JP2000256717A - Method for removing residual iron in blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of removing residual iron in a blast furnace which can drastically shorten the working period in comparison with the conventional method. SOLUTION: A part of the lower part of an iron shell 2 forming the outer periphery of the blast furnace 1 to form an opening part 5. The first blasting holes 81 are bored into the exposing part of the residual iron 6 and also, the second blasting holes 82, 83 are bored into the residual iron 6 by penetrating the iron shell 2 existing at the position except the opening part 5 in the lower outer periphery of the blast furnace 1. Explosives are loaded into the first and the second blasting holes 81, 82, 83 and the residual iron 6 is blasted and removed. It is desirable to execute the blasting by using the second blasting holes 82, 83 prior to the blasting by using the first blasting holes 81.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing residual iron in a blast furnace, which removes residual iron and refractory bricks in the blast furnace when renovating the blast furnace.

[0002]

2. Description of the Related Art As shown in FIG.
A stave cooler and a refractory brick 4 or only a stave cooler are attached to the inner peripheral surface of the steel shell 2 surrounding the outer periphery, and the refractory brick 4 is laminated on the furnace bottom. The service life of refractory bricks is about 15 years, and aging blast furnaces after this service life need to be repaired.

[0003] Prior to the repair work, the remaining iron 6 in the furnace is cooled,
Solidified, the residual iron at the time of solidification is high temperature (about 700
° C), the tensile strength is 2000-3000 kg / cm ² ,
The compressive strength is higher than that, and a method of removing residual iron using blasting has been conventionally used.

[0004] More specifically, as shown in FIG. 7 (a), first, a part of a steel shell 2 and a refractory brick 4 forming a lower side wall of a blast furnace 1 is partially removed, and openings 5 are formed at positions opposite to each other. , 5 are formed. Subsequently, blast holes 8, 8 are drilled by using a drilling machine at the portions exposed to the openings 5, 5 of the remaining pig iron 6 (the opening 5 is formed at one place or at two places at the center of the furnace. May be provided at a position 90 ° to the other.) Explosives are loaded into the blast holes 8, 8 and blasted, and as shown in FIG. 3B, the portion (removed portion) 18a is destroyed, and the scrap of the destroyed residual iron is discharged. Subsequently, as shown in FIGS. 3 (c) and 3 (d), the same drilling, explosive loading, blasting and discharge of the residual iron as described above are repeated, so that the openings 5 and 5 are moved to the center of the furnace. The removal part 18b is advanced forward and expanded to penetrate. As described above, penetrating the residual iron in the furnace from the opening is performed by forming a large working space for drilling blast holes in the residual iron on both sides of the penetrating part, and by providing a free surface (exposed This is for increasing the blasting efficiency when blasting the residual iron on both sides by forming a large surface (unrestricted surface).
After expanding the space in the furnace in this way, drilling, explosive loading, blasting, and discharging of residual iron waste were repeated from the inside of the furnace, and as shown in FIG. The brick 4 is completely removed.

[0005] The method for removing the residual pig iron has an outer diameter of 16.3 m.
When applied to the blast furnace described above, more than 20 blasts are required before a state in which the tunnel penetrates by blasting is formed. The amount of iron removed in this state is about half of the total remaining iron, and the remaining iron 6 can be removed by blasting about 10 times thereafter. The reason why the efficiency of the removal of residual iron increases in the latter half is that the exposed portion of the residual iron 6 that can form a blast hole by penetrating the tunnel is widened, and multiple drilling machines are introduced into the expanded space in the furnace. This is because many blast holes can be drilled in parallel, and as a result, much residual iron can be removed by one blast.

[0006]

However, the above-mentioned conventional method for removing residual iron from a blast furnace has a problem that if the amount of residual iron is as large as 1000 tons, it takes about 15 days to remove the residual iron. In addition, when only one opening is provided due to restrictions on the space around the blast furnace and restrictions on construction, more construction time is required. Furthermore, since it is necessary to enter the inside of the blast furnace and drill a blast hole, there is a problem that a danger to falling objects is always present.

