KR20000009737A - Production equipment of molten iron using fine iron ore - Google Patents

Abstract

PURPOSE: The molten iron production equipment is provided which minimizes the fine scatter in the fluid reduction of fine iron ore. CONSTITUTION: The equipment contains the following components. The first fluid bed furnace scatters small-sized iron ore and reduces middle-sized and large-sized iron ore by foam or turbulent fluid bed among the charging fine iron ores from a charging hopper. The second furnace reduces the scattered small-sized iron ore in the first furnace by foam fluid bed. The third furnace reduces the reduced iron discharged in the first and second furnace. Fused gas furnace produces molten iron with melting the reduced iron in the third furnace.

Description

Charter manufacturing apparatus using iron ore

The present invention relates to a fluidized bed-type two-stage reduction device for reducing a wider particle size distribution in a fluidized state, and more particularly, to classify the powdered iron ore having a wide particle size distribution according to the particle size and to reduce it in a fluidized bed. The present invention relates to a molten iron ore using an iron ore that can minimize the scattering of fine iron ore generated by the reduction by charging into a melt gasifier according to the particle size.

In the current molten iron production process, the blast furnace process is the mainstream. Recently, shaft-type molten iron reduction steel processes using pellets and lump ore have been commercialized to produce molten iron, but both processes have the limitation of using only raw material. .

In the blast furnace process, molten iron is produced using sintered ore processed by mixing coal coke, powdered iron ore and by-products. As a result, the increase in facility investment costs for pretreatment of raw materials and raw materials and pollution caused during pretreatment are seriously emerging, and environmental regulations are being strengthened accordingly. On the other hand, in the shaft-type molten iron reduction process is used to make the fine iron ore as a raw material pellets or to produce molten iron using a lump ore of limited particle size.

As such, in the blast furnace process or shaft-type molten reduction steelmaking process, powdered iron ore cannot be directly used and needs to be preliminarily processed. Therefore, it is possible to produce molten iron by directly using ferrous ore, which has abundant reserves and low cost, without undergoing pretreatment. The fluidized-bed molten reduced steelmaking process is drawing attention as the next-generation steelmaking process to replace the existing blast furnace process, and active researches are being conducted mainly in advanced steel countries.

In the above molten reduction steelmaking process, it is generally divided into a preliminary reduction process and a final reduction process. In the preliminary reduction step, preliminary reduction of raw ore in a solid state is carried out in a reduction furnace, and in the final reduction step, the reduced reduction iron is charged into a melting furnace. To produce molten iron. The preliminary reduction process is generally classified into moving bed type and fluidized bed type according to the raw material ore's particle size.In the case of ferrite ore with small particle size and wide particle size distribution, the fluidized bed type which reduces raw material ore while flowing from reducing furnace to reducing gas is breathable. It is known to be efficient in terms of gas utilization.

An example of the charterer manufacturing apparatus may be those disclosed in Korean Patent No. 117065.

The molten iron manufacturing apparatus, as shown in Figure 1, to form a fluidized bed in the shape of the fluidized bed to the stable flow of the iron ore having a wide particle size distribution, the iron ore is a bubble fluidized bed to improve the reduction rate and gas utilization The first fluidized bed furnace 10 to be dried / preheated in the state, the first cyclone 40 for collecting the fine iron ore contained in the exhaust gas of the first fluidized bed furnace, and the preheated iron ore dried in the first fluidized bed furnace The second fluidized bed furnace 20 for reducing, the second cyclone 50 for collecting the fine iron ore contained in the flue gas of the second fluidized bed furnace, and the final reduced powdered iron ore preliminarily reduced in the second fluidized bed furnace The molten iron is prepared by melting and reducing the reduced iron finally reduced in the furnace 30, the third cyclone 60 for collecting the fine iron ore contained in the exhaust gas of the third fluidized bed furnace, and the third fluidized bed furnace 30. And the the melter-gasifier 80 as the major component.

However, in the case of preliminary reduction of the iron ore using the conical three-stage fluidized-bed reduction furnace as described above, the fine raw iron ore, which is not captured in the first cyclone 40, is discharged through the gas outlet so that the ore is scattered and lost. The amount can be high. In particular, considering that most of the differentiation phenomenon during the reduction of iron ore occurs in the early stage of reduction, a large amount of fine iron ore produced by reduction and differentiation during the first reduction and mechanical differentiation by flow is scattered in the first fluidized bed. By overloading, it inhibits the efficient separation of flue gas and iron ore, so that a large amount of fine iron ore can be released and lost together with the flue gas.

