JPH10152709A - Structure of furnace body in smelting reduction equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smelting reduction equipment which can increase metallic iron ratio in an iron raw material, lowers the unit requirements of carbonaceous material and oxygen and also, can increase the production of molten iron, by enabling the use of large scale scraps as a part of the iron raw material and increasing the scrap ratio in the iron raw material without blowing gas from a tuyere below molten iron for stirring the metal. SOLUTION: This equipment is the one directly producing the molten iron by adding the metallic raw material, carbonaceous material and flux into the furnace body and blowing oxygen and/or oxygen-enriched gas into slag through lower tuyeres 13 penetrating the side surface of the furnace body 1 and arranged toward the slag 8. In such a case, what is called, a linear type electromagnetic induction stirring device 15 generating parallel moving magnetic field is arranged to generate the moving magnetic field in the horizontal direction at the bottom part of the furnace body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a smelting reduction facility for directly producing a molten metal by adding a metal raw material, a carbonaceous material, and a solvent to a furnace body and blowing pure oxygen and / or an oxygen-enriched gas. .

[0002]

2. Description of the Related Art In the smelting reduction, a metal raw material, a carbon material, and a medium solvent are added to a furnace body, and pure oxygen and / or an oxygen-enriched gas is blown into the furnace to reduce the metal oxide in the iron raw material in the slag. In this method, molten metal is directly produced. In this method, a high-temperature combustible gas of about 1600 to 1800 ° C. is generated from the smelting reduction furnace.

[0003] This smelting reduction method, compared with the conventional blast furnace method,
Due to the high flexibility of production volume, that is, easy change of production volume, easy stop and restart of equipment, and small capital investment, it has recently been receiving attention especially as a small-scale molten metal production method. is there.

Generally, in this type of smelting reduction method, a preliminarily reduced metal raw material, a carbon material, and a medium solvent are added to a furnace main body, and CO gas and H ₂ gas in a combustible gas generated from the furnace main body are used for metal reduction. A two-stage method for pre-reducing the raw material (for example,
20607, Japanese Unexamined Patent Publication No. 61-96019), and an unreduced metal raw material, a carbonaceous material, and a medium solvent are added into the furnace body, and the metal oxide in the metal raw material is reduced in the slag, CO gas, H ₂ in combustible gas generated from the furnace body
A one-stage method in which the gas is completely burned in a waste heat boiler, the sensible heat and latent heat of the combustible gas are vaporized and collected, and power is generated (for example, JP-A-1-502276, JP-A-61-27).
9608, JP-A-60-9815, etc.)
Classified as

[0005] The two-stage method has the advantage of higher energy efficiency than the one-stage method, but requires a pre-reduction furnace of a packed-bed type, a fluidized-bed type, etc., so that the equipment is complicated and the capital investment is high. There are drawbacks such as the limitation of the shape of the iron raw material due to the uniformity of the reaction in the furnace (for example, only a lump iron raw material can be used in a packed bed system and only a powdered iron raw material can be used in a fluidized bed system). So, recently a simple one
The column method is attracting attention.

[0006] In this one-stage method, the rate at which CO gas and H ₂ gas generated in the slag are burned in the furnace space above the slag (hereinafter referred to as a secondary combustion zone) (hereinafter referred to as furnace 2).
The secondary combustion rate in the furnace = (CO ₂ % + H ₂ O)
%) / (Defined as CO ₂ % + CO% + H ₂ O% + H ₂ %) and effectively transferring the combustion heat to the slag, thereby improving energy efficiency, that is, reducing the carbon unit consumption. It is widely known that this can be done.

However, if the slag is not sufficiently stirred in the vertical direction, the heat transfer to the lower layer of the slag becomes small, only the upper layer of the slag is heated, and the temperature difference between the secondary combustion zone and the upper layer of the slag becomes small, and There has been a problem that the amount of heat transfer from the secondary combustion zone to the slag is reduced, and as a result, even if the secondary combustion rate is increased, the cost of reducing the carbon unit consumption is reduced. In this case, since the amount of heat transfer from the secondary combustion zone to the slag decreases, the ambient temperature of the secondary combustion zone increases, and when the refractory is lined on the furnace wall of the secondary combustion zone, the refractory is not There was a problem that the amount of wear increased rapidly.

