KR19990052849A - Fluidized bed reduction device of two-stage iron ore and its method - Google Patents

Abstract

The present invention is to reduce the iron ore in the solid state in a fluidized bed reduction furnace to reduce the iron ore of a wide particle size, to produce a solid iron reduced in iron ore reduced by 85% or more to melt the molten gas in the molten gas furnace to form the final product pig iron The present invention relates to a two-stage iron ore fluidized bed reduction apparatus and a reduction method using the same.

The present invention improves the disadvantages of the conventional one-stage and three-stage fluidized bed furnaces and improves them into two-stage fluidized bed furnaces. In the first fluidized bed furnace, the ferrite ore is dried, preheated and pre-reduced in a reducing atmosphere, and the second fluidized bed furnace is used. In the final reduction configuration, the fluid transfer device consisting of the intermediate hopper (Hopper) and gas / solid closed valve is installed at the bottom of each fluidized bed through the gas distributor hole (Hole) during the abnormal operation The two-stage iron ore fluidized bed reduction apparatus and the reduction method using the same are circulated to the bottom of the iron ore falling back to the fluidized bed to prevent the reduction gas flow.

Description

Fluidized bed reduction device of two-stage iron ore and its method

The present invention relates to a two-stage iron-iron ore fluidized bed reduction apparatus for reducing iron ore having a large particle size, and a reduction method using the same. More specifically, iron ore is 85% so as to make pig iron as a final product by melting in a melt gasifier. The present invention relates to a fluidized bed reduction apparatus of two-stage iron ore for producing reduced solid iron (DRI) and a reduction method using the same.

Conventional blast furnace method is possible to reduce the iron ore by the fixed bed method due to the large size of the solid particles, but in the case of reduction of fine ore, if the flow rate is low like sticking bed, there is a possibility of operation interruption due to sticking. In order to secure air permeability, a fluidized bed method that smoothly moves solid particles by providing a sufficient flow rate is essential.

As an example of the reduction furnace which reduces a powdered iron ore using the said fluidized bed, the fluidized bed reduction furnace of Japanese Unexamined-Japanese-Patent No. 58-217615 is mentioned. As shown in Fig. 1, the fluidized bed-type iron ore reduction furnace is largely divided into a cylindrical reduction furnace 91 and a cyclone 95 in structure, and the cylindrical reduction furnace 91 has a raw iron ore charge 92 and a high temperature reduction furnace. The gas inlet 93 and the outlet 94 of the iron ore reduced by the reducing gas, the gas distribution plate 96 is built in the lower portion of the reduction furnace. When the ferrous ore is sent through the charging port 92 while supplying the reducing gas at the flow rate required for the ore flow through the lower gas distribution plate 96 of the cylindrical reduction furnace 91, the iron ore is mixed and stirred with a high temperature reducing gas. And react. At this time, when the fluidized bed height rises to the outlet 94 level after a predetermined time, the reduced iron ore is discharged through the outlet 94. In this case, the formed fluidized bed is a bubble fluidized bed in which bubbles are grown while reducing gas supplied from the cylindrical reduction furnace 91 becomes bubbles and passes through the particle layer on the upper part of the reduction furnace.

However, in the above-described fluidized bed reduction furnace, in order to reduce the amount of fine iron ore scattered to the outside of the reduction furnace in a smooth flow state in consideration of economic aspects such as productivity, to minimize the reducing gas consumption, and to maximize the gas utilization rate, Since the particle size of the loaded iron ore is strictly limited, there is a problem in that the iron ore having a wide particle size distribution cannot be processed. The particle size distribution of iron ore charged into the fluidized bed reduction furnace is generally limited to 0-0.5mm, -1mm, 1-2mm and the like without having a wide range of particle sizes. However, the particle size of the actual iron ore is almost 8mm or less. Therefore, in order to use the iron ore having the above-mentioned particle size, the iron ore to be charged is sieved to a prescribed granularity in advance, or classified and used below the prescribed granularity, resulting in economic loss due to reduced production speed, process and additional equipment burden. There is a problem.

