Abstract: Objective Siderite is a typical refractory iron ore. Strengthening the research on the beneficiation of siderite can effectively alleviate the shortage of iron ore supply in China and ensure the sustainable development of steel enterprises. Method A certain rhombic and red mixed iron ore in Gansu Province contains 38.16% iron. In view of the characteristics of this ore, an experimental study was conducted using the process flow of magnetic roasting - weak magnetic separation. Result Magnetic roasting was carried out at the conditions of no addition of reducing agent, roasting temperature of 700 ℃ and roasting time of 40 min. After grinding the roasted product to a particle size of -0.045 mm 85%, it was subjected to two stages of weak magnetic separation to obtain iron concentrate with an iron grade of 65.26% and an iron recovery rate of 86.46%. And the content of impurities such as SiO₂, Al₂O₃, S and P is low. Conclusion Magnetic roasting - weak magnetic separation is an effective process for the separation of siderite. The research provides a technical basis for the efficient utilization of siderite resources.