Formation of critical compounds in recycling slags - a study of the melt chemistry with MD simulations and of the solidified compounds in a micro preparation approach

我们在这个项目中研究的长期目标是了解熔渣的凝固。这将有助于以工程人工矿物（EnAM）的形式从火冶渣中有效地回收关键元素。LiAlO2是一种很有前途的从锂离子电池回收渣中回收锂的EnAM。Al的加入支持了其作为主要含Li相的形成。然而，如果Mn存在于熔体中，它的形成几乎完全被抑制。形成Li- mn尖晶石初生固溶体，而不是LiAlO2，然后形成其他几个含Li相。本项目的目的是在分子水平上了解尖晶石固溶体在Al2O3， MgO, CaO, Li2O， SiO2体系中Mn存在下的凝固过程。我们的方法将包括a)对最重要的离子进行MD模拟，以确定熔体的前驱体多相体和粘度；b)以及喷墨打印微样品基质的制备和表征，以及少量的小规模和大规模冶炼合成炉渣。这将阐明实际固化化合物的微观结构和组成。一旦了解了初次凝固，这些知识将是强制形成所需的EnAM LiAlO2的基础。我们开发的程序可以应用于其他系统和enam。

Our research's long-term goal in this project is to understand the solidification of slag melts. This will help an efficient recovery of critical elements from pyro-metallurgical slags in the form of engineered artificial minerals (EnAM). LiAlO2 has been identified as a promising EnAM to recover Li from Li-ion battery recycling slags. The addition of Al supports its formation as the major Li bearing phase. However, if Mn is present in the melt, its formation is nearly wholly suppressed. Instead of the LiAlO2, a primary Li-Mn spinel solid solution is formed and, later on, several other Li bearing phases. Our objective in this project is to understand the solidifying processes of spinel solid solution in the system Al2O3, MgO, CaO, Li2O, SiO2 in the presence of Mn on a molecular level. Our approach will include a) MD simulation of the most important ions to identify the precursor polytopes and viscosity of the melt and b) and the preparation and characterization of a matrix of inkjet-printed micro-specimens, as well as of a smaller number of small scale and large scale smelted synthetic slags. These will elucidate the microstructure and composition of the actual solidified compounds. Once the primary solidification is understood, the knowledge will be fundamental to enforce the formation of the desired EnAM LiAlO2. The procedures we develop can be adopted to other systems and EnAMs.