Solid-state reaction synthesis and chemical stability studies in Nd-doped zirconolite-rich ceramics  

作　　者：Dan Yin Kuibao Zhang Le Peng Zongsheng He Yuan Liu Haibin Zhang Xirui Lu Dan Yin;Kuibao Zhang;Le Peng;Zongsheng He;Yuan Liu;Haibin Zhang;Xirui Lu(State Key Laboratory Cultivation Base for Nonmetal Composite and Foundational Materials,Southwest University of Science and Technology;National Defense Key Discipline Lab of Nuclear Waste and Environmental Safety, Southwest University of Science and Technology;Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics)

机构地区：[1]State Key Laboratory Cultivation Base for Nonmetal Composite and Foundational Materials, Southwest University of Science and Technology, Mianyang 621010, China [2]National Defense Key Discipline Lab of Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang 621010, China [3]Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China

出　　处：《Journal of Rare Earths》2018年第5期492-498,共7页稀土学报（英文版）

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

摘　　要：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.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.

关 键 词：ZIRCONOLITE PEROVSKITE Pseudobrookite ND2O3 Chemical stability Rare earths 

分 类 号：TQ174.1[化学工程—陶瓷工业]