Hydrogen−based Mineral Phase Transformation−low Intensity Magnetic Separation−reverse Flotation of an Iron Ore Abroad

China's iron ore is heavily dependent on imports. In order to solve the problem of import dependence, enterprises are actively searching for available iron ore resources and developing independent innovation technologies. The hydrogen−based mineral phase conversion technology uses hydrogen or hydrogen−rich gas as a reducing agent to chemically react the ore in a suspended state and at a certain temperature, so that the weakly magnetic iron minerals in the ore are converted into strong magnetic magnetite or maghemite, and then magnetic separation is performed using magnetic differences between minerals. The iron grade of an iron ore is 52. 11%. Iron mainly exists in the form of hematite/limonite, accounting for 85. 54% of total iron. The main gangue mineral is quartz, with a content of 20. 87%. In order to determine the reasonable utilization process of the ore, the experimental study of hydrogen−based mineral phase transformation−low intensity magnetic separation−reverse flotation was carried out. The results show that when the reduction temperature is 540 ℃, the reduction time is 20 min, the reduction gas volume concentration is 25%, the reduction atmosphere V(CO)∶V(H₂)=1∶3, the grinding fineness −0. 074 mm content accounts for 72%, and the magnetic field strength is1600 Gs, the magnetic concentrate iron grade is 65. 55%, and the iron recovery rate is 98. 14%. The iron in the magnetic separation concentrate mainly exists in the magnetic iron. Compared with the iron content in the magnetic iron of the raw ore, the iron content in the magnetic iron increases by about 58%, and the content of hematite/limonite decreases to 0. 20%, indicating that the weak magnetic hematite/limonite minerals are reduced to strong magnetic magnetite after the conversion of the raw ore by the hydrogen−based mineral phase, and the iron minerals are effectively recovered during the weak magnetic separation process. The magnetic separation concentrate was ground to −0. 074 mm content of 88%. After one roughing, one cleaning and one scavenging reverse flotation test, the final concentrate with iron grade of 68. 47% and recovery rate of 97. 48% was obtained. The SiO₂ content was 3. 06%, which was about 18 percentage points lower than that of the raw ore. In this paper, through the process of ' hydrogen−based mineral phase transformation−low intensity magnetic separation−reverse flotation ', the experimental research on iron extraction and impurity reduction is completed. It is a suitable process for treating the ore. The process has great economic, social and environmental benefits, and improves the high−quality utilization of mineral resources. Ability, resource sustainability and market risk prevention capabilities.