As a process for solving this problem, a three-phase fluidized bed (Taper) type fluidized bed as shown in FIG. 2 is presented in Korean Patent No. 117065 (1997). In the reduction process using the fluidized bed furnace, the shape of the fluidized bed is in the form of a normal bed bottom, ie, conical, and the preheating of the iron ore in order to improve the reduction rate and the gas utilization rate can stably flow the iron ore having a wide particle size distribution. After the preliminary reduction, the final reduction consists of a three-stage fluidized bed continuous process. That is, the reduction process is iron ore is preheated in the bubble flow state in the top reactor 10, as shown in Figure 2, iron ore is pre-reduced in the bubble flow state in the central reactor 20, the bottom reactor 30 Is a three-stage fluidized bed continuous process where iron ore is finally reduced in a bubble flow state.

In Fig. 2, reference numerals 40, 50, and 60 denote cyclones, 70 denote raw material hoppers, and 80 denote melt gasifiers, respectively.

The conical three-stage fluidized-bed reduction reactor can stably flow the ferrite ore having a wider particle size distribution than the conventional one-stage cylindrical fluidized bed furnace, and can significantly reduce the reduction rate and the gas utilization rate, but is equipped with three stages. High investment costs and problems with only one reactor can affect other reactor operations, disrupting the entire process, and defluidizing or channeling, which are frequently encountered in fluidized bed operations. When there is an abnormal phenomenon such as iron ore is agglomerated into the lower portion of the dispersion plate through a gas distributor hole (Hole) can not be prevented to interfere with the flow of reducing gas.

The present invention not only makes efficient use of energy such as reactivity, gas utilization rate, gas consumption amount of solid iron ore particles, but also can be reduced more economically in reducing iron ore having a wide particle size distribution. It is an object of the present invention to provide a fluidized bed reduction apparatus and a reduction method of two-stage iron ore, which are configured to circulate the iron ore falling through the hole to the fluidized bed again.

1 is a front sectional structural view showing a fluidized bed reduction furnace of a conventional iron ore

2 is a block diagram showing a fluidized bed reduction furnace of a conventional three-stage taper type iron ore

Figure 3 is a block diagram showing a reduction device of a fluidized bed iron ore in accordance with the present invention

※ Explanation of code for main part of drawing ※

100... First fluidized bed furnace 101. First gas supply port

102... First dispersion plate 106 ... first ore outlet

107... First gas outlet 200... Second fluidized bed furnace

201... Second gas supply port 202... Second dispersion

206... Second ore outlet 207... Second gas outlet

300... First cyclone 400... Second cyclone

500... First intermediate hopper 600... Second intermediate hopper

700... Ore charging hopper 900... Melt gasifier

(Melter Gasifier)

The present invention provides a fluidized bed of two-stage iron ore in the first fluidized bed furnace, which is configured to dry, preheat and pre-reduce the iron ore in a reducing atmosphere and finally reduce the dried, preheated and pre-reduced iron ore in the second fluidized bed furnace. In the reducing apparatus,

A first taper-type fluidized bed furnace configured to dry, preheat and pre-reduce raw iron ore charged from the hopper while forming a bubble or turbulent fluidized bed;

A first cyclone configured to separate the fine iron ore contained in the exhaust gas into the first fluidized bed from the gas and recirculate downwardly into the first fluidized bed;

A second conical (Taper) fluidized bed configured to be finally reduced while forming a bubble or turbulent fluidized bed by using the exhaust gas of the preheated and pre-reduced ferrous iron ore in the first fluidized bed as a reducing gas;

A second structure configured to separate the fine iron ore contained in the flue gas in the second fluidized bed from the gas and recycle it to the lower part of the second fluidized bed, and the exhaust gas of the second fluidized bed in which the fine iron ore is separated is supplied as a reducing gas to the first fluidized bed. Cyclone;

Located between the first fluidized bed furnace and the second fluidized bed furnace, it is configured to store the ferrite ore dropped through the hole (Hole) of the distribution plate to the first fluidized bed furnace and to convey to the bottom of the second fluidized bed furnace A first intermediate hopper;

A second intermediate hopper located at the bottom of the second fluidized bed furnace and configured to store the ferrite ore dropped through the nozzle of the distribution plate to the second fluidized bed and then transport it to the bottom of the second fluidized bed. It relates to a fluidized bed reduction apparatus of two-stage iron ore comprising a.

