The mechanism of extraction of uranium(VI) from nitric acid solutions with anovel extractant N
N’-tetrahexylmalonamide (THMA) in n-octane was investigated. The effects of concentrations of aqueous nitric acid
extractant and sodium nitrate and also the temperature on extraction distribution ratios were studied. The extraction stoichiometry was established and the structure of extracted complex was analyzed by means of the IR spectra.The extraction constant of uranium(VI) with THMA and the reaction enthalpy were calculated.Compared with N
N’-tetrabutyl- malonamide (TBMA)
it is shown that the increase of the alkyl chain for THMA lowers the formation of third phase. The study of the effect of diluents indicates that the extractability of THMA in n-octane for uranium(Vl ) is higher than that in toluene.