The effects of rice straw (DC) and cotton stalk (MG) addition on Changping (CP) coal ash melting characteristics were studied with high-temperature optical microscopy

scanning electron microscopy coupled with energy dispersive spectrometer (SEM-EDS)

standard ash fusion temperature (AFT) tests and X-ray diffraction (XRD) analyses. The AFT of CP coal could be reduced effectively by adding both agricultural residues. In weak reducing atmosphere at high temperature

refractory mullite and quartz were main minerals of CP coal ash. The presence of agricultural residues could form low melting eutectic minerals

such as leucite

ringwoodite and anorthite

decreasing the AFT of CP coal. High temperature images of ash particles showed that CP coal ash fusion behavior was prolonged softening and subsequent melting of solid phases that resulted in sluggish flow and depressed dissolution of the refractory constituents. However

during the melting process of DC blended CP coal ash

active melts with low viscosity that could promote the reaction between the minerals and quickly dissolve the residual refractory were formed.