Flue gas recirculation in iron ore sintering process

Abstract

Flue gas recirculation has been introduced into iron ore sintering process to reduce pollutant emissions. Compared with the conventional process, the sintering indices reduce gradually with decreasing O₂ content in the recirculating gas. With sufficient O₂, the principle on the use of flue gas recirculation is proposed. The heat loss caused by the decrease in O₂ content is compensated by 250°C gas and 0.5%CO. The flame and heat transfer fronts of the sintering bed coincide using mixed gases of no more than 6%CO₂ and 8%H₂O (g). A novel technology of 35.5% flue gas recirculation ratio is proposed with qualified sintering indices.

Keywords:

• Flue gas recirculation
• Iron ore sintering
• Heat balance
• Fuel combustion

Acknowledgements

The research is financially supported by the National Natural Science Foundation of China (grant no. 51474237), the outstanding and creative doctor scholarship of Central South University (grant no. 2013bjjXj015) and 2014 Hunan Provincial Innovation Foundation for Postgraduate (grant no. CX2014B094).