Abstract: In order to solve the problem of low recovery and low grade of iron concentrate in Jingtieshan powder ore of Jiusteel， based on the process mineralogy analysis of preconcentrated concentrate with high intensity magnetic separation， Northeastern University carried out an extended test study on suspension magnetization roasting. The results show that the TFe grade of the preconcentrated concentrate with high intensity magnetic separation is 39.02%， the iron content in the sample is mainly hematite and siderite， the iron distribution rate is 67.81% and 28.36%， respectively， and the gangue minerals are mainly quartz， dolomite and barite. With the new process of high intensity magnetic separation tail-throwing-suspension roasting-magnetic separation-reverse flotation， the qualified iron concentrate with TFe grade of 60.67% and SiO₂ content of 4.52% was finally obtained， and the iron recovery rate was 76.27%. Compared with the original single high intensity magnetic separation process， the iron grade of concentrate by the new process was improved by 16.11 percentage points， the SiO₂ content was reduced by 6.83 percentage points， and the recovery was increased by 14.43 percentage points. The concentrate index was greatly improved， test results provided technical basis for the efficient utilization of iron powder resources in the next step.

Key words: Refractory iron oxide ore, Suspension magnetization roasting, Powder ore, High intensity magnetic preconcentration concentrate, High intensity magnetic separation, Reverse flotation