JP2020020011A - Pig-iron manufacturing facility and method for manufacturing pig-iron using the same - Google Patents

Abstract

To provide a pig-iron manufacturing facility using an oxygen blast furnace, capable of reducing the flow rate of a cooling gas to the oxygen blast furnace and efficiently cooling the temperature of tuyere tip of the oxygen blast furnace without requiring incidental facilities, and a method for manufacturing pig-iron using the same.SOLUTION: The pig-iron manufacturing facility using an oxygen blast furnace comprises: an oxygen blast furnace for blowing pure oxygen, a reduction material and a tuyere cooling gas from a tuyere to generate an oxygen blast furnace gas without substantially including nitrogen from a furnace top; and a coke oven using heat generated when combusting the oxygen blast furnace gas by an oxygen containing gas without substantially including nitrogen to form a coke oven combustion exhaust gas to carbonize coal. A part of the coke oven combustion exhaust gas generated in the coke oven without substantially including nitrogen is the tuyere cooling gas of the oxygen blast furnace.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pig iron manufacturing facility using an oxygen blast furnace and a pig iron manufacturing method using the same.

  BACKGROUND ART In recent years, steelworks have been strongly demanded to save energy on the background of global environmental problems and fossil fuel depletion problems. As a result, in recent blast furnace operations, low-reduced material ratio (low RAR) operation has been strongly promoted.

In a general blast furnace, coke and pulverized coal react with oxygen in hot air (air heated to about 1200 ° C.) at the tuyere to generate CO and H ₂ gas (reducing gas), and these reducing gases Reduction of iron ore in the furnace. Previously, the operation by the small blast furnace of the order of an internal volume of 100m ³ have been made, with the development of the request and the technology of productivity, blast furnace every year to increase the capacity, the mainstream is large blast furnace of 5000m ³ class in recent years ing. However, as the size of the blast furnace increases, it becomes necessary to increase the strength of coke and sintered ore charged into the blast furnace, and as a result, agglomeration of raw materials has been developed. On the other hand, in recent years, the quality of raw materials has been deteriorating, and it has been difficult to obtain high-strength raw materials as in the past. For this reason, there is a need for technology development for a small blast furnace that can operate with low-strength raw materials. In addition, due to stricter safety requirements in recent years, it is required that not only the blast furnace but also its peripheral equipment be miniaturized as much as possible to enhance maintainability.

  As one of the blast furnace miniaturization technologies, there is research on an oxygen blast furnace. In a normal blast furnace, hot air (air heated to a high temperature of about 1200 ° C.) is blown from a tuyere, whereas an oxygen blast furnace is a furnace in which pure oxygen is blown from a tuyere. Since the oxygen blast furnace can reduce the volume of the reducing gas flowing inside the blast furnace by half as compared with the normal blast furnace, there is an advantage that the size of the blast furnace can be significantly reduced while maintaining the production amount. In addition, since a hot blast stove is not required, peripheral equipment can be significantly reduced in size.

  However, in the oxygen blast furnace, since pure oxygen is blown from the tuyere, there is a problem that combustion with the pure oxygen occurs at the tuyere, and the flame temperature becomes extremely high. As described above, when the flame temperature is too high, troubles such as damage to the tuyere and the furnace wall and trouble in unloading of the blast furnace due to volatilization of slag components occur. Therefore, in the oxygen blast furnace, it is necessary to employ a technique for blowing a tuyere coolant together with pure oxygen from the tuyere and controlling the flame temperature to an appropriate temperature (2000-2600 ° C.).

Meanwhile, Patent Document 1 discloses that, in an oxygen blast furnace, CO ₂ or H ₂ O (steam) is blown from a tuyere as a tuyere coolant, and the endothermic pyrolysis reaction is used to reduce the flame temperature at the tuyere tip, thereby reducing the temperature. There is disclosed a technique for controlling the temperature to an appropriate level.

