Reduction Kinetics of Cold‐Bonded Briquette Prepared from Return Fines of Sinter with Carbon Monoxide and Coke

Abstract

Return fines of sinter is now being utilized in blast furnaces straight after cold briquetting, a novel method of return fines utilization. [1][2][3][4] This technique can prevent return fines from being repeatedly sintered at high temperatures. On the one hand, it can lower the amount of energy used by the sinter plant, and on the other, it can increase the output of the sintering process. The compressive strength, reduction degradation index, and reducibility index of coldbonded briquette prepared from return fines are close to those of the sinter, which is acceptable for use in a large blast furnace. Cold-bonded briquette prepared from return fines has successfully substituted 5-10% of the sinter in a 2800 m 3 blast furnace in Gansu Province, China. [1,4] However, the lack of knowledge regarding the cold-bonded briquette prepared from return fines' reduction kinetics in the blast furnace prevents further advancements in the cold-bonded briquette prepared from return fines' utilization ratio.Numerous studies have investigated the reduction kinetics of sinter under varying conditions. The sinter's porosity, particle size, and chemical composition affect its reduction kinetics. [5] For instance, sinter with greater porosity or with a large number of microscopic pores is usually reduced more quickly because the pores enable the reducing gas to reach the reaction's interface. However, macropores (>0.125 mm) are more crucial than micropores for the increased reduction rate of sinter because the reduction front of fine pores (<0.125 mm) is complex and irregular. [6] The reduction rate usually increases with the decreasing particle size of the sinter, and varied iron