The particle size distribution and unburned carbon content in fly ash from CFB boilers burning low rank Fujian anthracite and the main factors affecting the unburned combustibles in fly ash and the solution measures have been analysed.The results of study show that the particles with size less than 40 μm accounting for about 70% of the total mass weight of fly ash

and the peak value of unburned combustibles in fly ash appears in the range of particle size about 30 μm

while this part of particles can't be burned away at once

and this is the main cause resulting in somewhat high unburned combustible content in fly ash.After wet decarbonization separation of the fly ash

the unburned combustible content in pulverized carbon reaches above 70%

the unburned combustible content in pure ash is under 3%.The pure ash can be directly used for manufacturing products with high additional value

enhancing greatly the comprehensive utilization value of fly ash

boasting remarkable environment-protecting and economic benefits.