Regular Article

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

¹ State Key Laboratory of Advanced Steel Process and Products, Central Iron and Steel Research Institute, Beijing 100081, PR China
² School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China

^* e-mail: 907360382@qq.com

Received: 5 June 2018
Accepted: 14 November 2018

Abstract

The pressure to reduce NO_x emissions in iron ore sintering process is enlarging increasingly. The paper proposed a sintering granulation method to reduce NO_x 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 NO_x 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 NO_x 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.