Sustainable mine waste management: from microscale hydrogeochemical processes to macroscale prediction models

可持续矿山废物管理：从微观水文地球化学过程到宏观预测模型

• 批准号: RGPIN-2021-03133
• 负责人: Vriens, Bas
• 金额: $ 2.19万
• 依托单位: Queen's University
• 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=742394
• 关键词: Sustainable; mine; waste; management; microscale

*INTRODUCTION* Mine wastes can negatively impact the environment through the release of poor-quality drainage with harmful levels of acidity, metal(loid)s or other contaminants. Effective long-term management of mine waste storage facilities is predicated on the ability to forecast seepage rates and the chemical composition of these effluents for decades beyond mine closure. For this, a wide range of geochemical weathering reactions and coupled physical transport processes needs to be quantitatively understood. Mineralogical dynamics, effluent composition and solute speciation vary greatly across storage conditions and waste rock types but lack systematic characterization to date. Furthermore, our ability to integrate such microscale hydrogeochemical phenomena with practical, macroscale prediction models is still limited: effective waste management remains a costly technical challenge for the mining industry. *OBJECTIVES* The objectives of this research program are to advance our understanding of critical hydrogeochemical processes in mine wastes and to improve the application of this knowledge in prediction models for mine waste effluent quality. The proposed research occurs along two major themes: microscale processes and macroscale prediction models. These themes, respectively, have the objectives to i) experimentally constrain the controls of mineralogical dynamics and aqueous solute speciation on weathering rates and contaminant mobility, and ii) to create and evaluate long-term macroscale prediction models using reactive-transport modeling and dimensionless numbers analyses. *METHODS* Using controlled laboratory experiments, we will study the weathering rates, mineralogical surface dynamics and generated effluent qualities from different waste rock materials under contrasting exposure conditions. By analyzing the aqueous speciation of thiolated metalloids in effluent, we will determine the conditions in which these contaminant species are formed and degraded and thereby shed light on their environmental persistence. Second, we will monitor and quantify the evolution of the mineral assemblages and derive kinetic parameters and indicator proxies for bulk waste rock reactivity that can ultimately be used in prediction models. Finally, we will perform reactive-transport simulations to assess the importance of distinct hydrogeochemical, mineralogical, and physical transport processes towards overall drainage quality as a function of waste rock type and storage conditions. *IMPACT* This research program will train several graduate and undergraduate students in advanced analytical, experimental, and simulation techniques, using world-class infrastructure and extensive collaboration with (international) mining practitioners. Our results will produce fundamental knowledge on mine waste hydrogeochemistry as well as practical insights for improved mine waste management, helping Canadian companies to remain global frontrunners in sustainable mining.

*简介*矿井废物可能通过释放有害水平的酸度，金属（LOID）或其他污染物的质量排水量来对环境产生负面影响。有效的长期管理废物存储设施的长期管理基于预测渗透率的能力以及这些废水的化学成分数十年来，超出了我的关闭。为此，需要定量了解广泛的地球化学风化反应和耦合的物理运输过程。矿物学动力学，废水组成和溶质物种形成在储存条件和废岩类型之间差异很大，但迄今为止缺乏系统的表征。此外，我们将这种微观地球化学现象与实用的，宏观的预测模型相结合的能力仍然有限：有效的废物管理仍然是矿业行业的昂贵技术挑战。 *目标*该研究计划的目标是提高我们对矿井废物中关键水力地球化学过程的理解，并提高该知识在预测模型中的应用，以实现矿废物废水的质量。提出的研究沿两个主要主题进行：微观过程和宏观预测模型。这些主题分别具有i）i）实验性地限制了对风化速率和污染物迁移率的矿物学动力学和水溶性物种形成的控制，以及ii），以创建和评估长期的宏观镜头预测模型，使用反应性转移模型和无尺寸的无尺寸数字分析。 *方法*使用受控实验室实验，我们将研究风化速率，矿物学表面动力学以及在对比鲜明的暴露条件下从不同废物材料中产生的废水品质。通过分析废水中硫醇化金属素的水形态，我们将确定形成和降解这些污染物物种的条件，从而阐明它们的环境持久性。其次，我们将监视和量化矿物组合的演变，并得出散装岩石反应性的动力学参数和指标代理，最终可以在预测模型中使用。最后，我们将执行反应性传输模拟，以评估独特的水力地球化学，矿物质和物理运输过程对整体排水质量的重要性，这是废物岩石类型和存储条件的函数。 * Impact*该研究计划将使用世界一流的基础设施和（国际）矿业从业者进行高级分析，实验和仿真技术培训几位研究生和本科生。我们的结果将获得有关矿物废物水电化学的基本知识，以及改善矿废物管理的实用见解，帮助加拿大公司在可持续采矿中保持全球领先者。