Effects of temperature and circulating flue gas components on combustion and NOx Emissions characteristics of four types quasi-particles in iron ore sintering process

Abstract

It's significant to deeply understand the combustion and NOx yield characteristics of quasi-particles in flue gas recirculation sintering process. In present study, effects of temperature and different circulating flue gas components on the mass conversion rate and conversion of fuel-N to NOx of quasi-particles were investigated in a vertical quartz tube reactor. Four types quasi-particles were considered according to the existing state of coke in granules: C type, P type, S type and S' type. The mass conversion rate of four types quasi-particles ranked in the order of C>P>S>S' at different temperature. It was found that D1 model was most appropriate to describe the combustion characteristics of S, S' and P type while D3 model was better than other models to describe the combustion characteristics of C type quasi-particles through the comparison of correlation coefficients calculated by different mechanism models. Effect of circulating flue gas components on the conversion of fuel-N to NOx of quasi-particles was studied. O2 has a positive impact on the conversion of fuel-N to NOx for S, S' and C type but an inhibitory effect for P type quasi-particles. CO2 and CO could decrease the conversion rate of fuel-N to NOx for all types quasi-particles. Effect of H2O(g) on the conversion rate of fuel-N to NOx was different for four types quasi-particles. The conversion rate of fuel-N to NOx firstly increases then decreases for S', S and C type quasi-particles while continuously increases for P type quasi-particles with increasing H2O(g) content.