I&EC 133 |
 Extraction of U(VI), Np(V), Pu(IV), and Am(III) with tetraisobutyl-3-oxa-glutaramide (TiBOGA) was investigated. An organic phase of 0.2 mol/L TiBOGA in 40/60% (V/V) 1-octanol/kerosene showed good extractability for actinides (III, IV, V VI) from 0.1 to 4 mol/L HNO3. At 25 oC, the distribution ratio of the actinides (DAn) generally increased as [HNO3] was increased from 0.1 to 4 mol/L. The slope analysis of the dependence of DAn on the concentrations of reagents suggests that the formula of extracted complexes were UO2L2(NO3)2, NpO2L2(NO3), PuL(NO3)4, and AmL3(NO3)3, where L = TiBOGA. The enthalpy and entropy of extraction were calculated from the dependence of D on temperature in the range of 15 – 55 oC. A test run with 0.2 mol/L TiBOGA in 40/60% 1-octanol/kerosene was performed to separate actinides from a simulated acidic high-level liquid waste (HLLW), using tracer amounts of 238U(VI), 237Np(V), 239Pu(VI), and 241Am(III). The distribution ratios of U(VI), Np(V), Pu(VI), and Am(III) were 12.4, 3.9, 87, and >1000, respectively, confirming that TiBOGA is a promising extractant for the separation of actinides from acidic HLLW. Structures of the actinide complexes with tetramethyl-3-oxa-glutaramide (TMOGA) were determined by X-ray crystallography. Acknowledgment. Part of the experimental work was performed at the Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, China. |
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Separation of f-Elements, Sponsored by Separation Science and Technology Sub-Division
1:45 PM-4:50 PM, Tuesday, 12 September 2006 Moscone Center -- Room 250, Oral
Division of Industrial & Engineering Chemistry |