After the high-intensity magnetic separation tailings of limonite is separated with conventional physical methods,the iron concentrate obtained often has problems of lower grade and lower iron recovery,which is prone to cause problems such as resource waste. To improve the comprehensive utilization of limonite, this paper introduces an experimental study conducted on the magnetizing roasting and quality improvement of limonite-type iron tailings,which investigates the influences of key parameters such as roasting temperature,roasting time,reducing agent consumption, pretreatment temperature,and grinding-magnetic separation conditions on the separation indices of iron concentrate. X-ray diffraction (XRD) and thermodynamic analysis were employed to discuss the phase transformation and magnetization process during roasting,and Gibbs free-energy calculations were conducted to determine the thermodynamic feasibility and chemical reactions of magnetization at different temperature ranges. The results show that the “ high-temperaturemodification-magnetization-low-intensity magnetic separation” process can significantly improve the separation indices of this type of ore. After high-temperature pretreatment in an air atmosphere,the goethite phase in the iron tailings can completely dehydroxylate and transform into the hematite phase. The development of internal pores in the particles promotes the magnetization reduction reaction and the growth of magnetite grains. Under the separation conditions of a roasting temperature of 800 ℃,magnetization time of 30 min,reducing agent dosage of 3%,grinding fineness with a particle size of <0. 045 mm accounting for 45. 6%,and magnetic field intensity of 111. 4 kA/ m,an iron concentrate with an iron grade of 61. 59% and an iron recovery of 91. 38% was obtained. The study findings of this paper can provide important technical support for the resource utilization of complex limonite-type tailings