In addition, the present invention relates to a method for reducing iron ore using the fluidized-bed reduction device of the two-stage iron ore, wherein the first fluidized bed furnace is dried, preheated and pre-reduced in a reducing atmosphere and the second In the fluidized bed furnace, it is composed of the final reduction. A powder transfer device consisting of an intermediate hopper and a gas / solid sealed valve is installed at the bottom of each fluidized bed, and the lower part of the distribution plate is provided through a gas distributor hole during abnormal operation. The present invention relates to a method for reducing ferrous ore, in which pulverized ore falling back to the fluidized bed furnace is circulated to prevent the reduction gas flow.

Hereinafter, the present invention will be described in detail by the drawings.

As shown in FIG. 3, the two-stage fluidized-bed reduction apparatus of the iron-iron ore of the present invention is preheated and preliminarily formed to form a bubble or turbulent fluidized bed by reducing gas supplied to the raw iron-iron ore charged from the hopper 700. A first conical (Taper) fluidized bed furnace 100 configured to reduce;

The fine iron ore contained in the flue gas of the first fluidized bed furnace (100) is separated from the gas and recirculated to the bottom of the first fluidized bed (100), and the exhaust gas of the first fluidized bed furnace in which the fine iron ore is separated is discharged to the outside or to the atmosphere. A first cyclone 300 configured to be;

Taper type second fluidized bed furnace configured to finally reduce the preheated and pre-reduced iron ore in the first fluidized bed furnace 100 while forming a bubble or turbulent fluidized bed by exhaust gas (reducing gas) of the molten gasifier 800. 200;

The fine iron ore contained in the exhaust gas of the second fluidized bed furnace 200 is separated from the gas and recycled to the bottom of the second fluidized bed furnace 200, and the exhaust gas of the second fluidized bed furnace 200 in which the fine iron ore is separated is the first fluidized bed. A second cyclone 400 configured to be supplied to the reducing gas of the furnace 100;

Located between the first fluidized bed furnace (100) and the second fluidized bed furnace (200), the ferrite ore dropped through the holes of the distribution plate (102) of the first fluidized bed furnace (100) is stored and the second fluidized bed furnace (200) A first intermediate hopper 500 configured to feed downward;

Located at the bottom of the second fluidized bed furnace 200 and configured to store the ferrite ore dropped through the holes of the distribution plate 202 of the second fluidized bed furnace 200 and transported to the lower portion of the second fluidized bed furnace 200 It is configured to include two intermediate hopper (600).

The first fluidized bed furnace 100 is composed of a lower conical portion (100a) and the upper cylindrical portion (100b), the first gas supply port 101 for receiving a reducing gas at the lower end of the conical portion (100a) ) Is formed, and the first gas distribution plate 102 is mounted therein. A first ore outlet 106 is formed on the side wall, and the first ore outlet 106 communicates with the lower part of the second fluidized bed 200 through an ore communication relationship via the second conduit 103.

In addition, an iron ore supply port 105 is formed in the lower side wall, and the iron ore supply port 105 is connected to the hopper 700 through the first conduit 701 to transfer the iron ore into the first fluidized bed furnace 100. And a first gas outlet 107 is formed at an upper portion thereof, and the first gas outlet 107 communicates with an upper portion of the first cyclone 300 via a third conduit 301.

The first cyclone 300 is configured to separate the fine iron ore contained in the exhaust gas of the first fluidized bed furnace (100) with the gas and the separated fine iron ore at the bottom of the first cyclone (300) to the first fluidized bed furnace (100) A fourth conduit 302 is connected to the lower portion of the bottom of the circumference, and a fifth conduit 303 is connected to the upper portion of the exhaust pipe of the clean first fluidized bed 100 to finally discharge the exhaust gas.

The fourth conduit 302 is preferably located one end deep in the lower portion of the first fluidized bed (100) to supply the separated fine iron ore deeper in the lower portion of the first fluidized bed (100).

