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560亿加元。预计仅在加拿大北极地区，未来十年就将有80多亿美元的新矿产资源开发。这些活动涉及产生污染水，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。这些沃茨包括通过产生酸的废石堆和来自采矿的被称为尾矿的工艺废物的末端的径流，尾矿主要由土壤大小的颗粒、可溶性盐和水组成。通常使用大型堆或蓄水池来容纳这些废物。为了尽量减少对地下水和地表水的污染，需要以安全但经济上可行的方式加以控制。土工膜（通常1-2.5 mm厚的塑料片）和土工合成粘土衬垫（在两层织物之间封装的5-7 mm厚的粘土层）被认为是废石堆顶部的衬垫（即，作为工程覆盖物以将水和空气通过废物的移动限制到可忽略的水平）和在尾矿蓄水池的底部（即，作为工程屏障以减少污染物逃逸到周围环境中的量）。这些土工合成衬垫已被用于显著提高城市垃圾填埋场的环境保护。然而，很少有具体的数据，使他们的合理设计和长期评估在北极条件下，特别是考虑到全球气候变化的影响。需要进行研究，以评估在北极应用中，预计会有多少液体通过衬里泄漏，以及衬里在暴露于化学品和物理应力时能持续多长时间。大学研究人员、工程顾问和土工合成材料制造商之间建立这种伙伴关系的目的是为设计土工合成材料衬里建立科学合理的技术基础，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.