FIELD: metallurgy; methods of reduction of iron ore having wide distribution of particles including treatment by reducing gas. SUBSTANCE: device has first, second and third fluidized-bed furnaces. First furnace is used for performing first stage of preliminary reduction of iron ore having coarse (intermediate) particles of iron ore. Second furnace is used for performing first stage of preliminary reduction of fine particles of iron ore carried from first furnace. Third furnace is used for performing second stage of preliminary reduction of iron ore unloaded from first and second furnaces. Device is also provided with cyclones for entrapping fine particles of iron ore from waste gas escaping from furnaces for returning these particles to furnaces and gas reforming system of part of waste gas of one of cyclones. EFFECT: stabilization of fluidization of fine-grained iron ore for enhancing degree of reduction and utilization of gas; reduced losses caused by entrainment of ore. 6 cl, 2 dwg, 5 tbl, 1 ex
