A technology for suspension magnetization roasting-magnetic separation was proposed to separate iron minerals for recovery. The optimum parameters were as follows: a roasting temperature of 650 °C, a roasting time of 20 min, a CO concentration of 20%, and particles with a size less than 37 μm accounting for 67.14% of the roasted product. The total iron content and iron recovery of the magnetic concentrate were 56.71% and 90.50%, respectively. The phase transformation, magnetic transition, and microstructure evolution were systematically characterized through iron chemical phase analysis, X-ray diffraction, vibrating sample magnetometry, X-ray photoelectron spectroscopy, and transmission electron microscopy. The results demonstrated the transformation of hematite to magnetite, with the iron content in magnetite increasing from 0.41% in the raw ore to 91.47% in the roasted product.