JP2001064708A - Hot-repairing method of furnace wall in blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot-repairing method of the furnace wall in a blast furnace, by which such problems as to exist in a dry-type spreading method or wet-type spreading method can be resolved. SOLUTION: In the repairing method which spreads a refractory onto the damaged portion of the furnace wall refractory in the furnace inside part by stopping the blasting in the blast furnace, 2-15 mass% water and a prescribed ratio of dispersant to the refractory composition, are mixed into the refractory composition having the grain constitution containing <=5 mm maximum grain diameter and >=25% grain of <=0.075 mm grain diameter, and beforehand uniformly kneaded. After press-feeding this slurry-state monolithic refractory to a nozzle, a hardening promoter is added in the nozzle part and spread together with a high pressure gas to the damaged portion of the blast furnace wall. Since the refractory composition can uniformly be mixed, the problem existing in the dry-type spreading material can be improved. Further, it is not developed in this repairing method to solidify the refractory kneaded material before spreading onto the blast furnace wall and stick on a hose and the nozzle part in the wet-type spreading method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a refractory brick for covering a furnace inner wall of a blast furnace, which is damaged or falls off, causing an excessive heat load on the furnace shell or coke formed on the furnace inner wall. If the blast furnace condition is expected to deteriorate due to the hindrance to the smooth unloading of raw materials such as slag and sinter, the blast furnace is temporarily stopped to repair the damaged area and the blast furnace service life The present invention relates to a method for hot repair of a blast furnace wall which can extend the length of the blast furnace and stably operate the blast furnace.

[0002]

2. Description of the Related Art The inner wall of a blast furnace generally comprises a combination of a cooling board or stave cooler and a refractory brick. However, the furnace inner wall at the top of the shaft has a relatively low temperature,
It is only lined with a chamotte or high alumina brick with a thickness of about 600-800 mm.

[0003] According to the results of dismantling inspections or observations in the case where the raw material in the furnace is reduced, the portion lined with chamotte material or high alumina brick on the upper part of the shaft is a portion where deterioration such as wear or drop is likely to progress. I know. It is considered that this is because the friction during the fall of the raw material such as coke and ore in the furnace is large and the gas flow in the furnace is concentrated on the wall surface by the wall effect.

[0004] In the worn portion of the furnace wall caused by such a cause, a hot spot is generated in the furnace shell, which causes deformation, cracks, and the like, and shortens the life of the furnace body.
In addition, the wear of the furnace wall does not progress uniformly, but varies depending on the position in the circumferential direction and the height direction.Therefore, the profile in the furnace becomes uneven in the circumferential direction and the height direction, and the furnace wall becomes uneven. Irregularities may occur.

[0005] If the operation is continued while the above is left as it is, the smooth flow of the raw material in the furnace and the reducing gas is hindered. Deterioration of the inner wall of the furnace can affect the furnace condition, such as "shelf hanging", where the loading of the raw material stops temporarily, "slip", where the raw material drops several tens to several meters at a stroke, and reducing gas. There is a case where “gas swing” or the like in which the gas temporarily drifts occurs. When these phenomena occur, the blast furnace cannot perform a proper reducing action, which is a major operational problem.

In view of the above problems, conventionally, the blast furnace is temporarily shut down, and during that time, the above-mentioned damaged portion of the refractory brick at the upper part of the shaft is sprayed with a refractory material to repair it. Many methods have been reported in the past for safely and efficiently performing the method.

[0007] The method of spraying refractories is roughly classified into a dry method and a wet method. Of these, the dry method is to transport the compounded refractory powder through the hose with high-pressure air and add water through the spray nozzle at the construction site.
In the dry method, the powder refractory and water are not sufficiently mixed due to the spray nozzle, so that a large amount of dust is generated and the sprayed refractory is blown. There is a problem that a large amount of so-called rebound dross that falls without adhering to the attachment surface must be generated.

On the other hand, in the wet method, a slurry-like refractory material in which water and a refractory composition are kneaded in advance is charged into a compression pump,
The hose or pipe is pressure-fed, and a hardening accelerator is added and sprayed at the nozzle, but in this wet method,
Since the pressure is fed after kneading, there is a possibility that the refractory hardens in the hose or the pipe during the pressure feeding. In addition, there is a problem that the mixing with the curing accelerator at the nozzle portion is insufficient, and the sprayed refractory material flows down from the sprayed repair portion, and there is a possibility that a predetermined repair thickness and smoothness cannot be secured. .

