JPH11241108A - How to blow pulverized coal into the blast furnace - Google Patents

Abstract

(57) [Problem] To provide a blast furnace operating method in which a reducing gas is blown simultaneously with pulverized coal when pulverized coal is blown from a tuyere of a blast furnace. SOLUTION: When pulverized coal is injected from a blast furnace tuyere,
In advance, pulverized coal is introduced to the gasification furnace outside the blast furnace to supply oxygen to generate a reducing gas, and the gas is used as it is, or the reducing gas from the gasification furnace is guided to the gas reforming furnace, and is supplied to the gas. Further, steam and pulverized coal are blown into the reducing gas to make it a high-calorie and high-reducing performance gas. Further, the temperature of the reducing gas is adjusted, and the reducing gas is introduced into the blow pipe of the blast furnace tuyere at the same time as the pulverized coal. A method of injecting pulverized coal into a blast furnace through a lance or through a separately provided tuyere into the blast furnace. [Effect] Furnace heat of the blast furnace is secured, the tapping ratio is improved, the fuel ratio is reduced, and stable hot metal supply is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for blowing pulverized coal simultaneously with pulverized coal when blowing pulverized coal from a normal tuyere provided in a blast furnace or from a separately provided reducing material supply tuyere. It relates to a blast furnace operating method.

[0002]

2. Description of the Related Art In blast furnace operation, inexpensive, highly flammable and high calorific value fuel (pulverized coal, petroleum, naphtha, etc.) is blown from the tuyere as an alternative to coke to reduce hot metal production cost and productivity. We are trying to improve it,
No. 763 discloses the technique. Especially recently, pulverized coal injection is the mainstream in terms of price.

[0003] The pulverized coal blown into the blast furnace is burned instead of a part of coke in the blast furnace, and because of its good flammability and high calorific value, generates a large amount of reducing gas at high temperature and efficiently. Perform a suitable reduction reaction. Therefore, the iron ore charged from the furnace top is quickly reduced to a metallic state, and is melted into high-temperature hot metal, so that the furnace heat of the blast furnace is high and the productivity is improved.

Japanese Patent Laid-Open No. 4-268003 discloses that various gases are blown in addition to pulverized coal. According to the description of this publication, this technique is based on the description that when pulverized coal is blown into the interior of the blast furnace from the normal tuyere of the blast furnace, 100 to 500 mm before the pulverized coal injection position.
More natural gas (LNG), coke oven gas (COG),
The main point is to blow propane gas (LPG) or the like and adjust the ambient temperature at the pulverized coal blowing position to 1500 to 2000 ° C.

Further, Japanese Patent Application Laid-Open No. 4-358014 discloses that when pulverized coal is blown from a normal tuyere of a blast furnace, a reduction in the flame temperature due to the decomposition heat thereof is prevented, the furnace heat of the blast furnace is secured, and By maintaining the temperature inside the core of the blast furnace, the purpose is to improve the productivity and reduce the fuel ratio, and to pyrolyze pulverized coal outside the blast furnace in advance,
A technique is disclosed in which the entire amount of tar and char is blown from the tuyere, or the generated gas and tar are removed, and only the remaining char is blown from the tuyere. In addition, an operation enriched with oxygen during blowing is usually performed to increase productivity.

[0006]

In the conventional blast furnace operation, the amount of pulverized coal injected was naturally limited. That is, when a large amount of pulverized coal is blown, the unburned char is partially generated without burning the entire amount of the pulverized coal. This unburned char is often discharged from the furnace top along with the rising gas flow, and the replacement ratio of pulverized coal to coke decreases, causing an increase in fuel ratio and a decrease in production. Also, when this unburned char is trapped in the coke layer (furnace core) at the center of the lower part of the blast furnace, it impairs the liquid permeability of the molten iron slag flowing down this part, and consequently the gas permeability of this part. Blast furnace production is further reduced.

