A method of producing magnesium titanate and direct-reduced iron by coal-based reduction and magnetic separation of titanomagnetite

The invention relates to a method of producing magnesium titanate and direct-reduced iron by coal-based reduction and magnetic separation of titanomagnetite, and belongs to the field of resource utilization. Magnesium titanate powder adopting magnesium orthotitanate as the main crystalline phase and direct-reduced iron powder are obtained by subjecting the titanomagnetite to low-intensity magnetic separation for removing impurities, direct reduction calcination and multistage grinding and magnetic separation, thus achieving comprehensive utilization of valuable metals in the titanomagnetite. The method adopts the titanomagnetite and magnesite which are low in cost as main raw materials and is simple. Raw materials are wide in source, low in using amounts and low in cost. Coal is adopted as a reducing agent. The method is free of requirements on coal quality. The calcination temperature is 1250-1350 DGE C, which is 100-200 DEG C lower than that of solid phase reaction methods at present. Preparation of the magnesium titanate and production of the direct-reduced iron powder are completed synchronously. The magnesium orthotitanate crystalline phase and grade and the recovery rate of the direct-reduced iron are ensured, harmful elements are inhibited from entering products, and the calcination temperature is reduced. The direct-reduced iron powder the iron grade of which is higher than 90% and the recovery rate of which is higher than 95%, and the magnesium orthotitanate powder having purity higher than 99%, and are finally prepared.