JPH0790335A - Smelting reduction equipment - Google Patents

Abstract

PURPOSE:To provide a compact smelting reduction equipment capable of stably reducing operation by providing a cutting tube for a preliminary reducing material to a fluidized layer type preliminary reduction furnace and a smelting reduction furnace, which are vertically integrated. CONSTITUTION:A fluidized layer type preliminary reduction furnace 12 having a diffusing plate 13 on the bottom and a smelting reduction furnace 11 are vertically integrated by connecting their side walls 12a, 11a. In the smelting reduction furnace, the iron ore changed from a throw-in tube 19 into the preliminary reduction furnace 12 is fluidized with the reducing gas to be injected from a number of nozzle 13a of the diffusing plate 13 and preliminarily reduced, and the combustion gas is discharged into a combustion gas duct 21 from the top. The obtained preliminarily reduced iron ore is charged in the smelting reduction furnace 11 through a cutting tube 14 for the preliminarily reducing material to be charged. This cutting tube 14 is of L-shaped having an inlet 14a at the upper side part of the diffusing plate 13, and an outlet 14b at the lower side part. The preliminarily reduced iron ore is completely smelted and reduced with coal, flux, etc., to generate the smelted iron 16 and slag 17, and the generated reducing gas is fed to the preliminary reduction furnace 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-reduction furnace for pre-reducing a metal oxide ore such as iron ore in a solid state, and further melting the pre-reduced ore for final reduction. The present invention relates to a smelting reduction apparatus including a smelting reduction furnace.

[0002]

2. Description of the Related Art A smelting reduction furnace is a furnace in which a metal oxide ore such as an iron ore is reduced in a molten state by using a reducing agent such as coal and oxygen gas to obtain pig iron. This furnace has the advantage that it does not require pretreatment facilities for iron ore and coal and can flexibly adjust the production amount, but on the other hand, its energy utilization rate is low, so it is generally combined with a preliminary reduction furnace. It is used as a facility.

As an example, a "melting reduction apparatus" as shown in FIG. 6 is proposed in Japanese Patent Laid-Open No. 4-63216. FIG. 6 is a diagram showing a schematic cross section of a smelting reduction apparatus as an example. The pre-reduction furnace, the smelting reduction furnace, and the pipe line (combined passage of the pre-reduction iron and the reducing gas) between them are formed in the compound furnace 1 which is one furnace body. That is, in a compound furnace 1 having a vertically long cylindrical furnace body, a fluidized bed type preliminary reduction furnace portion 2 was provided in the upper portion, and a smelting reduction furnace portion 3 was provided in the lower portion.

Since both furnace parts 3 and 2 are vertically connected in a straight line, the space directly below the pre-reduction furnace part 2 is a wind box, and at the same time, it falls from the dispersion plate 4 and falls into the smelting reduction furnace part. It is also a pipe line 5 through which both the pre-reduced iron reaching 3 and the reducing gas generated in the smelting reduction furnace part 3 and directed to the pre-reduction furnace part 2 communicate. 4 is a dispersion plate.

In addition to the composite furnace 1, the exhaust gas pipe 6 of the preliminary reduction furnace portion 2 is provided with an opening adjustment damper 7 and
The air box, that is, the upper space of the smelting reduction furnace portion 3, and the tube furnace 5
However, a gas vent pipe 9 having an opening adjustment damper 8 is connected to the side wall of a certain portion. All of these are means for adjusting the amount of preliminary reduced iron dropped from the preliminary reduction furnace part 2 and supplied to the smelting reduction furnace part 3.

The gas vent pipe 9 and the damper 8 pass through the dispersion plate 4 by bypassing a part of the gas generated in the smelting reduction furnace part 3 to the downstream of the exhaust gas pipe 6 without sending it to the preliminary reduction furnace part 2. It is possible to adjust the flow rate of the gas and thus the amount of fall of the pre-reduced iron.

