Four typical Zhundong coal were selected for burning experiment on a one-dimensional furnace. By using the X-ray fluorescence(XRF) analyzer

the X-ray diffraction(XRD) analyzer and the field emission scanning electron microscopy combined with X-ray spectrum analyzer(FSEM-EDX)

this article analyzed the mineral and chemical composition of the Zhundong coal ash samples collected by silicon carbide sticks. The results show that

the high sodium coal was easy to form black molten solid sphere or film-like slag particles when burned in high temperature zone

which were extremely difficult to remove. While for the low sodium coal

multi-bubble-like slag or loose ash were formed

which were easy to be eliminated. Sodium feldspar and sodium chlorides were found in the residue samples burned by high sodium coal

and mullite crystals were observed in the low sodium coal ash. The morphology analysis further validated the ash mineral composition analysis

namely the sodium-rich components was a major cause of Zhundong coal slagging during combustion.