Study on CO–NO Removal Mechanism Based on Sintering Flue Gas Circulation.

In order to deeply explore the denitration mechanism of flue gas circulation in flue and sinter bed, starting from flue gas circulation, this paper studied the reaction behavior of circulating flue gas in flue and sinter through the principle of chemical thermodynamics. At the same time, the thermodynamic balance of CO–NO–O₂ was calculated. And the mechanism of CO–NO denitration was deduced and analyzed. On this basis, the sintering flue gas composition for CO–NO denitration mechanism was investigated by gas distribution tests and metallurgical properties of sinter tests. The study showed that the denitration route of reducing NO to N₂ by CO in flue gas was feasible. Thermodynamically, low temperature, high CO, and high Calcium Ferrite (CaFe₂O₄) were conducive to the CO–NO denitration. Sinter can catalyze CO–NO denitration. With the increase of temperature, the denitration effect showed the rule of first rising and then declining, and the best effect of sinter catalyzed CO–NO denitrification was at 640 °C. Therefore, reducing the O₂ content in the sintering circulating flue gas to enhance the reduction atmosphere, the flue gas passing through the sinter with high CaFe₂O₄ content at 640 °C can promote the reduction of NO by CO, which is conducive to the denitrification of sintering flue gas. There is a great prospect for sintering flue gas denitrification in the sinter-circle-cooling machines. [ABSTRACT FROM AUTHOR]