Hampel Sven, Alhafez Iyad Alabd, Schirmer Thomas, Merkert Nina, Wunderlich Sophie, Schnickmann Alena, Li Haojie, Fischlschweiger Michael, Fittschen Ursula Elisabeth Adriane
Institute of Inorganic and Analytical Chemistry, Clausthal University of Technology, Arnold-Sommerfeld-Straße 4, Clausthal-Zellerfeld 38678, Germany.
Institute of Applied Mechanics, Clausthal University of Technology, Arnold-Sommerfeld-Straße 6, Clausthal-Zellerfeld 38678, Germany.
ACS Omega. 2024 May 28;9(23):24584-24592. doi: 10.1021/acsomega.4c00723. eCollection 2024 Jun 11.
Engineered artificial minerals (EnAMs) are the core of a new concept of designing scavenger compounds for the recovery of critical elements from slags. It requires a fundamental understanding of solidification from complex oxide melts. Ion diffusivity and viscosity play vital roles in this process. In the melt, phase separations and ion transport give rise to gradients/increments in composition and, with it, to ion diffusivity, temperature, and viscosity. Due to this complexity, solidification phenomena are yet not well understood. If the melt is understood as increments of simple composition on a microscopic level, then the properties of these are more easily accessible from models and experiments. Here, we obtain these data for three stoichiometric lithium aluminum oxides. LiAlO is a promising EnAM for the recovery of lithium from lithium-ion battery pyrometallurgical processing. It is obtained through the addition of aluminum to the recycling slag melt. The high temperature properties spanning from below to above the liquidus temperature of three stoichiometric Li-Al-Oxides: LiAlO, LiAlO, and LiAlO are determined using molecular dynamic simulations. The compounds are also synthesized via the sol-gel route. The Li ion exhibits the largest diffusivity. They are quite mobile already below the liquidus temperature, i.e., for LiAlO at = 1700 K, the diffusion coefficient of the lithium ion equals = 3.0 × 10 m s. The other ions Al and O do not move considerably at that temperature. The diffusivity of Li is largest in the lithium-rich compound LiAlO with = 32 × 10 m s at 2500 K. The lower the viscosity, the higher the lithium content. The LiAlO exhibits a viscosity of η = 2.2 mPa s at 1328 K which matches well with the experimentally determined 2.5 mPa s at this temperature. The viscosity of LiAlO at 1800 K is more than two times higher. These data sets can help to describe the melts on a microscopic level and understand how the melt properties will change due to gradients in the Li/Al concentration.
工程人工矿物（EnAMs）是设计用于从炉渣中回收关键元素的 scavenger 化合物这一新概念的核心。这需要对复杂氧化物熔体的凝固有基本的了解。离子扩散率和粘度在这个过程中起着至关重要的作用。在熔体中，相分离和离子传输会导致成分的梯度/增量，随之而来的是离子扩散率、温度和粘度的变化。由于这种复杂性，凝固现象尚未得到很好的理解。如果将熔体在微观层面理解为简单成分的增量，那么这些成分的性质就更容易从模型和实验中获取。在这里，我们获得了三种化学计量比的锂铝氧化物的这些数据。LiAlO 是一种有前景的用于从锂离子电池火法冶金过程中回收锂的 EnAM。它是通过向回收炉渣熔体中添加铝而获得的。使用分子动力学模拟确定了三种化学计量比的 Li - Al - 氧化物（LiAlO、LiAlO 和 LiAlO）从低于到高于液相线温度的高温性质。这些化合物也通过溶胶 - 凝胶法合成。锂离子表现出最大的扩散率。它们在液相线温度以下就已经相当活跃，例如对于 LiAlO，在 = 1700 K 时，锂离子的扩散系数等于 = 3.0×10 m²/s。在该温度下，其他离子 Al 和 O 的移动并不显著。在 2500 K 时，Li 在富锂化合物 LiAlO 中的扩散率最大，为 = 32×10 m²/s。粘度越低，锂含量越高。LiAlO 在 1328 K 时的粘度为 η = 2.2 mPa·s，与该温度下实验测定的 2.5 mPa·s 非常匹配。LiAlO 在 1800 K 时的粘度则高出两倍多。这些数据集有助于在微观层面描述熔体，并理解由于 Li/Al 浓度梯度熔体性质将如何变化。
