Unlocking Iron from BIF-Type Iron Ore: Sustainable Extraction via Efficient Mineral Phase Transformation
摘要
To ensure the supply security of iron resources, there is an urgent need to enhance the utilization of complex refractory iron ores in China. The “hydrogen-based mineral phase transformation (HMPT)-magnetic separation (MS)” technology has been proposed for processing BIF-type iron ore. The pre-discarding tailings–grinding–separation process was adopted to separate HMPT products, and Fe concentrate with a TFe grade of 65.30% and recovery of 82.34% was obtained when the TFe grade of raw ore was 31.43%, achieving efficient separation of iron minerals from the gangue. Experimental studies demonstrate under the optimal conditions that the hematite was selectively converted into magnetite, with the maximum specific susceptibility increasing from 0.22 m3 kg−1 to 0.37 m3 kg−1. The specific surface area, total pore volume, and average pore size increased from 1.022 m2 g−1, 0.0028 cm3 g−1 , and 10.9466 nm to 1.383 m2 g−1, 0.0057 cm3 g−1 , and 16.5887 nm, respectively. Microstructural analysis revealed disrupted crystal structures and microcracks, increasing facilitating gas penetration and enhancing reduction efficiency.