The process based on supercritical fluid extraction for reprocessing of the spent nuclear fuel has some remarkable advantages over the plutonium-uranium extraction(PUREX) process.Especially,it can minimize the generat...The process based on supercritical fluid extraction for reprocessing of the spent nuclear fuel has some remarkable advantages over the plutonium-uranium extraction(PUREX) process.Especially,it can minimize the generation of secondary waste.Dynamic reactive extraction of neodymium oxide(Nd2O3) in supercritical carbon dioxide(SC-CO2) containing tri-n-butyl phosphate-nitric acid(TBP-HNO3) complex was investigated.Temperature showed a positive effect on the extraction efficiency,while pressure showed a negative effect when the unsaturated TBP-HNO3 complex was employed for the dynamic reactive extraction of Nd2O3 in SC-CO2.Both temperature and pressure effects indicated that the kinetic process of the reactive extraction was controlled by the chemical reaction.A kinetic model was proposed to describe the extraction process.展开更多
The tri-n-butyl phosphate-nitric acid （TBP-HNO3） complex prepared by contacting the pure TBP with the concentrated HNO3 can be used for direct dissolution of lanthanide and actinide oxides in the supercritical fluid...The tri-n-butyl phosphate-nitric acid （TBP-HNO3） complex prepared by contacting the pure TBP with the concentrated HNO3 can be used for direct dissolution of lanthanide and actinide oxides in the supercritical fluid carbon dioxide （SCF-CO2）. Properties of the TBP-HNO3 complex have been studied. Experimental results showed that when the initial HNO3/TBP volume ratio was varied from 1 ： 7 to 5 ： 1, the concentration of HNO3 in the TBP-HNO3 complex changed from 1.95 to 5.89 mol/L, the [HNO3]/[TBP] ratio of the TBP-HNO3 complex changed from 0.61 to 2.22, and the content of H20 in the TBP-HNO3 complex changed from 2.02% to 4.19%. All of the density, viscosity and surface tension of the TBP-HNO3 complex changed with the concentration of HNO3 in the complex, and were higher than those of the pure TBE The protons of HNO3 and H2O in the complex underwent rapid exchange to exhibit a singlet resonance peak in nuclear magnetic resonance spectra. When the TBP-HNO3 complex was dissolved in a low dielectric constant solvent, small droplets of HNO3 were formed that can be detected by NMR.展开更多
基金Supported by the National Natural Science Foundation of China （20506014）.
文摘The process based on supercritical fluid extraction for reprocessing of the spent nuclear fuel has some remarkable advantages over the plutonium-uranium extraction(PUREX) process.Especially,it can minimize the generation of secondary waste.Dynamic reactive extraction of neodymium oxide(Nd2O3) in supercritical carbon dioxide(SC-CO2) containing tri-n-butyl phosphate-nitric acid(TBP-HNO3) complex was investigated.Temperature showed a positive effect on the extraction efficiency,while pressure showed a negative effect when the unsaturated TBP-HNO3 complex was employed for the dynamic reactive extraction of Nd2O3 in SC-CO2.Both temperature and pressure effects indicated that the kinetic process of the reactive extraction was controlled by the chemical reaction.A kinetic model was proposed to describe the extraction process.
基金Project supported by the National Natural Science Foundation of China （No. 20506014）.
文摘The tri-n-butyl phosphate-nitric acid （TBP-HNO3） complex prepared by contacting the pure TBP with the concentrated HNO3 can be used for direct dissolution of lanthanide and actinide oxides in the supercritical fluid carbon dioxide （SCF-CO2）. Properties of the TBP-HNO3 complex have been studied. Experimental results showed that when the initial HNO3/TBP volume ratio was varied from 1 ： 7 to 5 ： 1, the concentration of HNO3 in the TBP-HNO3 complex changed from 1.95 to 5.89 mol/L, the [HNO3]/[TBP] ratio of the TBP-HNO3 complex changed from 0.61 to 2.22, and the content of H20 in the TBP-HNO3 complex changed from 2.02% to 4.19%. All of the density, viscosity and surface tension of the TBP-HNO3 complex changed with the concentration of HNO3 in the complex, and were higher than those of the pure TBE The protons of HNO3 and H2O in the complex underwent rapid exchange to exhibit a singlet resonance peak in nuclear magnetic resonance spectra. When the TBP-HNO3 complex was dissolved in a low dielectric constant solvent, small droplets of HNO3 were formed that can be detected by NMR.
