Geosynthetic liners for sustainable development of Arctic mineral resources

2015年，矿产资源开采为加拿大经济贡献了560亿美元。预计仅在未来十年，加拿大北极地区的新矿产资源开发就将投入80多亿美元。这些活动涉及污染水的产生，需要以可持续的方式进行管理，以维持和帮助发展这一重要的经济活动，同时保护地表水和地下水供应以及敏感的北极生态系统。这些水包括通过产生酸的废石堆和采矿过程中被称为尾矿的废料产生的径流，尾矿主要由土壤大小的颗粒、可溶性盐和水组成。大桩或蓄水池通常用来容纳这些废物。为了尽量减少对地面和地表水的污染，它们需要以一种安全但经济上可行的方式加以控制。土工膜（通常为1-2.5毫米厚的塑料片）和土工合成粘土衬垫（在两层纺织品之间包覆的5-7毫米厚的粘土层）被认为是废石堆顶部的衬垫（即，作为工程覆盖物，将水和空气通过废物的运动限制在可忽略的水平）和尾矿蓄水池底部的衬垫（即，作为工程屏障，以减少污染物逃逸到周围环境的数量）。这些土工合成衬垫已被用于显著加强城市堆填区的环境保护。然而，在北极条件下，特别是考虑到全球气候变化的影响，很少有具体的数据可以允许它们的合理设计和长期评估。需要进行研究，以评估预计有多少流体可能通过衬管泄漏，以及衬管在北极应用中暴露于化学物质和物理压力时能维持多久。大学研究人员、工程顾问和土工合成材料制造商之间的这种伙伴关系的目的是为设计土工合成材料衬垫建立科学可靠的技术基础，以实现北极矿产资源的可持续发展。这项研究将在一个对加拿大具有经济和环境重要性的领域为六名高素质人员提供专门培训。

Extraction of mineral resources contributed $56 billion to Canada's economy in 2015. More than $8 billion in new mineral resource development is anticipated in the next decade alone in the Canadian Arctic. These activities involve generation of contaminated water that needs to be managed in a sustainable manner to maintain and help grow this vital economic activity while protecting surface and ground water supplies, and the sensitive Arctic ecosystem. These waters include runoff through acid generating waste rock piles and end of process wastes from mining called tailings, which largely consist of soil size particles, soluble salts and water. Large piles or impoundments are commonly used to contain these wastes. To minimize ground and surface water contamination they need to be contained in a safe but economically feasible manner. Geomembranes (plastic sheets typically 1-2.5 mm thick) and geosynthetic clay liners (a 5-7 mm thick layer of clay encapsulated between two layers of textile) are being considered as liners on top of waste rock piles (i.e., as an engineered cover to limit the movement of water and air through the waste to a negligible level) and on the bottom of tailings impoundments (i.e., as an engineered barrier to reduce the quantity of contaminants from escaping into the surrounding environment). These geosynthetic liners have been used to significantly enhance environmental protection at municipal landfills. However, there is little specific data to permit their rational design and long-term assessment in Arctic conditions, especially considering the effects of global climate change. Research is needed to allow an assessment of how much fluid may be expected to leak through the liner and how long the liner will last when exposed to the chemicals and physical stresses in Arctic applications. The aim of this partnership between university researchers, engineering consultants, and geosynthetic manufacturers is to establish a scientifically sound technical basis for the design of geosynthetic liners to enable the sustainable development of Arctic mineral resources. The research will provide specialized training for six highly qualified personnel in an area of economic and environmental importance for Canada.