[0007]

However, in the smelting reduction apparatus as shown in FIG. 6 described above, since the supply of preliminary reduced iron is adjusted only by setting the opening of the opening adjustment damper, the following problems occur. is there. In the apparatus of FIG. 6, an opening adjustment damper 7 is provided in the exhaust gas pipe 6 of the preliminary reduction furnace portion 2, and an opening adjustment damper 8 is provided on the side wall of the portion which is the upper space of the smelting reduction furnace portion 3 and is also the tube furnace 5. The gas flow rate of the gas passing through the dispersion plate 4, that is, the amount of pre-reduced iron, is adjusted by adjusting the opening degree adjusting damper 7 of the exhaust gas pipe 6 and adjusting the gas releasing tube 9 by the damper 8. Adjust the fall amount.

Therefore, the solid state pre-reduced iron passing through the nozzle 4a of the dispersion plate 4 drops into the smelting reduction furnace 3 in a convection state with the reducing gas rising from the smelting reduction furnace 3, so that the smelting reduction furnace 3 The amount of the pre-reduced iron to be supplied to the fluctuating portion is likely to fluctuate, and it is difficult to perform sufficient adjustment only with the opening degree of the opening degree adjusting dampers 6 and 8. Therefore, sufficient smelting reduction in the smelting reduction furnace 3 is performed. I can't.

The present invention is intended to solve the above-mentioned problems, and the pre-reduction reaction of the pre-reduction charging material in the pre-reduction furnace can be stably controlled, and at the same time, the pre-reduction reaction from the smelting reduction furnace can be performed. It is an object of the present invention to provide a smelting reduction apparatus that can stably supply preliminary reduced iron and that has a compact overall apparatus.

[0010]

In order to achieve the above object, the present invention provides a smelting reduction furnace, and a gas generated in the reduction furnace as a reducing gas, which is introduced into the lower part of the smelting reduction furnace and jetted from a nozzle of a dispersion plate, A smelting reduction apparatus equipped with a fluidized bed type pre-reduction furnace which is brought into contact with a metal oxide charging material charged inside and is discharged from an upper gas discharge port. A pre-reduction charging material having a pipe opening at one end on the upper side of the dispersion plate of the integral furnace and a pipe opening at the other end on the lower side while being connected to the upper end of the side wall of the reduction furnace to form an integral furnace. The smelting reduction device is characterized by being provided with a cutout pipe.

[0011]

In the smelting reduction apparatus of the present invention, the upper portion of the smelting reduction furnace is directly connected to the lower portion of the fluidized bed type preliminary reduction furnace to form an integral furnace,
Separately from the nozzle of the dispersion plate, a cut-out pipe of the pre-reduction charging material having a pipe opening at one end at the upper side and a pipe opening at the other end at the lower side of the dispersion plate of the integral furnace is provided. The cutting pipe has a cutting function for adjusting the cutting amount of the preliminary reduction charging material.

In the smelting reduction apparatus of the present invention, the cut-out tube as described above is provided so as to have a pipe opening at one end at the upper side of the dispersion plate of the integrated furnace and a pipe opening at the other end at the lower side. Since it has a cutting function that can adjust the cutting amount and cutting time of the preliminary reduced iron from the lower part of the reduction furnace to the upper part of the smelting reduction furnace, the cutting of the charging material to the smelting reduction furnace can be independently adjusted arbitrarily, At the same time, the gas generated in the smelting reduction furnace can flow into the reducing gas preliminary reduction furnace via the cutout pipe.

