JPH10158707A - Structure for furnace body of smelting reduction equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smelting reduction equipment which can charge the raw material from only one piece of inlet even in the case of making the long side of a furnace body long by fluidizing slag in the long side direction of the furnace body having the rectangular shape in the horizontal cross-section in a structure for furnace body of a smelting reduction furnace, and further, can reduce the unit requirement of fuel by stirring the slag just above the boundary between molten iron and the slag without blowing gas from a tuyere to reduce the temp. difference between the slag and the molten iron. SOLUTION: Molten metal is directly produced by adding the metallic material, carbonaceous material and flux in the furnace body having the rectangular shape in the horizontal cross-section and blowing oxygen and/or oxygen-adding gas into the slag through the lower tuyere 13 penetrating the long side of the furnace body 1 in the horizontal direction and arranged toward the slag 8. In such a case, the lower tuyere 13 is directed at 15-45 deg. in the reverse direction to a raw material charging hole 5 sideward from the direction at the right angle to the long side of the furnace body 1.

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] In this smelting reduction method, since the reduction of the iron raw material is performed in the molten slag, it is widely known that the reduction rate, that is, the production rate of the hot metal, is almost proportional to the volume of the slag. Therefore, it is possible to increase the production rate of the hot metal by increasing the horizontal sectional area of the molten slag or the height of the molten slag. However, if the height of the molten slag increases unnecessarily, the equipment height of the smelting reduction furnace will increase, and the smelting reduction furnace will be discharged from the smelting reduction furnace with the raw material equipment for adding iron raw materials, carbonaceous materials, and medium solvents. The equipment height of the exhaust gas recovery equipment for recovering the combustible gas increases, and the height of the building that stores the exhaust gas recovery equipment must be increased, resulting in a significant increase in construction costs. Therefore, it is common practice to increase the horizontal cross-sectional area of the molten slag.

[0004] 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.

In general, 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. 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

Although the two-stage method has the advantage of higher energy efficiency than the one-stage method, it requires a pre-reduction furnace such as a packed-bed system or a fluidized-bed system, 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.

In this one-stage method, the rate at which CO gas and H ₂ gas generated in the slag are burned in a 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. 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 reduce the metal raw material and to vigorously agitate the slag in order to secure the amount of heat transfer from the secondary combustion zone to the slag. There was a major difficulty in the refining operation in transmitting the slag to the slag. In other words, there is a dilemma in that the non-oxygen gas causes a decrease in the temperature of the molten metal in order to greatly increase the amount of the molten metal stirring gas, while the inclusion of oxygen for maintaining the temperature causes the oxidation of the molten metal.

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 with this method, the following problems still remain because the inert gas is blown from the tuyere below the metal bath 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 an oxygen-added gas is blown into the slag through a lower tuyere directed at the slag by passing through each of two long sides of the furnace body having a rectangular horizontal section at right angles to the long side, Pure oxygen and / or an oxygen-added gas is blown into the secondary combustion zone through the upper tuyere directed to the secondary combustion zone through the slag, and a water-cooled panel is lined in a region facing the secondary combustion zone and slag on the inner surface of the furnace. Japanese Patent Laid-Open No. 1-50227
No. 6 proposes this.

The prior art proposed in Japanese Patent Application Laid-Open No. 1-502276 will be described with reference to FIGS. FIG. 4 is an elevational sectional view of a furnace body structure of a conventional smelting reduction facility proposed in Japanese Patent Application Laid-Open No. 1-502276, FIG. 5 is an AA sectional view of FIG. 4, and FIG. B-
It is B sectional drawing.

The furnace body 1 is fixed to a foundation 2, and the inner surface of the furnace is lined with a water-cooled panel 3 and a refractory 4. On the upper part of the furnace body 1, a raw material to which an iron raw material, a carbonaceous material, and a solvent are added. An inlet 5 and a gas outlet 6 for discharging combustible gas generated from the furnace body are provided. Hot metal 7 is stored at the bottom of the furnace body 1, and slag 8 having a lower specific gravity than the hot metal 7 is stored at the upper portion of the hot metal 7.
Therefore, the slag is continuously or intermittently discharged from the slag port 12 through the slag reservoir 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)

In this smelting reduction method, the formula (1),
Since the reduction reaction of (2) is performed in the slag 8, it is widely known that the reduction rate, that is, the production rate of the hot metal is substantially proportional to the volume of the slag.

