Mineral and Technological Features of Magnetite–Hematite Ores and Their Influence on the Choice of Processing Technology

Analysis of the current technical solutions for the processing of iron ores showed that the high-grade ores are directly exposed to metallurgical processing; by comparison, low-grade ores, depending on the mineralogical and material composition, are directed to beneficiation including gravitational, magnetic, and flotation processes or their combination. Obtaining high-quality concentrates with high iron content and low content of impurities from low-grade iron ores requires the maximum possible liberation of valuable minerals and a high accuracy of separating features (difference in density, magnetic susceptibility, wettability, etc.). Mineralogical studies have established that the main iron-bearing mineral is hematite, which contains 69.02 to 70.35% of iron distributed in the ore. Magnetite and hydrogoethite account for 16.71-17.74 and 8.04-10.50% of the component, respectively; the proportion of iron distributed in gangue minerals and finely dispersed iron hydroxides is very insignificant. Iron is mainly present in the trivalent form-Fe 2 O 3 content ranges from 50.69 to 51.88%; bivalent iron is present in small quantities-the FeO content in the samples ranges from 3.53 to 4.16%. The content of magnetic iron is 11.40-12.67%. Based on the obtained results by the investigation of the features of magnetite-hematite ores from the Mikhailovskoye deposit, a technological scheme of magneto-flotation beneficiation was proposed, which allows producing iron concentrates with 69% of iron content and less than 2.7% silicon dioxide for the production of pellets with subsequent metallization.