Therefore, in order to solve these problems,
Equipped with a bottom tuyere and an oxygen top blowing lance, put hot metal in a melting furnace with a refractory lining on the furnace wall, control the amount of gas blown from the bottom tuyere, and limit the slag composition and the amount of free carbon material. A method for performing smelting reduction by using a method has been proposed in Japanese Patent Application Laid-Open No. 60-9815.

However, in this method, it is necessary to vigorously stir the slag in order to reduce the metal raw material and secure the heat transfer amount from the secondary combustion zone to the slag. There was a major difficulty in the refining operation in transmitting the slag to the slag. That is, since the amount of the molten metal stirring gas is extremely large, a non-oxygen gas causes a decrease in the temperature of the molten metal. On the other hand, when oxygen is contained for maintaining the temperature, there is a dilemma in which the molten metal is oxidized.

Therefore, in order to solve these problems,
A tuyere that blows an inert gas to agitate the metal under the metal bath, and a tuyere that blows oxygen or an oxygen-enriched gas into the slag that is located above the metal bath and below the slag. A method using a smelting reduction furnace provided with a lance and having a furnace wall lined with a refractory is proposed in Japanese Patent Application Laid-Open No. 61-279608.

However, even this method still has the following problems in order to blow the inert gas from the tuyere below the surface of the metal bath in order to stir the metal. The inert gas blown from the tuyere below the metal bath causes molten metal particles to be blown up into the slag, and the oxygen or oxygen rich gas blown into the slag from the tuyere located above the metal bath and below the slag. It is re-oxidized by the oxidizing gas and hinders the reduction rate, that is, the production rate. Due to the inert gas blown from the tuyere below the metal bath, the molten metal particles are blown up into the slag and suspended in the slag, so the heat capacity and thermal conductivity of the slag increase, and the furnace wall in contact with the slag increases. Since a water-cooled structure cannot be used and a refractory structure must be used, the refractory is greatly worn by slag and must be repaired or replaced frequently.

Since the heat capacity and the thermal conductivity of the slag increase, the tuyere located on the metal bath surface and on the slag surface cannot be water-cooled, and must be replaced by a consumable tuyere. There is a need to. The tuyere below the metal bath cannot be water-cooled due to the large heat capacity and thermal conductivity of the molten metal, and must be replaced by a consumable tuyere. The refractory around the tuyere below the metal bath is heavily worn and needs to be repaired or replaced frequently.

Therefore, in order to solve these problems,
Pure oxygen and / or oxygenated gas is blown into the slag through the lower tuyere directed to the slag through the furnace body horizontally and through the upper tuyere directed through the furnace body to the secondary combustion zone. A structure in which pure oxygen and / or an oxygen-added gas is blown into a secondary combustion zone, and a water-cooled panel is lined in a region facing the secondary combustion zone and slag on the inner surface of the furnace is disclosed in Japanese Patent Laid-Open No. 1-502.
No. 276 has proposed this. Hereinafter, JP-A-1-50
A conventional smelting reduction facility proposed in Japanese Patent No. 2276 will be described with reference to FIGS. FIG.
FIG. 9 is a longitudinal sectional view of a conventional smelting reduction facility proposed in Japanese Patent Application Publication No. 502276, and FIG. 9 is a side view thereof.

A furnace body 1 is fixed to a foundation 2, a furnace inner surface is lined with a water-cooled panel 3 and a refractory 4, and an iron material such as iron ore, iron-containing dust, iron scrap, etc. A raw material input port 5 for adding carbonaceous material and a medium solvent, and a gas discharge port 6 for discharging combustible gas generated from the furnace body are provided. Hot metal 7 accumulates at the bottom of the furnace body 1, and slag 8 having a lower specific gravity than the hot metal 7 accumulates at the upper portion thereof.
The hot metal 7 is discharged continuously or intermittently from a tap hole 11 through a hot metal pool 9, and slag is discharged from a tap hole 12 through a slag pool 10.