Therefore, the flow rate and flow rate of the reducing gas generated in the smelting reduction furnace portion from the nozzle of the dispersion plate toward the preliminary reduction furnace portion can be controlled independently, and the nozzle of the dispersion plate has an ideal shape. Can be selected, so that the fluidized bed portion of the preliminary reduction furnace can be reliably formed. In addition, the entire smelting reduction apparatus becomes compact, and heat loss due to heat dissipation can be minimized. In addition, although the L-shaped cutting pipe device is used in the embodiment of the present invention for the function of adjusting the cutting amount, it is not limited to the above means, and other mechanical valve device, screw feeder device or the like may be used.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a vertical section of an embodiment of the present invention,
FIG. 2 is a view showing a cross section taken along line XX of FIG. Here, the case where iron ore is used as the metal oxide charging material will be described. In the figure, 11 is a smelting reduction furnace, 12 is a fluidized bed type pre-reduction furnace, 13 is a dispersion plate of the pre-reduction furnace, and 14 is a cut-out tube of the pre-reduction charging material.

In FIG. 1, the smelting reduction apparatus of the present invention has a smelting reduction furnace 11 and a gas generated in the reduction furnace 11 as a reducing gas, which is introduced into the lower portion thereof and ejected from a nozzle 13a of a dispersion plate, and charged inside. A fluidized bed type pre-reduction furnace 12 that is brought into contact with the powdery granular iron ore and discharged from an upper exhaust gas duct 21 is provided. The bottom end of the side wall 12a of the pre-reduction furnace 12 and the side wall of the smelting reduction furnace 11 are provided. 11a is connected to the upper end to form an integral furnace, and the dispersion plate 1 of the integral furnace
3, a cut-out pipe 14 of the pre-reduction charging material having a pipe opening 14a at one end at the upper side and a pipe opening 14b at the other end at the lower side is provided. In the lower part of the smelting reduction furnace 11, molten iron 16
In addition to the accumulation of the slag 17, a charging nozzle 11b for a reducing agent such as coal and an auxiliary material is provided.

In the upper pre-reduction furnace 12, the iron ore charging pipe 1
9. The circulation pipe 20 and the exhaust gas duct 21 for circulating and pre-reducing the fine ore collected by the cyclone 22 are provided, and the reducing gas generated in the smelting reduction furnace 11 is opened in the dispersion plate 13. It is blown from a large number of nozzles 13a and forms a stable fluidized bed portion 24 in the preliminary reduction furnace 12. Reference numeral 18 is an exhaust gas control valve.

Further, 11d is a nozzle for blowing decarbonate, 11c is a nozzle for blowing secondary combustion oxygen, 11e is a nozzle for blowing a stirring gas, 11f is a nozzle for blowing a powdery carbon material, and 11g is a molten metal or slag. This is the tap hole to be pulled out. On the other hand, a cutout pipe 14 for pre-reduced iron ore having an inlet end 14a on the furnace wall above the dispersion plate 13 and an outlet end 14b on the furnace wall below is provided.

An L-shaped cut-out pipe, which is one of the cut-out pipes 14 for the pre-reduction charging material used in the present invention, will be described with reference to FIG. Cylindrical cross section (cross section may be circular or rectangular)
Even if the granular material is put into the L-shaped cutout tube 14 from the inlet end 14a, it is not discharged from the outlet end 14b as it is.
A small auxiliary gas injection pipe 15 is provided on the vertical side of the cut-out pipe 14.
When a small amount of auxiliary gas (nitrogen gas, etc.) is blown into the pipe, the cutout pipe 1
The packed state of the powder or granules put in 4 loosens, and the powder or granules are cut out from the outlet end 14b together with the auxiliary gas.

In this case, the position of the auxiliary gas blowing pipe 15 is determined so as to have an appropriate seal height h so that the powder and granules do not blow upward. Further, the horizontal length l of the L-shaped cutout tube 14 is designed so that there is no natural drop (cutout) from the outlet end 14b due to the angle of repose of the powder or granular material. By adjusting the amount of the auxiliary gas with this L-shaped cutout tube 14, the cutout amount of the powder or granular material can be controlled arbitrarily, and since it has a very simple shape without a built-in mechanical device, it is especially suitable for hot work. It is excellent for handling powder and granules.

