JPH10183213A - Operation method of smelting reduction equipment and furnace body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of sensible heat of combustible gas and the amount of heat removed from a water-cooled panel facing the upper space by reducing the difference between the ambient temperature of the upper space and the temperature of the slag. As a result, the present invention provides an operation method of a smelting reduction facility and a furnace body structure thereof, which can reduce the carbonaceous material and the oxygen consumption rate. SOLUTION: A metal raw material, a carbon material, and a solvent are added to a furnace body lined with a water-cooled panel, and the slag is passed through a lower tuyere passing through a side surface of the furnace body horizontally and disposed toward the slag. Oxygen and / or oxygen-enriched gas is blown into the furnace, and oxygen and / or oxygen-enriched gas is blown through an upper tuyere and / or upper lance disposed through the furnace body to directly produce a molten metal. In the method, the tip of the upper tuyere and / or upper lance is disposed at a position above the lower tuyere and up to a height corresponding to the upper surface of the slag in the furnace, and A method for operating a smelting reduction facility, characterized by blowing oxygen and / or an oxygen-enriched gas.

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 1500 to 1700 ° C. is generated from the smelting reduction furnace. Compared to the conventional blast furnace method, this smelting reduction method has higher production flexibility, that is, it is easy to change the production amount, and it is easy to stop and restart the equipment, and the capital investment amount is small. In particular, it has recently attracted attention as a small-scale molten metal production method.

[0003] Generally, in this type of smelting reduction method, a preliminarily reduced metal 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

[0004] The two-stage method has the advantage of higher energy efficiency than the one-stage method, but 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 the furnace space above the slag (hereinafter referred to as the upper space) (hereinafter, the secondary combustion rate in the furnace). Nominal furnace internal combustion rate = (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 is reduced, only the upper layer of the slag is heated, and the temperature difference between the upper space and the upper layer of the slag is reduced. The amount of heat transferred to the slag is reduced, and as a result, even if the secondary combustion rate is increased, the reduction in the carbon unit consumption is reduced. In addition, since the amount of heat transfer from the upper space to the slag decreases, the ambient temperature in the upper space increases, and when the refractory is lined with the furnace wall in the upper space, the amount of wear of the refractory increases rapidly. was there.

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 agitate the slag in order to reduce the metal raw material and secure the amount of heat transfer from the upper space to the slag. There was a major difficulty in the refining operation in transmitting 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 in this method, the following problems still remain because the inert gas is blown from the tuyere below the metal bath surface 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 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. is there. 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 oxygen-enriched gas is blown into the slag through the lower tuyere directed to the slag through the furnace body in the horizontal direction, and is passed through the upper tuyere directed through the furnace body to the upper space. A structure in which pure oxygen and / or an oxygen-enriched gas is blown into a space and a water-cooled panel is lined in a region facing the upper space of the furnace inner surface and the slag is disclosed in JP-A-1-502276.
No. pp. 139 to 163.

A conventional technique proposed in Japanese Patent Application Laid-Open No. 1-502276 will be described below with reference to FIGS. FIG. 7 is a sectional view of a prior art furnace body structure proposed in Japanese Patent Application Laid-Open No. 1-502276, and FIG.
It is -A 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 carbon 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 accumulates at the bottom of the furnace 1, and foaming slag 8 having a lower specific gravity than the hot metal 7 accumulates at the upper portion thereof. The hot metal 7 passes through the hot metal outlet 9 via the tap hole 11, and the slag passes through the slag reservoir 10. The waste is discharged continuously or intermittently from the slag port 12 through the outlet.

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

A part of the carbon content in the carbonaceous material supplied from the raw material charging port 5 penetrates through the furnace body 1 and enters the foamed slag 8 through the lower tuyere 13 disposed toward the foamed slag 8. It is oxidized by the reaction shown in the following formula (3) with the oxygen to be blown. C + 1 / 2O ₂ → CO (exothermic reaction) ‥‥‥ (3) The energy efficiency of this smelting reduction furnace, that is, the basic unit of carbon material is:
It is determined by the total carbon content required for the reactions of the equations (1), (2) and (3).

According to the above formulas (1), (2) and (3), the CO gas generated in the foamed slag 8 causes convection in the foamed slag 8, so that the gas is located above the lower tuyere 13 in the furnace. The specific gravity of the foaming slag 8 is 10
It has been confirmed by the inventors of the present invention that the slag 17 has a specific gravity of 1/2 to 1/3 of the specific gravity of the slag 17 therein.