Patent Literature 2 discloses a method in which blast furnace furnace top gas is blown from a tuyere of an oxygen blast furnace together with pure oxygen and pulverized coal as a tuyere coolant. It is known that in this known method, CO ₂ contained in the furnace top gas causes endothermic pyrolysis at the tuyere, so that the flame temperature can be reduced and controlled to an appropriate temperature.

JP-A-60-159104 JP-A-62-27509

The technique disclosed in Patent Document 1 is a method of blowing steam or CO ₂ gas together with oxygen from the tuyere of an oxygen blast furnace. However, since the blast furnace tuyere is generally made of copper and water-cooled, the tuyere is The surface is cooled to about several tens of degrees Celsius. Therefore, when steam is blown from the tuyere, a part of the steam is cooled at the tuyere to be drained and flows out as water, so that the entire amount of steam cannot be used for the endothermic reaction. Therefore, in this case, it is difficult to control the flame temperature to the target value by blowing steam. In the case of CO ₂ gas, the problem of draining does not occur. On the other hand, pure CO ₂ gas does not exist in the natural world. For example, PSA method (from the top gas of an oxygen blast furnace containing about 50 vol% of CO ₂ gas) It is necessary to separate only CO ₂ gas by using a CO ₂ separation facility based on pressure fluctuation separation method). However, when blowing CO ₂ gas from the tuyere of the oxygen blast furnace, a large amount of CO ₂ gas of 30,000 Nm ³ / h per blast furnace is required. Therefore, in the case of an oxygen blast furnace, if a large amount of CO ₂ gas that is only required to be blown from the tuyere is generated by the gas separation equipment, a huge gas separation equipment is required, and the equipment becomes large in size. Happens.

Further, the method disclosed in Patent Document 2 is a method in which the top gas of the oxygen blast furnace itself is recirculated and blown into the tuyere, so that large-scale auxiliary equipment such as a gas separation equipment is not required. However, since about half of the top gas of the oxygen blast furnace is CO and the other half is CO ₂ , only half of the injected gas contributes to the endothermic pyrolysis reaction. Therefore, in order to lower the flame temperature tuyere until the appropriate temperature, it is blown requires 10000 m 3 / ^h stuff large amount of furnace top gas per tuyere. However, considering that the purpose of the oxygen blast furnace is to make it smaller than a normal blast furnace, it is desirable to reduce the gas flow rate blown from the tuyere as much as possible for convenience of equipment layout. Furnace gas circulation through which tuyere cooling gas is blown is not preferred.

  An object of the present invention is to provide a pig iron manufacturing equipment using an oxygen blast furnace, which can reduce the flow rate of the cooling gas to the oxygen blast furnace, can efficiently cool the tuyere temperature of the oxygen blast furnace without the need for ancillary equipment, and the same. The object of the present invention is to propose a method for producing pig iron using the method.

  As a result of intensive research to solve the above-mentioned problems of the prior art and to achieve the above object, the inventors have developed a novel pig iron manufacturing facility and a pig iron manufacturing method using the same as described below. Reached.

  That is, the pig iron production equipment of the present invention is a pig iron production equipment using an oxygen blast furnace, which blows pure oxygen and a reducing agent, tuyere cooling gas from the tuyeres, and substantially contains nitrogen from the furnace top. An oxygen blast furnace that generates no oxygen blast furnace gas, and carbonizes the coal using heat generated when the oxygen blast furnace gas is combusted with an oxygen-containing gas substantially free of nitrogen to produce a coke oven combustion exhaust gas. Pig iron, characterized in that a part of the coke oven flue gas substantially free of nitrogen generated in the coke oven is configured as a tuyere cooling gas of the oxygen blast furnace. It is a manufacturing facility.

In the pig iron manufacturing equipment according to the present invention configured as described above,
(1) using pure oxygen gas as the oxygen-containing gas substantially containing no nitrogen;
(2) a gas obtained by mixing the coke oven combustion exhaust gas with pure oxygen as the oxygen-containing gas substantially containing no nitrogen;
(3) using a gas obtained by mixing water vapor with pure oxygen as the oxygen-containing gas substantially containing no nitrogen;
Is considered to be a more preferable solution.

