPB。为了实现这一目标，采矿业和矿山回填工程师近年来一直非常重视在CPB中使用新型添加剂（化学外加剂，纳米颗粒）以开发新型CPB。然而，由于缺乏对含有这种添加剂的CPB的行为和性能的充分和基本的理解以及由于缺乏对这些CPB在现场经受的耦合热机械（TM）负载条件的考虑，许多先前开发这些新型CPB及其现场应用的尝试产生了令人失望的结果或失败。长期以来，人们一直在为缺乏对这些TM耦合过程的考虑进行辩护，理由是这样做很困难。然而，这并不意味着这些问题不重要。需要创新思维来应对这些挑战，从而解决技术上的这一缺陷。因此，研究响应的新方法和工具（例如，这些新型的CPB（CH-CPB或CPB与化学外加剂;纳米CPB或CPB含有纳米颗粒）在静态和动态载荷条件下的TM载荷以及用于评估这些类型的CPB在矿山中的各种热条件下的流动性，并用于制备最佳回填配方，在本研究计划中确定并提出。这些工具以及对这些新型CPB在各种现场TM负载条件下的行为和性能的透彻理解对于经济原因、矿工安全以及经济和环境可持续采矿战略的发展是必要的。