Investigation of a granule structure that focused on reducing NOx emissions in sintering process

Abstract

The pressure to reduce NOx emissions in iron ore sintering process is enlarging increasingly. The paper proposed a sintering granulation method to reduce NOx emissions. The main character of the method was to wrap all fuel on the surface of the pellet, and also increased the contact between iron ore and fluxes. The sinter-pot test results showed that NOx emissions of the method reduced by 19.9% and sinter quality improved, while SO2 emissions increased by 17.7% compared with that of the conventional method. The increase in the reducing atmosphere of the sinter bed and the development of calcium ferrite in sinter were the main causes of NOx emissions reduction and the improvement of the sinter quality. In addition, the promotion of the combustion of fuel resulted in the increase in SO2 emissions. The improvement of the sinter quality and the control of the sintering flue gas pollutants can also be realized through adjusting the distribution of fuel, fluxes and iron ore in the pellet reasonably.