Study On NO_x Emission And Reduction During Sintering Process

The production of steel is accompanied by the sintering process,and the nitrogen oxide emissions from the sintering process account for more than half of the total emissions of the entire steel industry.The reduction of nitrogen oxides in the sintering process is imminent.The emission reduction in the sintering process provides a new idea for the problem of sintering denitration,which is conducive to the green sustainable development of the steel.Paper studied inhibitor on the reduction of NO_x in coke combustion process and the effect of NO_x release during micro-sintering.The NO_x emission reduction effect of the inhibitor was verified by the sintering cup amplification test.The coke combustion experiment shows that both metal oxides and metal-ZSM-5can suppress the NO_x emission during coke combustion.Among the coke burning experiments,Ce O₂and Cu-ZSM-5 are the most effective inhibitors on NO_x emission reduction.In this basic research,the above two inhibitors were added to the sintering materials for micro-sintering experiments,and the effects of two different inhibitors on NO_x release during micro-sintering were investigated.The results show that when1%Ce O₂was added,the denitration efficiency of NO reached to 29.5%,and when1%Cu-ZSM-5 was added,the NO reduction rate reached to 13.5%.With the increase of the amount of the inhibitor,the effect of the inhibitor on the emission reduction of NO_x in the micro-sintering process is not enhanced.In order to verify the effectiveness of inhibitor reduction,this paper also carried out the sintering cup amplification test,and selected the inhibitors with the best emission reduction effect to carry out the sintering cup test.The results showed that the reduction rate of NO during the sintering cup test reached 25.3%when the amount of the inhibitor was 2%.Compared to sinters without inhibitors,the amount of sintered minerals with>40 mm grain size decreases,the amount of sintered minerals with other grain sizes increases,and the yield rate changes little;with the addition of2%inhibitor,the drum strength increases,with the amount of the inhibitors was 3%,the drum strength decreases.