Application of Modified Coke to NO_x Reduction with Recycling Flue Gas during Iron Ore Sintering Process

Abstract

A new process, named NO_x reduction by the modified coke with recycling flue gas, was proposed. The coke samples loaded with K₂CO₃, CaO and CeO₂ were characterized by SEM. The effects of the recycled flue gas and the modified coke on NO_x reduction were investigated with a quartz fixed bed reactor and a sintering pot. The results showed that the extent of the contact between additives and coke was: K₂CO₃>CaO>CeO₂. In the modified coke combustion with recycling flue gas, the concentration of NO_x emission was decreased, furthermore, the NO_x reduction ratio increased with the loading amount of additives. The NO_x reduction ratios were 36.7%, 20.2% and 26.2% respectively when the loading amount of K₂CO₃, CaO and CeO₂ was 2.0%. In sintering pot tests, the coke loaded with 2.0% CeO₂ was used as fuel and the recycled flue gas, simulated by the gas mixture with 50 ppm NO, was introduced to sintering process, the NO_x reduction ratio was 38.0%, which was about 13% higher than that of the base run with recycling flue gas.