Grant: Discovery Grants Program - Individual

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.