Synergistic extraction of uranyl nitrate by the binary system of N,N Di-isopropyl butylamide and HPMBP

The extraction of uranium at higher nitrate ion concentration and the binary synergistic extraction of uranium at lower nitrate ion concentration were investigated by using DIPBA and DIPBA-HPMBP respectively. At higher nitrate ion concentration, the extractive equilibrium constant of N, N-DIPBM was determined to be Logβ10 = -0.27. By determining the effect of temperature on the distribution ratio, ΔG0, ΔH and ΔS0 of the individual reaction were evaluated as follows: ΔG0 = -1.72 kJ/mol; ΔH = -16.2 kJ/mol; ΔS0 = -60 J/Kmol. At pH = 1.5, DIPBA and PMBP have synergistic effect. The formation of binary extracted complex, UO2(PMBP)2DIPBA, was confirmed by the conventional slope method. The equilibrium constant Logβ12 = 4.51, and the effect of temperature ΔSdeg12 = -14.4 J/Kmol were determined