Recycling of rare earths with ionic liquid solvents: Bridging the gap between molecular modelling and process design

虽然稀土金属的使用量相对较小，但它们在电子、信息技术和汽车工业等尖端技术中发挥着重要作用。这些金属用于制造计算机中使用的高功率磁铁，它们是风力涡轮机和电动汽车的部件，它们被用于荧光灯和几个催化过程。大约86%的稀土来自中国。人们已经认识到，如此依赖一个国家是一个重大风险。不幸的是，英国的含稀土矿物非常少，但要想变得更加自给自足，它能做的就是回收垃圾堆中的稀土。目前，英国在这一领域的活动很少，但最近的议会报告提醒人们注意保护稀土供应的必要性，有人预计这方面的努力会越来越多。然而，英国在使用液-液提取技术对核燃料进行再处理方面确实拥有强大的科学基础。我们一直在这个领域工作，与国家核实验室并肩工作。从这些活动中收集的知识可以有益地重新设计与化学有关的稀土的有效提取方法。这就是我们的意图。我们将重点研究以离子液体为萃取剂从废弃的高功率磁体中提取稀土Sm。我们的目标是扩大目前由比利时鲁汶的Binnemans小组研究的化学工艺。虽然我们相信我们的一般方法可以有效地应用于许多不同的过程，但我们的重点将放在三个系统上。我们的建议是首先在分子水平上研究这些体系，使用分子动力学模拟，以了解在提取过程中形成的分子结构。其次，我们将利用这些洞察力来构建基于可靠的热力学模型，这样我们就可以在一系列温度和组成范围内预测系统的性质。第三，我们将模拟和评估一个工业规模的提取过程，结合这些模型。最后，作为这些模型的基础之一，我们将与宾尼曼斯小组联系，以便能够合成更优化的离子液体来提取稀土。

While rare earth metals are used in relatively small quantities, they play a major role in cutting edge technologies, such as electronics, information technology and in automobile industries. These metals are used in the high-powered magnets used in computers, they are components of wind-turbines and electric cars, they are used in fluorescent lights and in several catalytic processes. Roughly 86% of all rare earths come from China. This has been recognised as a significant risk to be so dependent on one country. Unfortunately the UK possesses very few rare-earth containing minerals, but what it can do to become more self-sufficient is to recycle the rare-earths that are in waste-piles. Currently the UK has little activity in this area, but recent parliamentary reports draw attention to the need for protecting the supply of rare earths and one foresees a growing effort in this area.The UK does possess, however, a strong scientific base in the reprocessing of nuclear fuel using liquid-liquid extraction. We have worked in this area, alongside the National Nuclear laboratory. The knowledge gathered from these activities can usefully be re-chanelled into designing efficient extraction methodologies for the chemically-related rare earths. This is our intention.We will focus on the extraction of the rare-earth, Samarium, from waste high-powered magnets using ionic liquids as extractants. Our aim to to scale-up the chemical processes currently investigated by the Binnemans group in Leuven, Belgium. While we believe our general methodology can usefully be applied to many, disparate processes, our focus will be on three systems. Our proposal is firstly to study these systems at a molecular level, using molecular dynamics simulations, to understand the molecular structures that form during the extraction process. Secondly we shall use these insights to construct soundly based, reliable thermodynamic models so that we can predict system properties over a range of temperatures and compositions. Thirdly we will simulate and evaluate an industrial-scale extraction process, incorporating these models. Finally, one the basis of these models, we will liaise with the Binnemans group so that yet more optimised ionic liquids can be synthesised for rare earth extractions.