Enrichment and Recovery Fe-containing Phases from High Iron Gibbsite Ore Based on Metallized Reduction and Magnetic Separation

High iron gibbsite ore is a complex composition and microstructure ore, which features high iron content, high silica content, low alumina content and low A/S. In order to recover iron from high iron gibbsite ore, the process of metallized reduction and magnetic separation based on hot briquette agglomerates was researched systemically. The effect of reduction temperature, reduction time, and the mole ratio of fixed carbon to reducible oxygen (FC/O) on separation indexes was researched. The results show that, with the conditions of reduction temperature 1350iae, reduction time 70 min, FC/O 1.0, and magnetic field intensity of 50 mT, about 87.01% of the iron could be removed from high iron gibbsite ore as metallic iron. Meanwhile, 86.21% of the aluminum are staying in a non-magnetic fraction as alumina. The phase transition of iron-bearing minerals during reduction process are obtained as follows: Fe2O3 iu FeO (FeOi¤Al2O3) iu Fe. The experiments and thermomechanical analysis show that the formation of hercynite (FeAl2O4) limits the reduction rate of iron oxides to metallic iron. A higher recovery ratio of iron could be achieved by adding the catalyst.