The effects of temperature and Ce-dopant concentration on the synthesis of zirconolite glass-ceramic. Issue 9 (15th June 2019)

• Record Type: Journal Article
• Authors: Lv, Peng; Chen, Liang; Zhang, Bingtao; Zhang, Duofei; Yuan, Wei; Duan, Binghuang; Guan, Yedong; Pan, Chenglong; Chen, Zhehao; Zhang, Limin; Wang, Tieshan
• Is Part Of: Ceramics international. Volume 45:Issue 9(2019)
• Page Start: 11819
• Page End: 11825
• Publication Date: 2019-06-15
• Subjects: Zirconolite glass-ceramic -- Crystallization behavior -- Temperature effects -- Structure change -- Ce doping; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.03.060
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Zirconolite based glass-ceramic has been deemed as a promising waste form for high-level waste (HLW). In this study, the zirconolite (nominally CaZrTi2 O7 ) glass-ceramic based on a SiO2 -B2 O3 -Na2 O-CaO-ZrO2 -TiO2 -Al2 O3 system was sought to be synthesized by two-step thermal treatment. The temperature effects such as nucleation temperature and cooling rate were studied. The influence of the Ce-dopant concentration on crystallization behavior was also investigated. For characterization, powder X-ray diffraction (XRD), thermogravimetry-differential scanning calorimeter (TG-DSC) and scanning electron microscopy (SEM) were applied. Our results illustrate that homogeneous zirconolite with the particle size of 1.8 μm can be the target phase when the glass matrix underwent a rapid cooling process and the nucleation temperature was controlled at around 860 °C. Besides, the results also indicate that the distribution of the zirconolite along with its lattice parameters change regularly as the increase of CeO2 concentration. A larger crystal size of zirconolite phase and some trace amounts of precipitated phases are observed when the CeO2 concentration exceed 3 wt%. This work emphasizes the synthesis of zirconolite glass-ceramic in a SiO2 -B2 O3 -Na2 O-CaO-ZrO2 -TiO2 -Al2 O3 system, which is expected to provide basic technical data for underground disposal of HLW.