Dry magnetic separation (DMS) enables to separate the non-magnetic fraction of iron ores at the initial stage of their concentration and therefore to decrease cost of their further processing. However, a considerable amount of metal is lost in DMS tails at that. The efficiency of DMS considerably depends on difference between the upper and lower limits of the ore coarseness) ore coarseness range), delivered for concentration. At the Magnitogorsk steel-works crushing and concentration plant No. 5 this range is from 50 mm up to 15 mm. To determine the optimal ore size, delivered to DMS, studies accomplished to determine the specific magnetic susceptibility of the magnetite and the burden for the magnetite ore of Maly Kuibas deposit. After the study of different size iron ore separation, a reasonability of the DMS feed size decreasing down to 30–7 mm shown. A possibility to obtain additional product of 7–0 mm size determined, suitable for sintering. It will enable to decrease the amount of material, delivered for crushing and wet magnetic separation, as well as to decrease expenses for transporting and storage of wet separation tails. Peculiarities of fine magnetite ore processing by DMS in a suspended state considered, optimal parameters of the separator determined and its high efficiency for magnetite ore of 7–0 mm size concentration shown.

The Urals is one of the unique iron ore provinces of the world, including all the variety of iron ores. Siderite ores are represented by the Bakal group of deposits, in which siderite in mineralogical terms is not a chemically pure iron carbonate, but has an isomorphic admixture of magnesium and calcium, forming sideroplesite and pistomesite. The main iron ore mineral of the siderite ore of this deposit is an isomorphic mixture of iron, magnesium and manganese carbonates, which occur in different quantitative ratios. A scheme for ore dressing is proposed, which includes crushing to a size of 10-0 mm and dry magnetic separation in a suspended state at a magnetic field strength of 52 k/m. The study of dry magnetic separation of siderite ore was carried out on a suspended separator with a constant magnetic field and on an electromagnetic separator 138T-SEM. The resulting magnetic fraction is sent to the baking, subsequent crushing to a size of 2-0 mm and dry magnetic separation in the suspended state. To increase the mass fraction of iron and reduce the mass fraction of magnesium oxide, the magnetic fraction is sent for grinding and wet magnetic separation. The results of the experiments have showed that the enrichment using high-intensity dry magnetic separation of siderite ore from various sections of the deposit, the mass fraction of MgO decreased from 9.4-12.3% to 8.0-10.1%, and the mass fraction of iron increased from 28.8-33.4% to 31.4-40.8%. As a result, a product with a mass fraction of iron 59.3-60.1% and magnesium oxide 10.0-11.3% has been obtained. The developed enrichment technology allows us to obtain conditioned raw materials, which can serve as a promising raw material for PJSC Magnitogorsk Iron and Steel Works (PJSC MMK)