The second fluidized bed 200 is composed of a lower conical portion 200a and an upper cylindrical portion 200b, and a second gas supply hole 201 for receiving a reducing gas at a lower end of the conical portion 200a. ) Is formed, and the second gas distribution plate 202 is mounted therein.

A second ore outlet 206 is formed on the side wall, and the second ore outlet 206 communicates with the lower portion of the melt gasifier 800 through an eighth conduit 203 in an ore communication relationship.

In addition, a preliminary reduction ore supply port 205 is formed on the lower side wall, the preliminary reduction ore supply port 205 is connected to the first fluidized bed 100 through the second conduit 103 to dry, preheat and preliminary reduction. The fine iron ore flows into the second fluidized bed furnace 200, and a second gas outlet 127 is formed at an upper portion of the second gas outlet 207 through the tenth conduit 401. It is in communication with the top of the cyclone (400).

The second cyclone 400 is configured to separate the fine iron ore contained in the exhaust gas of the second fluidized bed furnace 200 with the gas, and the separated fine iron ore is disposed at the bottom of the second cyclone 200 in the second fluidized bed furnace 200. Is connected to a ninth conduit 402 for recycling to the bottom of the upper part, and a sixth conduit 403 for supplying the exhaust gas of the clean second fluidized bed 200 to the first fluidized bed 100. Is connected.

The ninth conduit 402 preferably places one end deeply below the second fluidized bed 200 so as to supply the separated fine iron ore deeply below the second fluidized bed 200.

The first intermediate hopper 500 is located between the first fluidized bed furnace 100 and the second fluidized bed furnace 200, and is connected to the lower end of the first fluidized bed furnace 100 through the seventh conduit 502. 11 is connected to the second fluidized bed 200 through conduit 504.

At least one gas and solid sealing valve for high temperature (501, 503) is attached to the front and rear ends of the seventh conduit (502) and the eleventh conduit (504), that is, the first intermediate hopper (500). As a result, during the operation or during an emergency, the ferrite ore dropped through the nozzle of the distribution plate 102 of the first fluidized bed furnace 100 may be stored and transported to the bottom of the second fluidized bed furnace 200 with an inert gas such as nitrogen. It becomes possible.

The eleventh conduit 504 has one end of the second fluidized bed so as to supply the ferrite ore dropped through the nozzle of the distribution plate 102 of the first fluidized bed 100 deeply below the second fluidized bed 200. It is desirable to locate deep into the bottom of the furnace 200.

The second intermediate hopper 600 is positioned below the second fluidized bed 200, is connected to the lower end of the second fluidized bed 200 through a thirteenth conduit 602, and further includes a twelfth conduit 604. It is connected to the bottom of the second fluidized bed furnace 200 through.

One or more gas and solid hermetic valves 601 and 603 are attached to front and rear ends of the thirteenth conduit 602 and the twelfth conduit 604, that is, the second intermediate hopper 600. Therefore, during the operation or during an emergency, the iron ore dropped through the nozzle (Hole) of the distribution plate 202 of the second fluidized bed 200 is stored and then returned to the bottom of the second fluidized bed 200 with an inert gas such as nitrogen. You can send it.

Hereinafter, a method of reducing the iron ore using the fluidized bed reduction apparatus of the two-stage iron ore of the present invention configured as described above will be described.

Preheated and pre-reduced reduction of the iron ore supplied to the first fluidized bed (100) while forming a bubble or turbulent fluidized bed with a flue gas (reduction gas) of the second fluidized bed (200), the reacted iron ore is the second conduit (103) And then reduced to form a fluid flow layer by using a reducing gas (melt gasification flue gas) supplied through the second flue gas supply port 201 through the second fluidized bed furnace 200 through the second fluidized bed furnace 200, and then the second ore Final discharge through the outlet 206. The ultrafine iron ore contained in the exhaust gas of the first fluidized bed furnace 100 is separated from the gas in the first cyclone 300 so as to be recycled to the lower portion of the first fluidized bed furnace 100 and to the exhaust gas of the second fluidized bed furnace 200. The contained ultrafine iron ore is separated from the gas in the second cyclone 400 to be recycled to the bottom of the second fluidized bed furnace 200.

