On a laboratory scale opposed multi-burner gasifier(OMBG),the fly ashes at different sampling mouths are collected and analyzed by SEM,EDS,XRF and Malvern mastersizer.Most fly ash particles produced in the gasification are irregular,aggregate or spherical.As for the composition of the particles,carbon is the main content,while S,Fe and Na get enriched.At the same time,the concentration of Al and Si in the fly ash particles is lower than that in the original slag.From the nozzle plane to the exit of gasification chamber,the carbon content of particles decreases along the axes of gasifier.The carbon content of particles decreases rapidly from the nozzle plane to No.7 sampling mouth and declines slowly from No.7 sampling mouth to the chamber exit.The size of particles generated in the gasification appears a triple-humped-distribution with peaks at 0.1—0.2 μm,2 μm and 14 μm.The particle size distribution in different sampling places is different.Above the impact plane,more ultra-fine particles are found and coarse particles are larger in location near the impact plane.In symmetrical up and down locations of the impact plane,the particle size distributions are similar,but there are more coarse particles below the impact plane.The coarse particle size decreases and the proportion of fine particles increases below the impact plane,while the proportion of coarse particles increases at the chamber exit.