In order to study the migration characteristics of mercury and adsorption characteristics of fly ash on mercury in industrial circulating fluidized bed(CFB) boiler burning high mercury coal in southwest China

Lumex RA-915M mercury online analyzer was used to monitor the flue gas in different positions of the boiler flue.Meanwhile

the feed coal

bottom ash

fly ash

desulfurization slurry and wastewater were sampled and analyzed.The results show that

more than 87% of the mercury in flue gas in front of the dust collector is enriched in fly ash

and only 0.07% of the mercury exists in bottom ash. The enrichment of mercury in fly ash is mainly due to the unburned carbon(UBC) content

mineral composition and pore structure of fly ash. The mercury removal efficiency of fabric filter and wet desulfurization equipment is 91.19% and 51.49%

respectively

and the mass concentration of mercury in flue gas discharged to atmosphere is only 3.43 μg/m3

which meets the national emission requirements.In addition

the fly ash was characterized

it finds that

the mercury content and UBC content in fly ash with different particle sizes has the same change trend. The mercury existing in the form of HgO and Hg0 in the fly ash is mainly enriched on surface of the fly ash.