高钙山鑫煤灰熔融及黏温特性分析

Research on Ash Fusibility and Viscosity-temperature Characteristics of High-calcium Shanxin Coal Ash

煤灰熔融性与黏温特性是决定气流床气化炉能否正常运行的重要参考指标。文中通过高钙山鑫煤中添加SiO2以降低灰熔融温度,改善黏温特性。采用FactSage6.2软件推断高温下不同温度区间煤灰熔融过程中的物相变化规律,并对灰熔点及黏度变化的机理进行分析。结合XRD分析测试方法,对山鑫煤和山鑫配煤矿物质变化进行比较分析。结果表明,山鑫煤灰熔点随着硅铝比S/A、酸碱比A/B的增大先降低后升高;加入的SiO2与Ca、Fe、Al、Mg形成低温共熔物使灰熔融特性与黏温特性得到改善。实验结果与Factsage的计算结果一致,表明液相线温度变化及矿物质转变可用该热力学平衡软件进行预测。

Coal ash fusibility and viscosity-temperature characteristic are the decisive indices to judge the operation of gasifiers.SiO2 was added to decrease the fusion temperature and improve the viscosity-temperature characteristic of the high-calcium Shanxin coal ash.The FactSage 6.2 software was used to deduce the phase change law when the coal ash melted under different temperature ranges.The changes of ash fusion temperature and viscosity caused by the addition of SiO2 were studied by mechanism analyses.Shanxin coal was compared with the blended Shanxin coal（S/A=7.36） in terms of mineral variation using X-ray diffraction（XRD）.The results show that the fusion temperature of Shanxin coal ash decreases firstly and then increases with the increase of S/A and A/B.The SiO2 added forms composites with Ca,Fe,Al,Mg to improve the ash fusibility and viscosity-temperature behavior.The experimental data are consistent with the simulation results by FactSage 6.2 software,indicating that the variation of liquidus temperature and mineral matters can be predicted by the software.