Emission characteristics of PM2.5from flue gas in simulated system and actual coal-fired power plant equipped with limestone-gypsum desulfurization system were investigated.The results show that the number concentration distribution of PM10 in raw flue gas

determined by ELPI in simulation system

presented a unimodal distribution while that in actual power plant was bimodal.Most of the fine particles were in submicron size range

with an irregular structure of sphere and a main composition of water-insoluble salic minerals.After desulfurization

the number peak particle size had moved from 0.07μm to 0.15μm

and the number of coarse particles decreased slightly.However

the particles sizing from in 0.1μm to 0.5μm increased instead

indicating the WFGD had a lower efficiency in removing the fine particles.Furthermore

a few crystalline particles in micron size appeared

with an increase in Ca

S and O elements.