Journal of Inorganic Materials ›› 2023, Vol. 38 ›› Issue (8): 910-916.DOI: 10.15541/jim20220775

Special Issue: 【结构材料】核用陶瓷(202309)

• RESEARCH ARTICLE • Previous Articles     Next Articles

Nd-doped ZrSiO4 Ceramics: Synthesis in Molten Salt at Low Temperature, Phase Evolution and Chemical Stability

LIU Jian1,2(), WANG Lingkun1,2, XU Baoliang1,2, ZHAO Qian1,2, WANG Yaoxuan1,2, DING Yi1,2, ZHANG Shengtai1,2,3(), DUAN Tao1,2()   

  1. 1. National Co-Innovation Center for Nuclear Waste Disposal and Environmental Safety, Southwest University of Science and Technology, Mianyang 621010, China
    2. State Key Laboratory of Environment-friendly Energy Materials, School of National Defence Science & Technology, Southwest University of Science and Technology, Mianyang 621010, China
    3. Innovation Research Team for Advanced Ceramics, Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China
  • Received:2022-12-28 Revised:2023-02-22 Published:2023-08-20 Online:2023-03-17
  • Contact: DUAN Tao, professor. E-mail:; ZHANG Shengtai, assistant.E-mail:
  • About author:LIU Jian(1995-), male, Master candidate. E-mail:
  • Supported by:
    National Natural Science Foundation of China(U2167221);National Natural Science Foundation of China(21906133);National Natural Science Foundation of China(22176157);Sichuan Youth Science and Technology Innovation Research Team of Sichuan Provincial Science and Technology Department(2021JDTD0019);National Defense Basic Scientific Research Project(JCKY2019404D001)


In contrast to conventional solid-phase sintering, molten salt method can provide a fast mass transfer and nucleation process at lower temperatures which has potential to synthesize the ceramic solid solution for immobilization of high-level nuclear waste (HLW). In this work, Nd-doped zircon (ZrSiO4) ceramics (Zr1-xNdxSiO4-x/2 (0≤x≤0.1)) were prepared by the molten salt synthesis(MSS) at different sintering temperatures (1100, 1200, 1300, 1400, 1500 ℃) for different sintering time (3, 6, 9, 12, and 15 h). Chemical stability of Nd-doped zircon ceramics in simulated geological disposal environment was studied by static leaching test (PCT). Zr1-xNdxSiO4-x/2 was synthesized by the molten salt method under the optimum molar ratio of molten salt to oxide at 10:1, sintering temperature at 1200 ℃ and sintering time of 6 h with the solid solution of Nd in ZrSiO4 being increased to 8% (in mol). The MSS can reduce the synthetic temperature, shorten the sintering time and save the solid solution. The immobilizing mechanism of ZrSiO4 ceramics for trivalent actinide nuclides is lattice immobilizing. Experimental results show that the normalized leaching rate (LRNd) of Nd is as low as ~10-5 g·m-2·d-1. ZrSiO4 ceramics have no phase evolution before and after leaching, suggesting good structural stability. TLeaching model consolidates that Nd leaching is due to dissolution of the ceramic surface layer. Data from this study show that MSS is a promising method to synthesize ceramics solid solution.

Key words: immobilization, zircon, molten salt, chemical stability

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