Effects of microwave heating on microstructures and structure properties of the manganese ore

• Thermodynamic indicated that manganese ore is readily transformed to Mn3O4.
• Manganese ore has profound influences on the microwave absorption characteristic.
• Microwave heating can be production of high grade ores from low-grade complex ore.

The present work attempts to investigate the formation–decomposition reaction of the manganese ore. Thermodynamic analysis indicates that the decomposition reaction of the manganese ore was feasible by adjusting the roasting temperature and duration time. The peak intensity of Mn3O4 phase of the microwave heated products increases with the increase of microwave heating temperature. The microwave treated manganese ore appears irregular with numerous small cracks and pits, which was caused by the decomposition reaction of MnCO3 phase and CaCO3 phase under microwave heating. It was concluded that microwave heating can be applied effectively and efficiently to the calcination processes of the manganese ore.