  Further, the pig iron production method of the present invention is the pig iron production method using the pig iron production equipment, wherein a part of the coke oven combustion exhaust gas substantially free of nitrogen generated in the coke oven is introduced into the tuyere of the oxygen blast furnace. It is a method for producing pig iron, which is used as a cooling gas for industrial use.

According to the pig iron production equipment and the pig iron production method according to the present invention, the oxygen blast furnace gas containing substantially no nitrogen discharged from the oxygen blast furnace using pure oxygen is used, and even in a coke oven, nitrogen is used without using air. Oxygen blast furnace gas can be burned using an oxygen-containing gas that does not contain oxygen, so that coke oven flue gas that is substantially free of nitrogen and composed of almost only CO ₂ can be generated. Become.

And, since as Komu blown from tuyeres of oxygen blast furnace a part of the coke oven combustion exhaust gas as the tuyere for the cooling gas, feathers a large amount of CO ₂ gas without using a large-scale CO ₂ separation equipment PSA such now Fukikomeru the mouth, and, for the coke oven flue gas is only substantially CO _2, wings with a small amount of tuyere cooling gas as compared with the case blown into the tuyere by recycling the blast furnace top gas The mouth temperature can be properly controlled. As a result, it is only necessary to provide a blow-in facility capable of injecting a small amount of tuyere cooling gas without adding an extra facility such as CO ₂ separation, so that the oxygen blast furnace and peripheral facilities can be downsized. Become.

  In a preferred embodiment of the present invention, in a coke oven facility, a part of the coke oven combustion exhaust gas is recirculated without using air and mixed with pure oxygen to obtain an oxygen-containing gas substantially containing no nitrogen. Then, it was made to burn with the oxygen blast furnace gas. Further, in another preferred embodiment of the present invention, steam is mixed with pure oxygen to form an oxygen-containing gas substantially free of nitrogen, and then combusted with oxygen blast furnace gas.

As a result, the tuyere tip temperature can be controlled to an appropriate value only by injecting a small amount of coke oven flue gas into the tuyere. Furthermore, in the coke oven, a part of the coke oven combustion exhaust gas or steam is mixed and diluted without using pure oxygen alone, but this causes abnormalities caused by pure oxygen combustion while maintaining nitrogen-free conditions. It is possible to suppress the generation of a combustion flame having a high temperature, and also to prevent the refractory damage in the coke oven while maintaining the tuyere tip cooling effect of the coke oven combustion exhaust gas. Furthermore, using the present invention, but amount that was not recirculated out of the coke oven flue gas and is discharged out of the system, the coke oven consists of only approximately CO ₂ substantially free of nitrogen since the combustion gas is generated, CCS (Carbon dioxide Capture and Storage , capture and storage of CO ₂₎ and CCU can be applied to (Carbon capture and utilization, CO ₂ Service), it can also contribute to the CO ₂ emission reduction It is.

It is a figure showing composition of an example of pig iron manufacturing equipment of the present invention. It is a figure showing composition of other examples of pig iron manufacturing equipment of the present invention. It is the schematic which shows the tuyere used for the oxygen blast furnace of the pig iron manufacturing equipment of this invention with the burner for blast furnace tuyeres. It is a figure which shows the structure of further another example of the pig iron manufacturing equipment of this invention. FIG. 2 is a diagram illustrating a configuration of a pig iron manufacturing facility of Comparative Example 1. FIG. 9 is a diagram illustrating a configuration of a pig iron manufacturing facility of Comparative Example 2. FIG. 9 is a diagram illustrating a configuration of a pig iron manufacturing facility of Comparative Example 3. FIG. 9 is a diagram illustrating a configuration of a pig iron manufacturing facility of Comparative Example 4.

