This article aims to reduce the environmental pollution while maximizing the recovery of REEs as well as associate resource-fluorine (F) from bastnaesite. This paper investigates the extraction equilibrium process and mechanism of Ce(IV)–HF–H₃BO₃–H₂SO₄ system using Cyanex 923. Extraction equilibrium process of different systems, including HF–H₂SO₄, H₃BO₃–HF–H₂SO₄, and Ce(IV)–HF–H₂SO₄, were studied in detail and the corresponding extraction mechanisms were also determined. It is noteworthy that a synergistic effect between B–F and an antagonistic effect between Ce(IV)–F were discovered first in the extraction process by Cyanex 923. Besides, H₃BO₃ is found to be able to promote the extraction of F in quantitation by Cyanex 923. FTIR and ¹¹B and ¹⁹F NMR were adopted to characterize the different loaded organic phase. Based on these results, the extraction mechanism of complicated system Ce(IV)-HF-H₃BO₃–H₂SO₄ was further determined. Besides, the effect of H₃BO₃ on the extraction and stripping of Ce(IV) in complicated system was studied. Moreover, it shows that the addition of H₃BO₃ has nothing to do with the purity of obtained CeF₃ particle from bastneasite liquor in the practical system. Adding H₃BO₃ into bastnaesite leach liquor, on the one hand, will be beneficial for the recovery yield of Ce and F. On the other hand, it can avoid from environmental pollution caused by emission of F-containing waste water as well as reducing the waste residue.

本文旨在减少环境污染，同时最大限度地从氟碳铈矿中回收稀土元素和伴生资源氟（F）。本文研究了使用 Cyanex 923的 Ce(IV)–HF–H ₃ BO ₃ –H ₂ SO ₄体系的萃取平衡过程和机理。不同体系的萃取平衡过程，包括 HF–H ₂ SO ₄、H ₃ BO ₃ –HF–H ₂ SO ₄和 Ce(IV)–HF–H ₂ SO ₄, 进行了详细研究，并确定了相应的提取机制。值得注意的是，Cyanex 923 在提取过程中首先发现了 B-F 之间的协同作用和 Ce(IV)-F 之间的拮抗作用。此外，发现H ₃ BO ₃能够促进 F 的提取通过 Cyanex 923 进行定量。采用 FTIR 和¹¹ B 和¹⁹ F NMR 来表征不同负载的有机相。基于这些结果，进一步确定了复杂体系Ce(IV)-HF-H ₃ BO ₃ -H ₂ SO ₄的萃取机理。此外，H ₃ BO _{3 的作用}研究了复杂体系中Ce(IV)的萃取和汽提。而且，在实际系统中，H ₃ BO _{3 的}加入与从氟碳铈矿液中得到的CeF ₃颗粒的纯度无关。在氟碳铈矿浸出液中加入H ₃ BO ₃，一方面有利于Ce和F的回收率，另一方面可以避免含F废水的排放和环境污染减少废渣。