Effect of alumina and silica on the reaction kinetics of carbon composite pellets at 1 473 K

Abstract

The influence of compositional changes in the CaO-FeOt-(Al 2O3) or (SiO2) ternary oxide system on the reaction kinetics of carbon composite pellet was investigated by Thermo-Gravimetric Analyzer (TGA) at 1 473 K (1 200°C). Measured CO and CO2 gas by Infrared gas analyzer and surface area change from BET analysis assisted with the reaction kinetics of carbon composite pellet. As a result, alumina increased the reduction rate of iron oxide by increasing surface area, while silica decreased reduction rate by lowering surface area of pellet samples. A modified reaction kinetic model considering both the Boudouard reaction and surface area variation was developed for a better explanation of reduction mechanisms occurring in carbon composite pellets. © 2014 ISIJ.