Effect of mineral form in coal on combustion characteristics and fusibility of coal ash

The existence form of minerals in Wucaiwan(WCW) coal were studied by extraction, XRD, SEM-EDX and ICP-OES. The influences of different forms of mineral on the combustion characteristics and the fusibility of ash were evaluated. The results indicate that the original minerals in WCW coal mainly include calcite, anhydrite, kaolinite, quartz and pyrite. The modes of occurrence of sodium in WCW coal are mainly in the form of water-soluble sodium. The organic bound sodium, magnesium and calcium can promote the combustion of coal to a certain extent. The fusibility of WCW coal ash is mainly influenced by the mol ratio of iron to calcium. The ash melting points decreases with increasing the Fe₂O₃/CaO mol ratio.