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藏的开采涉及大型露天开采和产生流体细粒尾矿。尾矿湖已经成为将这些尾矿整合到矿山关闭景观中的一项重要技术。这项技术涉及在采空区内的连续水罩下储存流体细粒尾矿。尾矿湖作为矿场关闭战略的成功取决于：(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。阿萨巴斯卡油砂地区油砂开采作业的关闭计划目前包括30个尾矿湖。本次研究将聚焦于加拿大辛克鲁德有限公司于2013年1月建立的第一个全规模油砂底坑湖--基矿湖。本研究的总体目标是更好地了解底坑湖内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四个主要研究目标来实现，这些目标集中在：(1)限制对生物成因气体的生产、消费和运输的控制；(2)研究生物地球化学过程与尾矿固结之间的关系；(3)评估通过低固体含量细尾矿进行的能量传输机制；以及(4)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和相应的生物地球化学和物理过程的概念和数值模型来整合。这项研究将提高对末端矿坑湖泊生物地球化学演化的理解，从而为正在制定的油砂矿山关闭计划提供信息。

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.