Different nanometer CeO_2-ZrO_2 mixed oxides doped with lanthanum or praseodymium were prepared by coprecipi-tation. The characteristics of all mixed oxides were tested by XRD, SEM, TEM, and XPS. XRD results showed th...Different nanometer CeO_2-ZrO_2 mixed oxides doped with lanthanum or praseodymium were prepared by coprecipi-tation. The characteristics of all mixed oxides were tested by XRD, SEM, TEM, and XPS. XRD results showed thatall oxides were formed solid solution with CaF_2 structure at low temperature and had good thermal stability. MoreCe^(4+) ions were rich on the surface by XPS, which were beneficial to oxygen storage. The particle mediun sizes (d_(50))of all oxides powders were approximately 10～20 nm by small angle scattering goniometer. When doped Zr^(4+) inCeO_2, the specific surface areas were improved at low or high temperature. The area of Ce_(0.6)Zr_(0.3)La_(0.04)Pr_(0.06)O_2powder had excess 110 m^2/g after calcining at 923 K for 4 h, even calcined at 1273 K for 4 h, the area was up to65 m^2/g.展开更多
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
文摘Different nanometer CeO_2-ZrO_2 mixed oxides doped with lanthanum or praseodymium were prepared by coprecipi-tation. The characteristics of all mixed oxides were tested by XRD, SEM, TEM, and XPS. XRD results showed thatall oxides were formed solid solution with CaF_2 structure at low temperature and had good thermal stability. MoreCe^(4+) ions were rich on the surface by XPS, which were beneficial to oxygen storage. The particle mediun sizes (d_(50))of all oxides powders were approximately 10～20 nm by small angle scattering goniometer. When doped Zr^(4+) inCeO_2, the specific surface areas were improved at low or high temperature. The area of Ce_(0.6)Zr_(0.3)La_(0.04)Pr_(0.06)O_2powder had excess 110 m^2/g after calcining at 923 K for 4 h, even calcined at 1273 K for 4 h, the area was up to65 m^2/g.
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.
