Recovery of fluorine utilizing complex properties of cerium(IV) to obtain high purity CeF3 by solvent extraction

Abstract

Abstract Utilizing complex properties of cerium(IV) with fluorine(I), this paper investigated the recovery of fluorine from nitrate solutions in the form of CeF 3 by solvent extraction. The extraction mechanism was studied firstly, and then CeF 3 was obtained from the extracted organic phase by reductive stripping. The effects of the main parameters such as HNO 3 concentration, extractant concentration, F(I) concentration, salting-out agent concentration and the temperature were examined and discussed. Showing that HNO 3 concentration, salting-out agent concentration and the temperature did not affect the extraction of Ce(IV). The presence of F(I) can decrease the extraction of Ce(IV). The extraction of HNO 3 , Ce(IV) and Ce(IV)-F have been studied respectively, and the extracted complexes are considered to be HNO 3 ·Cyanex923, Ce(NO 3 ) 4 ·2Cyanex923 and Ce(HF)(NO 3 ) 4 ·Cyanex923 individually. The extraction mechanisms were concluded according to slope analysis, and the loading capacities of Ce(IV) had been obtained. The Infrared Spectra of extracted complexes was determined, showing that the NO 3 − ion is a bidentate ligand. High purity CeF 3 nanoparticle was obtained and the size distribution, SEM and TEM images of the nanoparticle were given, CeF 3 nanoparticle was acquired also in H 2 SO 4 system and the difference between the two CeF 3 were compared.