关键词: 难选铁矿, 磁化焙烧, 还原, 磁选

Abstract: uquan Iron and Steel Co.，Ltd. and systematically conducted experimental re⁃ search on suspension magnetizing roasting—magnetic separation based on process mineralogy analysis. The primary valuable minerals in the raw ore are hematite and siderite. By systematically investigating the influence of key parameters：roasting temperature，CO concentration，roasting time，grinding fineness， and magnetic field intensity on separation performance，the optimal process conditions were determined. The results of the suspension magnetizing roasting—magnetic separation tests showed that under the condi⁃ tions of a roasting temperature of 475 ℃，roasting time of 8 minutes，CO concentration of 20%，grinding fineness of -0.1 mm，and magnetic field intensity of 144 kA/m，a magnetic concentrate with an iron grade of 55.97% and an iron recovery rate of 93.52% was obtained. XRD and chemical composition analyses indi⁃ cated that the magnetite content in the magnetic concentrate increased，while impurity components such as SiO₂，Ba，S，and K were significantly reduced，validating the effectiveness of this process in enhancing iron grade and reducing harmful elements. Phase analysis and SEM analysis revealed that after roasting， hematite and siderite were almost completely converted into magnetite. In the magnetic concentrate，iron mainly existed in the form of magnetic iron，with a distribution rate reaching 93.23%. The research find⁃ ings demonstrate that the magnetizing roasting—magnetic separation process has a favorable enrichment ef⁃ fect on iron minerals.

Key words: refractory iron ore, magnetizing roasting, reduction, magnetic separation