Harnessing magnetic fields for rare-earth complex crystallization–separations in aqueous solutions
Amit Kumar, Geng Han, Eric J. Schelter
Abstract
B 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.