Kumar Amit, Geng Han, Schelter Eric J
P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 S. 34th St. Philadelphia PA 19104 USA
RSC Adv. 2022 Sep 29;12(43):27895-27898. doi: 10.1039/d2ra04729b. eCollection 2022 Sep 28.
Magnetic field-directed crystallization separation of rare-earth (RE) metals is emerging as a new direction in the field of separation science, due to its simplicity, low energy input, and low cost of operation, as compared to traditional separation methods such as solvent extraction. Here, we report the use of FeNdB magnets for selective crystallization of paramagnetic Nd, Dy, Er, and Tm rare earth compounds from a mixture with diamagnetic La ones using the RE-DOTA complex system. All the separations were performed at milder temperatures of 3 °C to provide a thermal gradient, and the crystallizations were set up in aqueous solutions using the benign solvents water and acetone. A four-fold increase in the separation factor (41.4 ± 0.6) was observed for the Dy/La pair in the presence of a magnetic field as compared to the separation factor (10.5 ± 0.9) obtained without the application of the field. These results indicate that the use of the magnetic crystallization method for RE separations is effective in aqueous systems and can be a useful strategy for energy-efficient molecular separations of RE metals.
与溶剂萃取等传统分离方法相比，磁场导向的稀土（RE）金属结晶分离法因操作简单、能量输入低和运行成本低，正成为分离科学领域的一个新方向。在此，我们报告了使用钕铁硼磁体，利用稀土-二乙三胺五乙酸（RE-DOTA）络合物体系，从与抗磁性镧化合物的混合物中选择性结晶顺磁性钕、镝、铒和铥稀土化合物。所有分离均在3°C的温和温度下进行以提供热梯度，结晶在使用良性溶剂水和丙酮的水溶液中进行。与未施加磁场时获得的分离因子（10.5±0.9）相比，在磁场存在下，镝/镧对的分离因子增加了四倍（41.4±0.6）。这些结果表明，磁性结晶法用于稀土分离在水体系中是有效的，并且可以成为稀土金属节能分子分离的有用策略。