Therefore, in order to increase the pulverized coal injection limit, it is necessary to increase the coke strength for improving the pulverized coal flammability, ensure the liquid permeability of the hot metal slag, increase the blast furnace fuel ratio, and the like, thereby increasing the cost. Was a factor. For this reason, even if it can be used many times, 150 kg / t-pig
(Indicates the amount of pulverized coal blown per tapped iron (unit: kg, hereinafter expressed as kg / tp)). Therefore, it is conceivable that another reducing gas is used in combination.
G is difficult to use because production areas are unevenly distributed.
In view of the fuel balance of the steel industry as a whole, the use of COG at hand is more advantageous if it is used as a heat source for other steel heating furnaces from the viewpoint that the calorific value of the fuel can be used effectively. Disadvantageous.

Further, as disclosed in Japanese Patent Application Laid-Open No. 4-358014, a method of pyrolyzing pulverized coal outside a furnace and blowing a decomposition product into a blast furnace, or a method of blowing only char,
It is useful for preventing the flame temperature from dropping due to the thermal decomposition of pulverized coal at the tuyere of the blast furnace.However, in the blast furnace, it is necessary to supply the heat required for the thermal decomposition from the outside. Since the yield is low and a large amount of char or tar is generated at the same time as gas generation, a separation treatment of these products is required. In addition, when the blast furnace is directly blown into the blast furnace without being separated, there are disadvantageous problems such as a need to prevent clogging and adhesion of tar and char, and slag is directly blown into the blast furnace.

Further, an oxygen-enrichment operation is generally carried out for a high tapping operation. This operation raises the temperature of the tuyere tip (flame temperature) and the heat flow ratio (solids passing through the furnace). Speed × specific heat of solid) / (velocity of gas passing through the furnace × specific heat of gas) increases. This reduces the air flow corresponding to the enriched oxygen (which will reduce the amount of nitrogen),
The operation is to increase the CO concentration in the blast furnace bosh gas to increase the ore reduction rate, and as a result, to reduce the bosh gas.

[0010]

The gist of the present invention lies in the following means. (1) When pulverized coal is blown from the normal tuyere of the blast furnace, the pulverized coal is introduced into the gasifier outside the blast furnace to supply oxygen to generate a reducing gas, and the reducing gas is blown into the blast furnace tuyere simultaneously with the pulverized coal. A method of injecting pulverized coal into the blast furnace through a lance facing the pipe and supplying it to the blast furnace. (2) When pulverized coal is blown from a normal tuyere of a blast furnace, pulverized coal is introduced into a gasifier outside the blast furnace to supply oxygen to generate a reducing gas, and the reducing gas is guided to a gas reforming furnace.
Water vapor is further blown into the gas to increase the amount of hydrogen in the reducing gas, resulting in a gas with high calorie and high reducing performance, and passing the reducing gas through the lance facing the pulverized coal and into the blowpipe of the blast furnace tuyere. , A method of injecting pulverized coal into the blast furnace to be supplied into the blast furnace.

(3) When pulverized coal is blown from a normal tuyere of a blast furnace, pulverized coal is introduced into a gasifier outside the blast furnace to supply oxygen to generate a reducing gas, and the reducing gas is guided to a gas reforming furnace. Pulverized coal is further blown into the gas to increase the amount of reducing gas, resulting in a gas with high calorie and high reduction performance, and passing the reducing gas through the lance facing the pulverized coal and into the blow pipe of the blast furnace tuyere. , A method of injecting pulverized coal into the blast furnace to be supplied into the blast furnace. (4) When pulverized coal is blown from the normal tuyere of the blast furnace, pulverized coal is introduced into a gasifier outside the blast furnace to supply oxygen to generate a reducing gas, and the reducing gas is guided to a gas reforming furnace.
By further injecting steam and pulverized coal into the gas, the amount of hydrogen in the reducing gas and the amount of reducing gas are increased to produce a gas with high calorie and high reducing performance. A method of injecting pulverized coal into a blast furnace that feeds into the blast furnace through a lance facing the blow pipe at the mouth. (5) When the pulverized coal and the reducing gas are blown into the blast furnace, a reducing gas obtained by separating and removing slag generated during the generation of the reducing gas is used as the reducing gas. Charcoal blowing method.