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).

Further, the CO gas generated in the slag 8 and the hydrogen content in the carbonaceous material according to the equations (1), (2) and (3) are as follows:
Oxygen blown into the secondary combustion zone 15 through the upper tuyere 14 which is arranged toward the secondary combustion zone 16 through the furnace body 1 and 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 equations (4) and (5) are referred to as in-furnace secondary combustion, and the degree of the degree of 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 15 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 15 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 order to increase the amount of reduction in the unit carbon consumption when the secondary combustion rate in the furnace is increased, as described above, the reaction heat of the equations (4) and (5) in the secondary combustion zone 15 is used. It is effective to increase the amount of transfer to the slag 8, that is, to sufficiently agitate the slag in the vertical direction. However, the amount of heat transfer from the secondary combustion zone 15 to the slag 8 depends on the temperature of the atmosphere in the secondary combustion zone 15. Since it is also a function of the temperature difference of the slag 8, it is also very effective to reduce the temperature difference between the hot metal 7 and the slag 8 as much as possible and to lower the temperature of the slag 8. In this structure, all of the above-mentioned problems (1) to (5) are solved because there is no tuyere below the surface of the hot metal bath into which an inert gas is blown for stirring the metal.

[0025]

However, FIGS.
However, this type of furnace body structure still has the following problems. Two long sides 16 of a furnace body with a rectangular horizontal section
Is inserted into the slag through the lower tuyere 13 arranged at a right angle to the long side 16 in the direction perpendicular to the long side 16, the slag 8 is moved vertically. (Arrow in FIG. 4), and the horizontal cross section flows in the short side 17 direction (arrow in FIG. 6) of the rectangular furnace body,
It hardly flows in the direction of the long side 16 of the furnace body having a rectangular horizontal cross section.

Therefore, when only one raw material inlet 5 for adding the iron raw material, the carbonaceous material, and the medium solvent is provided in the upper part of the furnace body 1,
The concentration of iron and carbon materials in the slag just below the raw material inlet 5 and in the slag far from the raw material inlet 5 is likely to be non-uniform, increasing the production amount, that is, the long side of the furnace body having a rectangular horizontal cross section. When 16 is increased, it is necessary to install a plurality of raw material input ports 5, and a plurality of raw material input facilities are required,
Equipment costs increase.

Further, by providing a plurality of material input ports,
As shown in FIG. 4, the distance between the raw material inlet 5 and the gas outlet 6 must be reduced, and when the particle size of the metal raw material and the carbonaceous material is small, the combustible gas generated from the furnace body 1 is reduced. There is also a problem that the amount of the metal raw material and the carbonaceous material directly scattered from the raw material input port 5 to the gas discharge port 6 along with the flow of the gas increases.

Further, in this structure, since there is no tuyere below the metal bath surface into which an inert gas is blown to stir the hot metal 7, the slag located above the lower tuyere 13 is strongly stirred. The hot metal 7 located below the lower tuyere 13 and the interface between the hot metal 7 and the slag 8 are extremely quiet. for that reason,
Since the amount of heat transfer from the secondary combustion zone 15 to the slag 8 is large, the reduction reaction in the slag proceeds, but the hot metal 7
The amount of heat transfer to the slag 8 and the hot metal 7 becomes large as a result.

In the smelting reduction facility, the temperature of the hot metal discharged from the furnace is specified due to the restriction of the downward stroke. Therefore, if the temperature difference between the slag 8 and the hot metal 7 is large, the temperature of the slag 8 must be increased accordingly. However, the temperature of the combustible gas discharged from the furnace increases accordingly.

Therefore, when the temperature difference between the slag 8 and the hot metal 7 is, for example, about 100 ° C., the temperature of the slag 8 and the combustible gas discharged from the furnace is reduced by about Extra energy is required to increase the temperature by 100 ° C., and the carbonaceous material and the oxygen consumption rate increase accordingly.

Further, as described above, when the temperature of the combustible gas discharged from the furnace and the temperature of the slag 8 rises by about 100 ° C., the water-cooled panel 3 is lined in a region facing the secondary combustion zone 15 and the slag 8 on the inner surface of the furnace. In this case, since the heat removal from the water-cooled panel 3 increases, the carbonaceous material and the oxygen consumption rate further increase. This is because, in the water-cooled panel facing the secondary combustion zone 15, 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 8, heat transfer to the water-cooled panel is substantially proportional to (slag temperature)-(water-cooled panel) because convective heat transfer is mainly performed.

