JPH10158708A - Structure for furnace body of smelting reduction equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smelting reduction equipment capable of preventing carbonaceous material from floating and staying near the furnace side surface in the bath surface part of slag in the equipment for directly producing the molten metal and capable of accelerating redution reaction between the metallic material and the carbonaceous material in the molten slag by increasing the entrapped and suspended quantity of the carbonaceous material in the molten slag. SOLUTION: The molten metal is directly produced by adding the metallic raw material, carbonaceous material and flux into the furnace body having the rectangular shape in the horizontal cross-section and blowing and/or oxygen- adding gas into the slag through a lower tuyere 13 penetrating the long side of the furnace body 1 in the horizontal direction and arranged toward the slag 8. In this case, the carbonaceous material 19 is prevented from floating and staying near the furnace side surface in the bath surface part of the slag by regulating the position of the lower tuyere 13 to cause the rising fluid to the slag near the furnace side surface and the lowering fluid to the slag 8 at the center part of the furnace.

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 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.

A conventional technique proposed in Japanese Patent Application Laid-Open No. 1-502276 will be described with reference to FIGS. FIG. 13 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. 14 is an AA sectional view of FIG.
FIG. 14 is a sectional view taken along line BB of FIG. 13.

The furnace body 1 is fixed to a foundation 2, and the inside 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 iron raw material, 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.

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 through 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 above equations (1), (2) and (3) are:
Oxygen blown into the secondary combustion zone 15 through the upper tuyere 14 disposed toward the secondary combustion zone 15 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 reaction of the equations (4) and (5) is called secondary combustion in the furnace, and the degree of the secondary combustion is represented by the secondary combustion rate in the furnace 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 carbonaceous unit when the secondary combustion rate in the furnace is increased, as described above, the reaction heat slag 8 of the equations (4) and (5) in the secondary combustion zone 15 is used. It is effective to increase the moving amount of the slag, that is, to sufficiently agitate the slag in the vertical direction.

On the other hand, when the gas is blown into the hot metal 7 and the slag 8 through the tuyere provided vertically on the bottom of the furnace, the gas spreads at a constant divergence angle: 2θ (approximately 20) regardless of the gas flow rate.゜) is widely known from known literature (iron and steel, 61 (1981), No. 6, etc.). When gas is blown toward the slag 8 through the lower tuyere 13 provided in a direction perpendicular to the side of the furnace, that is, horizontally in the bottom of the furnace as shown in FIG. 14, similarly, regardless of the gas flow rate, The gas has a constant spread angle: 2θ (approximately 2
0 °) has also been confirmed by a model test performed by the inventors using water instead of the slag 8. Therefore, when the height from the lower tuyeres 13 to the 8 bath surface slag and H, spread in the slag 8 upper surface of the gas blown from the bottom tuyeres 13 Width: L ₃ is, L ₃ = 2
Expressed by H × tan .theta, the gas spread width: the L ₃ is sufficiently stirred.

Therefore, in the prior art proposed in Japanese Patent Application Laid-Open No. 1-502276, the slag is agitated almost uniformly over the entire region except for the portion in contact with the short side 17 of the rectangular furnace body, that is, the ascending flow is generated. to spacing of the lower tuyeres 13: spreading the L ₁ in the slag 8 upper surface of the gas blown from the bottom tuyeres 13 width: is the manner becomes substantially equal to L _3.

On the other hand, when the gas is blown horizontally through the tuyere toward the hot metal 7 and the slag 8, the distance L ₄ of the blown gas in the horizontal direction is proportional to the (1/3) th power of the Fr number. Is known literature (iron and steel, 61 (197
5), No. 4 etc.) are more widely known.

Here, the Fr number is obtained by the following equation (7). Fr number = {ρg / (ρl−ρg)} × {Vg ² F / (g · d)} (7) where ρg: gas density ρl: slag density Vg: gas ejection speed d: tuyere diameter g: gravity acceleration

[0027] Accordingly, it is blown to increase the amount of gas or blade diameter: by reducing the d, if increasing the gas ejection speed Vg, the horizontal reach of the blowing gas: Although L ₄ can be increased There are naturally limits due to restrictions on the amount of blown gas and gas pressure.

Therefore, in the prior art proposed in Japanese Patent Application Laid-Open No. 1-502276, the slag is agitated almost uniformly over the entire area other than the portion in contact with the long side 16 of the rectangular furnace body, that is, the ascending flow is generated. to the short-side direction of the length of the horizontal section at the height of the lower tuyeres of the furnace body: twice the horizontal reach of L ₅ the blowing gas:
It is set to be approximately equal to 2 × L ₄ . As a result, the length of the short side direction of the horizontal cross section at the height of the lower tuyere is made smaller than the length of the upper side of the furnace body, and a part of the wall constituting the long side of the furnace body is illustrated. As shown in FIG.