(6) When the pulverized coal and the reducing gas are blown into the blast furnace, a gas which maintains the temperature at the time of gas generation is used as the reducing gas. Charcoal blowing method. (7) When the pulverized coal and the reducing gas are blown into the blast furnace, a gas whose reducing gas temperature is lowered to more than 500 ° C. and 1200 ° C. or less is used. Charcoal blowing method. (8) The method for injecting pulverized coal into a blast furnace according to any one of (1) to (5), wherein when the pulverized coal and the reducing gas are injected into the blast furnace, a gas having a reduced gas temperature of 500 ° C. or less is used.

(9) When the pulverized coal and the reducing gas are blown into the blast furnace and the amount of the reducing gas to be supplied is large, it is used together with a separately provided reducing material supply tuyere in addition to the blow pipe of the blast furnace normal tuyere. A method of blowing pulverized coal into a blast furnace that supplies reducing gas. (10) A method for injecting pulverized coal into a blast furnace, wherein the separately provided reducing material supply tuyere in (9) is used as a dedicated tuyere for supplying the reducing gas. (11) A method of injecting pulverized coal into a blast furnace, wherein the reducing material supply tuyere separately provided in the above (9) is installed near a blast furnace normal tuyere.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The present inventors have conducted intensive studies and studies on how the amount of pulverized coal injected into a blast furnace can be increased as described above. The maximum amount used in the 150kg /
It was concluded that exceeding the tp limit would be difficult in operating the blast furnace stably. Then, as a reducing agent which can be substituted for the pulverized coal, various kinds of reducing agents proposed by the conventional method were tried, but none of the desired results were obtained. However, as a result of gasifying and using pulverized coal, it is effective as an alternative reducing agent for increasing the amount of pulverized coal, and further reforming of the gas has shown that a better reducing agent can be obtained. It has been found that the use of this reducing material makes it possible to increase the amount of pulverized coal and reducing gas (in pulverized coal conversion) to about 200 kg / tp, and completes the present invention. Was.

Hereinafter, the present invention will be described with reference to the drawings.
FIG. 1 shows a facility flow from production of reducing gas from pulverized coal to supply to a normal tuyere of a blast furnace and a reducing material supply tuyere. First, coal 5 is pulverized at 100
The powder is crushed into a fine powder of about μ, and then charged into the gasification furnace 3. On the other hand, oxygen 6 (which may be air or oxygen-enriched air) for partially burning the crushed pulverized coal 5 is supplied to the gasification furnace 3 to remove volatile components in the pulverized coal mainly containing hydrocarbons. Evaporate. Hydrocarbons react with oxygen to produce mainly carbon monoxide (CO) and hydrogen (H2), and the reaction proceeds partially to carbon dioxide (CO2) and water vapor (H2 O).

However, since the purpose is to generate a reducing gas, it is necessary to consider the excess oxygen ratio so as to suppress the generation of CO 2 and H 2 O as much as possible by limiting the supply to an amount corresponding to the amount of hydrocarbons in the coal 5. . The gas thus generated has a high heat of 1500 to 1600 ° C., and can be supplied to the blast furnace as it is. However, this gas is further introduced into the gas reforming furnace 4 to be pulverized coal. By supplying 7, a gas having a high calorie and high reduction performance can be obtained.

Further, in the gas reforming furnace 4, when the steam 8 is supplied, the supplied steam (H 2 O) is decomposed into H 2 and O 2 in a high-temperature atmosphere to increase the CO and H 2 concentrations in the reducing gas, This has the effect of compensating for the above-mentioned shortage of reducing power of the reducing gas. Further, the carbon in the supplied pulverized coal reacts with the completely burned CO2 and H2 O, and the reducing gas 9
Can be reformed into CO and H2 gas to increase the latent heat as a reducing gas.