Further, the CO gas and the hydrogen content in the carbonaceous material generated in the foamed slag 8 according to the above formulas (1), (2) and (3) are directed to the upper space 16 above the bath surface of the foamed slag 8. In the upper space 16 above the bath surface of the foamed slag 8 with oxygen blown into the upper space 16 through the upper tuyere 14 arranged through the furnace body 1, the following formulas (4),
The oxidation reaction shown in (5) is performed. CO + 1 / 2O ₂ → CO ₂ (exothermic reaction) ‥‥‥ (4) H ₂ + 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 upper space 16 through the upper tuyere 14. Furnace secondary combustion rate _{= (CO 2% + H 2} O%) / (CO 2% + CO% + H 2 O% + H 2%) ‥‥‥ (6) where, (6) CO _2% in the formula, 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 upper space 16 is transferred from the upper space 16 to the foamed slag 8, and the equation ( By reducing the amount of carbon necessary for the exothermic reaction of 3), the carbon unit consumption is reduced. In this structure, all of the above-mentioned problems (1) to (5) are solved because there is no tuyere below the surface of the metal bath into which an inert gas is blown to stir the metal.

[0020]

However, this kind of furnace body structure still has the following problems. In this structure, as described above, the above equations (1), (2), (3)
The CO gas and the hydrogen content in the carbonaceous material generated in the foaming slag 8 by the above process are passed through the upper tuyere 14 disposed through the furnace body 1 toward the upper space 16 above the bath surface of the foaming slag 8. By the oxygen blown into the space 16, the secondary combustion represented by the above formulas (4) and (5) is performed in the upper space 16 above the bath surface of the foamed slag 8.

As described above, in order to increase the amount of reduction in the unit carbonaceous unit when the secondary combustion rate in the furnace is increased, the foamed slag of the reaction heat of the equations (4) and (5) in the upper space 16 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 heat transfer from the upper space 16 to the foamed slag 8 is radiant heat transfer and convective heat transfer. Since the amount of heat transfer is also a function of the difference between the ambient temperature of the upper space 16 and the temperature of the foamed slag 8,
A certain difference between the ambient temperature and the temperature of the foamed slag 8 is required.

Therefore, when the difference between the ambient temperature of the upper space 16 and the temperature of the foamed slag 8 is, for example, about 200 ° C., the gas is discharged from the furnace as compared with the case where there is no difference between the ambient temperature of the upper space 16 and the temperature of the foamed slag 8. Combustible gas temperature about 2
Extra energy is required to increase the temperature by 00 ° C., and the carbonaceous material and the oxygen intensity increase accordingly.

Further, as described above, when the temperature of the combustible gas discharged from the furnace rises by about 200 ° C., when the water-cooled panel 3 is lined in a range facing the upper space 16 on the inner surface of the furnace,
Since the heat removal from the water-cooled panel 3 increases, the carbonaceous material and the oxygen consumption rate further increase. This is substantially proportional to (temperature of combustible gas) ⁴ − (water-cooled panel) ⁴ in the water-cooled panel facing the upper space 16 because the heat transfer to the water-cooled panel 3 is mainly radiant heat transfer. That's why.

In order to uniformly perform the secondary combustion of the equations (4) and (5) in the upper space 16, the upper space 16 needs a certain volume, and the water cooling panel 3 in a range facing the upper space 16 is required. The area of inevitably also increases to some extent,
Since the heat removal from the water-cooled panel 3 increases, the carbonaceous material and the oxygen consumption rate further increase.

The present invention has been made in order to solve the above problems, and the object thereof is to
By reducing the difference between the ambient temperature of the upper space 16 and the temperature of the foamed slag 8, the amount of sensible heat of the combustible gas and the amount of heat removed from the water cooling panel 3 facing the upper space 16 are reduced. It is an object of the present invention to provide an operation method of a smelting reduction facility and a furnace structure thereof, which enable reduction of an oxygen consumption unit.

[0026]

In order to solve the above problems, the present invention provides (1) a method of adding a metal raw material, a carbon material, and a solvent to a furnace body lined with a water-cooled panel, Oxygen and / or an oxygen-enriched gas is blown into the slag through a lower tuyere disposed to the slag through the side surface in a horizontal direction, and an upper tuyere and / or Or in a method of directly producing molten metal by blowing oxygen and / or an oxygen-enriched gas through an upper lance,
The tip of the upper tuyere and / or the upper lance is arranged at a position above the lower tuyere and up to a height corresponding to the upper surface of the slag in the furnace, and oxygen and / or A method for operating a smelting reduction facility characterized by blowing an oxygen-enriched gas. (2) In the facility for directly producing molten metal, the height from the lower tuyere to the slag port is defined as H ₁ . Then, from the lower tuyere to the upper tuyere and / or
Or the top lance to the tip height: H ₃ to H ₁ <H ₃ <
3 is a furnace structure of a smelting reduction facility, which is characterized by 3 × H ₁ .

