| Mercury is a kind of heavy metal element with high volatility. Nowadays, withthe rapid development of science and technology, the Hg released from coal in powerplant is the biggest artificial atmospheric pollution source of Hg, bringing seriouslynegative influence day by day. The Hg released from raw coal burning is partlyabsorbed by fly ash to further generate particulate mercury, and removed from theexisting pollution-control device in coal-fired power plant. However, the fly ashremoved from pollution-control device can still be used for the second time, duringthe process of secondary use the fly ash should undergo heat treatment, and then justin this process the particulate mercury will be released out secondarily to causeenvironment pollution. The particulate mercury absorbed in fly ash has differentkinds of compound forms and has different thermal stability with different forms, sothe research for forms of particulate mercury and thermal stability has a guidingsignificance on the reuse of fly ash in power plant boilers.This paper analysed two representative kinds of fly ash samples and analysedmicrostructure and chemical components after heat treatment, and then demonstratedthe influence of particle sizes and excess air coefficient on forms of particulatemercury and thermal stability as well as the influence of ESP on forms of particulatemercury and thermal stability.By analyzing the distribution rules of elements in fly ash, this paperdemonstrated the influence of particle size and excess air coefficient on thedistribution of elements in fly ash and then further showed the influence of thedistribution of elements on the distribution of particulate mercury.Besides, the study in the field that the Hg in fly ash releases dynamicalparameter by heat treatment was almost untouched, so this paper also calculated thedynamical parameter released from the Hg in fly ash, and finally obtained itsactivation energy E, the prefactor A and conversion function f (α). |
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