Enhancement of Cs vaporization from simulated granular ash through thermal treatment in N2 atmosphere with the addition of a mixture of CaCl2 and CaO
Enhancement of Cs vaporization from simulated granular ash through thermal treatment in N2 atmosphere with the addition of a mixture of CaCl2 and CaO
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DOI：
10.1016/j.fuel.2017.11.018
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发表时间：
2018-02
期刊：
影响因子：
7.4
通讯作者：
F. Jiao;N. Kinoshita;M. Kawaguchi;M. Asada;M. Honda;K. Sueki;Y. Ninomiya
中科院分区：
文献类型：
--
作者：
F. Jiao;N. Kinoshita;M. Kawaguchi;M. Asada;M. Honda;K. Sueki;Y. Ninomiya
研究了模拟颗粒灰中Cs的蒸发倾向，并在1100-1500 °C的N2气氛中加入CaCl 2和CaO的混合物。XRD和XPS被用来指定处理后的灰中含Cl物种。结果表明，CaCl 2的加入促进了Cs的挥发。Cs的蒸发率与温度呈非线性关系。在1400 °C下形成的灰熔体通过阻塞孔隙和/或减小灰颗粒的表面积来限制Cs物质的扩散，然而，通过将温度升高到1500 °C来补偿。与单独添加CaCl 2相比，CaCl 2和CaO的混合物的添加显著促进了灰中Cs的挥发。颗粒灰、CaCl 2和CaO之间通过化学反应生成的硅铝石/硅铝榴石，以及添加CaO产生的更多液相，有利于Cs与Cl反应，从而协同促进Cs的蒸发。建议在热处理过程中添加CaCl 2和CaO的混合物来去除受Cs污染的焚烧灰中的Cs。
This study aims to clarify the vaporization propensity of Cs in simulated granular ash through thermal treatment in N2atmosphere at 1100–1500 °C with the addition of a mixture of CaCl2and CaO. XRD and XPS were employed to specify Cl-bearing species in the treated ash. The results indicated that CaCl2addition facilitated the vaporization of Cs. The vaporization ratio of Cs as a function of temperature was nonlinear. The ash melt formed at 1400 °C constrained the diffusion of Cs species by blocking the pores and/or decreasing the surface area of the ash particles which, however, was compensated by increasing the temperature to 1500 °C. The addition of the mixture of CaCl2and CaO highly promoted the vaporization of Cs in the ash compared to that of the addition of CaCl2. Formation of wadalite/igumnovite through chemical reactions among granular ash, CaCl2and CaO, as well as more liquid produced by additional CaO, were in favor of the reaction of Cs with Cl, thereby synergistically promoting the Cs vaporization. Addition of the mixture of CaCl2and CaO is highly recommended to remove Cs from Cs-contaminated incineration ash during thermal treatment.