Basic properties of a silica-based octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) extraction resin (CMPO/SiO2-P) was investigated.Adsorption behavior for some rare earth elements (RE) which are con...Basic properties of a silica-based octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) extraction resin (CMPO/SiO2-P) was investigated.Adsorption behavior for some rare earth elements (RE) which are constituents of high level liquid waste (HLLW) and the long-term stability of the extraction resin in nitric acid solution were examined.The CMPO extraction resin was significantly stable in 3 mol·L?1 HNO3 solution at 50oC.Furthermore,the RE(III) were efficiently separated from non-adsorptive fission product (FP) elements such as Sr(II) in a column experiment using a highly nitric acid solution.The separation behaviors of the elements are considered to result from the difference in their adsorption and elution selectivity based on the complex formation with CMPO.There was no strong dependency of RE(III) separation efficiency on feed solution flow rate.Only from the perspectives of the acid-resistant behavior of CMPO extraction resin and the elution kinetics for the metal ions with the extraction resin,the CMPO extraction resin can be used in the modified MAREC process for HLLW partitioning.展开更多
In order to directly separate trivalent minor actinides （MA： Am, Cm） from fission products （FP） containing rare earths （RE） in high level radioactive liquid waste （HLLW）, the authors have challenged to develo...In order to directly separate trivalent minor actinides （MA： Am, Cm） from fission products （FP） containing rare earths （RE） in high level radioactive liquid waste （HLLW）, the authors have challenged to develop a simplified MA separation process by extraction chromatography using a single column. Attention has been paid to a new type of nitrogen-donor ligands, R-BTP （2,6-bis（5,6-dialkyl-1,2,4-triazin-3-yl） pyridine, R： alkyl group） as an extractant because it shows high extraction selectivity for Am（Ⅲ） over RE（Ⅲ）. It is known that the R-BTP ligands show different properties such as adsorbability and stability by hav- ing different alkyl groups. Therefore, some novel adsorbents were prepared by impregnating different types of R-BTP ligands （isohexyl-, isoheptyl- and cyheptyl-BTP） and a similar ligand to the R-BTP, ATP （2,6-bis（l-aryl-lH-tetrazol-5-yl）pyridines）, into the porous silica/polymer support （SiOrP particles）. This work deals with comparison in adsorption and desorption prop- erties of Am and some FP in HNO3 solution onto such R-BTP type adsorbents, as well as chemical and radiolytic stability of the adsorbents. Then the possibility of a single-column separation of MA from main FP was pursued by evaluating the results of column experiments using the most promising adsorbent （isohexyl-BTP/SiO2-P） under temperature control. In addition, elu- tion behaviors of U and Pd were also estimated.展开更多
文摘Basic properties of a silica-based octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) extraction resin (CMPO/SiO2-P) was investigated.Adsorption behavior for some rare earth elements (RE) which are constituents of high level liquid waste (HLLW) and the long-term stability of the extraction resin in nitric acid solution were examined.The CMPO extraction resin was significantly stable in 3 mol·L?1 HNO3 solution at 50oC.Furthermore,the RE(III) were efficiently separated from non-adsorptive fission product (FP) elements such as Sr(II) in a column experiment using a highly nitric acid solution.The separation behaviors of the elements are considered to result from the difference in their adsorption and elution selectivity based on the complex formation with CMPO.There was no strong dependency of RE(III) separation efficiency on feed solution flow rate.Only from the perspectives of the acid-resistant behavior of CMPO extraction resin and the elution kinetics for the metal ions with the extraction resin,the CMPO extraction resin can be used in the modified MAREC process for HLLW partitioning.
文摘In order to directly separate trivalent minor actinides （MA： Am, Cm） from fission products （FP） containing rare earths （RE） in high level radioactive liquid waste （HLLW）, the authors have challenged to develop a simplified MA separation process by extraction chromatography using a single column. Attention has been paid to a new type of nitrogen-donor ligands, R-BTP （2,6-bis（5,6-dialkyl-1,2,4-triazin-3-yl） pyridine, R： alkyl group） as an extractant because it shows high extraction selectivity for Am（Ⅲ） over RE（Ⅲ）. It is known that the R-BTP ligands show different properties such as adsorbability and stability by hav- ing different alkyl groups. Therefore, some novel adsorbents were prepared by impregnating different types of R-BTP ligands （isohexyl-, isoheptyl- and cyheptyl-BTP） and a similar ligand to the R-BTP, ATP （2,6-bis（l-aryl-lH-tetrazol-5-yl）pyridines）, into the porous silica/polymer support （SiOrP particles）. This work deals with comparison in adsorption and desorption prop- erties of Am and some FP in HNO3 solution onto such R-BTP type adsorbents, as well as chemical and radiolytic stability of the adsorbents. Then the possibility of a single-column separation of MA from main FP was pursued by evaluating the results of column experiments using the most promising adsorbent （isohexyl-BTP/SiO2-P） under temperature control. In addition, elu- tion behaviors of U and Pd were also estimated.