In addition, when reduced iron having a large particle size distribution discharged from the third fluidized bed furnace 30 is charged to the upper portion of the molten gasifier 80, the finely-reduced fine iron reduced in the lower portion of the melting furnace does not melt and scatters with the exhaust gas. There is a problem that can be.

Thus, the present inventors conducted research and experiments to solve the problems that may occur when manufacturing molten iron using the conventional fluidized bed pre-reduction device as described above, and to propose the present invention based on the results, The present invention is appropriately pre-reduced iron ore with a wide particle size distribution according to the particle size, and also by pre-reduced reduced iron charged into the melt gasifier at different locations according to the particle size to prepare the molten iron to stabilize the fluidity to improve the reduction rate and gas utilization rate In addition, to provide a molten iron manufacturing apparatus that can effectively reduce the amount of fine iron ore that is scattered and lost, the purpose is.

1 is a schematic diagram schematically showing a fluidized bed reduction furnace of a conventional iron ore

2 is a block diagram of a molten iron manufacturing apparatus according to the present invention

Explanation of symbols on the main parts of the drawings

100 ... loading hopper 101 ... chapter 1

110 first fluidized bed furnace 111 first circulation tube

112 ... first exhaust pipe 120 ... second fluidized bed

122 ... 2nd exhaust pipe 124 ... 2nd cyclone

125.Exhaust gas discharge pipe 126 ... 2nd circulation pipe

130 ... the third fluidized bed, 132 ... screw conveyor

134 second cyclone 136 third circulation tube

137 ... 3rd discharge pipe 139 ... 4th discharge pipe

140 Gas reforming system 141 Exhaust gas circulation pipe

150 ... melt gasification furnace 152 ... fourth circulation pipe

153 5th Gas Supply Pipe 154 3rd Cyclone

The present invention is an apparatus for producing molten iron using a iron ore,

Among the iron ore, which is supplied with reducing gas from the bottom and charged with iron ore through the first charging pipe in the charging hopper, the middle or allel ore is first reduced by a bubble or turbulent fluidized bed at the bottom thereof, and the fine ore is A cylindrical first fluidized bed furnace configured to discharge upwardly;

A second fluidized bed furnace in the Sanggwang River Strait, configured to primaryly reduce the fined iron ore while receiving the reduced gas from the bottom and receiving the fined iron ore discharged from the first fluidized bed to form a bubble fluidized bed;

A first cyclone configured to collect particulate ore contained in the exhaust gas of the second fluidized bed and re-supply it to the second fluidized bed, and finally discharge the exhaust gas from which the particulate ore is separated;

The secondary ore ore reduced primarily in the first fluidized bed furnace and the fine ore reduced primarily in the second fluidized bed furnace are formed to be discharged after secondary reduction while forming a bubble fluidized bed by reducing gas supplied from the bottom thereof. A third fluidized bed furnace;

The fine ore contained in the flue-gas of the third fluidized bed is collected, part of it is supplied to the third fluidized bed, the other part is supplied to the melt gasifier, and the flue gas from which the fine ore is separated is discharged through the government. A second cyclone configured to;

A molten gasifier configured to receive molten reduction preliminarily reduced iron from the third fluidized bed furnace to produce molten iron; And

The molten iron using the iron-iron ore which collects the fine ore contained in the flue gas of the melt gasifier, and supplies it back to the melt gasifier, and the exhaust gas from which the fine ore is separated is discharged through the government. It relates to a manufacturing apparatus of.

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

An example of a molten iron manufacturing apparatus according to the present invention is shown in FIG.