  FIG. 1 is a diagram showing a configuration of an example of the pig iron manufacturing equipment of the present invention. In the configuration shown in this figure, 1 is an oxygen blast furnace, 2 is a coke oven operated using an oxygen blast furnace gas (OB gas) generated from the furnace top of the oxygen blast furnace 1 and an oxygen-containing gas (here, oxygen), Reference numeral 3 denotes a burner for blowing a preheating gas generated by partially burning the oxygen blast furnace gas into the furnace, and reference numeral 4 denotes a tuyere used for blowing oxygen or the like into the oxygen blast furnace 1. In the operation of the oxygen blast furnace 1 having the above-described configuration, ore and coke are charged from the furnace top, and pulverized coal and the like are blown together with oxygen from the tuyere 4 at the lower part of the oxygen blast furnace.

  FIG. 2 is a diagram illustrating a configuration of another example of the pig iron manufacturing facility of the present invention. In the configuration illustrated in FIG. 2, the same members as those in the example illustrated in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the configuration shown in this drawing, in addition to the configuration shown in FIG. 1, a coke oven flue gas recirculation path 5 for mixing a part of the coke oven flue gas generated from the coke oven 2 with pure oxygen supplied to the coke oven 2. Is provided. This makes it possible to dilute pure oxygen (for example, about 20 vol% of oxygen).

  A feature of the present invention is that, in the pig iron manufacturing facility shown in FIGS. 1 and 2, a part of the coke oven combustion exhaust gas substantially free of nitrogen generated from the coke oven 2 is blown from the tuyere 4 of the oxygen blast furnace 1. In that it is used as a cooling gas. Hereinafter, the pig iron manufacturing equipment of the present invention will be specifically described.

  In a general blast furnace, a blowpipe and a blowing lance for pulverized coal are attached to the tuyere. However, since the oxygen blast furnace 1 blows pure oxygen from the tuyere 4 instead of hot air, the ignitability of the pulverized coal is poor. I have a problem. Therefore, in the oxygen blast furnace 1, a tuner 4 is provided with an oxygen blast furnace tuyere burner to promote ignition of the pulverized coal.

  FIG. 3 is a schematic diagram showing a tuyere used for an oxygen blast furnace of a pig iron manufacturing facility together with an oxygen blast furnace tuyere burner. In the configuration shown in this figure, reference numeral 11 denotes an oxygen blast furnace tuyere burner attached to the tuyere 4. The oxygen blast furnace tuyere burner 11 is installed by being pressed against the tuyere 4 so as not to leak gas to the outside. Here, the oxygen blast furnace tuyere burner 11 is constituted by a coaxial multiple tube including a central tube 12-1, an inner annular tube 12-2, and an outer annular tube 12-3. As an example, cooling gas is blown from the central pipe 12-1, pulverized coal is blown from the annular pipe between the inner annular pipe 12-2 and the central pipe 12-1, and the inner annular pipe 12-3 and the inner annular pipe 12-3 are blown. Pure oxygen is blown from an annular pipe between the annular pipe 12-2. Then, a raceway 6 in which pure oxygen and pulverized coal react is formed in the oxygen blast furnace at the end of the tuyere 4.

  The gas and pulverized coal are strongly mixed in the tuyere 4 by the oxygen blast furnace tuyere burner 11 having the above-described configuration, and can be quickly ignited and burned immediately after coming out of the tuyere 4. Further, in the oxygen blast furnace, since the amount of gas in the furnace is small, there is a problem that the temperature of the charge in the upper part of the furnace is insufficient. In order to avoid this, in the oxygen blast furnace 1, the oxygen blast furnace gas (OB gas) is partially burned by the burner 3 to about 1000 ° C., and then the preheating gas is blown into the blast furnace shaft. I have.

Since oxygen is blown from the tuyere 4 in the oxygen blast furnace 1 without blowing air, almost no nitrogen is generated in the furnace. Therefore, the oxygen blast furnace gas (OB gas) discharged from the oxygen blast furnace 1 is nitrogen-free. That is, the furnace top gas composition of a conventional hot air blast furnace, nitrogen 50% CO + _{H 2 25%,} while the CO ₂ + _H 2 O is about 25% CO + _{H 2} In the oxygen blast furnace 1 is 50% CO ₂ + H ₂ O is a composition of about 50%. Therefore, if the oxygen blast furnace gas of the oxygen blast furnace 1 is burned with pure oxygen and used for the operation of the coke oven 2 as in the pig iron manufacturing facility shown in FIG. 1, the coke oven combustion exhaust gas also becomes nitrogen-free. Also, if the coke oven flue gas is cooled to room temperature, water vapor can be naturally separated, and as a result, the coke oven flue gas discharged from the coke oven 2 is operated with only CO ₂ or the coke oven with excess oxygen. If this is the case, it will be a coke oven flue gas containing only CO ₂ and oxygen and no nitrogen.