In other words, when repairing the inner wall of a blast furnace, in addition to the high ambient temperature at the time of spraying,
Since the equipment is very large and it is necessary to perform long-distance pumping in a high-temperature atmosphere, the problem of the wet construction method in which the curing of the amorphous refractory proceeds during the pumping becomes significant. Therefore, the dry method has been often used.

[0010]

However, in repairing the inner wall of the blast furnace, the above-mentioned problems become apparent even in the case of the dry method, and the following problems exist. a. Since the timing of mixing with water is immediately before spraying, it is difficult to mix uniformly, and the amount of water to be added is increased to improve mixing. Therefore, the airtightness of the sprayed refractory becomes uneven, and the period during which the repair effect by spraying can be maintained is shortened.

B. Since the timing of mixing with water is immediately before the spraying, a part of the refractory particles is sprayed on the inner wall of the furnace without absorbing moisture, and a part of the refractory falls into the furnace without adhering to the wall. These refractory materials that have fallen without being adhered are heat-hardened in the furnace, not only hindering the flow of reducing gas in the furnace, but also entrain the raw materials and adhere to the furnace wall like deposits, causing shelving. , Which may cause deterioration of the furnace condition.

C. The refractory that has not absorbed moisture soars up as dust in the furnace, deteriorating the field of view, making it impossible to accurately spray at the desired spray location, significantly deteriorating the working environment, and impairing the health of workers.

In order to improve such a problem, for example, in Japanese Unexamined Patent Publication No. Hei 6-341766, in order to reduce the amount of rebound dross, compressed air is blown from a spray nozzle prior to spraying to reduce the inner surface of the furnace. There has been proposed a technique for performing cleaning. According to this technique, it is possible to remove deposits and the like on the inner surface of the furnace to some extent, so that it is considered that the effect of increasing the spraying efficiency and reducing the amount of rebound loss is obtained.

In Japanese Patent Application Laid-Open No. 5-256584, a damaged portion and a damage amount of a blast furnace wall are measured by a distance measuring device, and a refractory spray position and a spray amount are determined based on the measured values. Techniques for controlling and operating a spraying machine have been proposed. According to this technique, it is possible to solve the problem of workability in the furnace and the problem of safety due to dust and the like in the furnace.

[0015] However, JP-A-6-341766 and JP-A-5-256584 both have a fundamental defect that the timing of mixing with water is immediately before spraying. The biggest problems of the dry method, such as spraying into the furnace without absorbing moisture and adding a large amount of water, are not solved, and a large amount of rebound dross is generated.

In addition, JP-A-6-341766 discloses that
When performing cleaning by blowing air, a large amount of dust in the furnace together with deposits on the furnace wall soars, which deteriorates the visibility in the furnace, reduces work efficiency, and impairs the health of workers. Points still exist.

As described above, when the blast furnace hot repair is performed by the dry method, it is difficult to solve all the above-mentioned problems.

On the other hand, with regard to the wet method, for example, Japanese Patent Application Laid-Open No. Hei 10-232092 proposes a technique in which an amorphous refractory and moisture are kneaded before spraying. According to this technique, it is possible to sufficiently knead with water before spraying, so that good spraying results can be obtained.

However, for example, when repairing the inner wall surface of a blast furnace, the ambient temperature is as high as 470 K, and
In this high-temperature atmosphere, the distance for pumping the inside of the hose from the pressure pump becomes longer than 10 m, so that the refractories in the hose are hardened by the high temperature during the pumping and become clogged, making spraying impossible. It is considered to be. Therefore, unless this problem is solved, the wet construction method cannot be adopted when hot repairing the blast furnace wall.

In Japanese Patent Application Laid-Open No. Hei 5-4873, microcapsules which are not broken at the time of kneading but are broken by the atmospheric temperature at the time of spraying are used, and a hardening agent or a hardening accelerator is sealed therein. Techniques have been proposed for controlling the progress of thermosetting of refractories and preventing clogging in hoses.

However, even in this technique, when repairing the wall of a blast furnace, since the distance for pumping the inside of the hose under a high-temperature atmosphere is as long as 10 m or more, the microcapsules also melt during the pumping, and Hardening of the refractory proceeds and causes clogging. In addition, the cost of microencapsulating a curing agent, a curing accelerator, and the like increases, so that it is not practical in terms of cost in the case of blast furnace wall spraying in which a large amount is sprayed.

