Material, energy and exergy flows of the oxygen blast furnace process with sintering flue gas injection

The SO2 and NOx are typical hazardous substances for atmospheric environment and their emission loads are strictly limited in the steelmaking or other relevant chemical engineering industries. To effectively treat the SO2 and NOx in the sintering flue gas, the oxygen blast furnace is considered as a novel SO2 and NOx purification equipment. In this study, a mathematical model is established to analyze the material, energy and exergy flows of this novel system. Three simulation cases including ordinary blast furnace without sintering flue gas injection (Case 0), medium oxygen-enriched blast furnace (Case 1) and full oxygen blast furnace (Case 2) are studied. The results show that the maximum amount of the injected sintering flue gas in Cases 1 and 2 is 2240 m3/tHM and 3027 m3/tHM, respectively. The energy efficiency of Cases 1 and 2 is 24.88% and 29.17% higher than that of Case 0, but the exergy efficiency reduces by 0.62%, 0.45%. In Case 2, the treatment quantities of SO2 and NO2 are 1498.37 g/tHM and 898.48 g/tHM, respectively. Therefore, this process is a promising route of promoting the cleaner production in the steelmaking or other relevant chemical engineering industries.

Automated summary

In this study, a mathematical model is established to analyze the performance of an oxygen blast furnace in treating SO2 and NOx in the sintering flue gas. The results show that injecting sintering flue gas can significantly increase energy efficiency, but reduce exergy efficiency. Therefore, this method is a promising approach to promote cleaner production in the steelmaking or other relevant chemical engineering industries.