As shown in FIG. 2, the molten iron manufacturing apparatus of the present invention has a fluidized gas reduction apparatus 100 for preliminarily reducing powdered iron ore in a fluidized state and a melt gasification furnace 150 for melting molten reduction of pre-reduced reduced iron to produce molten iron. )

The fluidized-bed reduction device 100 is supplied with reducing gas from the bottom thereof, and charged with ore among the iron ore among the iron ore which is charged with the iron ore through the first charging pipe 101 in the charging hopper 100. A cylindrical first fluidized bed furnace 110 configured to be primary-reduced by a bubble or turbulent fluidized bed, and the particulate ore scattered to the top;

The second fluidized bed reactor in the Sangsang River Strait, configured to receive the fine-grained iron ore, which is supplied with reducing gas from the bottom, and is discharged from the first fluidized bed, to form a bubble fluidized bed and to reduce the fine iron ore. 120);

A first cyclone 124 configured to collect particulate ore contained in the exhaust gas of the second fluidized bed and re-supply it to the second fluidized bed, and finally discharge the exhaust gas from which the particulate ore is separated;

The secondary ore ore reduced in the first fluidized bed furnace and the fine ore reduced in the second fluidized bed furnace are reduced and discharged after forming the bubble fluidized bed by the reducing gas supplied from the bottom thereof. The third fluidized bed furnace 130;

The fine ore contained in the exhaust gas of the third fluidized bed furnace 130 is collected, and a part thereof is re-supplied to the third fluidized bed furnace, and the other part is supplied to the melt gasifier 150, and the exhaust gas from which the fine ore is separated is collected. Is configured to include a second cyclone 134 that is configured to discharge through its government.

A first gas supply pipe 114 for supplying a reducing gas into the reduction furnace is connected to a bottom of the first fluidized bed furnace 110, and a first gas distribution plate 113 is mounted in a lower portion thereof.

In addition, a first charging pipe 101a is connected to a charging hopper 100 on a side wall of the first fluidized bed 110 to supply preparation materials such as iron ore and limestone from the charging hopper 100 into the fluidized bed. The first circulation pipe 112 for discharging the primary / medium ore reduced to the third fluidized bed 130 and the first circulation pipe for supplying the scattered particulate ore to the second fluidized bed (120) 111 is connected, and the first circulation pipe 111 is positioned above the first discharge pipe 112.

The second fluidized bed 120 has an image narrowing structure formed of an enlarged upper portion 120a, an image light inclined portion 130b, and a reduced portion 120c.

The second gas distribution plate 123 is mounted in the reduced lower portion 120c, and the exhaust gas of the third fluidized bed furnace 130 used as the reducing gas is supplied to the bottom portion below the second gas distribution plate 123. The second reduction gas supply pipe 127 for connecting is connected.

In addition, on the sidewall of the reduced lower portion 120c on the second gas dispersion plate 123, the fine ore scattered from the first fluidized bed 110 and the fine ore collected by the first cyclone 124 are disposed. The first circulation pipe 111 for supplying into the second fluidized bed furnace 120 and the second discharge pipe 122 for discharging the first reduced fine ore are connected.

One end of the second discharge pipe 122 is connected to the side wall of the second fluidized bed 120, and the other end thereof is located in the reduced bottom 130c of the third fluidized bed 130.

In addition, the enlarged upper portion 120a of the second fluidized bed passage 120 is connected to the first cyclone 124 through a first exhaust gas discharge pipe 121.

A second portion of the first cyclone 124 to circulate the particulate ore contained in the exhaust gas of the second fluidized bed 120 through the first circulation pipe 111 to the second fluidized bed (120). The circulation pipe 126 is connected, and the second exhaust gas discharge pipe 125 for discharging the exhaust gas separated from the particulate ore is connected to the upper portion thereof.

The second circulation pipe 126 communicates with the first circulation pipe 111.

The third fluidized bed passage 130 has a vertical light narrowing structure formed of an enlarged upper portion 130a, an upper light inclined portion 130b, and a reduced lower portion 130c.

A third gas distribution plate 133 is mounted in the reduced lower portion 130c, and a third reducing gas supply pipe 153 for supplying a reducing gas is connected to a bottom portion below the second gas distribution plate 133. It is.

In addition, a primary reducing medium / elastic iron ore discharged from the first fluidized bed furnace 110 is supplied into the third fluidized bed furnace 130 on the sidewall of the reduced lower portion 130c on the third gas distribution plate 133. The first discharge pipe 112 is connected to, and the fourth discharge pipe 139 for discharging the secondary reduced reduced iron to the molten gasifier 150 is connected.

