摘要:
A two-stage fluidized bed reducing apparatus and a reducing method for fine iron ore of a wide particle size distribution with an increased degree of utilization of the reducing gas. Fine iron particles dropping through the holes of a gas distributor can be recycled into the fluidized bed furnace, thereby preventing an impediment of the reducing gas flow due to abnormal defluidizing or channeling. A first fluidized bed furnace dries, pre-heats and pre-reduces the fine iron ore, and a second fluidized bed furnace finally reduces the pre-reduced iron ore. Downstream of the respective fluidized beds are installed intermediate hoppers and gas/solid sealing valves. Thus, the fine iron ore particles which drop through the holes of gas distributors during the abnormal operation are recycled to the furnaces. Accordingly, the gas flow is not impeded.
摘要:
A device for three-stage fluidized bed for reducing a fine iron ore in accordance with the present invention comprises: a first single-type fluidized bed furnace for drying/pre-heating a fine iron ore in a bubbling fluidized state; a first cyclone for collecting fine iron ore particles entrained in an exhaust gas from the first fluidized bed furnace; a second single-type fluidized bed furnace for pre-reducing the fine iron ore dried/pre-heated in the first fluidized bed furnace; a second cyclone for collecting fine iron ore particles entrained in an exhaust gas from the second fluidized bed furnace; a third twin-type fluidized bed furnace comprising a first cylindrical reaction furnace and a second reaction furnace for finally reducing coarse iron ore particles and medium/fine iron ore particles, respectively, which are pre-reduced in the second fluidized bed furnace; a third cyclone for collecting medium/fine iron ore particles entrained in an exhaust gas from the first reaction furnace of the third fluidized bed furnace; and a fourth cyclone for collecting ultrafine iron ore particles entrained in an exhaust gas from the second furnace of the third fluidized bed furnace.
摘要:
A reduction apparatus and a method for efficient reduction of fine iron ores of wide grain range comprising serially arranged a drying/preheating furnace, a first reducing furnace for prereduction and a second reduction furnace for final reduction, each working with bubbling fluidized bed and being connected each to a cyclone for capturing iron ore dust contained in the exhaust gases, having each a tapered shape smoothly expanded outwards and thus considerably decreasing elutriation of fine particles, increasing the reduction efficiency and enhancing the utilization of the reducing gas.
摘要:
A fluidized bed reducing system for reducing a fine iron ore is disclosed, in which the structure of the fluidized bed reducing furnace is improved such that the coarse iron ore particles are distributed in the lower portion of the fluidized bed within the furnace and the fine iron ore particles are distributed in the upper portion of the fluidized bed. Thus, the average residence times of the particles in the furnace are adjusted differently for different ore sizes, so that the reducing efficiency can be improved, and that the residence time of the reducing gas in the furnace can be extended, thereby improving the degree of gas utilization. The fluidized bed reducing system for reducing a fine iron ore includes: an upper iron ore outlet for discharging fine iron ore particles; a lower iron ore outlet for discharging coarse iron ore particles; a gas distributor installed in a lower portion of a reducing furnace; a gas inlet formed on a lower portion of the reducing furnace for introducing a reducing gas; an iron ore inlet for supplying an iron ore of wide particle size distribution; a circulating duct connected to an upper portion of the reducing furnace for discharging extremely fine iron ore particles together with the reducing gas; a particle capturing device an extremely fine iron ore recycling duct. The fluidized bed reducing furnace includes a cylindrical upper portion and a tapered lower portion, the tapered portion being in a wide-upper-narrow-lower shape.
摘要:
A 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.
摘要:
The 2-stage fluidized bed furnace for pre-reducing a fine iron ore comprises a first stage fluidized bed furnace for receiving the fine iron ore from a storage hopper, discharging medium/small particle size iron ore to the upper part thereof, and reducing a coarse particle size iron ore while forming a bubbling fluidized bed; a second stage fluidized bed furnace for receiving the medium/small particle size iron ore discharged from the upper part of the first stage and reducing it while forming a turbulent fluidized bed; and a first hot cyclone for collecting the small particle size iron ore contained in the discharged gas from the second stage fluidized bed furnace, the first stage furnace being formed in an upper-narrowed, lower-expanded shape and comprising a narrow, upper portion, a transitional, slanted portion and a wide, lower portion, the second stage furnace being in an upper-expanded, lower-narrowed shape and comprising a wide, upper portion, a transitional, slanted portion and a narrow, lower portion.
摘要:
A smelting reduction apparatus and a method for producing molten pig iron using the smelting reduction apparatus are disclosed. The molten pig iron is produced by using iron ore, sintered ore or iron pellets, so that the reduced iron discharge operation from a pre-reducing furnace to a melter-gasifier would not give any influence to the operation of the pre-reducing furnace. An iron ore is pre-reduced at a pre-reducing furnace by utilizing a reducing off-gas which is produced from a melter-gasifier. The pre-reduced iron ore is melted and reduced at the melter-gasifier. The reducing gas which is discharged from the melter-gasifier is supplied through an ascending duct and a cyclone into the pre-reducing furnace. The fine iron ore which is collected at the cyclone is spouted through a recycling device and a melter-burner into the melter-gasifier. A part of the reducing off-gas which has passed through the cyclone is supplied through a ventury scrubber, a compressor and a compressed gas circulating duct into the ascending duct. In such an apparatus, a reduced iron discharge device is installed between the pre-reducing furnace and the melter-gasifier.
摘要:
A method for injecting fine iron ore in a smelting reducing process is disclosed, in which the carrier gas for the iron ore is the discharge gas from a melter gasifier without the need of separate carrier gas. It includes the steps of pre-reducing iron ore in a pre-reduction furnace, melting and reducing it in the melter gasifier, supplying the discharge gas from the melter gasifier through an ascending tube to a cyclone and to said pre-reduction furnace, directing the cooled and cleaned fine iron ore through a recycling system and a melting burner into the melter gasifier. A part of the discharge gas is supplied through a venturi scrubber, a first compressor and a circulating tube into an ascending tube. A part of the compressed gas circulating through the tube is recompressed by means of a second compressor and fine iron ore from a stored source is injected into ascending the tube by the recompressed gas by means of a pneumatic fine iron ore conveying system.