Sustainable and Lean Technologies for Critical Elements Recovery from Oil sands tailing streams

虽然稀土元素(REE)被认为是“稀有元素”，但它们在地壳中相对丰富；然而，与其他低丰度金属不同，它们很少形成经济矿床。稀土的应用范围很广，从用于充电电池到炼油。随着全球需求的增长，回收目前不能取代从矿石中主要开采稀土，寻找替代来源以确保供应链的长期安全是具有挑战性的。在可用的替代品中，油砂尾矿被视为潜在的未开发稀土矿藏。另一方面，生物湿法冶金是使用微生物的提取冶金学的一个分支，它代表了一种从油砂矿床/尾矿流中提取这些元素的可持续技术。目前，传统的稀土加工方法复杂，成本高，对条件要求苛刻，会产生大量含有钍、铀、氟化氢和酸性废水的有毒废物。相比之下，生物湿法冶金提供了一种更具成本效益和环境可持续的替代方案，分别覆盖了全球约5%和20%的黄金和铜需求。与传统的化学方法相比，为回收稀土而研究的新的生物处理方法可能提供一种可持续的替代方法。因此，该项目将探讨在油砂尾矿流(粗尾矿、液体细尾矿和泡沫处理尾矿)上应用无害环境的工艺(即生物湿法冶金)如何能够浸出和提取对当今的“更智能”和“更绿色”技术至关重要的关键元素(即稀土)。此外，尽管人们对油砂尾矿有很深的了解，但对稀土在石油废气中的生物地球化学影响、环境命运或动员，以及它们如何影响水化学、气体排放、脱水和沉积过程知之甚少。这些悬而未决的问题将在本研究中得到解决。除了推进新的生物湿法冶金方法外，拟议的研究计划还将开发创新的湿法冶金工艺，作为直接从油砂中提取有价值金属的第二种选择，而不需要尾矿后处理。不同的开采方法将通过先进的回收办法加以补充。通过建模、仿真系统和技术经济分析，最终建立完整的工艺流程。这项研究的结果将为尾矿管理提供更好的实践，同时降低环境影响和责任的风险。不包括本科生和研究生的高素质人员(HQP)将接受微生物生物技术、采矿和土木工程、化学工程和生物地球化学方面的培训，为他们未来在可持续采矿领域的领导职位做好准备。

Although Rare Earth Elements (REEs) are considered "rare elements", they are relatively abundant in the Earth's crust; however, unlike other low abundance metals, they are rarely form economic deposits. The application for REEs are broad ranging from their use in rechargeable batteries to petroleum refining. With the growing global demand, recycling cannot currently replace primary mining of REEs from ores and identifying alternative sources to secure the supply chain on the long term is challenging. Among the available alternatives, oil sands tailings are seen as a potential untapped reservoir for REEs. On the otherside, biohydrometallurgy, a branch of extractive metallurgy that uses microbes, represents a sustainable technique for extracting these elements from oil sands deposits/tailing streams. Currently, conventional REEs processing methods are complex, costly, require harsh conditions and generate large amounts of toxic waste containing thorium, uranium, hydrogen fluoride, and acidic wastewater. In contrast, biohydrometallurgy presents a more cost-effective and environmentally sustainable alternative and covers around 5% and 20% of the world's gold and copper demands, respectively. New bioprocessing methods investigated for the recovery of REEs may offer a sustainable alternative compared to conventional chemical approaches. Thus, this project will address how the application of environmentally benign processes (i.e., biohydrometallurgy) on oil sands tailing streams (coarse tailings, fluid fine tailings, and froth treatment tailings) can leach and extract critical elements (i.e. REEs) that are essential for today's "smarter" and "greener" technologies. Besides, despite the deep knowledge on oil sands tailings, little is known about the biogeochemical implications, environmental fate or mobilization of REEs in oil waste streams particularly and how they affect water chemistry, gas emissions, dewatering and deposition processes. These unresolved questions will be addressed in this research. In addition to advancing new biohydrometallurgy methods, the proposed research program will also develop inovative hydrometallurgy process as a second option for extracting valuable metals directly from oils sands without the need for tailings reprocessing. Different extraction approaches will be latter complemented through advanced recovery options. A whole flow-sheet will be finally established through modelling, simulation systems and techno-economic analysis. The results of this research will offer better practices for tailings management while reducing the risks of environmental impacts and liabilities. Highly qualified personnels (HQPs) uncluding undergraduate and graduate students will be trained in microbial biotechnology, mining and civil engineering, chemical engineering and biogeochemistry, positioning them for future leadership positions in sustainable mining.