Abstract
In recent years, the development of methods for processing poor and difficult-to-process iron ores has become important due to the depletion of rich iron ore deposits. The purpose of the research is to consider the possibility of obtaining direct reduced iron (granulated cast iron) by processing the siderite ore concentrate of LLC Bakalskoe Mining Administration of the Southern Urals (Bakal, Chelyabinsk region). The object of research was samples of concentrate containing iron oxide ~69.6% wt.; iron in the samples averaged 48.72%. The main compounds in the concentrate sample are magnesioferrite; in small quantities, quartz, feldspar, hematite, dolomite, siderite, and clay mineral may be present. Coal from the Shubarkol deposit (Karaganda, Kazakhstan) with a particle size of 0.25 mm was used as a carbonaceous reducing agent. Calcium and silicon oxides were added to the charge as fluxes to obtain a low-melting slag (with a melting point of ~1360 °C) of the following composition, wt.%: 25 CaO, 55 SiO2, 20 MgO. Melting of the pelletized charge was carried out in a laboratory furnace LHT 08/17 (Nabertherm, Germany), at an initial charging temperature of 1200°C, followed by gradual (within 10 min) heating to 1350 °C. Next, the crucible with the charge was also gradually heated to 1400°C and held at this temperature for 5 minutes. Then the temperature decreased to 1150 °C. As a result of the experiments, the possibility of obtaining granulated cast iron from the studied concentrate was confirmed; iron extraction was 65.9%. It is recommended to use this concentrate as an additional component of an iron-containing charge to produce granulated cast iron.
Keywords:
Bakal Mining Administration, ferromagnesian concentrate, pellets, flux, granular pig iron, slag.