Hydrofluorocarbon Diluent for CMPO Without Third Phase Formation: Extraction of Uranium(VI) and Lanthanide(III) Ions. Issue 7 (3rd May 2022)

• Record Type: Journal Article
• Authors: Tabata, Chihiro; Nakase, Masahiko; Harigai, Miki; Shirasaki, Kenji; Sunaga, Ayaki; Yamamura, Tomoo
• Is Part Of: Separation science and technology. Volume 57:Issue 7(2022)
• Page Start: 1097
• Page End: 1110
• Publication Date: 2022-05-03
• Subjects: Solvent extraction -- nuclear fuel reprocessing -- truex process; Separation (Technology) -- Periodicals; 660.284205
• DOI: 10.1080/01496395.2021.1970767
• Languages: English
• ISSNs: 0149-6395

Abstract

ABSTRACT: The extraction behaviors of trivalent lanthanides (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and hexavalent uranium with octylphenyl( N, N -diisobutylcarbamoylmethyl)phosphine oxide (CMPO) from a nitric acid medium were studied using hydrofluorocarbon (1, 1, 1, 2, 2, 3, 4, 5, 5, 5- decafluoropentane: HFC-43) as a nonflammable diluent. It was revealed that HFC-43 exhibits high solubility of CMPO even in the absence of tributylphosphate (TBP), which has typically been necessary to prevent third-phase formation in the conventional TRUEX process using n -dodecane as a diluent. Distribution ratios have been studied as a function of aqueous HNO 3 concentrations, CMPO concentrations, and ionic radii of lanthanide(III) ions. The stoichiometry of the extracted coordination complex was examined based on the slope analysis, and it was determined that two to three CMPO molecules are coordinated to one lanthanide or uranium ion. The feasibility of the process is indicated by the distribution ratio, which is comparable to the conventional system using n -dodecane as diluent. In addition, the safety benefits of applying the nonflammable solvent HFC to the TRUEX process are also presented.