In these structures, all of the above-mentioned problems (1) to (5) have been solved because there is no tuyere below the surface of the hot metal bath into which an inert gas is blown to stir the metal.

[0030]

However, even this kind of furnace body structure shown in FIGS. 13 to 15 still has the following problems. As described above, this kind of furnace body structure is such that a metal raw material and a carbonaceous material are added to a molten slag 8 in a furnace body from a raw material inlet 5 arranged at one upper portion of the furnace body, and a metal material, After the metal oxide is melted, a reduction reaction occurs with the carbonaceous material. In order to accelerate the reduction reaction, it is important to incorporate and suspend the carbonaceous material 19 having a lower specific gravity than the slag 8 in the slag 8. It is.

The two long sides 16 of the furnace body having a rectangular horizontal section
Has a structure in which pure oxygen and / or an oxygen-enriched gas is blown into the slag through the lower tuyere 13 which is provided to the slag by passing through each of them at right angles to the long side 16.
The long side direction cross section, that paying attention to Figure 13, as described above, the interval of the lower tuyeres 13: spreading the L ₁ in the slag 8 upper surface of the gas blown from the bottom tuyeres 13 Width: substantially equal to L ₃ As a result, ascending flow is generated in the slag almost uniformly over the entire area other than the portion in contact with the short side 17 of the furnace body, and the slag 8 flows from the furnace center toward the short side 17 of the furnace body at the bath surface portion of the slag 8. Horizontal flow occurs, and a downward flow occurs near the short side 17 of the furnace body. Therefore, molten slag 8
As shown in FIG. 13, a carbon material 19 having a lower specific gravity is flown in the horizontal direction from the center of the furnace toward the short side 17 of the furnace at the bath surface of the slag 8 in the short side 17 of the furnace. And floats and stays near the short side 17 of the furnace at the bath surface of the slag 8. Although a downward flow of the slag 8 occurs near the short side 17 of the furnace body, the furnace side, that is, the short side 1 of the furnace body 1
7, the carbon material 19 is prevented from getting caught in the slag 8 by the downward flow of the slag 8.

The cross section of the furnace body 1 in the short side direction, that is, FIG.
Focusing on slag 8, upward flow occurs at the center of the furnace, and horizontal flow from the center of the furnace toward the long side 16 of the furnace body occurs at the bath surface of the slag 8, near the long side 16 of the furnace body. , A downward flow occurs. Therefore, as shown in FIG. 15, the carbonaceous material 19 having a specific gravity lower than that of the molten slag 8 is flown in the horizontal direction from the center of the furnace toward the long side 16 of the furnace body at the bath surface of the slag 8. It is swept away in the long side 16 direction, and slag 8
Of the furnace near the long side 16 of the furnace surface.
Although the downward flow of the slag 8 occurs near the long side 16 of the furnace body, the carbon material 19 rides on the downward flow of the slag 8 due to the frictional resistance of the furnace side, that is, the long side 16 of the furnace body. Entrapment in the slag 8 is impeded.

Thus, as shown in FIG.
Floats and stays around the entire circumference of the long side 16 and the short side 17 of the furnace body of the bath surface portion. In addition, a large amount of carbonaceous material 19 tends to float and stay at the corner 18 of the furnace at the bath surface portion of the slag 8 due to the two interactions.

Furthermore, the ascending flow is generated in the slag 8 almost uniformly over the entire area other than the portion in contact with the short side 17 of the rectangular furnace body, and from the center of the furnace toward the short side 17 of the furnace body at the bath surface of the slag 8. Horizontal flow occurs and the short side 17 of the furnace body
Due to the downward flow generated in the vicinity, the suspended amount of the carbonaceous material 19 in the central portion of the furnace body of the slag 8 in the long side 16 direction is reduced by the downward flow of the slag 8 so that the carbonaceous material 19 descends. There is a problem that the number is particularly small as compared with the vicinity of the short side 17.

The above tendency has been confirmed by a model test conducted by the inventors using water instead of slag 8 and a material having a specific gravity lower than water, such as cork, instead of carbon.

As described above, the carbonaceous material 19 is entrained and suspended in the molten slag 8 by floating and staying over the entire periphery of the long side 16 and the short side 17 of the furnace body in the bath surface portion of the slag 8. There is a problem that the amount is relatively small and the reduction reaction rate between the metal material in the molten slag 8, that is, the metal oxide and the carbonaceous material 19 is relatively slow.

The suspended amount of the carbonaceous material 19 in the central portion of the furnace body of the slag 8 in the direction of the long side 16 corresponds to the vicinity of the short side 17 of the furnace body where the carbonaceous material 19 descends due to the downward flow of the slag. The metal material in the slag 8,
That is, the reduction reaction between the metal oxide and the carbonaceous material 19 takes place on the long side 1 of the furnace body.
There is a tendency that the vicinity of the short side 17 of the furnace body is larger than the central part in the six directions. The reduction reaction is an endothermic reaction as described above,
Although it is necessary to supply heat during the reaction, in a furnace in which the short side 17 and the long side 16 of the furnace body are lined with the water-cooled panel 3, the slag near the short side 17 and the long side 16 of the furnace body is water-cooled panel. It is not preferable that the reduction reaction is larger in the vicinity of the short side 17 of the furnace body than in the central part of the furnace body in the direction of the long side 16 because of the cooling by the furnace 3.