The present invention has been made in order to solve the above-mentioned problems.
The flow rate of the slag is also increased in the direction of the long side 16 of the furnace body having a rectangular horizontal section, thereby increasing the production amount.
It is an object of the present invention to provide a smelting reduction facility capable of reducing the number of smelting units to one.

Further, the slag just above the interface between the hot metal and the slag is stirred without blowing gas from the tuyere below the hot metal bath to stir the metal, so that the relative speed between the slag and the hot metal is increased, and It is an object of the present invention to provide a smelting reduction facility that increases the amount of heat transferred to hot metal and consequently reduces the temperature difference between slag and hot metal.

[0034]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a method of adding a metal material, a carbonaceous material, and a solvent to a furnace body having a rectangular horizontal cross section and horizontally extending the long side of the furnace body. Oxygen and / or oxygen-added gas is blown into the slag through the lower tuyere that is arranged toward the slag through
In the facility for directly producing molten metal, the lower tuyere is oriented sideways from a direction perpendicular to the long side of the furnace body by 15 to 45 ° in a direction opposite to the raw material inlet.

In the furnace body structure of the smelting reduction furnace of the present invention, the lower tuyere is oriented 15 to 45 ° in a direction opposite to the raw material inlet sideways from a direction perpendicular to the long side of the furnace body in the sideways direction. There is action.

By flowing the slag above the lower tuyere in a direction opposite to the raw material inlet in the long side direction of the furnace body having a rectangular horizontal cross section, the iron raw material and the carbon material concentration in the slag are made uniform in the long side direction. And increase the production amount, that is, when the long side of the furnace body having a rectangular horizontal cross section is enlarged, it becomes possible to use only one raw material input port, and it is possible to use one raw material input facility, Equipment costs are reduced. By using only one material inlet, the distance between the material inlet and the gas outlet can be increased, and even if the particle size of the metal material and the carbonaceous material is small, the combustible gas generated from the furnace body It is possible to prevent an increase in the amount of the metal raw material and the carbonaceous material directly scattered to the gas discharge port along the flow of the gas.

Further, the slag below the lower tuyere flows in the opposite direction to the slag above the lower tuyere, that is, in the direction of the raw material inlet, and the slag below the metal bath surface to stir the metal. Without blowing gas from the mouth, the slag just above the interface between the hot metal and the slag flows, increasing the relative speed between the slag and the hot metal, increasing the amount of heat transfer from the slag to the hot metal, and consequently the slag and the molten metal. The following effects are achieved by making it possible to reduce the temperature difference.

The temperature difference between the slag and the hot metal becomes smaller,
The temperature of the slag and the temperature of the combustible gas discharged from the furnace can be reduced by that much, and the carbonaceous material and the oxygen consumption rate are 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 range 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 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.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. 1 is a vertical sectional view of a furnace body structure of one embodiment of a smelting reduction facility according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG. .

In the smelting reduction facility according to the present invention shown in FIGS. 1 to 3, a metal raw material, a carbonaceous material and a solvent are added to a furnace body 1 having a rectangular horizontal cross section, and the long side 16 of the furnace body is horizontal. Tuyere 13 pierced in the direction and arranged toward the slag
In a facility for directly producing hot metal 7 by blowing oxygen and / or an oxygen-added gas into slag 8 through, the lower tuyere 13 is directed sideways from a direction perpendicular to the long side of the furnace body in a direction opposite to the raw material inlet 5. Are directed so that the angle θ is in the range of 15 to 45 °.

Accordingly, the slag above the lower tuyere 13 flows in the direction opposite to the raw material inlet 5 in the direction of the long side 16 of the furnace having a rectangular horizontal cross section. Further, the slag below the lower tuyere 13 flows in the opposite direction to the slag above the lower tuyere, that is, in the direction of the raw material inlet 5,
The slag 8 immediately above the interface between the hot metal 7 and the slag 8 is stirred without blowing gas from the tuyere below the metal bath surface to stir the metal, and the relative speed between the slag 8 and the hot metal 7 is increased. The amount of heat transfer from the iron to the hot metal 7 is increased.