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the furnace structure of a smelting reduction furnace according to the present invention, the upper tuyere and / or the upper tuyere are located above the lower tuyere and up to a height corresponding to the upper surface of the slag in the furnace. By arranging the tip of the upper lance, the CO gas generated in the foamed slag and the hydrogen content in the carbonaceous material are subjected to secondary combustion in the slag by the oxygen blown into the slag through the upper tuyere, thereby forming an upper space. No heat transfer from the slag to the slag is required, and as a result, the temperature difference between the slag and the combustible gas can be reduced without blowing gas from the tuyere below the metal bath to stir the metal. This has the following effects.

[0028] The temperature difference between the slag and the combustible gas is reduced, 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 can be reduced by the calorie. The temperature of the combustible gas discharged from the furnace can be reduced, and the heat removal of the water-cooled panel in the area facing the upper space on the inner surface of the furnace decreases, and the carbonaceous material and the oxygen consumption rate decrease by the amount of heat. By performing the secondary combustion reaction in the slag, it is possible to reduce the upper space, and the heat removal of the water-cooled panel in the area facing the upper space on the inner surface of the furnace is reduced. Oxygen intensity decreases. At the same time, the height of the furnace body can be reduced, and equipment costs can be reduced.

Since the molten metal particles are not blown up into the slag, they are not reoxidized by oxygen or an oxygen-enriched gas blown into the slag from the lower tuyere, and the reduction rate is improved, that is, the production rate is increased. improves. 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 lower tuyere in contact with the slag can be made water-cooled, and can be used semi-permanently, so that refractory 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.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view of a furnace body structure of a first embodiment of a smelting reduction facility according to the present invention, and FIG.
It is A sectional drawing. FIG. 3 is a sectional view of a furnace structure of a second embodiment of the smelting reduction facility according to the present invention, and FIG.
It is -A sectional drawing. FIG. 5 is a sectional view of a furnace body structure of a third embodiment of the smelting reduction facility according to the present invention, and FIG. 6 is a sectional view taken along line AA of FIG.

First, a first embodiment will be described with reference to FIGS. The iron oxide (FeO and Fe ₂ O ₃ ) in the iron raw material supplied from the raw material input port 5 is converted into the following formula (1) in the foamed slag 8 by the carbon content in the carbonaceous material also supplied from the raw material input port 5. ) And reduced by the reaction shown in (2). FeO + C → Fe + CO (endothermic reaction) ‥‥‥ (1) Fe ₂ O ₃ + 3C → 2Fe + 3CO (endothermic reaction) ‥‥‥ (2)

A part of the carbon content in the carbonaceous material supplied from the raw material charging port 5 penetrates through the furnace body 1 and enters the foamed slag 8 through the lower tuyere 13 disposed toward the foamed slag 8. It is oxidized by the reaction shown in the following formula (3) with the oxygen to be blown. C + 1 / 2O ₂ → CO (exothermic reaction) ‥‥‥ (3) The energy efficiency of this smelting reduction furnace, that is, the basic unit of carbon material is:
It is determined by the total carbon content required for the reactions of the equations (1), (2) and (3).

Further, the CO gas and the hydrogen content in the carbonaceous material generated in the foamed slag 8 according to the formulas (1), (2) and (3) are located above the lower tuyere 13 and in the furnace. Oxygen blown into the foamed slag 8 through the upper tuyere 14 disposed on the side surface of the furnace body 1 to a position corresponding to the upper surface of the foamed slag 8 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 + ２O ₂ → H ₂ O (exothermic reaction) ‥‥‥ (5)

When the secondary combustion rate in the furnace is increased, the reaction heat of the formulas (4) and (5) is transmitted to the foamed slag 8, and the carbon content required for the exothermic reaction of the formula (3) in the slag is reduced. By doing so, the basic unit of carbon material will decrease.

As described above, in order to increase the amount of reduction in the unit carbon consumption when the secondary combustion rate in the furnace is increased, the reaction heat of the equations (4) and (5) is applied to the foamed slag 8. Although it is effective to increase the amount of movement, in the present embodiment, the upper tuyere is placed on the side surface of the furnace body 1 above the lower tuyere and up to a position corresponding to the upper surface of the slag in the furnace. Is arranged,
By injecting oxygen and / or oxygen-enriched gas into the slag in the furnace, the secondary combustion reaction of the formulas (4) and (5) is performed in the foamed slag 8, and the secondary combustion reaction is performed. Since heat directly heats the foamed slag 8, it is generated by the secondary combustion reaction of (4) and (5) in the slag, and the upper space 1 is generated.
6, the temperature difference between the combustible gas and the foamed slag 8 almost disappears.

