The influence mechanism of ionic liquids on the ash melting and combustion characteristics of Zhundong high-alkali coal

This study investigated the ash reduction and quality improvement effects of four types of ionic liquids on Zhundong high-alkali coal, focusing on the evolution laws of coal ash melting and combustion performance under the ionic liquid system, which provided a theoretical basis for the subsequent utilization of high-alkali coal. Ionic liquids can effectively reduce inorganic mineral content and volatile matter yield, increase fixed carbon and oxygen content in coal, and reduce hydrogen and sulfur content. The silicon-aluminum ratio of coal ash increased, and the content of low-melting minerals in coal ash decreased, while the content of refractory minerals increased, leading to an increase in the melting temperature of coal ash. Ionic liquids can inhibit the oxidation reaction of coal, which is beneficial for suppressing spontaneous combustion of coal and improving safety during storage and transportation.