The iron oxide (FeO and Fe ₂ O ₃ ) in the iron raw material input from the raw material input port 5
Is reduced in the slag 8 by the reaction represented by the following formulas (1) and (2) by the carbon content in the carbonaceous material supplied from the reactor. FeO + C → Fe + CO (endothermic reaction) (1) Fe ₂ O ₃ + 3C → 2Fe + 3CO (endothermic reaction) (2)

Further, a part of the carbon content in the carbonaceous material supplied from the raw material charging port 5 is blown into the slag 8 through the lower tuyere 13 which penetrates the furnace body 1 and is disposed toward the slag 8. It is oxidized by oxygen and a reaction represented by the following formula (3). C + 1 / 2O ₂ → CO (exothermic reaction) (3)

The energy efficiency of this smelting reduction furnace, that is, the basic unit of carbonaceous material, is determined by the total amount of carbon necessary for the reactions of the formulas (1), (2) and (3). Therefore, when the ratio of metallic iron in the iron raw material is increased by increasing the scrap ratio in the iron raw material, the carbon content consumed in the equations (1) and (2) decreases, and the equations (1) and (2) Since the endothermic amount of 2) is reduced, the calorific value of formula (3) is reduced, and as a result, the total carbon content required for the reactions of formulas (1), (2) and (3) is reduced. Intensity decreases. In addition, the amount of oxygen necessary for the expression (3) and the expressions (5) and (6) described later decreases, thereby reducing the oxygen intensity.

Further, the CO gas generated in the slag 8 and the hydrogen content in the carbonaceous material according to the above equations (1), (2) and (3) are:
Oxygen blown into the secondary combustion zone 16 through the upper tuyere 14 disposed toward the secondary combustion zone 16 through the furnace body 1 is oxidized by a reaction represented by the following formulas (4) and (5). Is done. CO + 1 / 2O ₂ → CO ₂ (exothermic reaction) (4) H ₂ + 1 / 2O ₂ → H ₂ O (exothermic reaction) (5)

The reactions of the equations (4) and (5) are referred to as in-furnace secondary combustion, and the degree of the degree of the secondary combustion is represented by the in-furnace secondary combustion rate defined by the following equation (6). It is widely known that the secondary combustion rate can be increased by increasing the flow rate of oxygen blown into the secondary combustion zone 16 through the upper tuyere 14. Secondary combustion rate in furnace = (CO ₂ % + H ₂ O%) / (CO ₂ % + CO% + H ₂ O% + H ₂ %) (6) where CO _{2 in} equation (6) _{%, CO%, H 2 O} %, H 2
% Indicates the volume fraction of each component of the combustible gas at the gas outlet 6.

When the secondary combustion rate in the furnace is increased, a part of the reaction heat of the equations (4) and (5) in the secondary combustion zone 16 is transmitted to the slag 8, and the heat of the equation (3) in the slag is generated. By reducing the amount of carbon required for the reaction, the carbon unit consumption is reduced.
In this structure, since there is no tuyere below the metal bath surface into which an inert gas is blown to stir the above-mentioned metal,
All issues have been solved.

On the other hand, below the bottom of the furnace, the exposed surface of the molten metal formed by the upflow generated by induction stirring by a so-called pancake coil spirally wound in a flat plane parallel to the bottom of the furnace, The reaction zone is divided into a carbon dissolution reaction zone and a metal oxide reduction reaction zone by dissolved carbon in the molten metal, and a carbon-containing reducing material and a metal oxide material are separately supplied to each of the reaction zones. A method characterized by promoting the reduction of materials is disclosed in Japanese Patent Publication No. 54-243.
No. 61 has proposed this.

Further, the present invention relates to an electromagnetic stirring device for a continuous casting facility, comprising a pair of electromagnetic coils formed by a plurality of electromagnetic coils and operated by an AC power supply, for stirring the molten metal inside the slab by the pair of electromagnetic coils. A linear electromagnetic stirrer using a moving magnetic field parallel to the electromagnetic coil group formed by the group is disclosed in JP-A-63-183761.
In this publication, it is introduced as a conventional technique.

[0023]

However, even with the method proposed in Japanese Patent Laid-Open No. 1-502276, the blade below the surface of a metal bath into which an inert gas is blown to stir the hot metal 7 described above. Since there is no mouth, the slag 8 located above the lower tuyere 13 is strongly stirred, but the lower tuyere 1
Since the hot metal 7 located below 3 and the interface between the hot metal 7 and the slag 8 are extremely quiet, they still have the following problems.

