Gas–Solid Reaction Kinetic and Mechanism Between Fe3O4 and CH4

Iron and steel have a significant economic and application importance, therefore the reduction of iron oxides is of interest to many researchers. There is a high-energy demand for steel and iron making industries, and it is crucial to address the kinetics of reactions on natural gas as a source of energy and reducing agent for most steel companies. In this thermogravimetric study, the reaction kinetics of Fe3O4 fine particles by using CH4 reduction has been investigated at temperatures ranging from 800 to 1100 °C which have been compared with the results obtained from concentrate reduction by H2 and CO. Different models have been assessed to obtain the governing mechanism and kinetics parameters of this reaction. Unlike H2 and CO reducing agents, the sintering phenomenon increases the rate of CH4 reduction at temperatures more than 900 °C. Dependency of the reaction rate on the amount of Fe3O4 is classified as first-order reaction and this dependency on their particle size is a power function with a − 1.871 power. The reaction rate also is considered a power function of CH4 concentration with − 4.236 power. The reaction activation energy estimated equal to142.5 kJ mol−1.