Abstract: The iron content of the Shilu iron ore in Hainan province is 52. 45%. Within this composition,a substantial 86. 18% manifests as hematite/ limonite,with a minor presence of magnetite. To efficiently recover this ore,a systematic experimental study on Hydrogen-based Mineral Phase Transformation (HMPT)-magnetic separation process was carried out,and the products under the optimal conditions were analyzed by chemical composition,XRD and VSM. The results indicate that,under the optimal conditions of a feed particle size of -0. 074 mm accounting for 89. 41%,HMPT temperature of 525 ℃,HMPT time of 10 min,total gas flow rate of 500 mL/ min,H2 concentration of 20%,and HMPT product grinding fineness of -0. 045 mm accounting for 69. 68%,the iron concentrate with an iron grade of 65. 26% and an iron recovery rate of 95. 39% was obtained by magnetic separation. The iron concentrate obtained from the experiments exhibited an increase of 2. 7 percentage points in iron grade and a commendable 30 percentage point rise in iron recovery rate compared to the original gravity and magnetic separation combined process. The study not only provides technical support for the industrial application of HMPT-efficient sorting in Hainan Shilu iron ore,but also opens up new avenues for the green and efficient sorting of other complex and refractory iron ore resources.

Key words: iron ore,Hydrogen-based Mineral Phase Transformation (HMPT),magnetic separation,H₂ and CO molar ratio