Al2O3对神东煤灰渣熔体特性的影响

Effect of Al_2O_3 on Shendong Coal Ash Fusion Characteristics

向神东煤灰中添加Al_2O_3,通过煤灰熔融性测试,分析Al_2O_3对神东煤灰熔融温度的影响;通过激冷实验、X射线衍射(XRD)、热重分析及热力学软件FactSage,探究Al_2O_3对神东煤灰熔融特性的影响机理.结果表明,Al_2O_3始终起到提高煤灰熔融温度的作用.在Al_2O_3添加量(质量分数,下同)较低时,煤灰熔融温度升高趋势较为平缓;随着Al_2O_3添加量继续增大,煤灰熔融温度急剧升高.通过XRD检测及热力学软件FactSage模拟分析发现,Al_2O_3添加量较大时,在煤灰熔融过程中其与原煤灰中的SiO_2(以石英形式存在)形成了莫来石(3Al_2O_3·2SiO_2),从而造成了煤灰熔融温度急剧升高.

The influence of Al2O3 on Shendong coal ash fusion temperature was investiga- ted by adding various amounts of Al2O3. The impact mechanism of Al2O3 on Shendong coal ash fusion characteristics was explored using quench experiments, XRD, TG-DSC and thermodynamic software FactSage. The results show that with the increase of addition amount of Al2O3, the ash fusion temperature （AFT） rises gentle first and then zooms up. Through XRD and thermal analysis software FactSage, it is found that Al2O3 reacts with SiO2 derived from the original coal ash composition （in the form of quartz ） to form mullite （3Al2O3O2SiO2） in ash fusion process, which resulting in the sharp rise of coal ash fusion temperature with a higher added amount of Al2O3.