Zhundong coal is easy to burn with a high burn out rate

which is a good coal for power plants.However

the serious fouling and slag occurred on heating surface of the boiler causes serious problems for unit safe operation.In this paper

the slag and deposition samples were collected from a power plant firing Zhundong coal.The X-ray diffraction and environmental scanning electron microscope(ESEM)was applied to analyze the mineral composition of the depositions.The results indicate that

the depositions collected from different parts of the boiler have complex Na-containing mineral components

including sodium calcium aluminum oxides mineral crystal

sodium potassium aluminum silicate

nelpheline

and sodium calcium aluminum silicate.A lot of amorphous components were identified in high temperature area

which is mainly derived from the eutectic reaction of various minerals.Mineral crystals were mainly found in fouling and deposit samples

which was mainly due to the condensation of gas phase.