The content of heavy metal elements

such as Cd

Cr

Pb

Cu

Ni and Hg

in the fly ash collected in electrostatic precipitator （EP） under different operation conditions of a coal-fired CFB boiler （220t/h） in a thermal power plant of Hangzhou City has been analyzed by using atomic spectrum absorption analyzer and atomic fluorescence analyzer

and the effect of variable parameters

such as boiler load and Cd/S ratio

to the distribution of heavy metal elements in fly ash has been studied. The results of study indicate that the distribution of said elements in fly ash is generally as follows: Hg<Cd<Pb<Cu<Ni<Cr. The influence of variable boiler load to the distribution of heavy metal elements in fly ash collected in the EP is depending upon the variation pattern caused by load variation

as well as the volatility of each element itself. The addition of limestone into the process of fluidized bed combustion will also affect the distribution of heavy metal elements in fly ash.