Combustion behavior and influence mechanism of CO on iron ore sintering with flue gas recirculation

The properties of circulating gas have a significant effect on sintering with flue gas recirculation, and the influence of CO in sintering process was investigated. The results show that the post-combustion of CO conducts in sinter zone when flue gas passes through the sintering bed, which releases much heat and reduces the consumption of solid fuel. The ratio of coke breeze can be reduced from 5% to 4.7% with 2% CO in circulating flue gas. In addition, with the increase of CO content in circulating flue gas, the combustion efficiency of fuel is improved, and the flame front is increased slightly while still matches with the heat transfer front. These are beneficial to increasing the maximum temperature and prolonging the high temperature duration, especially in the upper layer of sintering bed. As a consequence, the productivity, vertical sintering velocity and quality of sinter are improved.