The change of mineral composition in ash and the effect of CaO on the melting characteristics of coal ash were studied by adding different contents of CaO to coal ash. At the same time, the Factsage thermodynamics software was used to simulate the mineral changes in the synthetic ash to support and verify the experimental results. The results show that with the increase of CaO content, the melting characteristic temperature of coal ash first decreases and then rises. After adding a certain amount of CaO, the quartz with higher melting point completely disappears, and the melting point of the coal ash reaches a minimum value. And with the increase of CaO content, the appearance of wollastonite and single crystal calcium oxide mineral makes the melting point of coal ash gradually increase. It can be seen from the phase diagram calculated by Factsage that as the CaO content increases, the corresponding position of the coal ash gradually moves from the hematite region to the calcareous region. And the phenomenon of low temperature eutectic occurs when the CaO content is 35%, which is consistent with the trend of temperature change of the melting characteristics. These phenomena all indicate that the change in the melting point of coal ash is nonlinear as the content of CaO minerals increases.

通过在粉煤灰中添加不同含量的CaO，研究了粉煤灰中矿物成分的变化以及CaO对粉煤灰熔融特性的影响。同时，使用Factsage热力学软件模拟合成灰中的矿物变化，以支持和验证实验结果。结果表明，随着CaO含量的增加，煤灰的熔融特征温度先降低后升高。加入一定量的CaO后，熔点更高的石英完全消失，粉煤灰的熔点达到最小值。随着CaO含量的增加，硅灰石和单晶氧化钙矿物的出现使煤灰的熔点逐渐升高。从Factsage计算出的相图可以看出，随着CaO含量的增加，煤灰的相应位置从赤铁矿区逐渐移向钙质区。当CaO含量为35％时，发生低温共晶现象，这与熔融特性的温度变化趋势一致。这些现象都表明，随着CaO矿物含量的增加，煤灰熔点的变化是非线性的。