Comprehensive treatment method for carrying out desulfurization, denitration, mercury removal and recycling on flue gas of boiler

The invention discloses a comprehensive treatment method for carrying out desulfurization, denitration, mercury removal and recycling on the flue gas of a boiler. Sodium hypochlorite which is low in price serves as an oxidation absorbent for purifying flue gas pollutants; SO2, NOx and Hg in the flue gas are oxidized by virtue of a wet oxidization process; oxidation products and part of CO2 in the flue gas are converted into ammonium bicarbonate, ammonium sulfate, ammonium nitrate and mercuric sulfide products with certain economical values; a reduction product of the sodium hypochlorite, namely sodium chloride, is reused as a production raw material of the sodium hypochlorite, and the method is a green process for purification treatment on the flue gas of the boiler. The removal rate of SO2 in the flue gas treated by virtue of the method exceeds 99 percent, the removal rate of NOx exceeds 90 percent, the removal rate of Hg exceeds 95 percent, and the obtained products such as ammonium bicarbonate, ammonium sulfate, ammonium nitrate and HgS are industrial first-grade products, so that recycling is realized.