The present invention has been made in order to solve the above-mentioned problems.
A large amount of the carbon material is prevented from floating and staying near the furnace side of the bath surface portion of the slag 8, that is, near the long side 16 and the short side 17 of the furnace body having a rectangular horizontal cross section. An object of the present invention is to provide a smelting reduction facility capable of promoting a reduction reaction between a metal material in a molten slag 8, that is, a metal oxide, and a carbonaceous material by increasing the amount of material involved in suspension.

Further, the suspended amount of the carbonaceous material 19 in the central portion of the furnace body of the slag 8 in the long side direction is increased, and the carbonaceous material 19 in the slag 8 is increased.
Of the metal material in the molten slag 8 by making the suspended concentration of the carbon material 19 in the central part of the furnace body in the longitudinal direction longer than that in the vicinity of the short side 17 of the furnace body. That is, an object of the present invention is to provide a smelting reduction facility capable of promoting a reduction reaction between a metal oxide and a carbon material 19.

[0040]

A metal raw material, a carbonaceous material, and a solvent are added to a furnace body having a rectangular horizontal section, and the furnace body is disposed so as to pass through the long side of the furnace body in the horizontal direction toward the slag. In equipment for directly producing molten metal by blowing oxygen and / or oxygen-added gas into slag through the lower tuyere, the height from the lower tuyere to the slag bath surface is H, and the spread of gas blown from the lower tuyere When the angle a 2 [Theta], 2 pairs of the lower tuyeres spacing of the central portion of the long side direction of the rectangular furnace body: with L ₆ of the _{2 × H × tanθ <L 6} ≦ 6 × H × tanθ,
Distance from the nearest lower tuyeres to the shorter side of the rectangular furnace up to the short side of the furnace body: the L ₂ is characterized in that the L ₂ ≦ H × tan .theta. Or interval of lower tuyere: L
₁ is 2 × H × tan θ <L ₁ ≦ 4 × H × tan θ, and the distance from the lower tuyere to the short side of the rectangular furnace body: L ₂
Is set to L ₂ ≦ H × tan θ.

Alternatively, assuming that the horizontal reaching distance of the blowing gas blown into the slag through the lower tuyere is L ₄ , the length in the short side direction of the horizontal section at the height of the lower tuyere of the furnace body: L _{5 is set} to 2 × L ₄ <L ₅ ≦ 4 × L _4, and the long side of the rectangular furnace body is constituted by a vertical wall. Alternatively, a nozzle for blowing gas horizontally toward the slag is provided on the long side and / or the short side of the rectangular furnace body above the lower tuyere and up to a position corresponding to the upper surface of the slag in the furnace. It is characterized by having. Alternatively, the furnace is characterized in that the corners of the furnace body having a rectangular horizontal section are chamfered or rounded.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION In the furnace body structure of a smelting reduction furnace according to the present invention, if the height from the lower tuyere to the slag bath surface is H and the spread angle of gas blown from the lower tuyere is 2θ, The distance between two pairs of lower tuyeres in the central part of the furnace body in the long side direction: L ₆ is 2 × H × tan θ <L ₆ ≦ 6 × H × tan
θ and the distance from the lower tuyere closest to the short side of the rectangular furnace body to the short side of the furnace body: L ₂ is L ₂ ≦ H × t
By setting anθ, ascending flow of the slag occurs near the short side of the furnace body, descending flow of the slag occurs at the central portion in the long side direction of the furnace body, and the short-side of the furnace body occurs at the bath surface of the slag. A horizontal flow is generated from the side toward the central portion of the furnace body in the long side direction. As a result, the carbon material having a lower specific gravity than the slag flows in the long side direction of the furnace body due to the horizontal flow from the short side of the furnace body to the central portion in the long side direction of the furnace body at the bath surface of the slag. It is washed away in the center and floats near the center of the slag bath surface in the longitudinal direction of the furnace body. The carbon material floating near the center of the furnace body in the long side direction has relatively little frictional resistance on the furnace side, so it relatively easily rides on the downward flow of the slag near the center of the furnace body in the long side direction and enters the slag. Entangled, the amount of suspended carbon material in the slag increases.

