Microwave-assisted breaking technology can achieve continuous mining of banded iron ore. To understand the response characteristics of iron ore under single-mode microwave irradiation and reveal its fracture mechanism under the influence of banded characteristics, this study employed single-mode microwave irradiation to compare the temperature distribution and microstructural damage of banded haematite under varying microwave parameters. The development of cracks under the influence of banded characteristics is analysed from both macroscopic and microscopic perspectives. The results indicate that microwave power exerts a more significant influence than irradiation time; power primarily modulates the breaking effect and efficiency, whereas irradiation time predominantly determines the breaking range. With regard to the heating mode, the axial direction of banded haematite can be divided into a direct influence zone, a nonuniform heat transfer influence zone, and a uniform heat transfer influence zone. High temperature and damage concentrate in the direct influence zone, each attenuating progressively with depth. The cracks in these regions are distributed within or between the useful mineral bands; their development characteristics are successively dominated by new cracks, with expansion being a supplement, are dominated by expansion, with new cracks being a supplement, or are dominated by expansion alone. • The fracture mechanism of banded iron ore under single-mode microwave irradiation was revealed. • The crack distribution of banded iron ore strongly correlates with the distribution of its bands. • The emphasis on microwave power and irradiation time is different in rock breaking. • The temperature and the degree of damage under single-mode microwave irradiation decrease from high to low along the radiation direction, showing a distinct regional distribution.
Zhu et al. (Sun,) studied this question.