Separation of REE(III) and Am(III) by Extraction with Compounds of Zirconium and Dibutyl Phosphoric Acid from Solutions of Nitric and Hydrochloric Acids

• Published in: Radiochemistry (New York, N.Y.) Vol. 63; no. 4; pp. 470 - 476
• Main Authors: Shishkin, D. N., Petrova, N. K.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.08.2021; Springer Nature B.V
• Subjects: Americium compounds; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Chloroform; Decalin; Hydrochloric acid; Nitrotoluene; Nonstoichiometric compounds; Nuclear Chemistry; Phosphoric acid; Rare earth elements; Separation; Solvents; Zirconium; DBPA; TPE; REE; extraction; zirconium; separation
• ISSN: 1066-3622; 1608-3288
• DOI: 10.1134/S106636222104010X

The behavior of rare-earth elements (REE) and americium during their extraction with compounds of zirconium and dibutyl phosphoric acid (DBPA) in various solvents from solutions of nitric and hydrochloric acids was studied. It was shown that at a large DBPA to Zr molar ratio, REE and Am(III) are extracted into the organic phase in the form of nonstoichiometric compounds consisting of REE and zirconium cations and tens or hundreds of DBPA molecules. The ability to form such compounds increases with an increase in the serial number of lanthanide. In a number of cases, the change in the concentration of zirconium in the organic phase leads to a noticeable change in the degrees of separation of the elements. The use of decalin as a diluent leads to a maximum increase in the distribution coefficients of REE(III) and Am(III). In hydrochloric acid systems with chloroform or o-nitrotoluene (ONT) solvents at a certain ratio of DBPA to Zr, americium is extracted worse than REE, which may allow their separation.