The objective of this study was to address the challenges associated with complex TRPO waste,by utiliz-ing a natural aluminosilicate material to produce glass-ceramic waste forms.When the simulated waste content was b...The objective of this study was to address the challenges associated with complex TRPO waste,by utiliz-ing a natural aluminosilicate material to produce glass-ceramic waste forms.When the simulated waste content was below 30 wt.%,glassy waste forms were successfully obtained.Ce and Fe played crucial roles in the formation of Si-O-Ce bonds and[FeO_(4)]-tetrahedra in the glass network,which effectively immo-bilized other waste elements.However,when the waste content exceeded 30 wt.%,the waste was incor-porated into feldspar,iron-manganese crystals,fluorite ceramic,and glass.This combination of ceramic and glass matrices synergistically immobilized the waste,resulting in excellent mechanical performance and chemical durability.The leaching rates of LR_(Ce)and LR_(Nd)were remarkably low around-10^(−6)to 10^(−7)g m^(−2)d^(−1),after 42 d.Furthermore,the study also investigated the role of multi-valence elements,such as Ce,Fe,and Mn,in the formation of iron-containing aluminosilicate glass-ceramics.The findings offer a novel approach to effectively immobilize complex nuclear waste.展开更多
In this study, Nd-bearing zirconolite-rich ceramics were prepared by solid-state reaction process using CaF2,ZrO2, Ti,TiO2, Fe2 O3 and Nd2O3 as the raw materials. Neodymium was used as trivalent actinide surrogate and...In this study, Nd-bearing zirconolite-rich ceramics were prepared by solid-state reaction process using CaF2,ZrO2, Ti,TiO2, Fe2 O3 and Nd2O3 as the raw materials. Neodymium was used as trivalent actinide surrogate and designed to substitute the Ca and Zr sites of zirconolite with general stoichiometry of Ca1-xZr1-xNd2 xTi2O7（0≤x≤0.3）. Density of Fe-Nd-O sample reaches a maximum value of 4.13 g/cm^2 after being sintered at 1325 ℃ for 42 h. Three major phases, namely zirconolite, perovskite and pseudobrookite, are observed in all these samples. The EDX result shows that Nd2O3 can be successfully incorporated into the lattice structure of the prepared zirconolite-rich minerals and replace the Ca sites of zirconolite and perovskite with Fe3＋ as the charge-compensating ion. Furthermore, the thermal conductivities are all in the range of 1.51-1.67 W/（m·K）. The normalized elemental leaching rates of Ca and Nd in the Fe-Nd-0.2 sample keep in low values of 6.20 × 10^-2 and 4.86 × 10^-4 g/（m^2·d） after 42 d.展开更多
This paper studies the helium ions irradiation effects on Nd and Ce co-doped Gd_2 Zr_2 O_7 ceramics. where Nd replaces the Gd site and Ce replaces the Zr site respectively. A series of（Gd_（1-x）Nd_x）_2（Zr_（1-y）C...This paper studies the helium ions irradiation effects on Nd and Ce co-doped Gd_2 Zr_2 O_7 ceramics. where Nd replaces the Gd site and Ce replaces the Zr site respectively. A series of（Gd_（1-x）Nd_x）_2（Zr_（1-y）Ce_y）_2 O_7（0 ≤ x, y ≤ 1） ceramics were irradiated with a 500 keV He ions at room temperature at fluences ranging from 1 × 10^（15） to 1 × 10^（17） ions/cm^2. The irradiated samples were characterized using GIXRD, Raman and SEM measurements. From the GIXRD and Raman observations, the results indicate that all the samples display a deficient fluorite structure after irradiation. The irradiation toleration increases with the irradiation depth increasing under experimental conditions, and Nd_2 Ce_2 O_7 has the best irradiation stability in the（Gd_（1-x）Nd_x）_2（Zr_（1-y）Ce_y）_2 O_7（0≤ x. y≤1）. Based on SEM results, the irradiated samples are still relatively dense and uniform, and no second phase exists.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21976146 and U2167221)the Project of State Key Laboratory of Environment-friendly Energy Materials,Southwest University of Science and Technology(No.23fksy10)+2 种基金the Open Foundation of Nuclear Medicine Laboratory of Mianyang Central Hospital(No.2021HYX028)the Sichuan Science and Technology Program(No.2023NSFSC0353)the Applied Basic Research Project of Science and Technology Department of Sichuan Province(No.2022NSFSC1197)。