Since the above reaction at this time is an endothermic reaction, the temperature of the high-temperature gas generated in the gasification furnace 3 can be reduced to about 1200 ° C., which is suitable for use in the blast furnace, so that the temperature of the reducing gas can be adjusted. It is. At this time, if the amount of reducing gas to be supplied is large, or if the gas temperature is higher than the temperature to be used in the blast furnace due to heat balance,
Since the gas volume changes depending on the temperature, there is a concern that the gas may exceed the transport limit in the lance for supplying to the blast furnace.
Therefore, it is necessary to consider reducing the temperature of the reducing gas to about 500 ° C. by using a heat exchanger or the like. For example, heat exchanged by the heat exchanger is preferable because it can be used effectively as a heat source for a boiler or the like. The reducing gas 9 thus obtained is supplied to the hot air 10 through a lance, and at the same time, the pulverized coal 19 is also supplied to the hot air 10 through another lance. The supply of the reducing gas 9 to the reducing material supply tuyere will be described later.

As described above, the present inventors gasify pulverized coal by reacting it with an oxidizing agent such as air or oxygen, and adjust the ratio of oxygen to pulverized coal to obtain a C + 1 / 2O 2 = CO reaction. C + C by pulverized coal addition, steam addition, etc. in order to generate a large amount of reducing gas using the partial combustion reaction and further change the gas composition to higher calorie or higher reducing performance
O2 = 2CO or C + H2 O = CO + H2 It was noted that the amount of CO and H2 could be increased by the reaction. According to the present invention, the temperature rise (about 1500 ° C.) due to gasification makes it possible to separate tar by gasification and slag melting and dropping, and further by combining pulverized coal addition, steam addition and the like. Since the temperature can be adjusted, it is extremely easy to blow into the blast furnace.

By using this reducing gas, the amount of pulverized coal derived from pulverized coal and the amount of pulverized coal to be blown can be substantially reduced to a level of, for example, 200 kg / tp · p, which is substantially inexpensive. Can also be reduced. In addition, the effect of the ash carried in when the pulverized coal injection amount is increased is eliminated, which leads to the stable operation of the blast furnace. Furthermore, in order to control the temperature of the tuyere tip and to secure the amount of Bosch gas, it can be used in combination with the oxygen-enriched operation, and it is easy to achieve a high production ratio operation.

In the present invention, the reducing gas that can be used in the blast furnace may be a crude gas containing impurities such as impurities generated in a gas reforming furnace, but a gas separated and removed from slag is mainly used. It is preferable to use a purified gas from which all impurities such as slag, char and ash are removed.
However, in order to completely separate and remove these contaminants, various types of complicated equipment are required for equipment, which is a major cause of the increase in the cost of reducing gas production, and also requires thorough maintenance and management of the reducing gas supply lance. This is a complicated task. Therefore, the stage of the gas to be used as the reducing gas should be determined based on the balance between the degree of the effect of the reducing gas (depending on the supply amount) supplied during the operation of the blast furnace and the cost of the reducing gas. It does not mean that only clean gas can be used.

FIG. 2 is a schematic view showing an example of a lance arrangement state for supplying a reducing gas together with pulverized coal to a normal tuyere of a blast furnace. In the figure, a normal tuyere 1
2 and a blow pipe 13 is connected to the rear end of the tuyere 12. Heated air or the like is supplied to the blow pipe 13 and is blown from the tuyere 12 into the furnace 14 through the blow pipe 13. In such a normal tuyere, the lances 17 and 18 penetrate the blow pipe 13 and open in the passage of the heated air, and the pulverized coal passes through the lance 17 and the reducing gas passes through the lance 18. It is configured to be blown into the blow pipe 13, and a jet 15 is formed by gas in front of the tuyere 12, and furthermore, a region in which coke filled in the furnace 14 burns while turning, that is, a race. A way 16 is formed.