The fourth discharge pipe 139 is provided on a side wall of the third fluidized bed furnace 130 through a screw conveyor 132 configured to discharge secondary reduced reduced iron in the third fluidized bed furnace 130 to the outside of the furnace. It is preferably connected to the side wall of the third fluidized bed passage (130).

In addition, the enlarged upper portion 130a of the third fluidized bed 130 is connected to the second cyclone 134 through a third exhaust gas discharge pipe 131.

A circulation pipe 134a is connected to a lower portion of the second cyclone 134, and a part of the particulate ore contained in the exhaust gas of the third fluidized bed furnace 130 is connected to the third fluidized bed in the circulation pipe 134a. The third circulation pipe 136 for circulating to 130 and the third discharge pipe 137 for charging the remaining portion of the particulate ore into the lower portion of the melt gasifier 150 are connected, and the circulation pipe 134a At the position where the third circulation pipe 136 and the third discharge pipe 137 are connected, the fine iron ore collected in the second cyclone 134 is divided into the third fluidized bed furnace 130 and the molten gasifier 150. A metering control valve 138 for charging is provided.

In addition, a fourth exhaust gas discharge pipe 135 for discharging the exhaust gas separated from the particulate ore is connected to an upper portion of the second cyclone 134, and the fourth exhaust gas discharge pipe 135 is the first fluidized bed passage 110. And the second gas introduction pipe 127 of the first gas introduction pipe 114 and the second fluidized bed passage 120 of the c).

Meanwhile, if necessary, a gas reforming system 140 configured to circulate the part of the exhaust gas discharged from the first cyclone to the first fluidized bed 110 and the second fluidized bed furnace 120 may be provided. have.

When the gas reforming system 140 is provided, the gas reforming system 140 is in communication with the fourth exhaust gas discharge pipe 135 through a reforming gas supply pipe 142 and through the exhaust gas circulation pipe 141. In communication with the second exhaust gas discharge pipe (125).

The melt gasifier 150 is configured to receive molten reduced secondary iron from the third fluidized bed furnace 130 to produce molten iron, and the melt gasifier 150 includes a third cyclone 154. The third cyclone 154 collects the fine ore contained in the exhaust gas of the molten gas furnace 150 and supplies it back to the molten gas furnace 150, and the exhaust gas from which the fine ore is separated provides its government. Is configured to discharge through.

An upper portion of the melt gasifier 150 is connected to the third cyclone 154 through a fifth exhaust gas discharge pipe 151.

A lower portion of the second cyclone 154 is connected to the fourth circulation pipe 152 for circulating the particulate ore contained in the exhaust gas of the melt gasifier 150 to the melt gasifier 150, the upper portion The fifth exhaust gas discharge pipe 153 is connected to discharge the exhaust gas separated from the particulate ore, and the fifth exhaust gas discharge pipe 153 supplies the exhaust gas of the molten gas furnace 150 to the third fluidized bed furnace 130. It is connected to the bottom of the third fluidized bed 130 in a gas communication relationship.

The third discharge pipe 137 is in communication with the fourth circulation pipe 152.

The height of the first fluidized bed 110 is preferably 10-20 times its inner diameter. The reason is that when the height is 10 times or less of the inner diameter, the iron ore in the furnace is not smooth and the iron ore of the medium / elasticity is not smooth. This is because scattering of the fine iron ore can not be efficiently carried out when it is scattered and can be passed to the second fluidized bed 120 and the height is 20 times or more of the inner diameter.

On the other hand, the inner diameter of the reduced lower portion (120c, 130c) of the second fluidized bed 120 and the third fluidized bed 130 maintains the inner diameter of the lower end of the ordinary light inclined portion (120b, 130b), the expansion target (120a, The inner diameter of 130a maintains the inner diameter of the upper end portions of the image light tilting portions 120b and 130b.

The inner diameters of the enlarged upper parts 120a and 130a are preferably selected in the range of 1.5-2.0 times the reduced lower inner diameter in order to reduce the gas flow rate in the furnace to suppress the scattering of the fine iron ore.

The total height of the second fluidized bed furnace 120 and the third fluidized bed furnace 130 is preferably selected to be within a range of 10-25 times the reduced inner diameter in order to secure sufficient flow space and to suppress the scattering of the fine iron ore. The height of the reduced lower portions 120c and 130c is preferably selected in the range of 1.0-1.5 times the height of the enlarged upper portions 120a and 130a.