Alternatively, the interval of the lower tuyere: L ₁ is 2 × H
× tanθ <L ₁ ≦ 4 × H × tan θ, and the distance from the lower tuyere to the short side of the rectangular furnace body: L ₂ is L ₂ ≦ H
× tanθ, ascending flow of slag occurs immediately above each lower tuyere and near the short side of the furnace body, descending flow of slag occurs in the central portion between each lower tuyere,
At the bath surface of the slag, a horizontal flow is generated from a position immediately above each lower tuyere to a position near the center between each lower tuyere. As a result, the carbonaceous material having a lower specific gravity than the slag flows into the lower part of each slag by flowing in the horizontal direction from just above each lower tuyere to near the center between each lower tuyere at the bath surface of the slag. It is washed off near the center between the tuyeres and floats near the center between the lower tuyeres of each of the slag bath surfaces. The carbonaceous material floating near the center between each lower tuyere relatively easily rides the downward flow of the slag near the center between each lower tuyere because there is no frictional resistance on the furnace side, and Entangled, the amount of suspended carbon material in the slag increases.

Alternatively, assuming that the horizontal reaching distance of the blown gas blown into the slag through the lower tuyere is L ₄ , the length in the short side direction of the horizontal section at the height of the lower tuyere of the furnace body: L _By setting ₅ to 2 × L ₄ <L ₅ ≦ 4 × L ₄ , ascending flow of the slag occurs near the long side of the furnace body, and descending flow of the slag occurs at the central portion in the long side direction of the furnace body. Then, in the bath surface portion of the slag, a horizontal flow is generated from the short side of the furnace body toward the central portion in the short side direction of the furnace body. As a result, the carbon material having a lower specific gravity than the slag flows in the short side direction of the furnace body due to the horizontal flow from the long side of the furnace body to the central portion in the short side direction of the furnace body at the bath surface portion of the slag. It is swept away in the center and floats near the center of the slag bath surface in the short side direction of the furnace body. The carbonaceous material floating near the center of the furnace body in the short side direction has relatively little frictional resistance on the furnace side, so it relatively easily rides on the downward flow of the slag near the center of the furnace body in the short side direction and enters the slag. Entangled, the amount of suspended carbon material in the slag increases.

Alternatively, above the lower tuyere,
A nozzle that blows gas horizontally toward the slag is provided on the long side and / or short side of the rectangular furnace body up to the position corresponding to the upper surface of the slag in the furnace. The material is swept away from the long side and / or short side of the rectangular furnace body toward the center of the furnace body at the bath surface portion of the slag, and there is no frictional resistance on the furnace side, so that the downflow of the slag is relatively easy. Ride, get caught in slag and suspend in slag.

Alternatively, since the corner of the furnace body having a rectangular horizontal cross section is chamfered or rounded, the corner area of the furnace body particularly in the bath surface portion of the slag where a large amount of carbonaceous material tends to stay. By reducing the amount of carbonaceous material, the amount of carbonaceous material floating on the bath surface of the slag is reduced, and the amount of carbonaceous material suspended in the slag is relatively increased.

As described above, the following operations are provided. Prevent carbon material from floating and staying near the furnace side of the bath surface part of the slag, that is, near the long side and short side of the furnace body having a rectangular horizontal section, and entrain and suspend the carbon material in the molten slag By increasing the amount, it is possible to promote the reduction reaction between the metal material in the molten slag, that is, the metal oxide and the carbonaceous material. Metal material in molten slag, that is, metal oxide and carbon material, that increases the amount of carbon material suspended in the central part of the furnace body of the slag in the long side direction and makes the suspended concentration of carbon material in the slag uniform. Can be made uniform. Alternatively, by making the suspended concentration of the carbon material in the central portion of the furnace body in the long side direction higher than that in the vicinity of the short side of the furnace body, the carbon material in the central portion in the long side direction of the furnace body that is not cooled by the water cooling panel can be obtained. The reduction rate can be made higher than near the short side 17 of the furnace body cooled by the water cooling panel.

[0048]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a vertical sectional view of a furnace body structure of one embodiment of a smelting reduction facility according to claim 1 of 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. It is sectional drawing.

In the smelting reduction facility according to the first aspect of the present invention shown in FIGS. 1 to 3, upward flow of the slag 8 occurs above the lower tuyere 13. Assuming that the height from the lower tuyere to the slag bath surface is H and the spread angle of the gas blown from the lower tuyere is 2θ, the spread width of the gas blown from the lower tuyere 13 on the upper surface of the slag 8: L ₃ is: L ₃ = 2 × H
× It can be expressed by tanθ.

Here, the cross section of the furnace body in the long side direction, that is, FIG.
Focusing on, the distance between two pairs of lower tuyeres at the center part of the furnace body in the long side direction: L _{6 is set} to L ₃ <L ₆ ≦ 3 × L ₃ , whereby the center part of the furnace body in the long side direction is obtained. Then, the downward flow of the slag 8 occurs. Here, the interval between two pairs of lower tuyeres in the central part in the long side direction of the furnace body: L ₆ is defined as L ₃ <L ₆ ≦ 3 × L ₃ when L ₆ ≦ L _3. The spread of the gas blown from the two pairs of lower tuyeres in the central part in the long side direction of the furnace body on the upper surface of the slag 8 overlaps each other,
This is because the ascending flow of the slag 8 is generated in the central portion of the furnace body in the long side direction, and the descending flow is not generated. Conversely, L
_{When 6} > 3 × L ₃ , a portion that does not flow is formed at the central portion in the long side direction of the furnace body.

