Kinetics and mechanisms of coke and sinter on the coupling reaction to evaluate the integrated effects of coke solution loss reaction on blast furnace processes

Abstract

The gas–solid coupling reaction kinetics at a constant temperature at each temperature point in the high-temperature cohesive zone in a blast furnace environment were simulated using industrial blast furnace raw material sinter, the low-reactivity conventional coke, and the high-reactivity unconventional coke. In this method, the coupling test of the sinter and coke at constant temperature was performed after a supporting thermogravimetric device was used to carry out pre-reduction, and the coupling reaction of industrial-grade sinter and coke were used to obtain the kinetic data and a mathematical description of the reaction mechanism. The results showed that in the high-temperature cohesive zone, the gasification reaction rate of the low-reactivity coke is the rate-controlling step of the gas–solid coupling reaction rate between the sinter and the conventional low-reactivity coke. By contrast, the rate-controlling step of the gas–solid coupling reaction rate between the sinter and highly-reactive coke is the reduction of sinter. The maximum difference between the initial reaction temperatures of the two kinds of coke samples is 30 °C. Using the same testing standard as coke strength after the reaction (CSR) to test the thermal strength of coke after the coupling reaction, it was found that there is little difference between the thermal strengths (CSRp) of the two kinds of coke after the reaction. The thermal strength of the high-reactivity coke is the worst at 1100 °C, and that of coke with low reactivity is the worst at 1200 °C. The highly reactive coke can operate smoothly in the blast furnace of the cohesive zone and this is explained from the perspective of kinetics. This knowledge provides guidance for the evaluation of the capability of coke to resist solution loss.