FLUIDIZED BED TYPE REDUCTION APPARATUS FOR IRON ORES AND METHOD FOR REDUCING IRON ORES USING THE APPARATUS

摘要

PCT No. PCT/KR95/00181 Sec. 371 Date Oct. 28, 1996 Sec. 102(e) Date Oct. 28, 1996 PCT Filed Dec. 28, 1995 PCT Pub. No. WO96/21044 PCT Pub. Date Jul. 11, 1996A three-stage, fluidized-bed-type reduction apparatus and a method for using it for reducing fine iron ores of wide size ranges, improving the gas utilization and reduction degree, reducing the residence time of iron ores, and increasing the prereduction rate of reduced iron. The apparatus includes serially arranged a drying/preheating furnace with a first cyclone connected to it, a primary prereduction furnace with a second cyclone connected to it, a secondary high-gas-velocity reduction furnace for finally reducing only a coarse ore portion of the prereduced iron ores at a bubbling fluidized state while carrying over the medium/fine ore portion of the iron ores, a secondary low-gas-velocity reduction furnace for finally reducing the medium/fine ores forming a bubbling fluidized bed thereof, an inner cyclone installed in the secondary low-gas-velocity reduction furnace, and a third cyclone for capturing dusty ores not captured by the inner cyclone.