The smelting reduction apparatus of the present invention has the above-mentioned L-shaped cutout tube 14, a pipe opening 14a at one end in the upper part of the dispersion plate 13 of the integrated furnace, and a pipe opening 14b at the other end in the lower part. As described above, by blowing nitrogen gas from each of the auxiliary gas blowing pipes 15, the amount of ore cut out can be adjusted regardless of the amount of reducing gas passing through the nozzle 13a of the dispersion plate, and the L-shaped Since the whole cut-out pipe 14 is incorporated in the furnace body side portion (inside the refractory), the entire smelting reduction apparatus becomes compact and the heat loss due to heat radiation can be minimized. In this way, the nozzle 1 of the dispersion plate
The design of 3a has no relation to the amount of ore cut out, so an ideal shape can be selected, and the fluidized bed portion 12a of the preliminary reduction furnace 12 can be reliably formed.

In the embodiment shown in FIGS. 1 and 2, the L-shaped cut-out pipe 14 is shown as four, but this is determined by the installed capacity of the entire apparatus and is limited to this number. Not a thing. Further, since the furnace diameter of the preliminary reduction furnace 12 is usually smaller than the furnace diameter of the smelting reduction furnace 11, the outlet end 14b of the L-shaped cutout tube 14 is located on the core side of the inner wall of the smelting reduction furnace 11. Therefore, it is convenient since troubles such as the powder for the preliminary reducing charging material inside the furnace are prevented from adhering.

Ball valves 23a and 23b shown in FIG.
Is for determining the discharge destination of the preliminary reduced ore fine powder collected by the cyclone 22, and may be a ball valve or the like as shown in the figure, or may be equipped with another switching device.

In the case of FIG. 1, when the ball valve 23a is opened and the ball valve 23b is closed, the preliminary reduced ore fine powder is returned to the return port 1.
By the circulation type operation reaching 2b and returning to the fluidized bed portion 24,
Conversely, the ball valve 23b is opened and the ball valve 23a
When closed, the pre-reduction ore differential reaches the return port 14c provided in the middle of the L-shaped cutout pipe 14, and the operation without circulation is directly supplied to the smelting reduction furnace 11.

Also, there may be an intermediate method between these methods, but each method is selected depending on the type of ore at that time and the target preliminary reduction rate of the ore, and this apparatus can correspond to either operation method.

The emergency discharge valve 14d that protrudes obliquely downward from the middle of the L-shaped cut-out pipe 14 is used to extract the ore by the preliminary reduction furnace 12 when the furnace is stopped or in other emergency, and is normally closed. Used in the state.

Further, the gas pressure adjusting valve 18 provided in the middle of the exhaust gas duct is for adjusting the flow rate and pressure of the exhaust gas, and the generated gas amount of the melting and reducing furnace which changes according to the change of the operating condition of the melting and reducing furnace 11. By controlling the flow rate and pressure of the exhaust gas so that the flow condition of the metal oxide charging material in the fluidized bed pre-reduction furnace is not affected by the increase or decrease of the This is a valve for adjusting the introduction flow rate and pressure of the generated gas.

The portion shown by hatching in the figure is basically made of refractory, but the upper inclined portion of the smelting reduction furnace 11 is a membrane type boiler (boiler tube It is also possible to install a large number of side-by-side welds and incorporate a wall-shaped heat exchange boiler) to recover the excess energy of the reducing gas and use it separately.

FIG. 3 is a view showing a cross section of another embodiment in which the incorporated shape of the L-shaped cutout tube used in the present invention is changed,
FIG. 4 is a view showing a cross section taken along the line YY. In FIGS. 3 and 4, the apparatus is suitable when the capacity of the apparatus is relatively small, and the L-shaped cutout tube 14 is positioned so as to contact the inner diameter of the preliminary reduction furnace 12, and the L-shaped cutout tube 14 is placed inside. The overhang makes the outer shell shape of the furnace simpler.

