Adjustment behaviors of blending coal on the ash fusion characteristics of coal with a high ash fusion temperature

To explore the effects of blending coal on the ash fusion temperature (AFT) of coal with a high AFT, Yima coal (YM) and Shenmu coal (SM) were added to Jincheng anthracite (JC) in different mass ratios. The variation in ash fusion characteristics was investigated on ash fusion analyzer. X-ray fluorescence spectrometer, X-ray diffracto-meter combined with Rietveld-based SIROQUANT software package and scanning electron microscopy were used to explore the adjustment mechanism of blending coal on the AFTs. Both blending coal can make the JC AFTs decrease to some extent. For YM, the AFT of the mixture decreased smoothly; however, for SM, the mixture AFT initially decreased smoothly (SM: 0-20 %), then sharply (SM: 20-30 %) and gradually again. The increase of low MP matter (anorthite, hercynite) content results in the AFT decrease of JC mixed ashes. Gehlenite formation due to high content of calcium oxide in SM makes the AFT variation in JC mixed ashes for two blending coals is difference. Compared to YM, the gehlenite could react with hercynite and quartz to generate glassy material, which made mixed JC decrease markedly when SM mass ratio increased from 20 to 30 %.