An object of the present invention is to provide a hot repair method for a blast furnace wall which can solve the problems of the above-mentioned dry spraying method and wet spraying method.

[0023]

In order to achieve the above-mentioned object, a method for hot repairing a blast furnace wall according to the present invention comprises a method for repairing a blast furnace wall having a maximum particle size of 5.0 mm or less and particles of 0.075 mm or less. % And a predetermined amount of water and a dispersant are added to the refractory composition having a particle size composition of at least 0.1%, and the mixture is uniformly kneaded. After the slurry-like amorphous refractory is pumped to the nozzle, a curing accelerator is added at the nozzle portion. Then, the high-pressure gas is sprayed onto the damaged part of the blast furnace wall. By doing so, the refractory composition, the water and the dispersant can be mixed uniformly, and furthermore, they do not harden before reaching the spray nozzle.

[0024]

DETAILED DESCRIPTION OF THE INVENTION The inventors of the present invention have conducted research to establish a wet spraying technique in a blast furnace, and have found that the above-mentioned problems can be solved under the following conditions. First, it has been found that by making the particle size of the refractory composition uniform, there is no unevenness in aggregation of the particles, and the effect of the dispersant for controlling the curing time is high.

That is, the progress of hardening of the refractory composition after kneading with water is closely related to the size of the constituent particles. The inventors repeated various experiments and investigated the effects of the particle size distribution of the refractory composition and the amount of the dispersant on the curing progress of the refractory composition. As a result, the maximum particle size of the refractory composition was 5.0 m.
m and less than 0.075 mm
It has been found that the use of the composition having the above-mentioned particle size has a high effect of the dispersant for controlling the progress of curing. The maximum particle size of the refractory composition is 5.0 mm or less, and 0.0
By using a material containing 75% or less of particles having a diameter of 75 mm or less, the irregular-shaped refractory does not thermally harden while being pumped in a high-temperature furnace.

The composition of the refractory composition applied to the hot repair method for the blast furnace wall according to the present invention is as follows.
Oxides such as alumina, silica, zirconia, calcia, and magnesia, silicon carbide, and the like are used. As the refractory powder, alumina cement and the like are used. In particular, alumina cement functions as a binder for irregular refractories and contributes to maintaining the effect of spray repair.

Next, the mixing ratio of water to the amorphous refractory will be described. According to the experiments by the inventors, when the mass ratio of the added water to the refractory composition is less than 2%, the fluidity of the amorphous refractory decreases, and the pressure loss when pumping the inside of the hose or the pipe increases, and the pumping is performed. It has been found that the properties are reduced and clogging occurs in hoses or pipes. On the other hand, it was found that when the amount of water added exceeds 15%, even if a curing accelerator is added in the nozzle, the effect is not exhibited, and dripping occurs during spraying. Therefore, in the present invention, the mixing ratio of moisture to the amorphous refractory is set to 2 to 15%.

Next, the mixing ratio of the dispersant to the refractory composition for extending the curing time will be described. Specific examples of the dispersant include sodium hexametaphosphate, sodium polyacrylate, sodium ligninsulfonate, sodium tripolyphosphate, and the like, and one or more of these can be used in combination.

According to the experiments performed by the inventors, the amount of these dispersants is related to the amount of water. However, if the amount is less than 0.01%, the effect of adding the dispersants is low, and the dispersants harden during pumping. It turns out that there are many cases. On the other hand, if it exceeds 2.0%, it may become an impurity in the refractory and, after spraying, may cause a problem that the releasability of the refractory is enhanced. From the above, the mixing ratio of the dispersant to the refractory composition,
It turned out that it is desirable to be 0.01-2.0%.

The hardening accelerator used in the hot repair method of the blast furnace wall according to the present invention is an auxiliary agent used for adjusting the hardening time of the refractory kneaded material, and includes potassium aluminate, Sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, calcium hydroxide, sulfuric acid, sulfate, nitrate, sodium carbonate, potassium carbonate, lithium salt and the like are employed.

These hardening accelerators are added at the nozzle portion, but a separate line dedicated to the nozzle portion may be provided. However, if the hardening accelerator is mixed with the high-pressure gas fed into the nozzle portion and sent, This is more preferable because only one line is required. The addition amount of this curing accelerator is not particularly limited, but is 0.1 to 3.% by mass with respect to the amorphous refractory.
0% is desirable, and is determined according to the type of the curing accelerator.