An object of the present invention is to provide a method for removing residual iron from a blast furnace, which can significantly shorten the construction period as compared with the conventional method.

[0008]

In order to achieve the above object, a method for removing residual iron from a blast furnace according to claim 1 is a method for removing residual iron from a blast furnace provided with an outer shell. An opening is formed by removing a part of a steel shell present on a lower outer periphery of the blast furnace, a first blast hole is formed in an exposed portion of the residual iron, and the opening is formed on a lower outer periphery of the blast furnace. A second blast hole is drilled in the residual iron by penetrating the iron shell existing at a position other than the part, and the first and second blast holes are charged with an explosive to blast and remove the residual iron. It is characterized by the following.

In the method for removing residual iron from the blast furnace according to the first aspect of the present invention, the explosive is charged into the first and second blast holes to blast and remove the residual iron. Not only the orientation, but also the removal of the residual iron from the opening in the direction along the inner peripheral surface of the steel shell, as a result, the side of the residual iron from the opening toward the back of the blast furnace A space is created on both sides (that is, a drilling work space is formed)
At the same time, free surfaces are formed on both sides of the residual iron, and the blasting efficiency of the residual iron (meaning that it can be blasted with a small amount of explosive or that the distance between blast holes can be lengthened with the same amount of explosive) . Therefore, the construction period is significantly reduced as compared with the conventional method, that is, the method of forming only the first blast holes.

The second blast hole can be formed immediately after the cooling of the residual iron prior to the first blast hole without waiting for the exposed portion of the residual iron to be obtained. Therefore, a sufficient working time for drilling the second blast hole can be secured until the blast using the second blast hole is actually performed. Therefore, the shape of the second blast hole is finished with high accuracy as designed. Further, since the drilling of the second blast hole is performed from outside the furnace, unlike the work performed in the furnace, there is no danger of falling objects and the work is performed safely.

Further, by forming a large number of second blast holes around the lower periphery of the blast furnace, the shape, size and hardness of the residual iron in the furnace can be accurately grasped over a wide range. Therefore, it is easy to make a plan for removing the remaining pig iron including a place where the first blast hole is to be drilled, a blast order, and the like. Therefore, the efficiency of residual iron removal is further improved, and the construction period is further shortened.

When water is injected into the second blast hole and cooled,
The temperature of the residual iron can be reduced quickly. Therefore, work efficiency in the furnace is improved, and the construction period is further shortened.

[0013] The method for removing residual iron from a blast furnace according to claim 2 is a method for removing residual iron from a blast furnace according to claim 1.
The blast using the second blast hole is performed prior to the blast using the first blast hole.

In the method for removing residual iron from the blast furnace according to the second aspect, the blasting using the second blast holes is performed prior to the blasting using the first blast holes. A removed portion of the remaining pig iron is generated before the direction toward the back of the blast furnace from the opening to the direction along the inner peripheral surface of the steel shell. That is, the exposed portion of the residual pig iron expands in the furnace, and the free surface of the residual pig iron blasted by the first blast hole is widened. Therefore, many first blast holes can be drilled in parallel, and the first
The blasting efficiency due to the blast holes can be increased, and as a result, much residual iron can be removed by one blasting. Therefore, the construction period is further reduced.

[0015] The method for removing residual iron from a blast furnace according to claim 3 is the method for removing residual iron from a blast furnace according to claim 1.
Partitioning the residual iron into a plurality of pieces in a direction from the opening toward the back of the blast furnace, piercing the first blast hole in a section on the side of the opening, and blasting; And blasting both ends of the next partition part in the second blast hole at the same time.

In the method for removing residual iron from a blast furnace according to the third aspect, when a certain section is blasted, both ends of a next section in front of the section are formed by using the second blast holes. Since the blasting occurs at the same time, similar to the second aspect, a removal portion of the residual iron occurs prior to the direction along the inner peripheral surface of the steel shell from the opening than the direction from the opening toward the back of the blast furnace. In the furnace, the exposed portion of the residual iron spreads, and the free surface of the next section blasted by the first blasting hole is widened. Therefore, many first blast holes can be drilled in parallel, and the blasting efficiency of the first blast holes can be increased,
As a result, much residual iron can be removed by one blast. Therefore, the construction period is further reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

As shown in FIG. 6, the blast furnace 1 to be rehabilitated has a stove cooler and a refractory brick 4 or only a stave cooler attached to the inner peripheral surface of a steel shell 2 surrounding the outer periphery. Has a structure in which refractory bricks 4 are laminated. The outer diameter of the blast furnace 1 is 16.3 m in this example. The residual pig iron 6 in the blast furnace 1 is appropriately cooled and solidified prior to removal.

