ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Separation of cerium(IV) and yttrium(III) from citrate medium by solvent extraction using D2EHPA in kerosene

E. M. Abu Elgoud, Z. H. Ismail, Y. A. El-Nadi, and H. F. Aly

Hot Laboratories Center, Atomic Energy Authority, Cairo, Egypt

E-mail: elsayedmustafa36@yahoo.com

Received: 19 October 2019  Accepted: 28 January 2020

Abstract:

The extraction and separation of cerium(IV) and yttrium(III) from citric acid solution using Di-2-ethylhexyl phosphoric acid, D2EHPA, in kerosene was investigated. The effects of the different parameters on the extraction process, including the shaking time, extractant concentration, phase ratio, acid concentration as well as, temperature, were separately investigated to achieve the maximum possible separation between Ce(IV) and Y(III). The extraction constant was modeled based on the most predominant citrate cationic species at pH 4.0. The stoichiometry of the extracted species was found to be [Ce(H₂Cit)₂·2A(HA)] and [Y(H₂Cit)·2A(HA)], (where HA denotes D2EHPA), based on the slope analysis method applied on the obtained results. The mean conditional extraction constants values K_C.ex were found to be 4.15 × 10² ± 0.05 and 5.36 ± 0.28 × 10³ for Ce(IV) and Y(III), respectively. The thermodynamic functions associated with the extraction reaction were evaluated and discussed. It was found that the extraction process is spontaneous and exothermic for both metal ions. Possible separation of Y(III) from Ce(IV) was given in terms of the separation factors at different extraction conditions.

Keywords: Extraction; REEs; Citric acid; D2EHPA; Separation

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01083-8

Chemical Papers 74 (8) 2461–2469 (2020)