Separation of uranium(VI) and americium(III) by Extraction from Na2CO3–H2O2 solutions using methyltrioctylammonium carbonate in toluene

Abstract

ABSTRACT Liquid–liquid extraction of carbonate and mixed peroxo-carbonate compounds of U(VI) and Am(III) from Na2CO3 aqueous solutions by methyltrioctylammonium carbonate in toluene has been studied. The main patterns of effect of extractant, Na2CO3, and H2O2 concentration on distribution and separation of U(VI) and Am(III) have been established. Using slope analysis and UV–vis spectroscopy, the compositions of U(VI) and Am(III) extractable compounds are established as (R4N)4[UO2(CO3)3], (R4N)4[UO2(О2)(CO3)2], and (R4N)6[(UO2)2(O2)(CO3)4] for U(VI); R4N[Am(CO3)2] and (R4N)3[Am(CO3)3] for Am(III), where R4N is the quaternary ammonium cation. The obtained data showed high efficiency of the studied carbonate system for extraction of U(VI) and its purification from Am(III). The maximum separation factor of U(VI) and Am(III) was 25.