Next, the gas pressure when the slurry-like refractory is sprayed will be described. According to our experiments,
When the pressure of the gas at the time of spraying the slurry refractory is 600
If the pressure is less than kPa, the adhesiveness of the refractory deteriorates, the maintenance period of the spray repair effect is shortened, and rebound dross falling into the furnace without reaching or even reaching the furnace wall is generated. On the other hand, at a pressure exceeding 1200 kPa, when sprayed on the inner wall of the furnace, the refractory trapped air and generated pores, resulting in reduced airtightness. From the above, the gas pressure when spraying a slurry-like refractory is 6
It turned out that it is desirable to set it to 00-1200 kPa.

In the repair of the inner wall of the blast furnace, the blast furnace is temporarily shut down, and repair is performed during that time. The spraying rate of the refractory composition depends on the furnace volume of the blast furnace and the repair range, but is required to be 2.5 to 10 tons per hour. By the way, with respect to the timing of kneading the refractory composition with water and a dispersant, the whole amount to be sprayed may be kneaded in advance, but from the viewpoint of shortening the time until kneading and spraying to the furnace wall. It is desirable that the refractory composition, water and dispersant be kneaded and sprayed sequentially while being kneaded using a kneading apparatus having a processing capacity of 2.5 tons or more.

Next, the reason why it is desirable to set the distance from the tip of the nozzle to the spray position on the furnace wall to be 500 mm or more when spraying in the furnace will be described. That is, if the distance is less than 500 mm, the refractory will be sprayed without being sufficiently diffused, and the amount of sprayed will differ depending on the location, and the possibility that irregularities will occur on the furnace wall increases. is there. When irregularities are generated on the furnace wall, as described above, the smooth distribution of the raw material in the furnace and the reducing gas is hindered, which causes a serious problem in operation. In addition, there is also a possibility that air bubbles may be generated in the refractory due to entrainment of air at the time of spraying. Note that the upper limit of the distance from the tip of the nozzle to the spray position on the furnace wall is appropriately determined within a range in which the gas pressure when spraying the slurry refractory does not become less than 600 kPa.

In addition, the inventors have repeated experiments on the piping or hose for pumping slurry-like refractories and the nozzle used for spraying, and as to the conditions of the spray nozzle and the pipe or hose used for pumping. The following findings were obtained.

First, for the spray nozzle, the inner diameter is set to 1
By setting it to 0 mm or more, good spraying results were obtained.
Note that the upper limit of the inner diameter is appropriately determined within a range in which the gas pressure at the time of spraying the slurry-like refractory does not become less than 600 kPa. On the other hand, when the inner diameter of the pipe or the hose was 40 mm or more and the radius of curvature was 500 mm or more, the slurry-like refractory could be pumped very smoothly.
If the inner diameter or radius of curvature of the pipe or hose is less than the above-mentioned values, pressure loss may increase and clogging may occur.

Further, after the blast furnace is shut down and before the refractory is sprayed, removing adhering matter and foreign matter at the repair target position on the furnace wall is an effective means for improving the spray repair effect. is there. Therefore, the inventors have found that good cleaning is possible by spraying water on the furnace wall. In particular, when water is sprayed, dust is not generated as in the case where gas is sprayed, and the water blown to the furnace wall evaporates immediately to become steam, so that there is no hindrance to the operation after blowing. In addition, since the vaporization heat is deprived during the spraying of the water, the atmospheric temperature near the spray repair is reduced, and there is also an effect of suppressing the progress of hardening of the refractory in the pipe or hose. In addition, even if the nozzle that sprays water uses a nozzle that sprays refractories,
Further, another nozzle may be used.

