NO_x reduction by coupling combustion with recycling flue gas in iron ore sintering process

A new process called ‘NO_x reduction by coupling combustion with recycling flue gas (RCCRF)’ was proposed to decrease NO_x emission during the iron ore sintering process. The simulation test of NO_x reduction was performed over sintered ore and in the process of coke combustion. Experimentally, NO_x reduction was also carried out by sintering pot test. For sintered ore, the amount of NO_x emission is reduced by 15wt%–25wt% at 400–550℃ using 2.0vol% H₂ or 2.0vol% CO, or reduced by 10wt%–30wt% at 560–720℃ using 0.15vol% NH₃. NO_x reduction is around 10wt% by coupling combustion of pyrolysis gas and coke, or around 16wt% by recycling flue gas into coke combustion. By RCCRF, the maximum NO_x reduction ratio is about 23wt% in coke combustion experiment and over 40wt% in sintering pot test.