The Effect of Flux on the Melting Characteristics of Coal Ash from the Liu-qiao No. 2 Coal Mine in North Anhui Province

Abstract The effect of flux on the melting characteristics of coal ash from the Liu-qiao No. 2 Coal Mine in north Anhui province (AQ) was investigated. The change of the compositions of mineral under various temperatures with the atmosphere of N2 and H2 mixture before and after adding flux into AQ was analyzed by infrared ray. Results show that mullite formed over 1000°C has an effect on increasing the ash fusion temperature of coal, and this is the major reason that leads to a high ash fusion temperature of AQ. The coal ash fusion temperature was obviously reduced by adding calcium-based flux, magnesium-based flux, and ferrum-based flux, respectively. While the added mass amount of calcium-based flux is 6.2% (coal as reference), or the added mass amount of magnesium-based flux is 2.8%, the ash fusion temperature of AQ could be reduced to below 1350°C to meet the requirements of the shell gasifier slag-tapping process. The low temperature eutectic mixtures are easily formed between flux with aluminium sil...