FIG. 5 shows a known drilling device 7 for forming a blast hole in the residual pig iron 6. In the drilling device 7, a movable table 11 is disposed on a mounting guide 10 so as to be movable back and forth, and the mounting guide 10 rotatably supports a rotary drill 9 integrally provided with a cutting bit 9a at a tip. The rotary drill 9 is provided with a rotary driving device 12 installed on a moving table 11.
Rotated by The moving table 11 includes a feed driving device 13
Is moved back and forth along a threaded rod (not shown) rotated by the The piercing device 7 is disposed on the elevating arm 15 of the movable carriage 14 and is moved to a desired piercing position by the movable carriage 14.

When the residual iron 6 is removed, first, as shown in FIG.
Is removed to form an opening 5. Thereby, the outer periphery of the residual iron 6 deposited on the inner bottom of the blast furnace 1 is partially exposed.

Here, the two-dot chain line in FIG. 1 represents a dividing line for dividing the residual iron 6 into a plurality of blocks. This lane marking is designed to remove the remaining pig iron 6 in blocks. As can be seen, the residual pig iron 6 is roughly divided into a single annular portion 61 along the inner peripheral surface of the refractory brick 4 and a circular portion 62 occupying the inside of the annular portion 61. The annular portion 61 is further divided into a plurality of blocks by radial lines extending substantially in the radial direction of the blast furnace 1. On the other hand, the circular portion 62 is divided into a plurality of blocks vertically and horizontally by a plurality of lines extending in a vertical direction toward the depth of the blast furnace 1 as viewed from the opening 5 and in a horizontal direction perpendicular thereto. The shape of the majority of blocks is planned according to the unloading conditions (size, weight, unloader capacity, etc.) of the crushed residual iron.
m and a height of about 1.0 to 1.5 m. Then, two or three blast holes are respectively formed in the vertical direction and the horizontal direction substantially along the division line. .., M indicate the order in which each block is removed by blasting, and blocks to which the same Western characters are attached are blasted at the same time, as described later. In this case, it is desirable that the blasting be performed sequentially from an end block having a large number of free surfaces to a central block having a small number of free surfaces at intervals of several thousandths of a second (referred to as stepping). In the circular portion 62, the blocks to be simultaneously blasted are arranged in a row in a substantially horizontal direction. In the drilling planning, in particular, the position and depth of the blast holes in the annular portion 61 are determined in advance from the state in which the refractory bricks 4 are eroded. It is desirable to measure the shape and dimensions of the blast furnace. In order to further improve the accuracy, a hole is formed in the steel shell 2 on the lower periphery of the blast furnace 1, and the refractory brick 4 is drilled to form the steel shell 2 and the residual iron 6.
It is desirable to measure the distance between

Next, one drilling device (see FIG. 5) 7 is disposed facing the opening 5 and one punching device is disposed at a position facing the steel bar 2 on both sides of the opening 5. Place 7 That is, a total of three punching devices 7 are arranged side by side. Then, the first blasting holes 8,
8, ... are drilled in the vertical direction at intervals of about 0.3 m. In addition,
Reference numeral 81 denotes a plurality of first blast holes 8, 8,... Formed by one punching device 7. In parallel with this, the outer two perforators 7 respectively penetrate the steel shell 2 on both sides of the opening 5 to form a block B of the annular portion 61 of the remaining pig iron 6 adjacent to the block A. The second blast holes 8, 8,... Are formed at intervals of about 0.3 m in the vertical direction along the division line. Reference numerals 82 and 83 denote a plurality of second blast holes 8, 8,... Formed by one punching device 7, respectively. Since the second blast holes 8, 8,... Can be drilled immediately after cooling the residual pig iron 6 by pouring water into the furnace, the second blast holes 8, 8, ... are kept until the blast using the second blast holes is actually performed. Can secure a sufficient working time to form the blast holes 8, 8,..., And the shapes of the second blast holes 8, 8,. Since the drilling of the second blast holes 8, 8,... Is performed from outside the furnace, unlike the work performed in the furnace, there is no danger of falling objects, the environment is not high temperature, and the work is performed safely. be able to. It should be noted that the second blast hole 8,
When drilling 8, ..., the steel shell 2 is
It is desirable to open a hole in the steel shell 2 in advance by a means such as gas cutting instead of directly penetrating directly with a.