Meanwhile, the distance from the lower tuyeres 13 to the shorter sides 17 of the rectangular furnace body: by the L ₂ is set to L ₂ ≦ L _3/2, short sides of the rectangular furnace from the lower tuyeres 13 17 The range up to is within the range of the spread width of the gas blown from the lower tuyere 13 on the upper surface of the slag 8, the ascending flow of the slag 8 occurs near the short side 17 of the furnace body, and the bath surface of the slag 8 Then, a horizontal flow is generated from the short side 17 of the furnace body toward the central portion in the long side direction of the furnace body.

As a result, the carbonaceous material 19 having a specific gravity lower than that of the slag 8 is caused to flow by the horizontal flow from the short side 17 of the furnace body toward the center of the furnace body in the long side direction at the bath surface portion of the slag 8. The slag 8 is swept away in the center of the furnace body in the long side direction, and floats near the center of the furnace body in the long side direction.
The carbonaceous material floating near the center in the long side direction of the furnace body relatively easily rides the downward flow of the slag 8 near the center in the long side direction of the furnace body because there is no frictional resistance on the furnace side. And the suspended amount of the carbonaceous material 19 in the slag 8 near the center in the long side direction of the furnace body increases.

The above tendency has been confirmed by a model test performed by the inventors using water instead of slag 8 and a material having a specific gravity lower than water such as cork instead of carbonaceous material.

FIG. 4 is a vertical sectional view of a furnace body structure of one embodiment of the smelting reduction facility according to claim 2 of the present invention, FIG. 5 is a sectional view taken along line AA of FIG. 4, and FIG. It is BB sectional drawing.
In the smelting reduction facility according to claim 2 of the present invention shown in FIGS. 4 to 6, upward flow of the slag 8 occurs above the lower tuyere 13.

Here, the cross section of the furnace body in the longitudinal direction, that is, FIG.
Focusing on, the interval of the lower tuyere 13: L ₁ is L ₃ <L ₁
By setting ≦ 2 × L ₃ , a downward flow of the slag 8 occurs in the central portion between the respective lower tuyeres 13. Here, the interval of the lower tuyeres: the a L ₁ was defined as _{L 3 <L 1 ≦ 2 ×} L 3 , if the L ₁ ≦ L ₃ is the gas blown from the bottom tuyeres 13 Slag This is because when the spreads on the upper surfaces of the slags 8 overlap with each other, an upward flow of the slag 8 is generated in a central portion between the lower tuyeres 13 and no downward flow is generated. Conversely, when L ₁ > 2 × L ₃ , a portion that does not flow is formed in the central portion between the lower tuyeres 13.

Meanwhile, the distance from the lower tuyeres 13 to the shorter sides 17 of the rectangular furnace body: the L ₂ by the L ₂ ≦ L _3/2, short sides of the rectangular furnace from the lower tuyeres 13 17 The range up to the slag 8 of the gas blown from the lower tuyere 13
Within the range of the spread width on the upper surface, the short side 17 of the furnace body
The slag 8 flows upward in the vicinity.

Accordingly, in the bath surface portion of the slag 8, a horizontal flow from the vicinity of the short side 17 of the furnace body and the vicinity immediately above each lower tuyere 13 to the vicinity of the center between the respective lower tuyeres 13 is generated. Occur.

As a result, the carbon material 19 having a specific gravity smaller than that of the slag 8 is supplied to the lower tuyere from the vicinity of the short side 17 of the furnace body and the vicinity of each lower tuyere 13 at the bath surface of the slag 8. 13, by the flow in the horizontal direction toward the center between the lower tuyeres 13, the slag 8
Floats in the vicinity of the center between the lower tuyeres 13 of each bath surface portion. Carbon material 1 floating near the center between each lower tuyere 13
No. 9 has relatively little frictional resistance on the furnace side, so that the slag 8 near the center between the respective lower tuyeres 13 gets on the downward flow and is caught in the slag 8 relatively easily. The suspended amount of the carbonaceous material 19 in the nearby slag 8 increases.

The above tendency has been confirmed by a model test conducted by the present inventors using water instead of slag 8 and a material having a lower specific gravity than water such as cork instead of carbonaceous material.

FIG. 7 is a vertical sectional view of a furnace body structure of one embodiment of the smelting reduction facility according to claim 3 of the present invention, FIG. 8 is a sectional view taken along line AA of FIG. 7, and FIG. It is BB sectional drawing.
In the smelting reduction facility according to the first aspect of the present invention shown in FIGS. 7 to 9, upward flow of the slag 8 occurs above the lower tuyere 13.