Since the structure is the same as that shown in FIG. 1 except for the above structure, the description of its function is omitted. The present apparatus is not limited to an iron smelting reduction apparatus for obtaining pig iron from iron ore as a raw material, and can be applied as a smelting reduction apparatus for obtaining ferroalloy (ferroalloy etc.) from other metal oxide ores.

[0030]

As described above, according to the present invention, the following effects are expected. (1) By directly connecting the upper part of the smelting reduction furnace and the lower part of the fluidized bed type preliminary reduction furnace, the entire apparatus can be designed compact and the construction cost can be reduced. (2) For the same reason, the surface area of the device can be reduced, so that the loss due to radiated heat can be reduced.

(3) The pre-reduction ore is cut out from the fluidized bed type pre-reduction furnace to the smelting reduction furnace by a cutting pipe, and it is incorporated into the furnace wall surface, so that the amount of ore cut-out can be controlled without impairing the performance of the fluidized bed. It can be controlled reliably. (4) In the preliminary reduction furnace, the preliminary reduction rate of ore can be adjusted to a predetermined value, and the amount of ore can be stabilized and cut out,
The final reduction performance in the smelting reduction furnace can be reliably exhibited.

[Brief description of drawings]

FIG. 1 is a view showing a vertical section of an embodiment of the present invention.

FIG. 2 is a view showing a cross section taken along line XX of FIG.

FIG. 3 is a view showing a vertical section of another embodiment of the present invention.

FIG. 4 is a view showing a cross section taken along the line YY of FIG.

FIG. 5 is an explanatory view of an L-shaped cutout tube used in the present invention.

FIG. 6 is a diagram showing a schematic cross section of a conventional smelting reduction apparatus.

[Explanation of symbols]

 11 Smelting Reduction Furnace 11a Side Wall 12 Fluidized Bed Type Preliminary Reduction Furnace 12a Side Wall 13 Dispersion Plate 13a Dispersion Plate Nozzle 13a 14 Preliminary Reduction Charge Material Cutout Pipe 14a Cutout Pipe One End Port 14b Cutout Pipe Other End Pipe Portion 15 Auxiliary gas blowing pipe 16 Molten iron 17 Slag 18 Exhaust gas regulating valve 19 Iron ore charging pipe 20 Circulation pipe 21 Exhaust gas duct 22 Cyclone 23a, 23b Ball valve 24 Fluidized bed part

[Procedure amendment]

[Submission date] December 13, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

However, in the smelting reduction apparatus as shown in FIG. 6 described above, since the supply of preliminary reduced iron is adjusted only by setting the opening of the opening adjustment damper, the following problems occur. is there. In the apparatus of FIG. 6, an opening adjustment damper 7 is provided in the exhaust gas pipe 6 of the preliminary reduction furnace portion 2, and an opening adjustment damper 8 is provided on the side wall of the portion which is the upper space of the smelting reduction furnace portion 3 and is also the tube furnace 5. The gas flow rate of the gas passing through the dispersion plate 4, that is, in the preliminary reduction furnace , is controlled by adjusting the opening degree adjusting damper 7 of the exhaust gas pipe 6 and adjusting the gas releasing tube 9 by the damper 8 . Flow of
Simultaneous formation of a layer and the amount of pre-reduced iron falling into the smelting reduction furnace
It is intended to be adjusted.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

Therefore, the solid state pre-reduced iron passing through the nozzle 4a of the dispersion plate 4 drops into the smelting reduction furnace 3 in a convection state with the reducing gas rising from the smelting reduction furnace 3, so that the smelting reduction furnace 3 The amount of the pre-reduced iron to be supplied to the fluctuating portion is likely to fluctuate, and it is difficult to perform sufficient adjustment only with the opening degree of the opening degree adjusting dampers 6 and 8. Therefore, sufficient smelting reduction in the smelting reduction furnace 3 is performed. I can't. Also, for the same reason
It is difficult to control the amount of gas blown into the preliminary reduction furnace.
Therefore, the fluidized bed in the pre-reduction furnace is not stably formed.
It is extremely difficult to obtain the target preliminary return rate
Become.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

