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

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