Next, the height of the upper surface of the foamed slag 8 in the furnace in this embodiment will be described with reference to FIG. In the present embodiment, the tap hole 11 and the tap hole 12 are provided at individual heights,
Hot metal 7 held in the furnace according to the siphon principle by its height
A smelting reduction facility that controls the volume of the foamed slag 8 and automatically discharges hot metal and slag more than that will be described. However, the present invention is directed to other tapping and slagging methods (for example, an opening method such as a blast furnace). It is needless to say that the present invention is also applied to a smelting reduction facility that employs the above.

In the tapping and tapping method based on the siphon principle in the present embodiment, the taphole 1
Height up to 2: H ₁ , foamed slag 8 from lower tuyere 13
The height to the upper surface: H ₂ has the relationship of the following equation. H ₁ = H ₂ × γ ₂ / γ ₁ ７ (7) where γ ₁ : specific gravity of calming slag 17 in slag reservoir 10 γ ₂ : specific gravity of foamed slag 8 in furnace

According to the above formulas (1), (2), and (3), the CO gas generated in the foamed slag 8 causes convection of the bubbles in the foamed slag 8, so that the gas flows upward from the lower tuyere 13 in the furnace. position foaming slag 8 specific gravity: gamma ₁ is the specific gravity of sedation slag 17 in 10 reservoir slag: gamma ₂ 1/2 to 1
/ 3. Therefore, from the lower tuyeres 13 to the taphole 12 Height: H ₁ is to the upper surface of the slag 8 bubbling from the lower tuyeres 13 Height: test of the inventors to be a two to three times the H ₂ It has been confirmed by operations.

In the present embodiment, the height from the lower tuyere 13 to the tip of the upper tuyere 14: H ₃ is defined as H ₁ <H ₃ <3 ×
By having a H _1, the tip of the upper tuyeres 14 is a above the lower tuyeres 13, on the position of up to a height corresponding to the upper surface of the foaming slag 8 within the furnace, become arranged as possible.

Next, a second embodiment will be described with reference to FIGS. In the second embodiment, the upper lance 15 is inserted obliquely downward from the side of the furnace body 1 above the upper surface of the slag in the furnace, and the tip of the upper tuyere 14 is positioned above the lower tuyere. Thus, oxygen and / or oxygen-enriched gas is blown into the slag in the furnace at a height up to the upper surface of the slag in the furnace.

Next, a third embodiment will be described with reference to FIGS. In the third embodiment, the upper lance 15 is inserted vertically downward from the upper surface of the furnace body 1 and the upper tuyere 1 is inserted.
4 is positioned above the lower tuyere and at a height up to the upper surface of the slag in the furnace, so that oxygen and / or oxygen-enriched gas is blown into the slag in the furnace. .

Also in the second and third embodiments, since the oxygen and / or oxygen-enriched gas is blown into the slag in the furnace, the secondary combustion reaction of the formulas (4) and (5) is performed. Is carried out in the foamed slag 8, and the heat of the secondary combustion reaction directly heats the foamed slag 8, so that it is generated by the secondary combustion reaction (4) and (5) in the slag and escapes to the upper space 16. The temperature difference between the combustible gas and the foamed slag 8 is almost eliminated.

Also in the second and third embodiments, the height from the lower tuyere 13 to the tip of the upper lance 15 is (1.1).
３3) × H ₁ , the tip of the upper lance 15 is located above the lower tuyere 13 and at a position up to the height corresponding to the upper surface of the foamed slag 8 in the furnace. . In the second and third embodiments, it is preferable that the upper tuyere 14 can be freely raised and lowered in consideration of repair of the upper lance 15 and the like.

Table 1 below shows an example of the prior art proposed in Japanese Patent Application Laid-Open No. 1-502276, and one example of the carbonaceous material and oxygen basic unit of the smelting reduction facility according to the present invention. The calorific value of the combustible gas was reduced by about 16%, and the heat removal rate of the water-cooled panel was reduced by about 38%.