  In a coke oven, the temperature must be about 1100 ° C. to 1500 ° C. because of the heat resistance of the refractory. On the other hand, if pure oxygen and oxygen blast furnace gas generated from the oxygen blast furnace are burned, a very high-temperature combustion gas exceeding 3000 ° C. may be generated, and it may not be possible to flow the coke oven as it is. Therefore, it is preferable to use a method of lowering the flame temperature by mixing and diluting another gas with pure oxygen. However, it is not preferable that the dilution gas contains nitrogen as described below. For this reason, in the preferred embodiment of the present invention shown in FIG. 2, the coke oven combustion exhaust gas of the coke oven 2 itself is recycled and used as the diluent gas containing no nitrogen.

Here, the coke oven combustion exhaust gas generated from the coke oven 2 using the oxygen blast furnace gas and the nitrogen-free oxygen-containing gas also contains no nitrogen. Therefore, even when this method is used, almost no nitrogen is contained, and substantially no nitrogen is contained. It is possible to generate a coke oven combustion exhaust gas composed solely of CO ₂ . Here, when mixing the coke oven combustion exhaust gas with the pure oxygen, as shown in FIG. 2, the coke oven combustion exhaust gas may be mixed with the pure oxygen and the coke oven combustion exhaust gas before the combustor of the coke oven 2. Since the exhaust gas itself does not contribute to the combustion reaction, the oxygen blast furnace gas and pure oxygen may be burned in a combustor and then mixed with the coke oven combustion exhaust gas. Moreover, you may use both together.

The tuyere coolant blown into the tuyere 4 of the oxygen blast furnace 1 is preferably a substance that causes a thermal decomposition reaction at a high-temperature tuyere tip. The tuyere tip is filled with coke. For example, CO ₂ and H ₂ O react with coke to cause an endothermic pyrolysis reaction as described below, and thus have a large cooling effect.
C (coke) + CO ₂ = 2CO-172.42 kJ / mol
C (coke) + H ₂ O = CO + H ₂ −131.27 kJ / mol
However, since CO, H ₂ , and N ₂ gases do not cause a thermal decomposition reaction, they have only a small cooling effect equivalent to sensible heat when blown into the tuyere. Therefore, the tuyere coolant blown into the tuyere is preferably a substance that causes thermal decomposition as much as possible, that is, a substance having a high concentration of CO ₂ or H ₂ O. Coke oven flue gas indicated above, which is configured only by the substantially CO ₂ hardly contains nitrogen, are suitable as tuyere cooling gas.

  In the present invention, there are an oxygen blast furnace gas substantially free of nitrogen, an oxygen-containing gas substantially free of nitrogen, and a coke oven combustion exhaust gas substantially free of nitrogen, which are blown into a tuyere. Nitrogen may be reduced to such an extent that the endothermic thermal decomposition reaction at the tuyere tip is not hindered, and it is not always necessary for the nitrogen to be zero. For example, if the nitrogen concentration is controlled so as to be 10 vol% or less, preferably 3 vol% or less, respectively, a sufficient endothermic thermal decomposition reaction at the tuyere tip occurs due to the coke oven combustion exhaust gas blown from the tuyere. The invention holds.

  Examples 1-2 and Comparative Examples 1-4 were prepared as shown below, and Examples 1-2 and Comparative Examples 1-4 were compared. FIGS. 2 and 4 show the configurations of the pig iron production facilities of Examples 1 to 2 and FIGS. 5 to 8 of Comparative Examples 1 to 4. In the example shown in FIGS. The same reference numerals are given to the same members as in the example shown in FIG.