The hot repair method for the blast furnace wall according to the present invention comprises:
The present invention has been made based on the findings of the inventors described above. In a method of blowing a refractory onto a damaged portion of a refractory on a furnace wall inside the furnace by shutting down the blast furnace, the maximum particle size is 5.0.
mm and particles of 0.075 mm or less
To the refractory composition having the above-mentioned particle size composition, water of 2 to 15% by mass relative to the refractory composition, and a predetermined ratio of a dispersant to the refractory composition are added and uniformly kneaded in advance, After the slurry-like amorphous refractory is fed to the nozzle by pressure, a hardening accelerator is added at the nozzle portion, and sprayed together with a high-pressure gas.
The kneading of the refractory composition, water, and dispersant, instead of being kneaded in advance, instead of sequentially kneading during repair work, or for adding a curing accelerator to a slurry-like amorphous refractory. Alternatively, a curing accelerator may be added to the high-pressure gas, or the amount of the dispersant added to the refractory composition may be from 0.01 to
2.0%, and the pressure of the high pressure gas is 600 to 1
200 kPa, the distance from the nozzle tip to the spray position of the furnace wall is 500 mm or more, and the inner diameter is 10 m.
m or more, or use a pipe or hose with an inner diameter of 40 mm or more, a radius of curvature of 500 mm or more, or an irregular refractory Or spray water on the furnace wall before spraying.

The hot repair method of the blast furnace wall according to the present invention comprises:
With the above configuration, the refractory composition and water, a dispersant, and a curing accelerator can be uniformly mixed, and unevenness does not occur when spraying the refractory. In addition, it does not harden in the pipe or hose before reaching the spray nozzle. In addition, there is little dust and rebound loss in the blast furnace, so it is safe and efficient.

Further, according to the hot repair method for a blast furnace furnace wall according to the present invention, a pipe through which a cooling gas or liquid can pass is embedded in the furnace wall so that the embedding depth in the steel shell can be changed. In the case of application to a blast furnace, the pipe serves as a guide by spraying the pipe with a refractory, so that rebound loss can be suppressed. If the wear is severe, a gap is created between the embedded pipe and the furnace wall, and the rebound loss suppression effect during refractory spraying may deteriorate, pull the pipe forward.
The gap between the furnace wall and the pipe is eliminated, and the pipe can be set at a position where the rebound loss suppressing effect is high.
In this way, more effective repair can be performed.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The results of experiments conducted to confirm the effects of the method for hot repair of blast furnace walls according to the present invention will be described below.

Alumina aggregates, silicon carbide-based aggregates and alumina cements having the particle sizes shown in Table 1 below were used as the amorphous refractories. The refractory composition was kneaded with water and sodium hexametaphosphate as a dispersant in the proportions shown in Table 1 below in advance using a kneading apparatus having a processing capacity of 5 tons per hour on the ground. It was conveyed to the blast furnace top of 45 m, and then about 15 m from the blast furnace manhole to the spray nozzle near the furnace wall by a refractory hose. At the nozzle portion, sodium aluminate was added as a hardening accelerator. At the indicated pressure, 40 tons were sprayed together with the gas on the worn part of the blast furnace wall.

In this experiment, in the comparative examples in which the particle size composition and the amount of added water of the refractory composition were out of the range of the present invention, the amount of the mixed dispersant, the blowing gas pressure, the distance from the nozzle tip to the furnace wall, The presence / absence of cleaning by water injection, the inner diameter of the nozzle, the inner diameter and curvature radius of the hose, and the presence / absence of a guide pipe are also shown. A similar experiment was conducted by a dry method (conventional in Tables 1 and 2 below) in which powder such as a refractory composition and water were separately conveyed and mixed in a nozzle immediately before spraying. And compared.

The results are shown in Table 2 below. In the conventional dry method, although there was no hose trouble, rebound loss was as high as 25%, and adhesion was uneven, so that the repair effect could be maintained. It was as short as five days. In addition, the particle size composition of the refractory composition, the amount of added water is out of the range of the present invention, the comparative example was not able to spray due to a hose trouble, also those that could be sprayed,
The repair effect was slightly longer than that of the conventional dry method and could be maintained for 15 days, but rebound loss was as high as 26%.
The adhesion was uneven.

On the other hand, according to the method of the present invention, any one of the claims has no rebound dross and no trouble with the hose, and has a good adhesion state.
The repair effect was maintained for more than a day. In the present embodiment, ones corresponding to claims 2 and 3 and
Although other embodiments of claims 4 to 11 are not shown, it is needless to say that similar effects were obtained according to experiments by the present inventors.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

As described above, according to the hot repair method for a blast furnace furnace wall according to the present invention, the furnace wall portion of the blast furnace is damaged, thereby causing "loading shelf hanging", "slip", When the influence of "gas swing" or the like appears, the blast furnace is temporarily stopped, and refractory is hot-sprayed and repaired on the damaged portion of the furnace wall refractory brick. Since the timing of mixing with water is immediately before spraying, it is difficult to mix uniformly. Therefore, the airtightness of the sprayed refractory becomes uneven, and the period during which the repair effect by spraying can be maintained is shortened.

