Experiment And Mechanism Study On Denitrification Of Sintered Flue Gas By Wet Absorption Combined Ozonation

55% pollutants in iron and steel industry come from sintering process whose flue gas is complex,unstable and high oxygen?about 15%?.At present,there is a lack of an effective NOx control method for sintering flue gas.With the deterioration of the environment and the higher emission standards,it is badly in need of an effective denitration technology to control NOx in sintering flue gas.In this paper,the feasibility of wet absorption combined with ozone oxidation denitrification technology in the sintering flue gas was studied through the laboratory mechanism experiment and the pilot test.The experimental study of simulated flue gas according to sintering flue gas oxidized by O3 was carried out.The effects of different temperatures,ozone dosage and concentration on oxidation of NO and SO₂ were studied in the experiment.By comparing the ozone utilization rate,high NO oxidation rate,NO oxidation rate and SO₂ oxidation rate,the temperature range,dosage and oxidation reaction time of the engineering are determined.When the amount of ozone was equal to NO at the temperature of 110 ?,the utilization rate of ozone is the highest and the oxidation rate of NO is higher.At this time the oxidation rate of sulfur dioxide is less than 5%.The above control conditions are suitable for engineering applications.Ozone oxidation was also tested on a 300 sintering machine.It was found that the actual ozone utilization rate was 90%,and the oxidation rate of NO was over 90%.Secondly,aiming at the high oxidation quantity of sintering flue gas,we had developed a series of wet denitrification agents and additives.Under different conditions?temperature,PH,concentration,mass transfer and type of absorbent?,the effective composition of the traditional denitrifying agent were investigated.We developed an additive whose main body was the effective component of the traditional denitrification agent,suitable for high oxygen environment.Ethanol was selected as an oxygen inhibitor and an absorption enhancer in the process of NO₂ absorption through comparison of various additives.By exploring the factors,we determined the best way to absorb NO₂ by sodium sulfite adding into ethanol.The study showed that the gas phase composition had a great influence on the absorption of NO₂.The addition of SO₂ is beneficial to the absorption of NO₂.But the addition of O₂ significantly inhibited NO₂ absorption.Oxygen is a very unfavorable factor in the absorption of NO₂ in the solution of sodium sulfite.The addition of oxygen would greatly increase the consumption the solution and make the absorption efficiency of the solution lower.The synergistic approach of ethanol indirectly reacted with N02 by inhibiting the excessive oxidation consumption of sulfite.The enrichment of ions?NO3-,NO₂-,SO42-?had a great inhibitory effect on the absorption of NO₂.Increasing the addition of ethanol could effectively inhibit this negative effect.Sodium sulfite combined with ethanol was a wet absorbant adapted to the characteristics of sintering flue gas.In the end,the denitrifying agent was tested by small test and pilot test.It was found to be an effective denitrifying agent.The performance of denitrifying agent was tested by changing the ratio of liquid to gas,concentration,PH and ozone dosage providing guidances for wider applications...