文摘The objective of this study was to address the challenges associated with complex TRPO waste,by utiliz-ing a natural aluminosilicate material to produce glass-ceramic waste forms.When the simulated waste content was below 30 wt.%,glassy waste forms were successfully obtained.Ce and Fe played crucial roles in the formation of Si-O-Ce bonds and[FeO_(4)]-tetrahedra in the glass network,which effectively immo-bilized other waste elements.However,when the waste content exceeded 30 wt.%,the waste was incor-porated into feldspar,iron-manganese crystals,fluorite ceramic,and glass.This combination of ceramic and glass matrices synergistically immobilized the waste,resulting in excellent mechanical performance and chemical durability.The leaching rates of LR_(Ce)and LR_(Nd)were remarkably low around-10^(−6)to 10^(−7)g m^(−2)d^(−1),after 42 d.Furthermore,the study also investigated the role of multi-valence elements,such as Ce,Fe,and Mn,in the formation of iron-containing aluminosilicate glass-ceramics.The findings offer a novel approach to effectively immobilize complex nuclear waste.
基金Project supported by the National Natural Science Foundation of China(51672228)the Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials(11zxfk26)Science Development Foundation of China Academy of Engineering Physics
文摘In this study, Nd-bearing zirconolite-rich ceramics were prepared by solid-state reaction process using CaF2,ZrO2, Ti,TiO2, Fe2 O3 and Nd2O3 as the raw materials. Neodymium was used as trivalent actinide surrogate and designed to substitute the Ca and Zr sites of zirconolite with general stoichiometry of Ca1-xZr1-xNd2 xTi2O7（0≤x≤0.3）. Density of Fe-Nd-O sample reaches a maximum value of 4.13 g/cm^2 after being sintered at 1325 ℃ for 42 h. Three major phases, namely zirconolite, perovskite and pseudobrookite, are observed in all these samples. The EDX result shows that Nd2O3 can be successfully incorporated into the lattice structure of the prepared zirconolite-rich minerals and replace the Ca sites of zirconolite and perovskite with Fe3＋ as the charge-compensating ion. Furthermore, the thermal conductivities are all in the range of 1.51-1.67 W/（m·K）. The normalized elemental leaching rates of Ca and Nd in the Fe-Nd-0.2 sample keep in low values of 6.20 × 10^-2 and 4.86 × 10^-4 g/（m^2·d） after 42 d.
基金Project supported by the National Natural Science Foundation of China(21507105,51574201)Ministry of Housing and Urban-Rural Development(2014-K3-037)+1 种基金Sichuan Science and Technology Innovation Talent Project(2016119)Scientific and Technical Youth Innovation Group(Southwest Petroleum University)(2015CXTD05)
文摘This paper studies the helium ions irradiation effects on Nd and Ce co-doped Gd_2 Zr_2 O_7 ceramics. where Nd replaces the Gd site and Ce replaces the Zr site respectively. A series of（Gd_（1-x）Nd_x）_2（Zr_（1-y）Ce_y）_2 O_7（0 ≤ x, y ≤ 1） ceramics were irradiated with a 500 keV He ions at room temperature at fluences ranging from 1 × 10^（15） to 1 × 10^（17） ions/cm^2. The irradiated samples were characterized using GIXRD, Raman and SEM measurements. From the GIXRD and Raman observations, the results indicate that all the samples display a deficient fluorite structure after irradiation. The irradiation toleration increases with the irradiation depth increasing under experimental conditions, and Nd_2 Ce_2 O_7 has the best irradiation stability in the（Gd_（1-x）Nd_x）_2（Zr_（1-y）Ce_y）_2 O_7（0≤ x. y≤1）. Based on SEM results, the irradiated samples are still relatively dense and uniform, and no second phase exists.
