Tri-n-butyl phosphate as an extracting solvent for inorganic nitrates—III The plutonium nitrates

Some bis (dialkylphosphinyl) methanes as solvent extractants

“…Tetravalent metals probably extract as disolvates of TBP although other solvates have been reported and should be considered. Dilution data which agree with the formation of a disolvate have been reported for zirconium (43,44,(52)(53)(54), hafnium (55,56), neptunium (43), plutonium (32,43,57), and thorium (43, [58][59][60][61]. Solovkin (62) reported that the solva tion number of zirconium with TBP varies from 1.0 to 1.…”

“…The hexavalent actinides extract as disolvates. Plu tonium forms the complex PuO^(NOg)^-2TBP (43, 57,69,70) and neptunium the complex NpO^(NOg)^-2TBP (43). The formation of UOg(NOg)2•2TBP was proposed by Moore (71) and has been confirmed by many workers (38,43,45,(72)(73)(74)(75)(76)(77)(78).…”

Sasse Modeling of a Uranium Molybdenum Separation Flowsheet

“…The distribution coefficients for U(VI) and Pu(IV) decrease as the temperature increases. 18,22 One may assume that the decrease in the distribution coefficients results from a general tendency of metal ions to associate with NO 3 -ions to form extractable complexes to a lesser extent as temperatures increase; if this assumption holds, then the distribution coefficients for Mo(VI) and Pu(III) also should decrease as the temperature increases. It follows that, at the lower temperatures for 1A, 1B, and 1D Banks, the modeled solution components would extract into the organic phase somewhat better than predicted by the SASSE model.…”

“…22,23,24,25 The distribution coefficients at higher TBP concentrations are adjusted downward to equivalent values for 7.5 vol % TBP by multiplying by the ratio of 7.5 vol % to the respective vol % TBP for the data, taken to the 1.4 power. The exponent is based on a correlation of distribution coefficients at 7 M HNO 3 and various TBP concentrations, 25 shown in Figure 8-12.…”

“…7 The Pu(III) distribution coefficient is scaled linearly to measured distribution coefficients for HNO 3 solutions in contact with 19 vol % TBP and 36 vol % TBP in kerosene at 19 to 23 °C. 21,22,23 The 7.5 vol % TBP correlation used to model the proposed flowsheet is scaled to the 19 vol % TBP data, and the 30 vol % TBP correlation used for the validation calculations is scaled to the 36 vol % TBP data. Such scaling should yield conservatively high values for estimated distribution coefficients, since the measured 36 vol % TBP coefficients are more that twice the measured 19 vol % TBP coefficients.…”