[0045]

[Table 1]

Although the present embodiment has been described with respect to the case of reducing iron, the present invention is also applicable 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. Further, in the present embodiment, the case where the horizontal section of the furnace body is a smelting reduction facility having a rectangular shape is described, but it goes without saying that the present invention is also applied to the case where the horizontal section of the furnace body is a smelting reduction facility having a circular shape. .

[0047]

As described above, in the present invention, by disposing the tip of the upper tuyere at a position above the lower tuyere and up to a height corresponding to the upper surface of the slag in the furnace,
CO gas generated by foaming slag and hydrogen content in carbonaceous material are
The secondary combustion in the slag by the oxygen blown into the slag through the upper tuyere eliminates the need for heat transfer from the upper space to the slag, and as a result, the blade below the metal bath surface to stir the metal. The following effects can be expected by making it possible to reduce the temperature difference between the slag and the combustible gas without blowing the gas from the mouth.

[0048] The temperature difference between the slag and the combustible gas is reduced, the temperature of the combustible gas discharged from the furnace can be reduced by that much, and the carbonaceous material and oxygen basic unit can be reduced by the calorific value. The temperature of the combustible gas discharged from the furnace can be reduced, and the heat removal of the water-cooled panel in the area facing the upper space on the inner surface of the furnace decreases, and the carbonaceous material and the oxygen consumption rate decrease by the amount of heat. By performing the secondary combustion reaction in the slag, it is possible to reduce the upper space, and the heat removal of the water-cooled panel in the area facing the upper space on the inner surface of the furnace is reduced. Oxygen intensity decreases. At the same time, the height of the furnace body can be reduced, and equipment costs can be reduced.

Since the molten metal particles are not blown up into the slag, they are not reoxidized by oxygen or an oxygen-enriched gas blown into the slag from the lower tuyere, and the reduction rate, that is, the production rate is improved. improves. 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 lower tuyere in contact with the slag can be made water-cooled, and can be used semi-permanently. 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 sectional view of a furnace body structure of a first 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 of a furnace body structure of a smelting reduction facility according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a sectional view of a furnace structure of a third embodiment of the smelting reduction facility according to the present invention.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a sectional view of a furnace structure of a conventional smelting reduction facility.

FIG. 8 is a sectional view taken along line AA of FIG. 8;

[Explanation of symbols]

 1: Furnace 2: Basic 3: Water-cooled panel 4: Refractory 5: Raw material inlet 6: Gas outlet 7: Hot metal 8: Foamed slag 9: Hot metal pool 10: Slag pool 11: Tap hole 12: Slag port 13: Lower tuyere 14: Upper tuyere 15: Upper lance 16: Upper space 17: Calming slag

[Procedure amendment]

[Submission date] March 26, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Change

[Correction contents]

[0045]

[Table 1] ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 27, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

Also in the second and third embodiments, the height from the lower tuyere 13 to the tip of the upper lance 15 is set to ( 1 to
By 3) and × H ₁ was, the tip of the upper lances 15 is a above the lower tuyeres 13, would be positioned at a location to a height corresponding to the upper surface of the foaming slag 8 within the furnace. In the second and third embodiments, it is preferable that the upper tuyere 14 can be freely raised and lowered in consideration of repair of the upper lance 15 and the like.

Claims (2)

[Claims] 1. A metal raw material, a carbonaceous material, and a solvent are added to a furnace body lined with a water-cooled panel, and the lower body is penetrated in a horizontal direction through a side surface of the furnace body to form a lower tuyere disposed toward a slag. Oxygen and / or oxygen-enriched gas is blown into the slag, and oxygen and / or oxygen-enriched gas is blown through the upper tuyere and / or upper lance disposed through the furnace body to directly melt the molten metal. In the manufacturing method, the tip of the upper tuyere and / or the upper lance is disposed at a position above the lower tuyere and up to a height corresponding to the upper surface of the slag in the furnace. A method for operating a smelting reduction facility, wherein oxygen and / or an oxygen-enriched gas is blown into the apparatus. 2. A metal raw material, a carbonaceous material, and a solvent are added to a furnace body lined with a water-cooled panel, and the lower body is penetrated in a horizontal direction through a side surface of the furnace body to a lower tuyere disposed toward a slag. Oxygen and / or oxygen-enriched gas is blown into the slag, and oxygen and / or oxygen-enriched gas is blown through the upper tuyere and / or upper lance disposed through the furnace body to directly melt the molten metal. in equipment manufacturing for, when the height of the tapping opening from the lower tuyeres to H _1, the upper tuyeres and / or upper lances to the tip height from the lower tuyeres: the H ₃ H ₁ < A furnace structure of a smelting reduction facility, wherein H ₃ <3 × H ₁ .