Sintering characteristics of Wucaiwan coal ash and effect of different additives

The effect of different additives on sintering characteristics of Wucaiwan coal ash was studied by TMA combined with XRD, in-situ hot stage microscope and FactSage thermodynamic software. The results show that the additives could improve the sintering problems of coal ash, but the effect of different additives on sintering characteristics is various. For example, the sintering temperature increases by 70 ℃ when 10% of the sand is added, but the sintering temperature does not increase by addition of coal gangue in the range of 0-15%. Further studies show that the variation of sintering characteristics can be attributed to the change of initial liquid phase temperature, compositions, content and decomposition temperature of sulfates in coal ash.