Abstract: The effect of ferrum-based flux on the melting characteristics of coal ash in coal blends from the Liu-qiao No.2 coal mine in Wan-bei (AQ) was investigated. The change of the compositions of mineral under various temperatures before and after adding ferrum-based flux into AQ was studied by XRD and FT-IR. Results show that the presence of mullite formed over 1000℃ increases the melting point of coal-ash, leading to high melting temperature of AQ coal-ash. The coal ash fusion temperature will be decreased by adding ferrum-based flux. The eutectic mixtures such as fayalite and hercynite are easily formed between ferrum compounds under high temperature, which remarkably decreases the coal ash fusion temperature.