In the smelting reduction apparatus of the present invention, the cut-out tube as described above is provided so as to have a pipe opening at one end at the upper side of the dispersion plate of the integrated furnace and a pipe opening at the other end at the lower side. It is provided with the cut function capable of controlling the cut amount and cut timing of pre-reduced iron from the bottom of the reducing furnace to the smelting reduction furnace top, a nozzle of the extraction of instrumentation Irizai to smelting reduction furnace dispersion plate
Regardless of the amount of passing gas, it can be adjusted independently and arbitrarily.
Sufficient smelting reduction in smelting reduction furnace
You can

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

Further, the flow rate and flow rate of the reducing gas generated in the smelting reduction furnace part and directed from the nozzle of the dispersion plate to the preliminary reduction furnace part can be controlled independently, and the design of the nozzle of the dispersion plate is ideal. Since the shape can be selected, it is possible to reliably form the fluidized bed part of the preliminary reduction furnace.
The preliminary return of can be managed according to a predetermined target. Also,
The entire smelting reduction device becomes compact, and heat loss due to heat dissipation can be minimized. In the embodiment of the present invention, the cutting amount adjusting function uses the L-shaped cutting pipe device. However, the cutting amount adjusting function is not limited to the above-mentioned means, and another mechanical valve device,
Means such as a screw feeder device may be used.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

In the embodiment shown in FIGS. 1 and 2, the L-shaped cut-out pipe 14 is shown as four, but this is determined by the installed capacity of the entire apparatus and is limited to this number. Not a thing. Moreover, since the furnace diameter of the pre-reduction furnace 12 is usually smaller than the furnace diameter of the smelting reduction furnace 11, the outlet end 14b of the L-shaped cutout tube 14 is on the core side of the inner wall of the smelting reduction furnace 11. Therefore, troubles such as prereduced instrumentation Irizai powder adheres to the furnace wall is avoided, which is advantageous.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

Ball valves 23a and 23b shown in FIG.
Intended to determine the discharge destination of the pre-reduced ore fines which are collections capturing a cyclone 22, may be a as shown in the drawing ball valve or the like, may be incorporated other switching device.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

In the case of FIG. 1, when the ball valve 23a is opened and the ball valve 23B is closed, the preliminary reduced ore fine powder is returned to the return port 1.
Leads to 2b, Ri Do the circulating operation back to the fluidized bed portion 24,
Conversely, the ball valve 23b is opened and the ball valve 23a
When is closed, the fine powder of pre-reduced ore reaches the return port 14c provided in the middle of the L-shaped cutout tube 14, and the operation without circulation is directly supplied to the smelting reduction furnace 11.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

The emergency discharge valve 14d that protrudes obliquely downward from the middle of the L-shaped cut-out pipe 14 is used to withdraw ore from the preliminary reduction furnace 12 when the furnace is stopped or in other emergency, and is normally closed. Used in the state.

[Procedure Amendment 9]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 10]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Claims (1)

[Claims] 1. A smelting reduction furnace, and the gas generated in the reduction furnace is introduced as a reducing gas into the lower part of the smelting reduction furnace to be ejected from a nozzle of a dispersion plate and brought into contact with a metal oxide charging material charged inside. A smelting reduction apparatus equipped with a fluidized bed type preliminary reduction furnace for discharging from an upper gas discharge port, wherein a lower end of a side wall of the preliminary reduction furnace and an upper end of a side wall of the smelting reduction furnace are connected to form an integral furnace. In addition, the smelting reduction apparatus is characterized in that a cut-out pipe of the preliminary reduction charging material having a pipe opening at one end at the upper side and a pipe opening at the other end at the lower side of the dispersion plate of the integrated furnace is provided.