| CaF2高温分解特性试验研究 |
| 摘要点击 1797 全文点击 2192 投稿时间：2001-06-13 修订日期：2001-08-22 |
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| 中文关键词 CaF2 高温稳定性 直接吸收法 水解反应 动力学 |
| 英文关键词 CaF2 high temperature stability gaseous fluorides direct absorption technique hydrolysis kinetics |
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| 中文摘要 |
| 作为燃煤和砖瓦烧制过程中钙基固氟剂燃烧固氟的最终产物CaF2,其高温稳定特性对固氟效率有重要影响本义在固定床反应器上采用气态氟化物直接吸收分析法,结合XRD、DTA法对CaF2晶体粉末在大气、干燥大气和饱和大气下的高温稳定性进行了实验研究.结果表明,在高温条件下CaF2发生水解反应,水解反应起始温度830±10℃,水解率随燃烧温度和停留时间的增加而增加,空气中水蒸气含量对水解率有显著影响.动力学计算表明温度在850℃～1350℃范围内水解反应为一级反应,反应活化能E=115±2kJ/mol.研究结果对燃煤和砖瓦烧制过程中高温高效钙基燃烧固氟剂的开发有指导意义. |
| 英文摘要 |
| In this paper, the stabilities of CaF2 in atmosphere, dry and moist air at elevated temperatures were studied by gaseous fluorides direct absorption and fluoride ion selective electrode (ISE) measurements technique supplemented by differential thermal analysis (DTA), chemical analysis (pyrohydrolysis ISE method) and X ray diffraction (XRD) analysis. The principal reaction was shown to be hydrolysis of CaF2 at high temperature and CaF2 were actually hydrolyzed appreciably at about 830±10℃ in moist atmospheres. Kinetics calculation showed that hydrolysis reaction was first order and the activation energy for the hydrolysis was 115±2kJ/mol, applicable over the range 850℃～1350℃. The research results will be of significance for fluoride pollution control during coal combustion and clay brickmaking. |
