Application of modified coke to NOx reduction with recycling flue gas during iron ore sintering process

Abstract

A new process, named NOx reduction by the modified coke with recycling flue gas, was proposed. The coke samples loaded with K 2CO3, CaO and CeO2 were characterized by SEM. The effects of the recycled flue gas and the modified coke on NOx 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>Ca0>CeO2. In the modified coke combustion with recycling flue gas, the concentration of NOx emission was decreased, furthermore, the NOx reduction ratio increased with the loading amount of additives. The NOx 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 NOx reduction ratio was 38.0%, which was about 13% higher than that of the base run with recycling flue gas. © 2008 ISIJ.