When iron scrap is used as a part of the iron raw material, a relatively small amount of small scraps such as shredders and Dalai powder, that is, a scrap having a large surface area per volume can be dissolved, but a relatively large amount of large scraps can be dissolved. , It is difficult to dissolve scrap having a small surface area per volume. This is because large scrap has a higher specific gravity and a smaller surface area per volume than slag, so it cannot reach the molten metal bath without being completely dissolved in the slag, and furthermore, the molten metal bath is hardly agitated. Therefore, since the amount of heat transfer from the molten metal bath per scrap surface area is small, the dissolution rate is low, and it is easy to remain in the molten metal bath.

Since the amount of heat transfer from the secondary combustion zone to the slag is large, the reduction reaction in the slag proceeds, but the amount of heat transfer from the slag to the molten metal is small, and as a result, the temperature difference between the slag and the molten metal increases. . In the smelting reduction facility, the temperature of the molten metal discharged from the furnace is specified due to restrictions on the down process, so if the temperature difference between the slag and the molten metal is large, the temperature of the slag must be increased by that much, and that much Only the temperature of the combustible gas discharged from the furnace also rises. Therefore, if the temperature difference between the slag and the molten metal is, for example, about 100 ° C,
Compared to the case where there is no temperature difference between the slag and the molten metal, extra energy is required to raise the temperature of the slag and the combustible gas by about 100 ° C. Become.

As described above, when the temperature of the flammable gas and slag discharged from the furnace rises by about 100 ° C., when the water-cooled panel is lined in the area facing the secondary combustion zone and slag on the inner surface of the furnace, To increase the heat removal of
The carbonaceous material and the oxygen consumption rate will be further increased. This is because, in the water-cooled panel facing the secondary combustion zone, the heat transfer to the water-cooled panel is mainly radiant heat transfer, and is substantially proportional to (combustible gas temperature) ⁴ − (water-cooled panel) ⁴ , This is because, in the water-cooled panel facing the slag, the heat transfer to the water-cooled panel is substantially proportional to (slag temperature)-(water-cooled panel) because convective heat transfer is mainly performed.

On the other hand, in the method proposed in Japanese Patent Application Laid-Open No. 1-502276, iron oxide (FeO and Fe ₂ O ₃ ) in the iron raw material is reduced in the slag 8 by the carbon content in the carbonaceous material. Therefore, the carbon-containing reducing material and the metal oxide material are supplied to the exposed surface of the hot metal 7 formed by the ascending flow generated by the induction stirring, which is proposed in Japanese Patent Publication No. 54-24361. Even if a technology characterized by promoting the reduction of materials is applied, no improvement can be expected.

In addition, when the exposed surface of the hot metal 7 is formed by the upward flow, the hot metal 7 comes into direct contact with the atmospheric gas in the secondary combustion zone 16 or the oxygen blown from the upper tuyere 14 and is reoxidized. As a result, there is an adverse effect that the hot metal production is reduced. Also, the hot metal 7 is turned into slag 8 by the upward flow.
And is in direct contact with the oxygen blown from the lower tuyere 13 and is re-oxidized, with the result that the production of hot metal is reduced.

The present invention has been made in order to solve the above-mentioned problems.
A horizontal flow is generated in the molten metal bath without blowing gas from the tuyeres below the metal bath to stir the metal, and without generating an upward flow in the molten metal bath, and the molten metal is scrapped. It is an object of the present invention to provide a smelting reduction facility capable of increasing the relative speed of the steel, increasing the amount of heat transfer from the molten metal to the scrap, and using a large scrap as a part of the iron raw material.

In addition, a horizontal flow is generated in the molten metal to increase the relative speed between the slag and the molten metal, thereby increasing the amount of heat transfer from the slag to the molten metal, and as a result, reducing the temperature difference between the slag and the molten metal. It is an object to provide a smelting reduction facility.

