Chemical stability of Ce-doped zircon ceramics: Influence of pH, temperature and their coupling effects

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• 作者：Yi XIE (谢 忆)^a ; Long FAN (樊 龙)^a ; Xiaoyan SHU (舒小艳)^a ; Fangting CHI (匙芳廷)^a ; Yi DING (丁 艺)^a ; Dengsheng MA (马登生)^a ; Xirui LU (卢喜瑞)^a ; ^b ; ^{luxiruimvp116@163.com}
• 关键词：high-level radioactive waste ; waste form ; zircon ; chemical durability ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：35
• 期：2
• 页码：164-171
• 全文大小：6553 K
• 卷排序：35

文摘

Zircon was employed to immobilize simulated tetravalentactinide nuclide (Ce4+). Zr1−xCexSiO4 (0≤x≤0.10) ceramics were synthesized and their chemical durabilities were investigated systematically. The effects of pH and temperature on the chemical durability of the as-prepared compounds were investigated using the MCC-1 static leaching test, and their coupling effects were also explored. It was found that the normalized release rates of Ce in deionized water and alkaline solutions (pH=10) were smaller than those in acid solutions (pH=4). At a certain pH value, the normalized release rate of Ce (LRCe) increased with the temperature in the initial period. However, the leaching progress almost reached a balance after 14 days, and both of the pH and the temperature had slight impact on the leaching of Ce element. Moreover, the LRCe were below 10−5 g/m2/d after 42 days, which was lower than those of other nuclear waste forms in all discussed leachates.