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

加拿大阿尔伯塔省北部油砂矿床的开采涉及大型露天作业和流体细尾矿的产生。尾坑湖已成为将这些尾矿整合到闭坑景观中的重要技术。该技术涉及在采空区内连续水覆盖下储存流体细粒尾矿。尾坑湖作为闭坑策略的成功取决于：(1)有机和无机成分的固定化；(2)建立可持续的生物群落；(3)将淹没尾砂与上覆水柱隔离。目前，阿萨巴斯卡油砂地区油砂开采作业的关闭计划中包括30个底坑湖。本研究将重点关注Base Mine Lake，这是第一个完整的油砂端坑湖，由Syncrude Canada Ltd.于2013年1月建立。本研究的总体目标是更好地了解端坑湖生物地球化学传质过程与物理传质过程之间的关系。这一目标将通过完成以下四个主要研究目标来实现：(i)限制对生物气体的生产、消费和运输的控制；审查生物地球化学过程与尾矿固结之间的关系；（三）通过低固体含量细尾砂评估能量传输机制；（iv）评估使用保守示踪剂对物理运输的控制。这些数据将通过发展尾矿固结和相应的生物地球化学和物理过程的概念和数值模型加以综合。这项研究将提高对尾坑湖生物地球化学演化的认识，从而为油砂矿山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.