[0031]

In order to solve the above-mentioned problems, the present invention relates to a method of adding a metal raw material, a carbonaceous material, and a solvent to a furnace body and horizontally penetrating a side surface of the furnace body to form a slag. Oxygen and / or in the slag through the lower tuyere
Or, by blowing oxygen-added gas, in a facility for directly producing molten metal, a so-called linear electromagnetic induction stirrer that generates a parallel moving magnetic field is provided at the bottom of the furnace body,
A moving magnetic field in a horizontal direction is generated at the bottom of the furnace body. Alternatively, there is provided a furnace body structure of a smelting reduction facility, wherein an electromagnetic induction heating device is provided at the bottom of the furnace body.

In the furnace body structure of the smelting reduction furnace according to the present invention, an electromagnetic induction stirrer or an electromagnetic induction heater is disposed at the bottom of the furnace main body, so that the blade below the metal bath surface is stirred to stir the metal. Without blowing gas from the mouth,
Also, without generating an upward flow in the molten metal bath, a horizontal flow is generated in the molten metal bath to increase the relative speed between the molten metal and the scrap and between the slag and the molten metal, and the molten metal is recycled from the scrap and the slag to the molten metal. It is possible to increase the amount of heat transfer to the surface, thereby having the following effects.

Large scrap can be used as a part of the iron raw material. Since the scrap ratio in the iron raw material can be increased, the metal iron ratio in the iron raw material can be increased, the carbon material and the oxygen consumption rate can be reduced, and the hot metal production rate can be increased.

[0034] The temperature difference between the slag and the molten metal is reduced, the temperature of the slag and the temperature of the combustible gas discharged from the furnace can be reduced accordingly, and the carbonaceous material and the oxygen consumption rate can be reduced by the amount of heat. When the temperature of the slag and the combustible gas discharged from the furnace can be reduced, and the water-cooled panel is lined in the area facing the secondary combustion zone and the slag inside the furnace, the heat removal of the water-cooled panel decreases and the heat , The amount of carbonaceous material and oxygen consumption decreases.

When the temperature of the combustible gas discharged from the furnace can be lowered and the refractory is lined in a region facing the secondary combustion zone on the inner surface of the furnace, the wear rate of the refractory can be reduced, so that repair or repair can be performed. The frequency of replacement is reduced. Since the molten metal particles are not blown up into the slag, they are not reoxidized by oxygen or oxygen-enriched gas blown into the slag from the lower tuyere, so that the reduction rate, that is, the production rate is improved.

Since the molten metal particles are not blown up into the slag, the heat capacity and the thermal conductivity of the slag are reduced, and the furnace wall and the lower tuyere in contact with the slag can be water-cooled and can be used semi-permanently. , Refractories, tuyere costs and the frequency of outages for repairs and replacements are drastically reduced. Since the tuyere below the metal bath is not required, refractories, tuyere costs and the frequency of shutdowns for repair and replacement are drastically reduced.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
It will be described based on. FIG. 1 is a vertical sectional view of a furnace body structure of an embodiment of a smelting reduction facility according to the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a sectional view taken along line AA of FIG.

Although the present embodiment describes the case of iron reduction, the present invention also applies to a smelting reduction facility for non-ferrous metals and iron alloys (for example, chromium, nickel, manganese, etc.) produced by a similar smelting reduction method. It goes without saying that it applies.

In order to increase the reduction of the carbon unit consumption when the in-furnace secondary combustion rate is increased, the reaction of the above equations (4) and (5) in the secondary combustion zone 16 is performed as described above. It is effective to increase the amount of heat transferred to the slag 8, that is, to sufficiently agitate the slag in the vertical direction, but the amount of heat transferred from the secondary combustion zone 16 to the slag 8 depends on the atmosphere in the secondary combustion zone 16. Since it is also a function of the difference between the temperature and the temperature of the slag 8, it is also very effective to reduce the temperature difference between the molten metal 7 and the slag 8 as much as possible to lower the temperature of the slag 8.

When iron scrap is used as a part of the iron raw material, the molten metal 7 is agitated as described above to increase the relative speed between the molten metal and the scrap 17 so that the molten metal 7 Increasing the amount of heat transfer is also very effective.

Therefore, in the smelting reduction equipment according to the present invention shown in FIG. 1, a so-called linear type in which an alternating current is applied to the bottom of the furnace main body 1 through a coil 19 provided with a multilayer winding to generate a parallel moving magnetic field. An electromagnetic induction stirrer 15 is provided.

