Innovations in Urban Mining

随着人们对保护城市环境的迫切需要的认识日益增强，世界各地遵守环境法规的动力也随之增强，循环经济、城市采矿和回收报废产品的规模迅速扩大。这一发现项目--城市采矿创新--为从二次资源中回收战略材料领域开辟了一个新的方向。拟议的跨学科研究将侧重于发展对超临界流体萃取(SCFE)的基本了解和实际应用。超临界流体萃取也被称为“航空冶金”，即利用空气或气体进行冶金，从废弃的电子电气设备中提取锂、钴、稀土元素和金。建议的超临界流体冶金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法。在这一发现计划中，首先，我们将通过实施系统的统计方法，为绿色高效的城市电子垃圾回收开发首个针对锂离子电池、荧光灯和电子电路板回收的优化超临界流体力学工艺。其次，将利用一种开创性的跨学科方法来阐明超临界流体萃取过程中络合过程的控制机制，以及在超临界条件下运行的过程中的动力学，使用X射线吸收光谱(XAS)和光源同步加速器。这一方法将有助于揭示超临界流体萃取过程中形成的金属络合物的结构配位和原子间相互作用。目前还没有这样的知识，这限制了确定反应堆大小和几何形状的能力。第三，我们将为超临界二氧化碳中的螯合金属的相平衡产生第一个同类数据集，这是目前尚不可用的。我们还将通过开发热力学模型来阐明系统的复杂热力学，这些模型可以准确地预测从固体中提取有价值的产品的行为，这反过来将使工艺设计和工艺的经济评估成为可能。拟议的研究计划的成功实施将有利于加拿大的经济和环境，同时创造一个世界领先的行业。这一发现计划中积累的知识也将帮助其他研究人员将SCFE过程的适用性扩展到新的高度。如果这一过程被证明是成功的，它将把提取和回收过程从环境不可持续转变为自然友好和绿色过程。这项研究的结果将直接为加拿大的三组利益攸关方提供信息：运营商、公众和政策制定者。该项目的一个同样重要的成果是一支由高素质人员组成的专业团队，他们拥有全球独特的技能和对SCFE的洞察力，以支持未来的绿色城市采矿应用。

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 metal-chelated 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.