On the other hand, it is preferable that the inclination angle of the ordinary light inclined portion (120b, 130b) is selected in the range of 30-50 degrees from the vertical line.

Hereinafter, the method of manufacturing molten iron using the molten iron manufacturing apparatus of this invention is demonstrated.

The fine iron ore in the ore charged from the ore charging hopper 101 through the first charging pipe 101a to the first fluidized bed 110 is scattered through the first circulation pipe 111 and It is first reduced while forming a bubble or turbulent fluidized bed by the reducing gas flowing into the first gas supply pipe 114 from the first fluidized bed 110 and passing through the first gas distribution plate 113.

The fine iron ore scattered from the first fluidized bed 110 and charged into the second fluidized bed 120 through the first circulation pipe 111 is the reducing gas and the first fluidized bed introduced into the second gas supply pipe 127. The primary fine iron ore that is first reduced while forming a bubble flow layer by the gas introduced with the ore from the furnace 110 and scattered through the first gas discharge pipe 121 together with the exhaust gas in the second fluidized bed furnace 120 is The gas is separated from the first cyclone 124 and circulated to the second fluidized bed passage 120 through the second circulation pipe 126 and the first circulation pipe 111.

Meanwhile, the exhaust gas separated from the iron ore in the first cyclone 124 is mostly discharged through the second exhaust gas discharge pipe 125, and some of them are circulated to the gas reforming system 140 through the exhaust gas circulation pipe 141 as necessary. After reforming, the gas is supplied to the first fluidized bed 110 and the second fluidized bed 120 through the reformed gas supply pipe 142.

The iron ore first reduced in the first fluidized bed 110 and the second fluidized bed 110 is charged into the third fluidized bed 130 through the first discharge pipe 112 and the second discharge pipe 122, respectively. 5 is bubbled by the reducing gas introduced into the gas supply pipe 153 and secondary reduced.

In addition, the ultra-fine iron ore scattered with the exhaust gas in the third fluidized bed 130 to the third gas discharge pipe 131 is separated from the exhaust gas in the second cyclone 134, a part of which is a circulation pipe 134a, a fixed quantity It is circulated to the third fluidized bed passage 130 through the control valve 138 and the third circulation pipe 136, the remaining part of the circulation pipe 134a, metering control valve 138, the third discharge pipe 137 and It is supplied to the melt gasifier 150 through the fourth circulation pipe 152.

In addition, the exhaust gas from which the fine ore is separated from the second cyclone 143 is supplied as a reducing and fluidizing gas to the first fluidized bed 110 and the second fluidized bed 120 through the fourth exhaust gas discharge pipe 135.

As described above, the reduced iron secondary reduced in the third fluidized bed furnace 130 is charged into the melt gasifier 150 through the fourth discharge pipe 139 to be melt-reduced, thereby producing molten iron.

In addition, the ultra-fine iron ore scattered with the exhaust gas in the melt gasification furnace 150 to the fifth gas discharge pipe 151 is separated from the exhaust gas in the third cyclone 154 to melt the gas through the fourth circulation pipe 152. The exhaust gas circulated to the furnace 150 and the fine ore is separated is supplied to the third fluidized bed furnace 130 as a reducing and fluidizing gas through the fifth exhaust gas discharge pipe 153.

The gas flow rate in the first fluidized bed furnace 110 is preferably set in the range of 1.2-3.5 times the minimum fluidization rate of the iron ore staying in the furnace for efficient separation and flow of fine and medium / allele ore.

The flow rate of the gas in the furnace of the second fluidized bed 120 and the third fluidized bed 130 is preferably selected to be in the range of 1.2-2.5 times the minimum fluidization rate of the iron ore staying in the furnace, which is the proper flow rate of the bubble fluidized bed. Do.

As described above, in the case of manufacturing molten iron using the molten iron manufacturing apparatus of the present invention, the heavy or opposing iron ore primarily reduced in the first fluidized bed furnace 110 is the fluidized bed stop part of the third fluidized bed furnace 130. The fine iron ore discharged through the first discharge pipe 112 connected to the third fluidized bed furnace 130 and first reduced in the second fluidized bed furnace 120 is lowered to the bottom of the fluidized bed of the third fluidized bed furnace 130. It is charged to the third fluidized bed 130 through the second discharge pipe 122 connected.

