Solid-phase Decarburization Kinetics of High-carbon Ferromanganese Powders by Microwave Heating

Solid-phase decarburization of high-carbon ferromanganese powders (HCFPs) was conducted using calcium carbonate powders (CCPs) as a decarburizer by microwave heating. Solid-phase decarburization kinetics was investigated by isothermal method. The results show that the HCFPs show excellent microwave absorption at a higher average heating rate of 80 °C/min, while CCPs exhibit poor microwave absorption at a lower heating rate of 5—20 °C/min; the heating characteristics are in-between when HCFPs and CCPs are mixed. The average heating rates of the mixture are 32. 14, 31. 25, 31. 43, and 30. 77 °C/min when the mixture is heated up to 900, 1000, 1100, and 1200 °C, respectively. The good microwave absorption property of the mixed material lays the foundation for the solid-phase decarburization of HCFPs containing CCPs. Solid-phase decarburization of HCFPs containing CCPs is a first-order reaction by microwave heating. Apparent activation energy of solid-phase decarburization is 55. 07 kJ/mol, which is far less than that of ordinary carbon gasification reaction and that of solid-phase decarburization under the same decarburization condition by conventional heating. It indicates that microwave heating not only produces thermal effect, but also has non-thermal effect.