(196k) Rare-Earth Separation Based on the Differences of Ionic Magnetic Moment Via Quasi-Liquid Strategy

Fujian Li^{1, 2*}, Bangyu Fan^{1, 2, 3}, Yanyan Cheng^{1, 2, 4}, Zhongzhi Wang^{1, 2, 4},

Suojiang Zhang^{1, 2}, Lu Bai^{1, 2}, Na Wang^{1, 2} and Xiangping Zhang^{1, 2*}

1 CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering and Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, PR China

2 Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341000, PR China

3 College of Chemistry, Nanchang University, Nanchang 330031, PR China

4 School of Rare earths, University of Science and Technology of China, Ganzhou 341000, PR China

*Corresponding author, Email: fjli19@ipe.ac.cn, xpzhang@ipe.ac.cn

The separation of rare earth elements (REEs) is particularly difficult due to their similar physicochemical properties. Based on the tiny differences of ionic radius, solvent extraction has been developed as the “mass method” in industry with hundreds of stages, extremely intensive chemical consumption and large capital investments. The differences of the ionic magnetic moment among REEs are greater than that of ionic radius. Herein, a novel method based on the large ionic magnetic moment differences of REEs was proposed to promote the separation efficiency. REEs were firstly dissolved in the ionic liquid, then the ordering degree of REEs was improved with the Z-bond effect, and finally the magnetic moment differences between paramagnetic and diamagnetic REEs in quasi-liquid (QL) system were enhanced. Taking the separation of Er/Y, Ho/Y and Er/Ho as examples, the results showed that Er(III) and Ho(III) contained ionic liquids(ILs) had obvious magnetic response, while ILs containing Y(III) had no response. The separation factors of Er/Y and Ho/Y were achieved at 9.0 and 28.82, respectively. It was obviously higher than that of the traditional separation method with β_Er/Y and β_Ho/Y of 1.4 and 1.64 by P507. Magnetic separation via quasi-liquid system strategy provides a possibility of novel, green, and efficient method for rare earth separation.

Keywords: rare earth element, different magnetic moment, magnetic separation, ionic liquid