Fusibility Characteristics of Fine Chars from Pilot-Scale Fluidized-Bed Gasification

To explore the fusibility characteristics of fine chars from gasification using an ash agglomeration fluidized bed, fine char samples of Shenmu bituminite (F-SM) and Jincheng anthracite (F-JC) were analyzed by X-ray fluorescence spectrometry, pressure-drop sintering technique, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. Differences in elemental distributions and surface morphologies of the samples due to variations in petrographic composition and reactivity of their respective raw coals were observed. The ash fusion temperatures and sintering temperatures increased in the order F-SM < raw Shenmu bituminite < F-JC < raw Jincheng anthracite, because of the increase in total base content of their ash. The particle size of F-SM had a multipeak distribution, whereas that of F-JC had a two-peak distribution. During sintering, molten, low-melting minerals flowed between the surfaces of adjacent ash particles and led to particle aggregation and aggregate densification.