That is, in the molten iron manufacturing apparatus of this invention, it is comprised so that the charging position to the 3rd fluidized bed furnace 130 of fine and medium or opposing ores may differ.

The reason for changing the charging position as described above is that if the fine ore is charged at the same position as the medium / opposing fine ore because it may be scattered without having a sufficient residence time during the secondary reduction in the third fluidized bed (130) This is to secure sufficient residence time for secondary reduction by lowering the charging position of the intermediate / optical ore.

In addition, the molten iron manufacturing apparatus of the present invention is the secondary reduced iron in the third fluidized bed 130, the reduced iron is discharged to the screw conveyor 132 located at the lower end of the third fluidized bed 130 to melt gasification furnace 150 Particulate reduced iron that is charged into the upper end of the melt gasifier 150 through the fourth discharge pipe 139 connected to the upper part, and is reduced by secondary flow in the third fluidized bed furnace 130 in the second cyclone 134. Separated from the exhaust gas, a part is circulated to the third fluidized bed furnace 130 and a part is scattered in the melt gasifier 150 to circulate the particulate dust separated from the third cyclone 154 back to the melt gasifier 150. It is configured to be charged to the lower portion of the melt gasifier 150 through the third discharge pipe 137 connected to the fourth circulation pipe 152.

As described above, in the present invention, the fine iron is separated from the medium / allele of the reduced iron and charged into the molten gasifier 150 to reduce the amount of particulate dust generated in the molten gasifier 150, and the third cyclone ( By reducing the load in 154, it is possible to reduce the amount of dust introduced into the reduction furnace.

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

Example

Reduced iron was prepared under the conditions shown in Tables 4 and 5 by using a molten iron ore having a chemical composition and particle size distribution of Tables 2 and 3 as a molten iron manufacturing apparatus of FIG.

Internal diameter and height of fluidized bed preliminary reactor Fluidized bed size First fluidized bed Inner diameter: 0.2m Height: 4.0m Second fluidized bed Reduced inner diameter: 0.4 m Expanded target inner diameter: 0.8 m Reduced bottom height: 3.5 m (from the top of the distribution plate) Third fluidized bed Reduced inner diameter: 0.3 m Expanded target inner diameter: 0.6 m Reduced bottom height: 3 m (from the top of the distribution plate)

Chemical Composition of Raw Ore ingredient T.Fe FeO SiO ₂ Al ₂ O ₃ Mn S P moisture wt.% 63.49 0.37 4.32 2.33 0.05 0.007 0.063 5.41

Particle Size Distribution of Raw Ore Particle size (mm) <0.125 0.25-0.125 0.5 ~ 0.25 1 ~ 0.5 3 ~ 1 5 ~ 3 8 ~ 5 wt.% 15.0 10.2 10.1 10.2 23.9 18.6 12.0

Reducing gas condition Gas composition CO: 65%, CO ₂ : 5%, H ₂ : 25%, N ₂ : 5% Temperature 750 ~ 850 ℃ pressure 1.5 ~ 2.0 kgf / cm ²

Gas flow rate in fluidized bed Fluidized bed size First fluidized bed Flow rate: 4.0 m / s Second fluidized bed Lower flow rate: 0.4 m / s Target flow rate: 0.1 m / s Third fluidized bed Lower flow rate: 2.0 m / s Target flow rate: 0.5 m / s

As a result of the production of reduced iron under the above conditions, ore loading started from the charging hopper to the first fluidized bed furnace, and about 60 minutes later, the reduced iron was discharged through the reduced-iron discharge pipe, and the average reduction rate was 88-92%. A uniform reduction rate could be obtained without. In addition, the average gas utilization was 30-32%, and the gas source unit was 1300-1400 Nm ³ / t-ore. On the other hand, the scattering ratio was very good within 5%.

As described above, the present invention has the effect that it is possible to provide a molten iron manufacturing apparatus that can reduce the scattering loss that may occur during the reduction of the iron ore having a wide particle size distribution and can more efficiently manufacture molten iron.

