Innovations in Urban Mining

随着人们日益认识到保护城市环境的迫切需要，以及随后世界各地遵守环境条例的动机增加，循环经济、城市采矿和使用寿命结束的产品的再循环已迅速扩大。这个探索项目“城市采矿创新”为从二次资源中回收战略材料领域指明了新的方向。拟议的跨学科研究将侧重于发展对超临界流体萃取（SCFE）（也称为“航空冶金”）的基本理解和实际应用，即利用空气或气体从废弃电气和电子设备中提取锂，钴，稀土元素和金的冶金。建议的SCFE工艺是对环境有害的传统湿法冶金或火法冶金工艺的替代方案。

With the growing awareness around the crucial need to protect the urban environment and, subsequently, increased motivation for compliance with environmental regulations around the world, the circular economy, urban mining and recycling of end-of-life products have been rapidly expanding. This Discovery project Innovations in Urban Mining sets out a new direction in the field of recycling of strategic materials from secondary resources. The proposed interdisciplinary research will focus on developing fundamental understanding and practical applications of supercritical fluid extraction (SCFE) also called “aerio-metallurgy”, i.e., metallurgy using air or gas to extract lithium, cobalt, rare earth elements, and gold from waste electrical and electronic equipment. The proposed SCFE process is an alternative to the conventional hydrometallurgical or pyrometallurgical processes that are harmful to the environment. In this Discovery program, first, we will develop a first-of-a-kind optimized SCFE process for recycling of lithium ion batteries, fluorescent lamps, and electronic circuit boards by implementing systematic statistical approaches for green and efficient urban mining of electronic waste. Second, a ground-breaking interdisciplinary approach will be utilized to elucidate the mechanism governing the complexation process during SCFE and the kinetics in processes running under supercritical conditions using X-ray absorption spectroscopy (XAS) and Light Source synchrotron. This approach will shed light on the structural coordination and interatomic interactions of metalchelated complexes formed during SCFE. Such knowledge is not currently available, which limits the ability to determine the size and geometry of the reactor. Third, we will produce the first-of-a-kind data set for phase equilibria of chelated metals in supercritical CO2 that is not currently available. We will also shed light on the complex thermodynamics of the system by developing thermodynamic models that could accurately predict the extraction behavior of valuable products from solids that in turn will enable the process design and economic evaluation of the process. Successful implementation of the proposed research program will benefit the Canadian economy and environment while creating a world-leading industry. The developed knowledge in this Discovery program would also help other researchers expand the applicability of the SCFE process to new heights. If this process is proven to be successful, it will transform extraction and recycling processes from environmentally unsustainable to nature friendly and green processes. The results of this research will directly inform three sets of stakeholders in Canada: operators; the public; and policy makers. An equally important output of this project is a specialized team of highly qualified personnel with globally unique skills and insights into SCFE to power green urban mining applications in the future.