<Example 1>
As a first example applicable to the present invention, in an oxygen blast furnace 1 into which oxygen is blown from a tuyere 4, an oxygen blast furnace gas containing almost no nitrogen of the oxygen blast furnace 1 is poured into a coke oven 2 as shown in FIG. Let's base on an example. Further, in the coke oven 2, an oxygen-containing gas in which oxygen and coke oven combustion exhaust gas are mixed is generated, and mixed with the oxygen blast furnace gas and burned in the coke oven 2. The coke oven flue gas of the coke oven 2 was substantially only CO ₂ , and the coke oven flue gas was sent to the tuyere 4 of the oxygen blast furnace 1, and oxygen gas was blown from the tuyere 4 together with pulverized coal.

<Example 2>
As a second example applicable to the present invention, in an oxygen blast furnace 1 in which oxygen is blown from a tuyere 4, an oxygen blast furnace gas containing almost no nitrogen of the oxygen blast furnace 1 is poured into the coke oven 2 as shown in FIG. In the coke oven 2, an oxygen-containing gas in which oxygen and steam are mixed is generated, and mixed with the oxygen blast furnace gas in the coke oven 2 and burned. The steam blown into the coke oven 2 is naturally liquefied and separated during the cooling of the exhaust gas, so that the exhaust gas from the coke oven is almost only CO ₂ . Oxygen gas was blown from the tuyere 4 together with pulverized coal.

<Comparative Example 1>
As disclosed in Patent Document 1, as shown in FIG. 5, CO ₂ separation is performed from a blast furnace gas (B gas) by a CO ₂ separation facility 21 using PSA, and the separated CO ₂ is used as a cooling gas as a tuyere. 4 and the oxygen blast furnace 1 was operated.
<Comparative Example 2>
This is also an example shown in Patent Document 1, and as shown in FIG. 6, steam was blown from a tuyere 4 as a cooling gas, and the oxygen blast furnace 1 was operated.
<Comparative Example 3>
This is an example shown in Patent Document 2, in which the oxygen blast furnace 1 was operated by circulating the furnace top gas from the tuyere 4 and blowing it as a cooling gas as shown in FIG.
<Comparative Example 4>
As shown in FIG. 8, this is an example in which air is used instead of pure oxygen as the oxygen-containing gas of the coke oven. The oxygen blast furnace gas (OB gas) generated from the top of the oxygen blast furnace 1 and the air are mixed with the coke oven 2. The oxygen blast furnace 1 was operated by burning it in a boiler and blowing the coke oven combustion exhaust gas generated in the coke oven 2 from the tuyere 4 as a cooling gas.

First, the specifications of the oxygen blast furnace were unified when comparing Examples 1 and 2 and Comparative Examples 1 to 4 which are suitable for the present invention described above. That is, the tapping amount was 10000 t / day, the number of tuyeres was 40, the coke ratio was 375 kg / t, and the pulverized coal ratio was 200 kg / t. Further, as the preheating gas injection, the blast furnace gas was partially burned with pure oxygen so as to have a temperature of 1000 ° C., and was blown from the blast furnace shaft at 135,000 Nm ³ / h. Further, various tuyere coolant (cooling gas) was blown in such an amount that the tuyere tip temperature became 2400 ° C.

Table 1 below shows the results of comparison between Examples 1 and 2 and Comparative Examples 1 to 4.

As can be seen from the results shown in Table 1, in Examples 1 and 2, the temperature of the tuyere tip was reduced by blowing 781 Nm ³ / h of coke oven combustion exhaust gas (nitrogen-less) as a temperature control gas (cooling gas) into each tuyere. It was confirmed that the temperature could be controlled at 2400 ° C. and that the operation could be performed without any special facilities.

On the other hand, in Comparative Example 1 using CO ₂ separation, the flow rate of the CO ₂ gas as the temperature control gas was the same as in the example, and the tuyere tip temperature could be controlled with a relatively small amount of the temperature control gas. However, in Comparative Example 1, a large amount of CO ₂ had to be generated from the oxygen blast furnace gas, and a large-scale CO ₂ separation facility using PSA was required. Was.

