Review on controllable adjustment of coal ash melting characteristics with high ash melting point

The coal with a high ash melting point accounts for about 57% of the coal reserves in China. It would face the problem of ″ ash deposit fouling and slagging″ when it is directly used for entrained-bed gasification.Exploring the adjustments of ash melting characteristics for the coal with a high ash melting point is of great significance to the stable operation for entrained-bed gasifier. The influence rules of flux and coal blending on the ash melting temperature were analyzed. A review on how to realize the controllable adjustment of ash melting characteristics was given from three aspects including fluxes( Fe2O3,Ca O,Mg O,Na2 O,K2O and complex flux),coal blending,and software analysis( thermodynamics calculation of Fact Sage and quantization calculation of Gaussian) based on the viewpoints of mineral evolution mechanism. Finally the advantage of high precision on predicting coal ash melting temperature on the basis of support vector machine was discussed. Furthermore,some suggestions were given on looking for new flux to improve the stability of changing the ash melting temperature and establishing a relationship between ash composition and ash melting temperature based on support vector machine to guide and optimize the choice of blending coal and the ratio,thus providing the theoretical support for the clean and efficient utilization of coal with a high ash melting point.