Effect Of Fusing Agent On Ash Fusion Characteristic And Slag Viscosity Of Huainan Coal

Huainan coal can't be used directly in Texaco gasifier for its high fusion temperature(FT>1500°C). To resolve the problem, adding fluxes is a feasible method to lower the ash melting temperature and improve the ash fusion characteristics.In this article, the ash fusion characteristics of four Huainan coal samples, HN113, HN115, HN119 and KL1, selected from Huainan coal mine area, were studied by adding fluxes ADN, ADC, ADF and their mixture. The fusing mechanism of coal ash in the existence of fluxing agent is discussed with the help of FTIR and XRD spectra. The decrease of coal ash fusion temperature is explained through forming of lower-temperature eutectic mixtures. Meanwhile, the influence of flux on slag viscosity is also studied. A new method is developed to assess the fluidity of slag, and the pertinence between the amount of flux and fluidity is studied. The results show as follows:(1) The ash fusion temperature can be decreased remarkably by adding ADN, ADF for the four coal ashes, while ash fusion temperature shows different change tendency by adding ADC. Such as the adding amount of ADN flux which can decrease the fusion temperature of HN1115, HN119, KL1 and HN113 to 1380°C is 7.0%, 11.7%, 2.5% and 9.6% respectively. (The adding amount of flux is expressed by mass percent of ash base.)(2) The compound flux composed by ADN, ADC and ADF can also decrease the ash fusion temperature of Huainan coal. On the premise that the total adding amount of compound flux is fixed, the proportion of two fluxes is adjusted. The results indicate that the ash fusion temperature shows ascending tendency when the proportion of ADC is increased. If increase the proportion of ADN, the ash fusion temperature shows downtrend.(3) The ash meling-point is determined by the content of mullite. The content of anorthite and albite will increase by adding flux. Mullite reacts with other minerals to form low melting eutectic results in ash melting point lowered.(4) Slag viscosity can also be affected by fluxes. The three kinds of fluxes all can decrease the slag viscosity of Huainan coal. Especially the ADN flux...