Claims (5)

The first fluidized bed furnace 110, which scatters fine particles from the wide particle size distribution of the iron ore charged from the charging hopper 101 through the first charging pipe 101a, and recovers only the iron ore of the medium / elasticity by the bubble or the turbulent fluidized bed (110). ); A second fluidized bed furnace 120 for first reducing the fine iron ore scattered from the first fluidized bed furnace 110 by the bubble fluidized bed; A third fluidized bed furnace 130 for reducing the reduced iron discharged by primary reduction in the first fluidized bed furnace 110 and the second fluidized bed furnace 120 by the bubbled fluidized bed; A first cyclone 124 for collecting the ultrafine iron ore contained in the exhaust gas discharged from the second fluidized bed 120 and circulating to the second fluidized bed 120; A second cyclone 134 for collecting the ultrafine iron ore contained in the exhaust gas discharged from the third fluidized bed 130 and circulating to the third fluidized bed 130; The first fluidized bed passage 110 has a cylindrical structure, and a first gas distribution plate 113 is mounted at a lower portion thereof, and a lower portion of the first fluidized bed furnace 110 is configured to supply exhaust gas of a third fluidized bed furnace 130 used as a reducing gas. The first reducing gas supply pipe 114 is connected, the side wall of the first charging pipe 101 for supplying the preparation material such as iron ore and limestone stored in the raw material loading hopper 110 into the first fluidized bed furnace 110 and A first discharge pipe 112 for discharging primary / reduced heavy or alleles is connected, and a first circulation pipe 111 for discharging and circulating fine ore is formed at an upper portion of the first discharge pipe 112. 1 is connected to the side wall of the fluidized bed passage (110); The second fluidized bed 120 has an upper light narrowing structure composed of an enlarged upper portion 120a, an upper light inclined portion 130b, and a reduced lower portion 120c, and a second gas distribution plate in the reduced lower portion 120c. 123 is mounted, and a second reduction gas supply pipe 127 for supplying exhaust gas of the third fluidized bed furnace 130 used as the reducing gas is connected to the bottom of the second gas distribution plate 123. On the side wall of the reduced lower portion 120c on the second gas dispersion plate 123, the fine ore scattered from the first fluidized bed 110 and the fine ore collected by the first cyclone 124 are disposed in the second fluidized bed. The first circulation pipe 111 for supplying into the furnace 120 and the second discharge pipe 122 for discharging the first reduced fine ore are connected, and the enlarged upper portion 120a is the first exhaust gas discharge pipe 121. Is connected to the first cyclone (124) through; A second circulation pipe 126 is connected to a lower portion of the first cyclone 124 to circulate particulate ore contained in the exhaust gas of the second fluidized bed furnace 120 to the second fluidized bed furnace 120. A second exhaust gas discharge pipe 125 for discharging exhaust gas separated from particulate ore is connected to an upper portion thereof, and the second circulation pipe 126 is in communication with the first circulation pipe 111; The third fluidized bed 130 has an upper light narrowing structure composed of an enlarged upper portion 130a, an upper light inclined portion 130b, and a reduced lower portion 130c, and a third gas distribution plate ( 133 is mounted, and a third reducing gas supply pipe 137 for supplying a reducing gas is connected to a bottom portion of the second gas distribution plate 133. A fourth discharge pipe 139 for discharging secondary reduced reduced iron is connected, and the enlarged upper portion 130a is connected to the second cyclone 134 through a third exhaust gas discharge pipe 131; And A fourth exhaust gas discharge pipe 135 for discharging the exhaust gas separated from the particulate ore is connected to an upper portion of the second cyclone 134, and the fourth exhaust gas discharge pipe 135 is connected to the first fluidized bed 110. In the two-stage fluidized bed reduction device of the iron ore is configured to communicate with the second gas introduction pipe 127 of the first gas introduction pipe 114 and the second fluidized bed furnace 120, A molten gasifier (150) configured to receive molten reduced secondary iron from the third fluidized bed (130) to manufacture molten iron; One end of the first discharge pipe (112) is connected to a side wall of the first fluidized bed (110), and the other end thereof is connected to a side wall of a third fluidized bed (130); One end of the second discharge pipe 122 is connected to a side wall of the second fluidized bed furnace 120, and the other end thereof