摘要
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-H_(3)BO_(3)-H_(2)SO_(4)system using Cyanex 923.Extraction equilibrium process of different systems,including HF-H_(2)SO_(4),H_(3)BO_(3)-HF-H_(2)SO_(4),and Ce(Ⅳ)-HF-H_(2)SO_(4),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,H_(3)BO_(3)is found to be able to promote the extraction of F in quantitation by Cyanex 923.FTIR and^(11)B and^(19)F NMR were adopted to characterize the different loaded organic phase.Based on these results,the extraction mechanism of complicated system Ce(Ⅳ)-HF-H_(3)BO_(3)-H_(2)SO_(4)was further determined.Besides,the effect of H_(3)BO_(3)on the extraction and stripping of Ce(Ⅳ)in complicated system was studied.Moreover,it shows that the addition of H_(3)BO_(3)has nothing to do with the purity of obtained CeF_(3)particle from bastneasite liquor in the practical system.Adding H_(3)BO_(3)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.
基金
Project supported by the Open Research Fund for State Key Laboratory of Baiyunobo Rare Earth Resources Researches and Comprehensive Utilization(E0900001)
the National Basic Research Program of China(2012CBA01202)
the National Natural Science Foundation of China(51174184)。