FIG. 4 is an electric system diagram of the electromagnetic induction stirrer 15, and FIG. 5 is an example of a structural diagram of the coil 19 of the electromagnetic induction stirrer 15 (arrows in the figure indicate directions of current).

The electromagnetic force acting on the hot metal 7 due to the magnetic field generated by the coil 19 depends on the distance from the coil 19 and the coil 19
It depends on the magnetic permeability of the refractory 4 and the furnace shell 20 and the like between the iron and the hot metal 7 and the frequency of the coil 19. For this reason, the frequency is desirably set to a low frequency of about 0.3 to 10 Hz in consideration of the magnetic permeability of the refractory 4, the furnace shell 20, and the like. Therefore, as shown in FIG. 4, a frequency converter 22 is provided between the transformer 21 and the electromagnetic induction stirrer 15.

The coil 19 of the electromagnetic induction stirrer 15 is shown in FIG.
As shown in FIG.
When a low-frequency alternating current of 10 to 10 Hz is applied, the magnetic field moves horizontally in the direction shown in FIG.
Due to the electromagnetic force acting on the hot metal 7 by the magnetic field, a flow parallel to the bottom of the furnace is generated in the hot metal 7 as shown in FIGS.

As a result, the relative speed between the hot metal 7 and the scrap 17 and between the slag 8 and the hot metal 7 increases, and the heat transfer amount from the hot metal 7 to the scrap 17 and from the slag 8 to the hot metal 7 increases. Since a flow parallel to the bottom of the furnace occurs in the hot metal 7, a hot metal exposed portion is formed, and the hot metal 7 comes into direct contact with the atmospheric gas in the secondary combustion zone 16 or the oxygen blown from the upper tuyere 14 and is reoxidized. Don't worry. In addition, hot metal 7
Is blown up by the slag 8 and directly comes into contact with oxygen blown from the lower tuyere 13, so that there is no fear of re-oxidation.

As described above, the scrap 17 is charged from the raw material charging port 5 in the same manner as other iron raw materials such as iron ore, so that the electromagnetic induction stirring device 15 is provided at the bottom of the furnace main body 1 as shown in FIG. It is sufficient to set it just below the raw material inlet 5. In addition, when the scrap 17 is charged from a scrap input port different from the raw material input port 5, it is appropriate that the electromagnetic induction stirrer 15 is installed only near the bottom of the furnace body 1 directly below the scrap input port. is there.

Table 1 shows one example of the carbonaceous material and the oxygen consumption rate of the smelting reduction facility according to the prior art and the present invention proposed in Japanese Patent Application Laid-Open No. 1-502276. In contrast to the conventional technology in which large-scale scrap is difficult to dissolve, in the smelting reduction facility according to the present invention, the scrap ratio in the input iron raw material is 30 to
By increasing to 50%, the carbonaceous unit consumption and the oxygen consumption unit were reduced by 35 to 50% and 40 to 55%, respectively, compared to the prior art. The hot metal production rate per 8 volumes of slag, that is, the hot metal production rate in the furnace body 1 having the same shape is about 1.5 to 1.5.
Improved by a factor of two.

[0048]

[Table 1]

Second Embodiment A second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a vertical sectional view of a furnace body structure of a second embodiment of the smelting reduction facility according to the present invention, and FIG. 7 is a side view thereof.

In the smelting reduction facility according to the present invention shown in FIG. 6, a channel-type electromagnetic induction heating device 18 utilizing a commercial frequency is provided on the bottom side surface of the furnace main body 1.
6 occurs in the molten metal 7, the relative velocity between the molten metal and the scrap 17 increases, the amount of heat transfer from the hot metal 7 to the scrap 17 increases, and furthermore, the slag 8 and the hot metal 7 The temperature difference between the slag 8 and the hot metal 7 can be reduced by promoting the heat transfer by increasing the relative speed and by compensating the temperature by the induction heating of the hot metal 7. In the present embodiment, in addition to the effect of stirring the hot metal 7 shown in the first embodiment, it is possible to further reduce the unit consumption of coal in accordance with the degree of heating of the hot metal 7 by induction heating.