Next, the blowing amount of the reducing gas with respect to the blowing amount of the pulverized coal into the blast furnace is, as described above, the maximum value of the pulverized coal amount in the current blast furnace operation is said to be 150 kg / tp at the maximum. ing. However, according to the present invention, by using a reducing gas (reducing gas is reduced to pulverized coal) in addition to the conventional pulverized coal, the total injection amount of both is 200 kg / t.
-It becomes possible to p. If the amount of the reducing gas is increased, the amount of pulverized coal to be blown can be reduced.

The amount of these two injections naturally depends on the stability of the furnace conditions in the operation of the blast furnace and the scale of the injection equipment, and it is difficult to determine an appropriate range. The amount of carbon and the amount of hydrogen used for the reduction of ore injected from the blast furnace tuyere are included in pulverized coal (C) and the amount contained in reducing gas (G) (reducing gas is converted to pulverized coal. (G + C) between (G + C), although it depends on the absolute amount of (G + C).
C) is preferably practically 0.05 to 0.75.

Operation is possible even when the above value approaches 0 or 1; however, when the value is close to 1, the supply amount of the reducing gas increases, so that the reducing gas blowing lance and the reducing gas It requires some contrivance that is suitable for mass blowing into the blowpipe to be blown. For example, FIG.
As shown in the inside of the blow pipe of the normal tuyere of the blast furnace,
A reducing gas supply pipe 20 having a flat shape whose cross section perpendicular to the axis of the blowpipe is substantially rectangular is installed with the major axis direction parallel to the blowpipe axis and at an acute angle to reduce. It is also necessary to consider dealing with the large supply of waste.

FIG. 4 is a schematic diagram showing an example of a unit (reducing material supply tuyere) that can be employed when the value of (G) / (G + C) exceeds the range of 0.75. FIG. In the present invention, when a large amount of reducing gas to be supplied exceeds the above range, in addition to the normal tuyere of the blast furnace connected to the blow pipe, a separate reducing material supply tuyere 25 is installed near the normal tuyere, the tuyere combination with is intended to supply feed pulverized coal and / or reducing gas, the separately provided reducing material feed tuyeres, it is desirable that the dedicated tuyeres of the reducing gas supply.

When the value of (G) / (G + C) is equal to 0.
(G) / (G + C)
Is about 0.50, reducing the amount of reducing gas to be supplied to the blow pipe and supplying reducing gas from a separately installed reducing material supply tuyere (dedicated tuyere) can be performed without any problem. The degree of freedom of the tuyere increases. In addition, when the supply of the reducing gas during the pulverized coal injection from the normal tuyere of the blast furnace causes some trouble, and a predetermined amount of the reducing gas cannot be secured (regardless of the number of lances during the pulverized coal injection). , The reducing gas supply line is entirely switched to supply the reducing gas from the above-described reducing material supply tuyere, and the desired (G) / (G +
It is also possible to secure the value of C).

Naturally, even when the reducing gas supply tuyere is not actively used, a small amount of the reducing gas having a pressure enough to withstand the internal pressure of the blast furnace is constantly used. The gas or semi-molten material in the blast furnace must be prevented from flowing back into the reducing gas supply tuyere. In this way, by installing a separate tuyere for supplying the reducing gas in addition to the normal tuyere of the blast furnace, the degree of freedom of the supply of the reducing gas is greatly increased, and a great effect on the operation of the blast furnace can be expected.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the effects of the present invention will be described with reference to embodiments applied to an actual blast furnace. The operating blast furnace has an internal volume of 3
This is a blast furnace having pulverized coal having a volume of 273 m ³ , and various reducing gases were blown into the blast furnace at the same time as pulverized coal through a tuyere in the blast furnace through a blow pipe. As the lance, the double lance shown in FIG. 2 was used.

