Abstract: This is an essay in the field of metallurgical engineering. Bayer red mud and sintered red mud were added to Ningxia coal in a certain proportion to study the influence of the two different red mud on the ash melting temperature of Ningxia coal. Factsage software was used to study the ash melting temperature change mechanism. The experimental results show that Ningxia coal ash contains a large amount of mullite, which causes the ash melting point of coal ash to be higher, and adding red mud to it can effectively reduce the melting point of coal ash. With the increase in the amount of Bayer red mud added, the composition of mullite in coal ash gradually decreases, while anorthite and albite gradually increase, reducing the melting temperature of coal ash. With the increase of sintered red mud addition, the content of mullite in coal ash gradually decreases, and the content of feldspar gradually increases. The main reason that red mud reduces the melting temperature of coal ash in Ningxia is that the alkaline oxides in the red mud react with the acidic oxides in the coal ash to form low-melting minerals and the interaction between these minerals generates low temperature. Communion.