Original Article

Effect of Ca/Fe additives on the serial reactions of coke and sinter with CO₂

North China University of Science and Technology, Tangshan, Hebei Province 063210, China

^* e-mail: sunz@ncst.edu.cn

Received: 30 July 2022
Accepted: 2 January 2023

Abstract

To investigate the effect of Ca/Fe additives on the coke-sinter serial reaction with CO₂, the serial reactions of the high-reactivity cokes with Ca/Fe additives and sinter were studied. The results showed that the Ca/Fe additives promote the coupling degree of sinter-coke serial reaction. The reduction degree of sinter has a linear correlation with the carbon loss ratio of coke, and the intercept (b) and slope (k) obtained from the fitting linear function are used to characterize the serial reaction. The intercept (b) increases with the carbon loss ratio of coke derived from CRI, which indicated that b value can represent the intrinsic ability of coke to reduce oxygen atom in iron ore. The slope (k) decreases with the increase of carbon loss ratio of coke, and k value can characterize the matching degree of the sinter-coke serial reaction. Also, the Ca/Fe additives lower the OTI index of cokes, and the solution-loss reactions are easy to take place on the surface of the high-reactivity cokes. The Ca additive has more effect on the large pore evolution of coke structures during reaction than the Fe additive. Therefore, the Ca additive has more catalytic activity than the Fe additive, and the high-reactivity coke should be mixed with the high-reducibility ore to get higher efficiency of blast furnace.