内蒙古准格尔燃煤电厂高铝粉煤灰的矿物组成与特征

Mineral abundances of high-alumina fly ash from the Jungar Power Plant,Inner Mongolia,China

运用X射线衍射分析（XRD）和带能谱仪的扫描电镜（SEM—EDX）等方法研究了内蒙古准格尔燃煤电厂高铝粉煤灰的矿物学特征．结果表明，飞灰和底灰均由玻璃体、矿物和未燃炭组成．燃煤产物中的矿物有莫来石、刚玉、石英，以及少量方解石和钾长石．莫来石在飞灰中的含量高达37．4％．刚玉可能是高铝粉煤灰中典型的次生矿物．随着飞灰粒径的减小，刚玉含量上升，玻璃体和莫来石含量总体上分别呈减少和略微上升的趋势．莫来石含量在粒径300—360目的飞灰中达到最高值，可能是由于颗粒较小的飞灰虽然在炉膛内停留时间较短，但局部受热温度更高，更有利于莫来石的结晶．

The mineralogy of the high-alumina fly ash from the Jungar Power Plant, Inner Mongolia was studied using X-ray diffraction analysis （XRD） and a scanning electron microscope equipped with an energy-dispersive X- ray spectrometer （ SEM - EDX）. The fly and bottom ashes are both composed of amorphous glass, minerals and unburut coal particles. Minerals in the residues including mullite, corundum, quartz, and a trace amount of calcite and K-feldspar. The mullite content reaches 37.4% in the fly ash. Corundum may be the typical secondary minerals in the high-alumina fly ash. The corundum content increases along with the particle size of fly ashes decreasing. Moreover, in general, the content of amorphous glass and mullite decreases and slightly increases, respectively. The 300 -360 mesh fraction is highest in mullite content. The fly ash with smaller particle size stayed in the boiler with a relatively short time interval and probably influenced by partial high-temperature which favored the mullite formation.