In the present invention, when there is an abnormality such as defluidizing or channeling which is frequently generated in fluidized bed operation, the ferrite ore falls to the bottom of the dispersion plate through a gas distributor hole. Since there is a phenomenon that obstructs the flow of reducing gas, the high-temperature valves 501 and 601 of the first and second intermediate hoppers 500 and 600 are opened first at regular intervals during operation and in emergency such as gas supply shutoff. The iron ore accumulated in the gas distribution plates of the first and second fluidized bed furnaces 100 and 200 is stored in the first and second intermediate hoppers 500 and 600, respectively, and then the front end valves 501 and 601 are closed. The high temperature valves 503 and 603 at the rear end of the first and second intermediate hoppers 500 and 600 are opened to blow inert gas such as nitrogen into the lower portion of the second fluidized bed furnace 200.

In the case of reducing the iron ore using a two-stage fluidized bed reduction furnace as in the present invention, the preheating and pre-reduction in the first fluidized bed furnace 100 is carried out at 700-850 ° C. and in the second fluidized bed furnace 200. The final reduction of is preferably carried out at 750-900 ° C., and the operating pressure is preferably performed at 1-5 atm at absolute pressure. The gas flow rates just above the dispersion plates in the first fluidized bed furnace 100 and the second fluidized bed furnace 200 are 1.2-2.5 times or less the minimum fluidization rate of the iron ore staying in the furnace, in consideration of the smooth flow and scattering amount. Preferably, the inclination angle of the conical portion is preferably 5-20 ° in the vertical line, and the height of the conical portions 100a and 200a from the distribution plate is 5-10 times the inner diameter of the lower dispersion plate, and the cylindrical portions 100b and 200b. ) The height is preferably 3-5 times the inner diameter.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example

Reduction was carried out under the reduction conditions shown in Table 2 to Table 4 using the reduction apparatus of FIG. 3 having the same size as in Table 1 below.

Fluidized bed reduction furnace height and internal First fluidized bed furnace Cone part (distribution plate) Inner diameter: 0.6m Cone part tilt angle: 5 ° Cone part height (on the surface of the distributor plate): 3 m Cylindrical part inner diameter: 1.1 m Cylindrical part height: 3.5 m Second fluidized bed furnace Cone part (distribution plate) Inner diameter: 0.6m Cone part tilt angle: 5 ° Cone part height (on the surface of the distributor plate): 3 m Cylindrical part inner diameter: 1.1 m Cylindrical part height: 3.5 m

Chemical Composition and Particle Size Distribution of Raw Iron Powders 1. Chemical Composition T.Fe: 62.17, FeO: 0.51, SiO ₂ : 5.5, TiO ₂ : 0.11, Mn: 0.05, SO.012, P: 0.65, Crystalline number: 2.32 2. Particle size distribution -0.05mm: 4.6%, 0.05-0.15mm: 5.4%, 0.15-0.5mm: 16.8%, 0.5-4.75mm: 59.4% 4.75-8mm: 13.8%

Reducing gas component, temperature and pressure 1. Gas composition CO: 65%, H ₂ : 25, CO ₂ : 5%, N ₂ : 5% 2. Temperature Preheating and preliminary reduction: approx. 800 ° C Final reduction: approx. 850 ° C 3. Pressure Preheating and preliminary reduction: 1.8kgf / ㎠ Final reduction: 2.0kgf / ㎠

Gas Flow Rate in Fluidized Bed Reduction Furnace First fluidized bed furnace Flow rate at the dispersion plate surface: 1.4 m / s Flow rate at the cylindrical section (air column): 0.4 m / s Second fluidized bed furnace Flow rate at surface of dispersion plate: 1.4 m / s Flow rate at cylindrical section (air column): 0.4 m / s

After reducing the iron ore as described above, the average gas utilization rate and gas source unit were examined, and the gas utilization rate was about 30-35%, and the gas source unit was 1200-1500 Nm 3 / ton-ore. In addition, the reduced iron discharged from the first and second outlets ranged from 30-40% and 85-95%, respectively, and it was possible to discharge ore within 60 minutes after ore input from the ore hopper. It was found to be excellent.

