Vaporization Mechanisms of Water-Insoluble Cs in Ash During Thermal Treatment with Calcium Chloride Addition
Vaporization Mechanisms of Water-Insoluble Cs in Ash During Thermal Treatment with Calcium Chloride Addition
复制标题
添加氯化钙热处理过程中灰分中不溶于水的Cs的蒸发机理
DOI：
10.1021/acs.est.6b03635
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发表时间：
2016
影响因子：
11.4
通讯作者：
Yoshihiko Ninomiya
中科院分区：
文献类型：
--
作者：
Facun Jiao;Norie Iwata;Norikazu Kinoshita;Masato Kawaguchi;Motoyuki Asada;Maki Honda, Keisuke Sueki;Yoshihiko Ninomiya
在500-1500 °C温度范围内，利用电加热炉系统研究了煤灰和掺铯煤灰中不溶于水的铯在CaCl 2热处理过程中的蒸发机理.结果表明，火山灰中不溶于水的铯以铯榴石的形式与铝硅酸盐共生。添加10%CaCl2时，在高于1200 °C的温度下，原灰中Cs的最大蒸发率达到约80%;而添加30%CaCl2时，在高于1300 °C的温度下，Cs的蒸发率约为95%。通过Cs与CaCl 2的化学反应形成的中间化合物CsCaCl 3负责Cs蒸发，该中间化合物随后在温度升高时分解。CaCl 2分解释放的气态氯对Cs的间接氯化作用不明显。在900-1250 °C温度范围内，添加30%CaCl 2的退火产物中CaCl 2含量较高，从而延缓了CsCaCl 3的分解，降低了Cs的蒸发率。添加CaCl 2的热处理是一种从铯污染的焚烧灰中去除铯的方法。
The vaporization mechanisms of water-insoluble Cs in raw ash and Cs-doped ash during thermal treatment with CaCl2addition was systematically examined in a lab-scale electrical heating furnace over a temperature range of 500–1500 °C. The results indicate that the water-insoluble Cs in the ash was associated with aluminosilicate as pollucite. Addition of 10% CaCl2caused the maximum vaporization ratio of Cs in the raw ash to reach approximately 80% at temperatures higher than 1200 °C, whereas approximately 95% of Cs was vaporized at temperatures higher than 1300 °C when 30% CaCl2was added. The formation of an intermediate compound, CsCaCl3, through the chemical reaction of Cs with CaCl2was responsible for Cs vaporization by means of the subsequent decomposition of this intermediate upon the increase in temperature. The indirect chlorination of Cs by the gaseous chlorine released from the decomposition of CaCl2was insignificant. A high CaCl2content in the resulting annealed products with 30% CaCl2addition delayed the decomposition of CsCaCl3and thus lowered the Cs vaporization ratio compared to that with 10% CaCl2addition at 900–1250 °C. Thermal treatment with CaCl2addition is a proposed method to remove Cs from Cs-contaminated incineration ash.