Study on Microstructure Evolution of Oolitic Hematite during Microwave Fluidization Roasting

To explore the microstructure evolution of oolitic hematite during microwave fluidization roasting, COMSOL multiphysics and scanning electron microscopy (SEM)–energy-dispersive spectrometry (EDS) were used to simulate evolution. The simulation results indicated that with extension heating time increase power, surface temperature in particle model progressively increased, rate was fastest, followed by quartz apatite; simultaneously, stress difference between three mineral interfaces increased. SEM–EDS illustrated there microcracks at interface iron minerals gangue minerals, such as apatite, more obvious minerals. With treatment time, gradually extended expanded inward along outer edge formed core structure. Appropriately increasing roasting temperature, prolonging CO concentration made loose rough, produced cracks pores, while ore presented a honeycomb morphology.