As described above, the present invention is installed in the lower portion of each fluidized bed (100, 200) by the intermediate hopper (Hopper) and the gas / solid sealed valve is installed through the gas distributor (Gas distributor) hole during the abnormal operation By circulating the iron ore falling to the bottom of the plate back to the fluidized bed, there is an effect that can operate for a long time without the phenomenon that the reducing gas flow is blocked.

In addition, the present invention can confirm that the reduction rate and gas source unit can be as good as the three-stage process proposed in the Republic of Korea Patent No. 117065 (1997) by the two-stage process alone, three-stage in terms of equipment investment and production costs It is better than the process.

In addition, the present invention can obtain a reduced iron with a relatively uniform reduction rate regardless of the particle size of the iron ore and at the same time can obtain a reduced iron classified by particle diameter, it is possible to supply a reduced iron of the appropriate size for each input facility and input location when reducing iron is introduced into the furnace. According to the supply flow rate of the reducing gas, the amount and particle size of the reduced iron discharged through each outlet can be controlled, and the reduction rate can be controlled by controlling the residence time in the iron ore furnace.

Claims (8)

In the first fluidized bed furnace, the powdered iron ore is dried, preheated and pre-reduced in a reducing atmosphere, and in the second fluidized bed furnace, the dried, preheated and pre-reduced iron ore is finally reduced. In Raw, powdered ore charged from the hopper 700 is dried, preheated and pre-reduced while forming a bubble or turbulent fluidized bed by the exhaust gas (reduction gas) of the second fluidized bed furnace 200 supplied through the first gas supply port 101. And a first conical (Taper) fluidized bed furnace 100 configured to be discharged to the lower portion of the second fluidized bed furnace 200 through the first ore outlet 106. A first cyclone (300) configured to separate the fine iron ore contained in the exhaust gas of the first fluidized bed (100) from the gas and recycle the lower part of the first fluidized bed (100); Exhaust gas of the molten gasifier 800 in which the dried, preheated and pre-reduced iron ore is supplied through the second gas supply port 201 in the first fluidized bed furnace 100 supplied through the preliminary reduction ore supply port 205. (Taper) -type second fluidized bed furnace 200 configured to be finally reduced and discharged through the second ore outlet 206 while forming a bubble or turbulent fluidized bed by (reduced gas); A second cyclone 400 configured to separate the fine iron ore contained in the exhaust gas of the second fluidized bed furnace 200 from the gas and recycle to the lower portion of the second fluidized bed furnace 200; Located between the first fluidized bed furnace (100) and the second fluidized bed furnace (200), and stored the iron ore dropped through the hole (hole) of the distribution plate 102 of the first fluidized bed furnace (100) A first intermediate hopper 500 configured to convey the lower portion of the second fluidized bed furnace 200 to the furnace; and Located below the second fluidized bed furnace 200, the ferrite ore dropped through the holes of the dispersion plate 202 of the second fluidized bed furnace 200 is stored and then is inert gas under the second fluidized bed furnace 200. A second intermediate hopper 600 configured to be fed into the The first ore outlet 106 and the preliminary reduced ore supply port 205 are connected in an ore communication relationship by a second conduit 103, The first cyclone 300 is connected to the upper portion of the first fluidized bed 100 through the third conduit 301, and is connected to the lower portion of the first fluidized bed 100 through the fourth conduit 302. , The second cyclone 400 is connected to the upper portion of the second fluidized bed 200 through the tenth conduit 401, and is connected to the lower portion of the second fluidized bed 200 through the ninth conduit 402. And connected to the lower portion of the first fluidized bed 100 through the sixth conduit (403), The first intermediate hopper 500 is connected to the lower end of the first fluidized bed 100 through the seventh conduit 502, and is connected to the lower part of the second fluidized bed 200 through the eleventh conduit 504. ,And The second intermediate hopper 600 is connected to the bottom of the second fluidized bed 200 through the thirteenth conduit 602 and to the bottom of the second fluidized bed 200 through the twelfth conduit 604. Fluidized bed reduction device of two-stage iron ore characterized in