煤灰熔融行为及其矿物质作用机制的量化研究  

Experimental Study and Quantum Chemistry Calculation on Coal Ash Fusion Behavior and Related Mineral Evolution Mechanism

作　　者：代百乾[1] 乌晓江[1,2] 陈玉爽[1] 张忠孝[1,3] 

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]上海锅炉厂有限公司,上海200245 [3]上海交通大学机械与动力工程学院,上海200240

出　　处：《动力工程学报》2014年第1期70-76,共7页Journal of Chinese Society of Power Engineering

基　　金：国家自然科学基金资助项目(51276212,50906055);上海市青年教师培养资助计划(slg11024)

摘　　要：选取典型高灰熔点和低灰熔点煤种,利用X射线衍射仪(XRD)和扫描电镜能谱仪(SEMEDX)对高温气化条件下煤灰熔融行为及其矿物质演变规律进行了实验研究与量子化学计算.结果表明:高温下大量莫来石的生成是导致煤灰试样A具有高灰熔融温度的主要原因;煤灰试样B中由于存在较多的硬石膏、钠长石等低熔融矿物质,且CaO与莫来石反应生成钙长石与钙黄长石的化学反应在煤灰试样B熔融过程中起到了关键作用,从而使其具有低的熔融温度.经量子化学计算分析表明,由于莫来石易与电子接受体结合而难与电子给予体结合,在煤灰熔融过程中,莫来石易与煤灰中常见的碱性阳离子(Ca2+、Mg2+、Fe2+、Na+、K+)电子接受体反应生成其他物质,通过添加不同的阳离子可促使莫来石向不同矿物质转变,可以进一步控制煤灰的熔融变化过程及其熔融温度.Two typical kinds of coal respectively with high and low ash fusion point were taken as the object of study, corresponding ash fusion behavior and related mineral evolution mechanism under high tempera ture gasification conditions were analyzed using XRD and SEM EDX method, and calculated with quantum chemistry method. Results show that the high ash fusion temperature （AFT） of ash A is resulted from the formation of large amount of mullite at high temperatures; whereas the low AFT of ash B is caused by flu- xing minerals such as anhydrite and soda feldspar etc. existing in ash B, and also by the chemical reaction of CaO with mullite to form anorthite and gehlenite during ash melting process. Since mullite is likely to combine with electron acceptors rather than with electron donors, it easily reacts with metal cations such as Ca2＋ , Mg2＋ , Fe2＋ , Na＋ and K＋ etc. , to generate some other minerals, therefore, the ash fusion be- havior can be controlled through adding different kinds of metal cations to change the AFT of coal ash.

关 键 词：煤灰 熔融行为 量子化学 矿物质演变 

分 类 号：TM611.3[电气工程—电力系统及自动化]