In Comparative Example 2 in which steam was blown from the tuyere, the flow rate of steam as the temperature control gas was 906 Nm ³ / h, which was slightly higher than that of the embodiment. It could be confirmed. However, in Comparative Example 2, it was found that there was a problem from the viewpoint of controllability of the temperature of the tuyere tip because the problem that the steam was drained on the tuyere surface occurred.

Furthermore, in Comparative Example 3 in which the oxygen blast furnace gas was recirculated and blown from the tuyere, it was confirmed that the embodiment could be practiced without any special facilities. However, in Comparative Example 3, since about half of the oxygen blast furnace gas was CO and the other half was CO ₂ , the concentration of CO ₂ causing endothermic pyrolysis was low. As a result, the blowing amount of the oxygen blast furnace gas was as high as 1260 Nm ³ / h, so that the blowing equipment around the tuyere became huge, and it was found that the layout around the tuyere was difficult to implement.

Furthermore, in Comparative Example 4 in which air was used instead of pure oxygen as the oxygen-containing gas in the coke oven, more than half of the coke oven combustion exhaust gas was nitrogen, so the concentration of CO ₂ causing endothermic pyrolysis was increased. Decreased. As a result, similarly to Comparative Example 3, it was found that there was a problem in that the flow rate of the coke oven combustion exhaust gas blown into the tuyeres became huge.

  From the above results, it was confirmed that the methods of Examples 1 and 2 of the present invention had no defects and could perform significant operations as compared with the methods of Comparative Examples 1 to 4.

According to pig iron production facility of the present invention, since substantially coke oven flue gas consists of only approximately CO ₂ free of nitrogen is generated, pure oxygen and a reducing material from tuyeres cooling gas blown rare, Operated using an oxygen blast furnace that generates an oxygen blast furnace gas substantially free of nitrogen from the furnace top, and an oxygen blast furnace gas generated from the furnace top of the oxygen blast furnace and an oxygen-containing gas substantially free of nitrogen. not only pig iron production facility consisting of a coke oven, CCS (Carbon dioxide Capture and Storage , CO capture and storage ₂₎ and CCU also be applied to (Carbon capture and utilization, CO ₂ utilized), to CO ₂ emission reduction It is possible to contribute.

1 oxygen blast 2 coke oven 3 burners 4 birds port 5 coke oven flue gas recirculation passage 6 raceway 11 blast blades, mouth burners 12-1 central tube 12-2 annular tube 12-3 outer annular pipe 21 CO ₂ separation equipment

Claims (5)

  A pig iron manufacturing facility using an oxygen blast furnace, which blows pure oxygen and a reducing agent, tuyere cooling gas from the tuyere and generates an oxygen blast furnace gas containing substantially no nitrogen from the furnace top. A coke oven for burning the oxygen blast furnace gas with an oxygen-containing gas containing substantially no nitrogen to generate coal coke oven combustion exhaust gas and carbonizing coal using heat generated. A part of the coke oven combustion exhaust gas substantially free of nitrogen generated in the step (a), serving as a tuyere cooling gas of the oxygen blast furnace.   The pig iron manufacturing facility according to claim 1, wherein pure oxygen gas is used as said substantially nitrogen-free oxygen-containing gas.   2. The pig iron manufacturing facility according to claim 1, wherein a gas obtained by mixing the coke oven combustion exhaust gas with pure oxygen is used as the substantially nitrogen-free oxygen-containing gas. 3.   The pig iron production facility according to claim 1, wherein a gas obtained by mixing pure oxygen with steam is used as the oxygen-containing gas substantially containing no nitrogen. In a pig iron manufacturing method using the pig iron manufacturing equipment according to any one of claims 1 to 4,
A method for producing pig iron, comprising using a part of a coke oven combustion exhaust gas substantially free of nitrogen generated in the coke oven as a tuyere cooling gas of the oxygen blast furnace.

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