标题: Synergistic solidification of radioactive waste salts by thermal synthesis of sodalite derived from kaolinite

作者: Feng, JY (Feng, Junyi); Jiang, YQ (Jiang, Yuqi); Du, KF (Du, Kaifa); Li, W (Li, Wei); Yin, HY (Yin, Huayi); Deng, BW (Deng, Bowen); Wang, DH (Wang, Dihua)

来源出版物: SEPARATION AND PURIFICATION TECHNOLOGY  卷: 369  文献号: 132842  DOI: 10.1016/j.seppur.2025.132842  Published Date: 2025 OCT 7  

摘要: Capturing and solidifying the fission elements in radioactive waste salt is an urgent task for the safe treatment and final disposal of spent fuels. In this paper, we present a synergistic method that combines low-temperature solution-based precursor preparation with high-temperature solid-phase sintering to synthesize sodalite while simultaneously solidifying radioactive waste salts in situ using kaolinite, a clay mineral that is economically viable and widely available. Various material characterization methods were employed to elucidate the mechanism of sodalite's solidification of fission elements. The results demonstrated that a sodalite solidified body with strong thermal stability and high mechanical strength could be achieved when the precursor was sintered at 800 degrees C for 2 h. The sodalite solidified body synthesized under 50 MPa pressure exhibits a specific surface area of 2.14 m(2)/g, a low porosity of 1.30%, a high bulk density of 2.20 g/cm(3), and a fracture toughness of 3.16 MPa center dot m(1/2). Normalized leaching rate experiments indicated that the solidification effect of sodalite on Cs, Sr, Ba, and Ce was significant. Specifically, the normalized leaching rates of Cs, Sr, Ba, and Ce all remained well below 5 x 10(-4) g center dot cm(-2)center dot d(-1) after 28 days. Furthermore, the solidification of these four fission elements by sodalite involves mechanisms such as ion exchange, lattice solidification, coordination chelation, and physical and chemical adsorption. In summary, the sodalite synthesized by this method exhibited excellent curing performance without the need for additional sintering agents or secondary glass coatings. The findings of this study will serve as a valuable reference for the final disposal of irradiated nuclear fuels.

作者关键词: Nuclear energy; Radioactive waste salt; Solidification; Stabilization; Sodalite; Kaolinite

KeyWords Plus: GLASS-CERAMICS; HEAT-CAPACITY; IMMOBILIZATION; FORMS; POLLUCITE; CESIUM; DISSOLUTION; BENTONITE; KINETICS; ZEOLITE

地址: [Feng, Junyi; Jiang, Yuqi; Du, Kaifa; Li, Wei; Yin, Huayi; Deng, Bowen; Wang, Dihua] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430072, Peoples R China.

通讯作者地址: Deng, BW; Wang, DH (通讯作者)，Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430072, Peoples R China.

电子邮件地址: bwdeng@whu.edu.cn; wangdh@whu.edu.cn

影响因子：8.2