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

Utilizing complex properties of cerium(IV) with fluorine(I), this paper investigated the recovery of fluorine from nitrate solutions in the form of CeF3 by solvent extraction. The extraction mechanism was studied firstly, and then CeF3 was obtained from the extracted organic phase by reductive stripping. The effects of the main parameters such as HNO3 concentration, extractant concentration, F(I) concentration, salting-out agent concentration and the temperature were examined and discussed. Showing that HNO3 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 HNO3, Ce(IV) and Ce(IV)-F have been studied respectively, and the extracted complexes are considered to be HNO3 center dot Cyanex923, Ce(NO3)(4)center dot 2Cyanex923 and Ce(HF) (NO3)(4)center dot 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 NO3- ion is a bidentate ligand. High purity CeF3 nanoparticle was obtained and the size distribution, SEM and TEM images of the nanoparticle were given, CeF3 nanoparticle was acquired also in H2SO4 system and the difference between the two CeF3 were compared.