Examining controls on mass loading to an oil sands end pit lake

加拿大阿尔伯塔北方油砂矿床的开采涉及大型露天矿作业和流体细粒尾矿的产生。端坑湖已成为将这些尾矿融入矿山关闭景观的重要技术。该技术涉及在一个已开采的坑内的连续水覆盖下储存流体细粒尾矿。作为矿山关闭战略，底坑湖的成功取决于：（1）固定有机和无机成分;（2）建立可持续的生物群落;（3）将淹没的尾矿与上覆水柱隔离。目前，阿萨巴斯卡油砂地区的油砂开采作业关闭计划中包括30个底坑湖。本研究将集中在基地矿湖，第一个全面的油砂最终坑湖，这是成立于2013年1月由加拿大合成原油有限公司。本研究的总体目标是更好地了解地球化学传质过程和物理质量运输过程之间的关系，在最终坑湖。这一目标将通过完成四个主要研究目标来实现，重点是：（一）限制对生物气体的生产、消费和运输的控制;（二）研究地球化学过程与尾矿固结之间的关系;（三）通过低固体含量细粒尾矿评估能源运输机制;（四）使用保守示踪剂评价对物理运输的控制。这些数据将通过开发尾矿固结及相应的地球化学和物理过程的概念和数值模型加以综合。这项研究将提高对底坑湖泊生物地球化学演变的理解，因此，为油砂矿关闭计划的持续发展提供信息。

Mining of oil sand deposits in northern Alberta, Canada involves large open pit operations and generation of fluid fine tailings. End pit lakes have become an important technology for integrating these tailings into mine closure landscapes. This technology involves storage of fluid fine tailings under a continuous water cover within a mined-out pit. The success of end pit lakes as a mine closure strategy depends upon: (1) immobilization of organic and inorganic constituents; (2) establishment of sustainable biological communities; and (3) isolation of submerged tailings from the overlying water column. Thirty end pit lakes are currently included in closure plans for oil sands mining operations in the Athabasca oil sands region. This research will focus on Base Mine Lake, the first full-scale oil sands end pit lake, which was established in January 2013 by Syncrude Canada Ltd. The overall goal of this research is to better understand relationships between biogeochemical mass-transfer processes and physical mass-transport processes within end pit lakes. This goal will be achieved through completion of four key research objectives focused on: (i) constraining controls on the production, consumption, and transport of biogenic gases; (ii) examining relationships between biogeochemical processes and tailings consolidation; (iii) assessing energy transport mechanisms through low solids content fine tailings; and (iv) evaluating controls on physical transport using conservative tracers. These data will be integrated through development of conceptual and numerical models of tailings consolidation and corresponding biogeochemical and physical processes. This research will improve understanding of the biogeochemical evolution of end pit lakes and, therefore, inform ongoing development of closure plans for oil sands mines.