that the configuration. According to claim 1, wherein the fourth conduit 302 is located one end deep in the lower portion of the first fluidized bed (100) to supply the separated fine iron ore deeper in the lower portion of the first fluidized bed (100), The ninth conduit 402 locates one end deep in the lower portion of the second fluidized bed furnace 200 to supply the separated fine iron ore deeply in the lower portion of the second fluidized bed furnace 200, and The eleventh conduit 504 has one end of the second fluidized bed so as to supply the ferrite ore dropped through the nozzle of the distribution plate 102 of the first fluidized bed 100 deeply below the second fluidized bed 200. A fluidized bed reduction apparatus of two-stage iron ore, characterized in that located deep in the bottom of the furnace (200). 3. The gas and solid hermetic valves 501 according to claim 1, wherein the seventh conduit 502, the eleventh conduit 504, the thirteenth conduit 602, and the twelfth conduit 604 are gas and solid hermetic valves 501, respectively. , 503, 601, 603) is a fluidized bed reduction device of two-stage iron ore characterized in that one or more attached. According to claim 1 or claim 2, The first fluidized bed 100 and the second fluidized bed 200 is composed of a conical portion (100a) and a cylindrical portion (100b), the inclination angle of the conical portion is 5- 20 °, and the height of the conical portions 100a and 200a from the distribution plate is 5-10 times the inner diameter of the lower dispersion plate, and the height of the cylindrical portions 100b and 200b is 3-5 times the inner diameter. Fluidized bed reduction device of two-stage iron ore. According to claim 3, The first fluidized bed 100 and the second fluidized bed 200 is composed of a conical portion (100a) and a cylindrical portion (100b), the inclination angle of the conical portion is 5-20 ° from the vertical line The height of the conical portions 100a, 200a from the distribution plate is 5-10 times the inner diameter of the lower dispersion plate, and the height of the cylindrical portions 100b, 200b is 3-5 times the inner diameter. Fluidized bed reduction device of iron ore. In the first fluidized bed furnace, the ferrite ore is preheated and pre-reduced in a reducing atmosphere, and in the second fluidized bed furnace, the method for reducing the iron ore is finally reduced to dry, preheated and pre-reduced iron ore to the first fluidized bed furnace (100). The fed iron ore is dried, preheated and pre-reduced while forming a bubble or turbulent fluidized bed with exhaust gas (reduction gas) of the second fluidized bed furnace 200, and the reacted iron ore is reacted with the second conduit 103 via a second conduit 103. The gas is reduced to the bottom of the fluidized bed 200 to form a bubble fluidized bed using a reducing gas (melt gasification flue gas) supplied through the second flue gas supply port 201, and then the second ore outlet 206 is reduced. Through the final discharge; The ultrafine iron ore contained in the exhaust gas of the first fluidized bed furnace 100 is separated from the gas in the first cyclone 300 so as to be recycled to the lower portion of the first fluidized bed furnace 100 and to the exhaust gas of the second fluidized bed furnace 200. The contained ultrafine iron ore is separated from the gas in the second cyclone 400 to be recycled to the bottom of the second fluidized bed furnace 200; And Regularly in the middle of the operation and in the event of an emergency, first open the high-temperature valves 501, 601 of the first and second intermediate hoppers 500, 600, first of the first and second fluidized bed furnaces 100, 200. The iron ore accumulated under the gas distribution plate is stored in the first and second intermediate hoppers 500 and 600, respectively, and then the front end high temperature valves 501 and 601 are closed, and the first and second intermediate hoppers 500 and 600 are closed again. Opening the high-temperature valve (503, 603) of the step of blowing the inert gas such as nitrogen, and stored stored iron ore, respectively, characterized in that configured to convey to the lower portion of the second fluidized bed furnace (200). The gas flow rate just above the dispersion plates in the first fluidized bed furnace 100 and the second fluidized bed furnace 200 is selected to be 1,2-2.5 times or less of the minimum fluidization rate of the iron ore staying in the furnace. Reduction method of iron ore, characterized in that. The process according to claim 6 or 7, wherein the preheating and pre-reduction in the first fluidized bed (100) is at 700-850 ° C and the final reduction in the second fluidized bed (200) is at 750-900 ° C, and The operating pressure in each furnace is 1-5 atm absolute pressure reducing iron ore.