Theoretical Calculations and Experimental Investigation of Separation of Dy<sup>3+</sup>, Er<sup>3+</sup>, Tm<sup>3+</sup> and Yb<sup>3+</sup> by Cascade Extraction in TOGDA–Kerosene/Hydrochloric Acid System
Yuzhen Bai,
Aijun Gong,
Lina Qiu,
Yiwen Wang,
Ge Gao,
Weiyu Zhao,
Yang Liu,
Jiayi Yin,
Xinyu Huang,
Yiyang Chen
Affiliations
Yuzhen Bai
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Aijun Gong
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Lina Qiu
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Yiwen Wang
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Ge Gao
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Weiyu Zhao
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Yang Liu
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Jiayi Yin
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Xinyu Huang
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Yiyang Chen
School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
The hot spot extraction agent N,N,N′,N′-tetraoctyl-3-oxoglutaramide (TODGA) has the advantages of novelty, high efficiency and environmental protection in the separation of rare earths by tandem extraction. In this paper, the characteristic parameters for the separation of dysprosium, erbium, thulium and ytterbium ions in the TOGDA–kerosene/hydrochloric acid system for tandem extraction were calculated. Using a 10% TODGA–kerosene/5 mol·L−1 hydrochloric acid extraction system, the mixture containing Dy3+ 0.258 mol·L−1, Er3+ 0.252 mol·L−1, Tm3+ 0.248 mol·L−1 and Yb3+ 0.242 mol·L−1 can be separated by three separation steps, and four products of Dy3+, Er3+, Tm3+ and Yb3+ can be obtained. The purity of the four products was 99.80%, 99.20%, 99.70% and 99.70%, and the yields were 99.03%, 98.97%, 97.88% and 96.98%, in order. In this paper, the reasons were analyzed for the differences in the ability of the TODGA system to extract heavy rare earth ions (REEs) in terms of density functionality, complex structure and bond valence model. These will provide more basic data and guidance for the industrial application of TODGA.
