为掌握高温条件下不同温度段的煤灰熔融过程的物相变化规律,试验选取具有代表性的低灰熔点清水营煤和高灰熔点青龙矿煤为原料,采用FactSage6.1计算软件中的Equilib模型进行数值计算,利用高温黏度计对2种煤灰进行黏度测试。结果表明,Al2O3和SiO2含量较高的青龙矿煤灰在熔融的过程中产生大量的莫来石,这决定了青龙矿煤灰的高灰熔点。清水营煤的低灰熔点主要是由于钙长石和石英的低温共融主导熔融过程,赤铁矿在高温熔渣中下起到助熔的作用。钙长石和赤铁矿助熔矿物能降低灰渣的黏度,莫来石的存在则会增加灰渣黏度。数值计算的结果与试验结果基本一致,表明化学热力学反应平衡分析方法是研究灰渣熔融特性一种有效手段。
The typical samples of low ash fusion temperature coal (Qingshuiying) and high ash fusion temperature coal (Qinglong) were selected to investigate the phase change rules when the coal ash melting under different temperature range.The Equilib model was used to numerical calculation,and the calculation was performed on Factsage software,version 6.1.The viscosities of two coal samples were measured by using high-temperature viscometer.The results indicated that the large amounts of mullite were produced from the Qinglong coal sample that has higher level Al2O3 and SiO2.And the higher ash fusion temperature is depended on the amount of mullite.The lower temperature melting process of the calcium feldspar with quartz determines the Qingshuiying coal sample has lower fusion temperature point.The hematite has promotion effect on the melting process.The anorthite and hematite flux can reduce the slag viscosity,but the mullite flux will increase the slag viscosity.The numerical calculation results are agreement with the experimental data.The results proved that the chemical thermodynamic equilibrium analysis method suitable for investigating the characteristics of ash melting.