Non-isothermal kinetics of coke and iron ore melting reduction with variable activation energy model

Due to the significant consumption of coke in blast furnace ironmaking, a large amount of carbon emissions is generated. Thus, addressing the issues of energy conservation and carbon emission reduction in blast furnace ironmaking is imperative. The melting reduction reaction constitutes the predominant portion of carbon consumption during the ironmaking process. However, its kinetic behavior remains unclear to date, impeding energy-saving and carbon reduction efforts in blast furnaces. Consequently, this study conducted melting reduction experiments on two types of sinters and coke under simulated blast furnace conditions. A variable activation energy model (VAEM) was established for kinetic analysis of melting reduction. The conclusion is as follows: the variable activation energies of two types of sinters were determined to vary between 110 and 50 kJ/ mol and 115-60 kJ/mol, the pre-exponential factors were 1.36 and 2.57. The deviation analysis showed that the predicted values using VAEM deviated from the experimental values by 1.17 % and 0.95 %. The reliability of VAEM was demonstrated. In turn, the kinetic behavior of coke and iron ore melting reduction was declared. It offers a theoretical basis for promoting the rational use of coke resources in blast furnace ironmaking and reducing carbon emissions.