B. Since the timing of mixing with the water is immediately before spraying, some of the refractory particles are sprayed into the furnace without absorbing moisture, and the refractories fall onto the raw material in the furnace without adhering to the walls. These refractories harden in the furnace and not only impede the flow of the reducing gas inside the furnace, but also entrain the raw materials and adhere to the furnace walls like deposits, causing "hanging shelves" and deteriorating the furnace conditions. May cause.

C. Refractories that do not absorb moisture fly up as dust in the furnace, which deteriorates the field of view, making it impossible to spray precisely where you want to spray, as well as significantly deteriorating the work environment and impairing the health of workers. . That is, the problem associated with the conventional dry spraying method can be improved.

Further, according to the hot repair method for the blast furnace wall according to the present invention, the atmosphere temperature for repair is as high as about 450 K, and the hose length from the pressure pump to the spray nozzle is as long as 10 m or more. Due to this, the refractory kneaded material sticks before spraying on the blast furnace wall, and it hardens in the hose or nozzle part, making it impossible to spray.
Problems associated with general wet spraying methods can also be solved.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F27D 1/16 F27D 1/16 C C04B 35/68 (72) Inventor Masahiro Kashiwada 1850 Minato, Minato, Wakayama-shi, Wakayama Prefecture. Sumitomo Metal Industries, Ltd.Wakayama Works (72) Inventor Akio Kasahara 1850 Minato, Wakayama, Wakayama Prefecture Sumitomo Metal Works, Ltd.Wakayama Works (72) Inventor Hiroshi Tomita 1850 Minato, Wakayama, Wakayama Sumitomo Metal Works 4K015 BA05 BA08 4K051 AA01 AB03 HA08 LA02 LA11 LJ01 LJ04

Claims (11)

[Claims] 1. A method for repairing a refractory by spraying a refractory onto a damaged part of a refractory inside a furnace by shutting down a blast furnace, wherein the maximum particle size is 5.0 mm or less and 0.075 mm or less. Is added to a refractory composition having a particle size composition of 25% or more, water at a mass ratio of 2 to 15% with respect to the refractory composition, and a predetermined ratio of a dispersant with respect to the refractory composition, and uniformly kneading in advance. A method for hot repairing the wall of a blast furnace, characterized in that after the slurry-like irregular refractory is fed to a nozzle, a hardening accelerator is added to the nozzle portion and sprayed together with a high-pressure gas. 2. The hot repair of a blast furnace furnace wall according to claim 1, wherein the refractory composition, water and the dispersant are kneaded in advance, instead of being kneaded in advance, during the repair work. Method. 3. The blast furnace wall heat according to claim 1, wherein a hardening accelerator is added to the high-pressure gas instead of adding the hardening accelerator to the slurry-like amorphous refractory. Repair method. 4. An amount of a dispersant added to a refractory composition,
The amount is set to 0.01 to 2.0%.
3. The hot repair method for a blast furnace wall according to any one of the above items 3. 5. The pressure of a high pressure gas is 600 to 1200 kP.
The hot repair method for a blast furnace wall according to any one of claims 1 to 4, wherein a. 6. The method according to claim 1, wherein the distance from the nozzle tip to the spray position of the furnace wall is 500 mm or more.
6. The hot repair method for a blast furnace wall according to any one of items 5 to 5. 7. The hot repair method for a blast furnace furnace wall according to claim 1, wherein a nozzle having an inner diameter of 10 mm or more is used. 8. The hot repair of a blast furnace wall according to claim 1, wherein a pipe or a hose having an inner diameter of 40 mm or more is used as a pipe or a hose for pressure-feeding the refractory to the nozzle. Method. 9. The hot blast furnace wall according to claim 1, wherein a pipe or a hose for pressure-feeding the refractory to the nozzle has a radius of curvature of 500 mm or more. Repair method. 10. The hot repair method for a blast furnace furnace wall according to claim 1, wherein water is injected into the furnace wall before spraying the irregular-shaped refractory. 11. A blast furnace preliminarily buried in a furnace wall, wherein a pipe through which a gas or a liquid for cooling can be passed and whose burying depth in a steel shell can be changed is applied. 10. The hot repair method for a blast furnace wall according to any one of items 10 to 10.