Dissolution and ion structure of NdF₃ in LiF molten salt

The constitution form of ions in the LiF-NdF₃ molten salt system is very important for the analytical electrolytic reduction of neodymium electrode process. In this paper, the ion structure of LiF-NdF₃ molten salt system was analyzed by cryoscopic method. The possible ion clusters in the molten salt system were analyzed by Temkin and Flood models and thermodynamic calculation. The results show that the dissolution model of NdF₃ in LiF is consistent with TemkinⅠ, TemkinⅡ, TemkinⅥ, TemkinⅦ, and Flood Ⅱ, Flood Ⅵ, Flood Ⅶ. In LiF-NdF₃ molten salt system with LiF as the solvent, 1~2 Nd³⁺ ion clusters are formed in F-Nd ion clusters, and NdF₃ is dissolved in LiF to form dissociative Nd³⁺, F^-, Li⁺ and Li⁺·NdF₄^-, Li⁺·Nd₂F₇^-, as well as 2Li⁺·Nd₂F₈^2- molecular clusters.