With respect to the horizontal angle of the lower tuyere 13, from the result of the model test conducted by the inventors, θ was set to 45 °.
By doing so, the oxygen and / or oxygen-added gas bubbles blown into the slag 8 through the lower tuyere 13 do not reach the center of the furnace body 1 in the direction of the short side 17, but the center of the furnace 1 in the direction of the short side 17. Is not sufficiently stirred, and θ is 15
° or less, it was confirmed that the flow of the slag above the lower tuyere 13 in the direction of the long side 16 of the furnace body in the direction opposite to the raw material inlet 5 was not sufficiently generated. The angle is preferably in the range of 15 to 45 °.

Table 1 shows one example of the carbonaceous material and the oxygen consumption rate in the test operation of the smelting reduction facility according to the prior art and the present invention proposed in Japanese Patent Application Laid-Open No. 1-502276. The test conditions are as follows. Furnace body area (area of horizontal cross section at the height of lower tuyere 13): 20 m ² Lateral angle θ of lower tuyere 13: 30 ° of the present invention, conventional technology 0 ° Molten metal raw material type: iron ore Carbon material type: coal

[0046]

[Table 1]

Although the present embodiment has been described for the case of iron reduction, the present invention is also applicable to a non-ferrous metal and iron alloy (for example, chromium, nickel, manganese, etc.) smelting reduction equipment manufactured by a similar smelting reduction method. It goes without saying that it applies.

[0048]

According to the furnace body structure of the smelting reduction furnace of the present invention, a metal raw material, a carbonaceous material and a solvent are added to the furnace body, and the furnace body is horizontally penetrated and distributed toward the slag. In a facility for directly producing molten metal by injecting oxygen and / or oxygen-added gas into slag through the provided lower tuyere, the lower tuyere is directed sideways from the direction perpendicular to the side of the furnace body in the direction opposite to the raw material inlet. The following effects can be expected by directing the beam at 15 to 45 degrees.

By flowing slag above the lower tuyere in the direction opposite to the raw material inlet in the long side direction of the furnace body having a rectangular horizontal cross section, the iron raw material and the carbon material concentration in the slag are made uniform in the long side direction. And increase the production amount, that is, when the long side of the furnace body having a rectangular horizontal cross section is enlarged, it becomes possible to use only one raw material input port, and it is possible to use one raw material input facility, Equipment costs are reduced. By using only one material inlet, the distance between the material inlet and the gas outlet can be increased, and even if the particle size of the metal material and the carbonaceous material is small, the combustible gas generated from the furnace body It is possible to prevent an increase in the amount of the metal raw material and the carbonaceous material directly scattered to the gas discharge port along the flow of the gas.

Further, the slag below the lower tuyere flows in the opposite direction to the slag above the lower tuyere, that is, in the direction of the raw material inlet, and the slag below the metal bath surface is stirred to stir the metal. Without blowing gas from the mouth, the slag just above the interface between the hot metal and the slag flows, increasing the relative speed between the slag and the hot metal, increasing the amount of heat transfer from the slag to the hot metal, and consequently the slag and the molten metal. The ability to reduce the temperature difference has the following effects.

The temperature difference between the slag and the hot metal becomes smaller,
The temperature of the slag and the temperature of the combustible gas discharged from the furnace can be reduced by that much, and the carbonaceous material and the oxygen consumption rate are 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 the area 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 have a water-cooled structure 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 one embodiment of a smelting reduction facility according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

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

FIG. 4 is a vertical sectional view of a furnace body structure of a conventional smelting reduction facility.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a sectional view taken along line BB of FIG. 4;

[Explanation of symbols]

 1: Furnace 2: Base 3: Water-cooled panel 4: Refractory 5: Raw material inlet 6: Gas outlet 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: Secondary combustion zone 16: Long side of furnace body having a rectangular horizontal section 17: Short side of furnace body having a horizontal cross section θ: Lateral angle of lower tuyere 13

Claims (1)

[Claims] 1. A metal raw material in a furnace body having a rectangular horizontal section,
A carbon material and a medium solvent are added, and oxygen and / or an oxygen-added gas is blown into the slag through a lower tuyere that is horizontally provided through the long side of the furnace body and directed toward the slag. Wherein the lower tuyere is directed sideways from a direction perpendicular to the long side of the furnace body by 15 to 45 degrees in a direction opposite to the raw material inlet.