Mechanism of Carbothermic Reduction of Fe<sub>3</sub>O<sub>4</sub> Irradiated by Microwave with 2.45 GHz

The reaction mechanism of the carbothermic reduction Fe3O4 powder heated by radiating multi-mode microwave with 2.45 GHz and 2.8 kW was clarified means gas analysis changing contact state mixed powder. process classified in three stages. In stage I, magnetic loss induction current graphite (Gr) reached peak temperature 1000°C to 1200°C 30 s 40 after irradiation, then dropped rapidly at 600°C 700°C. reduced FeO. II, FeO Gr, entropy production maximum about 100 s. III, molten pig iron produced light emission. rate always larger for Boudouard than or This indicates that is preferentially promoted near points between Gr particles. dominant reactions were determined be Fe3O4+CO→3FeO+CO2, FeO+CO→Fe+CO2 from smaller negative value Gibbs energy change reactions. I pre-exponential factor increased time. apparent activation oxide lower conventional heating.