[0030]

[Table 1]

Table 1 shows that gas (A) obtained by partial combustion of pulverized coal, gas (B) obtained by adding steam, and gas (C) obtained by adding pulverized coal, and both steam and pulverized coal were added. The composition of the gas (D) obtained as a result of the experiment and the gas (E) obtained by separating and removing Lalag from the gas (D) were also shown. Table 2 shows the operating conditions when the reducing gas was blown into the blast furnace using these reducing gases, and Table 3 shows the operation results obtained by the operation.

[0032]

[Table 2]

[0033]

[Table 3]

The working numbers 1 to 5 in this embodiment are examples in which the type of the reducing gas is changed and the appropriate amount of the reducing gas that is normally used is blown, and the working numbers 7 to 11 are the same as in the case of the kind of the reducing gas and the blowing gas temperature. And Examples 12 to 16 are examples in which the type of the reducing gas is changed and a large amount of the reducing gas is blown. Implementation number 18-2
Reference numeral 2 denotes an example in which a reducing gas is blown from a separately provided dedicated tuyere under the same conditions as in the execution numbers 12 to 16. Implementation number 17
Examples 23 and 23 are examples in which the amount of the reducing gas is further increased, and Example No. 17 is an example in which the reducing gas is blown in from the normal tuyere, and Example No. 23 is an example in which the reducing gas is blown using the dedicated tuyere in addition to the normal tuyere. For comparison, conventional examples in which a reducing gas was not used are also shown as working numbers 24 and 25 at the same time.

As is clear from Tables 2 and 3, from the comparison between Examples 5 and 6, the pulverized coal ratio was 150 kg / tp
The effect of the difference in gas type (gas component, gas temperature) under a constant gas of 50 kg / tp also indicates that the higher the gas temperature, the lower the coke ratio and the higher the tapping rate. It can also be seen that the higher the CO and H2, the lower the coke ratio. Further, when the combined amount of pulverized coal and reducing gas (200 kg / tp) is kept constant and the reducing gas blowing amount is increased (replacement with pulverized coal blowing), the coke ratio decreases (for example, execution number 1). And execution number 18).

The total amount of pulverized coal and reducing gas (2
(00 kg / tp) is constant, and the coke ratio is increased when the amount of reducing gas blown is reduced, but the tapping amount can be increased from the base (conventional example) (for example, execution number 1 and execution number 24). , 25). In the case of blowing a large amount of gas at high temperature, the pressure loss increased due to the increase in the gas volume in the blast furnace and the pipe diameter increased, so that a certain effect was recognized, but the furnace condition became slightly unstable ( For example, implementation number 12).

As described above, the blowing of the reducing gas under the same pulverized coal makes it possible to lower the coke ratio by blowing the reducing gas. From the above, according to the present invention, in the conventional example, the pulverized coal injection amount was 150 kg / t.
・ P was the limit, but by simultaneously injecting reducing gas, 200 kg / t in total of pulverized coal and reducing gas
-It was possible to inject up to p, and it was possible to increase the tapping rate and reduce the coke ratio under stable blast furnace operation.

[0038]

As described above, in the present invention, pulverized coal is generated in advance in a gasifier outside a blast furnace in a gasifier, and if necessary, the gas is further converted into high calorie in a reformer. Gas with high conversion performance and high pulverized coal is blown from the tuyere at the same time to secure the heat of the blast furnace, improve the tapping ratio, reduce the fuel ratio, and enable stable hot metal supply. Become.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flow of a reducing gas production.

FIG. 2 is a schematic view showing a lance arrangement state of a tuyere portion of a blast furnace.

FIG. 3 is a side sectional view showing a state in which a reducing material supply pipe is installed in a blow pipe.