is located in the reduced lower portion 130c of the third fluidized bed furnace 130; A circulation pipe 134a is connected to a lower portion of the second cyclone 134, and a portion of the particulate ore contained in the exhaust gas of the third fluidized bed furnace 130 is connected to the circulation pipe 134a in the third fluidized bed furnace ( The third circulation pipe 136 for circulating to 130 and the third discharge pipe 137 for charging the remaining part of the particulate ore into the lower portion of the melt gasifier 150 is connected, the circulation pipe 134a, At the position where the third circulation pipe 136 and the third discharge pipe 137 are connected, the fine iron ore collected by the second cyclone 134 is divided into the third fluidized bed furnace 130 and the molten gasifier 150. A fixed amount control valve 138 is provided to; And An upper portion of the melt gasifier 150 is connected to the third cyclone 154 through a fifth exhaust gas discharge pipe 151, and a lower portion of the second cyclone 154 is disposed in the exhaust gas of the melter gas furnace 150. The fourth circulation pipe 152 for circulating the contained fine ore to the melt gasifier 150 is connected, the upper portion of the fifth exhaust gas discharge pipe 153 for discharging the exhaust gas separated from the fine ore is connected The fifth exhaust gas discharge pipe 153 is connected to the bottom of the third fluidized bed furnace 130 in gas communication with the bottom of the third fluidized bed furnace 130 to supply the exhaust gas of the molten gas furnace 150 to the third fluidized bed furnace 130. The third discharge pipe 137 is a molten iron manufacturing apparatus using the iron ore, characterized in that configured to communicate with the fourth circulation pipe 152. The gas reforming system 140 of claim 1, further comprising a gas reforming system 140 for reforming a part of the exhaust gas discharged from the first cyclone 124 to circulate the first flow passage 110 and the second flow passage 120. and; And The gas reforming system 140 is configured to communicate with the fourth exhaust gas discharge pipe 135 through a reforming gas supply pipe 142, and to communicate with the second exhaust gas discharge pipe 125 through an exhaust gas circulation pipe 141. Molten iron manufacturing apparatus using powdered iron ore According to claim 1 or 2, The side wall of the third fluidized bed 130 is provided with a screw conveyor 132 configured to discharge the final reduced iron in the third fluidized bed 130 to the outside of the furnace and And And the fourth discharge pipe 139 is a molten iron manufacturing apparatus using a ferrous iron ore, characterized in that configured to be connected to the side wall of the third fluidized bed 130 through a screw conveyor 132 According to claim 1 or 2, wherein the height of the first fluidized bed 110 is 10-20 times of the inner diameter, the reduced lower portion (120c) of the second fluidized bed 120 and the third fluidized bed 130 The inner diameter of 130c) maintains the inner diameter of the lower ends of the upper light inclined portions 120b and 130b, and the inner diameter of the enlarged target portions 120a and 130a maintains the inner diameter of the upper ends of the upper light inclined portions 120b and 130b. The inner diameters of the upper parts 120a and 130a are 1.5-2.0 times the reduced inner diameter, and the total heights of the second fluidized bed 120 and the third fluidized bed 130 are 10-25 times the reduced inner diameter, and the reduced lower part 120c. , The height of the 130c is 1.0-1.5 times the height of the enlarged upper portion (120a, 130a), and the angle of inclination of the ordinary light inclined portion (120b, 130b) is 30-50 degrees with respect to the vertical line Charter Manufacturing Equipment According to claim 3, wherein the height of the first fluidized bed 110 is 10-20 times the inner diameter, the inner diameter of the reduced lower portion (120c, 130c) of the second fluidized bed 120 and the third fluidized bed (130) The inner diameter of the lower end portions of the upper light inclined portions 120b and 130b is maintained, and the inner diameter of the enlarged target portions 120a and 130a maintains the inner diameter of the upper ends of the upper light inclined portions 120b and 130b. The inner diameter of 130a) is 1.5-2.0 times smaller than the reduced lower inner diameter, and the total height of the second fluidized bed 120 and the third fluidized bed 130 is 10-25 times smaller than the reduced lower inner diameter. The height is 1.0-1.5 times the height of the enlarged upper portion (120a, 130a), and the molten iron manufacturing apparatus using the iron-iron ore, characterized in that the inclination angle of the image inclined portion (120b, 130b) is 30-50 degrees with respect to the vertical line.