Abstract: Daxigou refractory siderite ore was investigated through high intensity magnetic preconcentration-magnetization roasting-magnetic separation. The results showed that high intensity magnetic concentrate with iron grade of 28.47% and recovery of 96.78% was obtained under the test conditions that the grinding fineness of 55% ores is less than 74μm， high intensity magnetic field for roughing is 318kA/m and magnetic field for scavenging is 717kA/m. Iron concentrate with iron grade of 59.29% and recovery of 87.50% was obtained under roasting temperature of 700℃， roasting time of 40min with neutral atmosphere， 95% grinding fineness less than 43μm and low intensity magnetic field intensity of 104kA/m. The analysis results of XRD， optical microscope and VSM showed that refractory siderite and limonite are transformed into easily separated magnetite by roasted， meanwhile， the surface of the newly generated magnetite showed loose and porous， symbiosis between magnetite and gangue minerals is close， and the magnetization intensity and specific susceptibility increase greatly.

Key words: siderite ore, high intensity magnetic preconcentration, magnetization roasting, magnetite； specific susceptibility