FIG. 4 is a schematic view showing an arrangement state of a separately provided tuyere in addition to a normal blast furnace tuyere.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blast furnace 2 Crushing equipment 3 Gasifier 4 Gas reformer 5 Coal 6 Oxygen 7 Pulverized coal 8 Steam 9 Reducing gas 10 Hot air 11 Furnace wall 12 Normal tuyere 13 Blow pipe 14 Furnace 15 Jet 16 Raceway 17 Pulverized coal supply Lance 18 Reducing gas supply lance 19 Pulverized coal 20 Reducing material supply pipe 25 Reducing material supply tuyere

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshio Okuno 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division

Claims (11)

[Claims] 1. When pulverized coal is blown from a normal tuyere of a blast furnace, the pulverized coal is introduced into a gasifier outside the blast furnace and oxygen is supplied to generate a reducing gas. Through the lance facing the blow pipe of
A method for injecting pulverized coal into a blast furnace, characterized in that the coal is supplied into the blast furnace. 2. When pulverized coal is blown from a normal tuyere of a blast furnace, pulverized coal is introduced into a gasification furnace outside the blast furnace to supply oxygen to generate a reducing gas, and the reducing gas is guided to a gas reforming furnace. Water vapor is further blown into the gas to increase the amount of hydrogen in the reducing gas, resulting in a gas with high calorie and high reducing performance, and passing the reducing gas through the lance facing the pulverized coal and into the blowpipe of the blast furnace tuyere. And pulverized coal is injected into the blast furnace. 3. When pulverized coal is blown from a normal tuyere of a blast furnace, pulverized coal is introduced into a gasifier outside the blast furnace to supply oxygen to generate a reducing gas, and the reducing gas is guided to a gas reforming furnace. Pulverized coal is further blown into the gas to increase the amount of reducing gas, and it is made into a gas of high calorie and high reduction performance, and the reduced gas is passed through a lance facing the blowpipe of the blast furnace tuyere at the same time as pulverized coal, A method for injecting pulverized coal into a blast furnace, characterized in that the coal is supplied into the blast furnace. 4. When pulverized coal is blown from a normal tuyere of a blast furnace, pulverized coal is introduced into a gasifier outside the blast furnace to supply oxygen to generate a reducing gas, and the reducing gas is guided to a gas reforming furnace. By further injecting steam and pulverized coal into the gas, the amount of hydrogen in the reducing gas and the amount of reducing gas are increased to produce a gas with high calorie and high reducing performance. A method for injecting pulverized coal into a blast furnace, characterized in that the coal is supplied into a blast furnace through a lance facing a blow pipe at a mouth. 5. The method according to claim 1, wherein when the pulverized coal and the reducing gas are blown into the blast furnace, a reducing gas obtained by separating and removing slag generated during the generation of the reducing gas is used as the reducing gas. 2. A method for injecting pulverized coal into a blast furnace according to item 1. 6. The method according to claim 1, wherein when the pulverized coal and the reducing gas are blown into the blast furnace, a gas having a temperature maintained at the time of gas generation is used as the reducing gas.
The method for injecting pulverized coal into a blast furnace according to any one of the above. 7. The method according to claim 1, wherein when the pulverized coal and the reducing gas are blown into the blast furnace, a gas whose temperature has been reduced to more than 500 ° C. and 1200 ° C. or less is used. 2. A method for injecting pulverized coal into a blast furnace according to item 1. 8. The blast furnace according to claim 1, wherein when the pulverized coal and the reducing gas are blown into the blast furnace, a gas whose reducing gas temperature is lowered to 500 ° C. or less is used. How to blow pulverized coal into 9. When the pulverized coal and the reducing gas are blown into the blast furnace and a large amount of the reducing gas is supplied, the reducing gas is reduced by using a reducing material supply tuyere separately provided in addition to the blow pipe of the blast furnace normal tuyere. A method of injecting pulverized coal into a blast furnace, characterized by supplying gas. 10. A method for injecting pulverized coal into a blast furnace, wherein the separately provided reducing material supply tuyere according to claim 9 is used as a dedicated tuyere for supplying a reducing gas. 11. A method for injecting pulverized coal into a blast furnace, wherein the separately provided reducing material supply tuyere according to claim 9 is installed and used in the vicinity of a normal blast furnace tuyere.