煤和生物质灰中氧化钾含量对灰熔融特性的影响

通过模拟煤和生物质的灰成分并测试其熔融温度，探究了不同成分的灰中K₂O对灰熔融特性的影响作用。利用FactSage 7.0对各组灰分的熔融过程进行了热力学模拟和平衡计算，从矿物质反应和变化的角度为不同组分的灰中K₂O对熔融特性的影响提供理论依据。利用XRD验证了计算中所预测的矿物质的存在。结果表明：灰中K₂O的含量对灰熔融特性的影响会受到灰分中硅、铝、钙等元素含量的影响。对于CaO含量较低的煤灰，适量增加K₂O的含量有助于降低灰分的初始变形温度、软化温度和半球温度，但对流动温度几乎没有影响；对于CaO含量较高的煤灰，适量增加K₂O的含量能够全面降低灰的熔融温度；对于生物质灰，当K₂O的含量低于30%时，增加K₂O的含量有助于降低灰熔点，继续增加K₂O的含量则对灰熔点几乎没有作用。

The effect of K2O in coal and biomass ash on ash fusibility

Based on ash fusion temperature(AFT) tests and thermochemistry simulations of coal and biomass ashes,the effects of K₂O in different ash compositions on ash fusibility are explored. Thermodynamic database FactSage 7.0 was employed to simulate the ash melting process and make equilibrium calculations in order to provide an insight mechanism of the effect of K₂O on ash fusibility. The existence of some minerals predicted by FactSage calculation is also proven by XRD results. The results show that the effect of K₂O on ash fusibility is influenced by the contents of other elements in ash,such as Si,Al and Ca. For coal ash with relatively low CaO content,adding K₂O in ash in a proper amount can reduce initial deformation temperature, softening temperature, and hemispherical temperature,while having little influence on flow temperature. For coal ash with high CaO content, adding K₂O in ash in a proper amount can reduce all of the four ash fusion temperatures. For biomass ash,the ash fusion temperatures could be reduced by increasing the content of K₂O,but only when the content of K₂O is lower than 30%.