Distribution of Mercury in the Combustion Products of Coal Dust in Boilers with Liquid Slag Removal

The efficiency of trapping of solid particles and mercury compounds in the operation of wet centrifugal scrubbers with a closed-cycle water spray system at a thermal power plant was evaluated. Procedures were proposed for the monitoring of mercury at all of the steps of a process cycle. A balance on mercury in the combustion of coal dust in a TP-87 boiler was calculated. It was found that at least a half of mercury that entered in the firebox of boiler with coal was released as Hg(0) vapor with flue gases into the atmosphere. It was demonstrated that the introduction of chemical oxidizing agents into scrubber spray water dramatically increased the efficiency of mercury trapping from flue gases.