Here, the cross section of the furnace body in the short side direction, that is, FIG.
When the horizontal reach of the blown gas blown into the slag 8 through the lower tuyere 13 is defined as L ₄ , the length of the furnace body in the horizontal direction at the height of the lower tuyere 13 in the short side direction is considered. is: by L ₅ of the _{2 × L 4 <L 5 ≦} 4 × L 4, descending flow of the slag 8 is generated in the central portion in the short side direction of the furnace body. Here, the lower tuyere 13 of the furnace body
Short-side direction of the length of the height of the horizontal section: L ₅ and 2 ×
L ₄ <L ₅ ≦ 4 × L ₄ is defined as L ₅ ≦ 2 × L ₄
In this case, the spread of the gas blown from the lower tuyere 13 on the upper surface of the slag 8 overlaps with each other, so that the ascending flow of the slag 8 is generated at the central portion in the short side direction of the furnace body, and This is because no flow occurs. Conversely, when L ₅ > 4 × L ₄ , a portion that does not flow is formed at the central portion in the short side direction of the furnace body.

On the other hand, since the long side of the rectangular furnace main body is constituted by the vertical wall, the ascending flow of the slag 8 occurs near the long side 16 of the furnace body, and the slag 8 is formed at the central portion in the short side direction of the furnace body.
Is generated, and in the bath surface portion of the slag 8, a horizontal flow is generated from the long side 16 of the furnace body toward the central portion in the short side direction of the furnace body.

As a result, the carbonaceous material 19 having a lower specific gravity than the slag 8 flows in the bath surface of the slag 8 from the long side 16 of the furnace body to the central part in the short side direction of the furnace body in the horizontal direction. The slag 8 is swept away toward the center of the furnace body in the short side direction.
Floats near the center in the short side direction of the furnace on the bath surface. The carbonaceous material 19 floating near the center in the short side direction of the furnace body relatively easily rides on the downward flow of the slag 8 near the center in the short side direction of the furnace body because there is no frictional resistance on the furnace side. And the amount of carbonaceous material 19 suspended in the slag increases.

The above tendency has been confirmed by a model test conducted by the inventors using water instead of slag 8 and a material having a lower specific gravity than water such as cork instead of carbonaceous material.

FIG. 10 shows claims 3 and 4 of the present invention.
11 is an elevational sectional view of a furnace body structure of one embodiment of the smelting reduction facility according to the present invention, FIG. 11 is an AA sectional view of FIG. 10, and FIG.
FIG. In the smelting reduction facility according to claim 2 of the present invention shown in FIGS.
3, a long side 16 and / or a short side 17 of the rectangular furnace body up to a position corresponding to the upper surface of the slag 8 in the furnace.
In addition, a nozzle 20 for blowing gas toward the slag 8 in the horizontal direction is provided, and a corner 18 of the furnace body having a rectangular horizontal section is chamfered.

Therefore, the carbon material 19 having a specific gravity lighter than that of the slag 8 is supplied to the nozzle 20 provided in the horizontal direction toward the slag 8.
Gas is blown from the long side 16 and / or short side 17 of the rectangular furnace body toward the center of the furnace body 1 at the bath surface portion of the slag 8 and there is no frictional resistance on the furnace side. The slag 8 is easily caught in the downward flow of the slag 8, and the suspended amount of the carbonaceous material 19 in the slag 8 increases.

On the other hand, by reducing the area of the corner 18 of the furnace in the bath surface portion of the slag where a large amount of carbon material tends to stay, the amount of the carbon material 19 floating on the bath surface portion of the slag 8 is reduced. It decreases and relatively increases the amount of the carbonaceous material 19 suspended in the slag 8.

The above tendency has been confirmed by a model test conducted by the inventors using water instead of slag 8 and a material having a specific gravity lower than water such as cork instead of carbonaceous material.

In the above embodiment, the case of reducing iron has been described. However, the present invention relates 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 also applies.

[0070]

According to the furnace structure of the smelting reduction furnace of the present invention, if the height from the lower tuyere to the slag bath is H, and the divergence angle of the gas blown from the lower tuyere is 2θ, the rectangular furnace Spacing between two pairs of lower tuyeres at the center in the long side direction of the body: L _{6 is set} to 2 × H × tan θ <L ₆ ≦ 6 × H × tan θ, and the lower part closest to the short side of the rectangular furnace body Distance from the tuyere to the short side of the furnace body: By setting L ₂ to L ₂ ≦ H × tan θ, ascending flow of slag occurs near the short side of the furnace body, and the center of the furnace body in the long side direction is generated. Downflow of the slag occurs in the portion, and in the bath surface portion of the slag, a horizontal flow from the short side of the furnace body toward the central portion in the long side direction of the furnace body occurs. As a result, the carbon material having a lower specific gravity than the slag flows in the long side direction of the furnace body due to the horizontal flow from the short side of the furnace body to the central portion in the long side direction of the furnace body at the bath surface of the slag. It is washed away in the center and floats near the center of the slag bath surface in the longitudinal direction of the furnace body. The carbon material floating near the center of the furnace body in the long side direction has relatively little frictional resistance on the furnace side, so it relatively easily rides on the downward flow of the slag near the center of the furnace body in the long side direction and enters the slag. Entangled, the amount of suspended carbon material in the slag increases.