[0051]

In the furnace body structure of the smelting reduction furnace according to the present invention, the electromagnetic induction stirrer is provided at the bottom of the furnace body, so that the gas is introduced from the tuyere below the metal bath surface to stir the metal. Without blowing the molten metal, it is possible to increase the relative speed between the molten metal and the scrap and the slag and the molten metal, and to increase the heat transfer amount from the molten metal to the scrap and the slag to the molten metal. Thus, the following effects can be expected.

[0052] Large scrap can be used as a part of the iron raw material. Since the scrap ratio in the iron raw material can be increased, the metal iron ratio in the iron raw material can be increased, the carbon material and the oxygen consumption rate can be reduced, and the hot metal production rate can be increased.

The temperature difference between the slag and the molten metal is reduced, the temperature of the slag and the temperature of the combustible gas discharged from the furnace can be reduced by that much, and the amount of carbon material and oxygen consumption can be reduced by the amount of heat. When the temperature of the slag and the combustible gas discharged from the furnace can be reduced, and the water-cooled panel is lined in the area facing the secondary combustion zone and the slag inside the furnace, the heat removal of the water-cooled panel decreases and the heat , The amount of carbonaceous material and oxygen consumption decreases.

When the temperature of the combustible gas discharged from the furnace can be lowered and the refractory is lined in a region facing the secondary combustion zone on the inner surface of the furnace, the wear rate of the refractory can be reduced, so that repair or repair can be performed. The frequency of replacement is reduced. Since the molten metal particles are not blown up into the slag, they are not reoxidized by oxygen or oxygen-enriched gas blown into the slag from the lower tuyere, so that the reduction rate, that is, the production rate is improved.

Since the molten metal particles are not blown up into the slag, the heat capacity and the thermal conductivity of the slag are reduced, and the furnace wall and the lower tuyere in contact with the slag can be water-cooled and can be used semipermanently. , Refractories, tuyere costs and the frequency of outages for repairs and replacements are drastically reduced. Since the tuyere below the metal bath is not required, refractories, tuyere costs and the frequency of shutdowns for repair and replacement are drastically reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a furnace body structure showing a first embodiment of a smelting reduction facility according to the present invention.

FIG. 2 is a side sectional view of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a diagram showing an electric system of the electromagnetic induction stirrer of FIG. 1;

FIG. 5 is an explanatory view showing one example of a coil structure of the electromagnetic induction stirrer of FIG. 1;

FIG. 6 is a vertical sectional view of a furnace structure showing a second embodiment of the smelting reduction facility according to the present invention.

FIG. 7 is a side view of FIG. 4;

FIG. 8 is a vertical sectional view of a furnace structure of a conventional smelting reduction facility.

FIG. 9 is a side view of FIG. 6;

[Description of Signs] 1: Furnace 2: Base 3: Water-cooled panel 4: Refractory 5: Raw material input port 6: Gas discharge port 7: Hot metal 8: Slag 9: Hot metal pool 10: Slag pool 11: Tap hole 12 : Slag port 13: Lower tuyere 14: Upper tuyere 15: Electromagnetic induction stirrer 16: Secondary combustion zone 17: Scrap 18: Electromagnetic induction heating device 19: Coil 20: Furnace shell 21: Transformer 22: Frequency converter

Claims (2)

[Claims] 1. A metal raw material, a carbonaceous material, and a medium solvent are added to a furnace body, and oxygen and / or oxygen is contained in the slag through a lower tuyere penetrating a side surface of the furnace body in a horizontal direction toward the slag. Or, by blowing oxygen-added gas, in a facility for directly producing molten metal, a linear electromagnetic induction stirrer that generates a moving magnetic field in the horizontal direction at the bottom of the furnace body is provided at the bottom of the furnace body. The furnace structure of the smelting reduction facility. 2. A metal raw material, a carbonaceous material, and a medium solvent are added to a furnace body, and oxygen and / or oxygen is contained in the slag through a lower tuyere that penetrates horizontally through a side surface of the furnace body and is disposed toward the slag. Alternatively, in a facility for directly producing molten metal by blowing an oxygen-added gas, an electromagnetic induction heating device is provided at a bottom portion of the furnace main body, wherein a furnace body structure of the smelting reduction facility is provided.