Abstract: In order to research the coal ash ingredients diffusion on slagging influence on the SiC-based liner in utility boiler, the slag sample on the SiC-based refractory liner producing during the operation process of utility boiler is investigated by scanning electron microscopy(SEM), energy dispersive spectrometer (EDS), X-ray diffraction(XRD), and the slagging samples’ properties of phase transformation on, and component distribution along the slagging transverse direction are studied. The results show that the crystallinity of ash slag mainly depends on the phase transformation of material and crystallization of anorthite, hercynite and SiO2, especially the closer the SiC-based liner surface, the smaller the ash crystalling phase becomes. The alkaline ionic components of ash slag in clingy SiC-based fireproof board spread evenly, and along the slagging direction this diffusion tends gradually thermodynamic steady state, which effectively avoid the rerosion and slagging of molten coal ash of high Si content to SiC-based liner.

Key words: Diffusion behavior, Refractory liner, SiC, Slagging, Utility boiler, Guided Wave, longitudinal mode, notch frequencyproperty, strand , tension measurement