[0071] Alternatively, the lower tuyeres Interval: L ₁ a 2 × H
× tanθ <L ₁ ≦ 4 × H × tan θ, and the distance from the lower tuyere to the short side of the rectangular furnace body: L ₂ is L ₂ ≦ H
× tanθ, ascending flow of slag occurs immediately above each lower tuyere and near the short side of the furnace body, descending flow of slag occurs in the central portion between each lower tuyere,
At the bath surface of the slag, a horizontal flow is generated from a position immediately above each lower tuyere to a position near the center between each lower tuyere. As a result, the carbonaceous material having a lower specific gravity than the slag flows into the lower part of each slag by flowing in the horizontal direction from just above each lower tuyere to near the center between each lower tuyere at the bath surface of the slag. It is washed off near the center between the tuyeres and floats near the center between the lower tuyeres of each of the slag bath surfaces. The carbonaceous material floating near the center between each lower tuyere relatively easily rides the downward flow of the slag near the center between each lower tuyere because there is no frictional resistance on the furnace side, and Entangled, the amount of carbon material suspended in the slag increases.

Alternatively, assuming that the horizontal reaching distance of the blown gas blown into the slag through the lower tuyere is L ₄ , the length of the furnace body in the short side direction of the horizontal cross section at the height of the lower tuyere: L ₅ a by a _{2 × L 4 <L 5 ≦} 4 × L 4, increase the flow of the slag is generated near the longer sides of the furnace body, the downward flow of the slag in the central portion of the long side direction of the furnace body Then, in the bath surface portion of the slag, a horizontal flow is generated from the short side of the furnace body toward the central portion in the short side direction of the furnace body.
As a result, the carbon material having a lower specific gravity than the slag flows in the short side direction of the furnace body due to the horizontal flow from the long side of the furnace body to the central portion in the short side direction of the furnace body at the bath surface portion of the slag. It is swept away in the center and floats near the center of the slag bath surface in the short side direction of the furnace body. The carbonaceous material floating near the center of the furnace body in the short side direction has relatively little frictional resistance on the furnace side, so it relatively easily rides on the downward flow of the slag near the center of the furnace body in the short side direction and enters the slag. Entangled, the amount of suspended carbon material in the slag increases.

Alternatively, above the lower tuyere,
A nozzle that blows gas horizontally toward the slag is provided on the long side and / or short side of the rectangular furnace body up to the position corresponding to the upper surface of the slag in the furnace. The material is swept away from the long side and / or short side of the rectangular furnace body toward the center of the furnace body at the bath surface portion of the slag, and there is no frictional resistance on the furnace side, so that the downflow of the slag is relatively easy. Riding, it gets caught in the slag, and the amount of carbon material suspended in the slag increases.

Alternatively, since the corners of the furnace body having a rectangular horizontal section are chamfered or rounded, the corner area of the furnace body particularly in the slag bath surface portion where a large amount of carbonaceous material tends to stagnate. By reducing the amount of carbonaceous material, the amount of carbonaceous material floating on the bath surface of the slag is reduced, and the amount of carbonaceous material suspended in the slag is relatively increased.

As described above, the following effects can be expected. Prevent carbon material from floating and staying near the furnace side of the bath surface part of the slag, that is, near the long side and short side of the furnace body having a rectangular horizontal section, and entrain and suspend the carbon material in the molten slag By increasing the amount, it is possible to promote the reduction reaction between the metal material in the molten slag, that is, the metal oxide and the carbonaceous material. By increasing the amount of carbon material suspended in the central part of the slag furnace body in the long side direction and making the concentration of carbon material suspended in the slag uniform, the metal material in the molten slag, that is, metal oxide It is possible to make the reduction reaction with the carbonaceous material uniform. Alternatively, by making the suspended concentration of the carbon material in the central portion of the furnace body in the long side direction higher than that in the vicinity of the short side of the furnace body, the carbon material in the central portion in the long side direction of the furnace body that is not cooled by the water cooling panel can be obtained. The reduction rate can be made higher than near the short side 17 of the furnace body cooled by the water cooling panel.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a furnace structure of an embodiment of a smelting reduction facility according to claim 1 of 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 structure of one embodiment of a smelting reduction facility according to claim 2 of the present invention.

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;

FIG. 7 is a vertical sectional view of a furnace structure of one embodiment of a smelting reduction facility according to claim 3 of the present invention.

