燃煤电厂脱硫石膏汞形态及热稳定性分析

分析燃煤电厂脱硫石膏中汞的化合物形态及其释放规律,对脱硫石膏的利用具有指导意义。利用X-射线荧光光谱仪（XRF）对2个火电厂石膏样品进行成分分析;为确定石膏中汞的热稳定性和形态分布,对各石膏样品和石膏滤渣样品进行2种加热方式的热处理,测定热处理前后各样品的失重率和汞含量。研究结果表明, 2个电厂脱硫石膏汞的初始释放温度不同,分别为100 ℃和200 ℃;石膏及石膏滤渣样品的快速释放温度在200~400 ℃;所有样品在500 ℃时基本完成汞的释放;石膏滤渣中的总汞含量有所减少;脱硫石膏中含有的汞化合物主要有HgCl₂和HgS。

Analysis of Mercury Species and Thermal Stability of Desulphrized Gypsum in Coal-fired Boiler

Identifying the Hg species and release characteristics have guiding significance for WFGD gypsum utilization. The X-ray fluorescence spectrometry(XRF) was used to make the composition analysis of the two gypsum samples of the coal-fired power plant. In order to determine the thermostability and species distribution of Hg in gypsum, the gypsum sample and gypsum residue sample were heated by two heating method and the gypsum weight loss and Hg contents were measured after heating treatment. The results show that the Hg release began at 100 ℃ and 200 ℃ respectively for the two gypsum samples; the rapid release occurred at the temperature between 200 ℃ and 400 ℃; the Hg release finished at 500 ℃for all the gypsum samples; the Hg in gypsum residue decreased and the main Hg compounds in WFGD were HgCl₂ and HgS.