The behavior of N,N,N′,N′-tetrabutylmalonamide(TBMA) in extraction of Tm(Ⅲ) using toluene as diluent has been investigated. The effects of the concentrations of TBMA, nitric acid, lithium nitrate, and temperature on the extraction have been studied. The composition of the extracted species was found to be Tm(NO3)3·3TBMA as characterized by IR spectrometry. The apparent equilibrium constant of extraction has been determined to be (0.61±0.18) L^6/mol^-6 at 298 K. Enthalpy of the extraction reaction is -27.61 kJ/mol.
Study on the extraction and separation of rare earth with new extractants is important in the rare earth chemistry and nuclear reprocessing. In this work, the extraction of Ce?with N,N,N′,N′ tetrabutylmalonamide (TBMA) in toluene from nitrate media has been investigated. The effect of the concentration of nitric acid, TBMA and salting out agent (LiNO3) and also the temperature on the distribution ratios was examined. The stoichiometries of the extracted complexes were determined to be Ce(NO3)3·3TBMA and Ce(NO3)3·4TBMA, respectively. The apparent extraction constants and the enthalpy of the extraction were calculated based on the extraction data, which are logKex1=3.97, logKex2=4.75 and =-31.25kJ·mol-1, respectively. The IR spectra of the loaded organic phase supported the suggested extraction mechanism.