Ash formation during coal gasification was investigated based on benchscale OMB gasifier Particle size and composition of the initial minerals and the resulting fly ash were measured by SEM

XRF

XRD and Malvern Laser Particle Size AnalyzerThe results showed that particle size distribution and composition of fly ash were significantly different between fly ash at impinging zone and fly ash at gasifier outletParticle size distribution of fly ash at impinging zone was slightly finer than that of raw coal

composition of fly ash at impinging zone was quartz

calcite and FeSParticle size distribution of fly ash at gasifier outlet dramatically decreased compared to that of fly ash at impinging zone

and composition of fly ash at gasifier outlet was quartz

calcite

FeS

mullite

anorthite

gehlenite and calcium oxideAsh formation mechanisms at different gasification stages were also differentPart of fixed carbon combustion and excluded mineral transformation were the mechanisms of ash formation at the combustion stage

char fragmentation and included mineral liberation and transformation were the mechanisms of ash formation at the char gasification stage.