FIG. 8 is a sectional view taken along line AA of FIG. 7;

FIG. 9 is a sectional view taken along line BB of FIG. 7;

FIG. 10 is a vertical sectional view of a furnace structure of one embodiment of a smelting reduction facility according to claims 4 and 5 of the present invention.

FIG. 11 is a sectional view taken along line AA of FIG. 10;

FIG. 12 is a sectional view taken along line BB of FIG. 10;

FIG. 13 is a vertical sectional view of a furnace body structure of a conventional smelting reduction facility.

FIG. 14 is a sectional view taken along line AA of FIG. 13;

FIG. 15 is a sectional view taken along line BB of FIG. 13;

[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 a furnace body having a rectangular horizontal section 17: Short side of a furnace body having a horizontal horizontal section 18: Corner of a furnace body having a rectangular horizontal section part 19: carbonaceous material 20: nozzle H: from the lower tuyeres 13 to the bath surface of the slag 8 height 2 [Theta]: divergence angle of the gas blown from the bottom tuyeres 13 L _1: distance of the lower tuyeres 13 L _2: lower Distance from tuyere 13 to short side 17 of rectangular furnace body L ₃ : Spread width of gas blown from lower tuyere 13 on upper surface of slag 8 L ₄ : Horizontal flow of gas blown from lower tuyere 13 distance L _5: length of the short side direction of the height of the lower tuyeres 13 of the furnace body L ₆ : Interval between two pairs of lower tuyeres at the center of the furnace body in the long side direction

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 26, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction contents]

Here, the Fr number is obtained by the following equation (7). Fr number = {ρg / (ρl -ρg) } × {Vg 2 / (g · d)} ‥‥ (7) where, ρg: Gas Density Lowell: Slag Density Vg: gas injection rate d: blade diameter g: Gravity acceleration

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masahide Nagatomi 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Plant Design Co., Ltd.

Claims (11)

[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. Assuming that the height from the lower tuyere to the slag bath surface is H and the divergence angle of the gas blown from the lower tuyere is 2θ, two pairs of the central part of the rectangular furnace body in the long side direction are provided. Of lower tuyere: L ₆ is 2 × H × tan θ
<L ₆ ≦ 6 × H × tan θ, and the distance from the lower tuyere closest to the short side of the rectangular furnace body to the short side of the furnace body: L ₂ should be L ₂ ≦ H × tan θ. The furnace structure of the smelting reduction facility. 2. 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. In a facility for directly producing slag, assuming that the height from the lower tuyere to the slag bath surface is H and the spread angle of gas blown from the lower tuyere is 2θ, the interval between lower tuyeres: L ₁ is 2 ×
H × tan θ <L ₁ ≦ 4 × H × tan θ, and the distance from the lower tuyere closest to the short side of the rectangular furnace body to the short side of the furnace body: L ₂ is L ₂ ≦ H × tan θ. The furnace structure of a smelting reduction facility, characterized in that: 3. 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. In a facility for directly manufacturing the furnace, assuming that the horizontal reaching distance of the blown gas blown into the slag through the lower tuyere is L ₄ , the length of the horizontal section in the short side direction at the height of the lower tuyere of the furnace body : L ₅ and _{2 × L 4 <L 5 ≦} 4
With the × L _4, a furnace structure of a smelting reduction facility, characterized by composing the long sides of the rectangular furnace body in the vertical wall. 4. 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. Directly above the lower tuyere and on the long side and / or short side of the rectangular furnace body up to a position corresponding to the upper surface of the slag in the furnace, the gas is directed horizontally toward the slag. The furnace structure of the smelting reduction facility, which is provided with a nozzle for blowing air. 5. 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 the lower tuyere that extends through the long side of the furnace body in the horizontal direction toward the slag to melt the molten metal. The furnace body structure of a smelting reduction facility, characterized in that in a facility for directly manufacturing a smelting reduction facility, a corner of a furnace body having a rectangular horizontal section is chamfered or rounded. 6. The furnace structure of a smelting reduction facility according to claim 1, to which the features of the furnace structure of the smelting reduction facility according to claim 3 are added. 7. The furnace structure of a smelting reduction facility according to claim 2, wherein the furnace structure of the smelting reduction facility according to claim 3 is added. 8. The furnace structure of a smelting reduction facility according to claim 4, wherein the structure of the furnace body of the smelting reduction facility according to claim 5 is added. 9. The smelting reduction facility according to claim 1, wherein the furnace structure of the smelting reduction facility according to any one of claims 4 and 5 is added. Furnace structure. 10. A smelting reduction facility according to claim 2, wherein the furnace structure of the smelting reduction facility according to any one of claims 4 and 5 is added. Furnace structure. 11. The smelting reduction facility according to claim 3, wherein the furnace structure of the smelting reduction facility according to any one of claims 4 and 5 is added. Furnace structure.