Next, an explosive is loaded into the first blast holes 8, 8, ... along the division line of the block A. At this time, since each of the blast holes 8 has a constant diameter over the entire length and is formed as a straight hole by the cutting bit 9a of the drill 9, the explosive can be easily and accurately loaded.

Next, the charged explosive was blasted, and as shown in FIG.
Destroys the refractory brick 4 sandwiched between them. Subsequently, the broken residual iron and the shear of the refractory brick 4 are discharged.

Next, a new first blast hole 8, 8,... Is formed by the single piercing device 7 through the opening 5 and along the division line of the block B of the exposed circular portion 62 of the residual pig iron 6.
Drilling. In parallel with this, the remaining two perforators 7
Are moved clockwise and counterclockwise along the outer periphery of the blast furnace 1 by the moving cart 14, respectively,
, In the annular portion 61 of the remaining pig iron 6, the second blast holes 8, 8,... Are sequentially formed along the division lines of the blocks C, D,. . In other words, the remaining pig iron 6
Out of the first blast hole of the circular portion 62
The second blast hole is formed in advance.

Next, as soon as the first blast holes 8, 8,... Are formed along the division line of the block B of the circular portion 62, the first blast holes along the division line of the block B of the circular portion 62 are formed. The explosive is loaded into the holes 8, 8, ... and the second blast holes 8, 8, ... along the division line of the block B of the already formed annular portion 61. As soon as the first blast hole of the circular portion 62 has been drilled, the explosive loading operation can proceed to the second blasting of the annular portion 61 prior to the formation of the first blast hole 8, 8,. This is because the blast holes 8, 8, ... are formed.

Next, the charged explosive is blasted, and the remnant pig iron of the block B of the circular portion 62 and the block B of the annular portion 61 and the refractory sandwiched between the block B of the annular portion 61 and the steel shell 2 are blasted. Destroy brick 4. Subsequently, the broken residual iron and the shear of the refractory brick 4 are discharged.

Similarly, a block forming a row of a circular portion 62 to which a certain European character is attached, and the blast furnace 1
And the block with the same European character attached to the preceding annular portion 61 in the direction toward the back is simultaneously blasted and removed.
In this case, the removal of the residual iron 6 is caused not only in the direction from the opening 5 toward the back of the blast furnace 1 but also in the direction along the inner peripheral surface of the steel shell 2 from the opening 5. Can be. Therefore, the construction period can be significantly reduced as compared with the conventional method, that is, the method of forming only the first blast holes.
Since the blasting of the block of the annular portion 61 is performed earlier in the direction toward the depth of the blast furnace 1 than the blasting of the block of the circular portion 62, both ends of the block following the circular portion 62 are free. A surface is formed. Therefore, the blasting efficiency of the circular portion 62 can be improved.

As shown in FIG. 3, when the removal of the block G is completed, two perforators 7 can be introduced into the blast furnace 1. With these two units, the blocks H, I and L of the circular portion 62 can be formed. As shown in FIG. 4, when the removal of the block I is completed, three perforators 7 can be introduced into the blast furnace 1. Circular part 6 with these three
Two blocks J and K can be drilled. Therefore, many first blast holes 8, 8,... Can be efficiently formed in the exposed block of the circular portion 62 in parallel. As a result, a large amount of residual iron can be removed by one blast, and the construction period can be further shortened. The blocks G, G,..., I,
, J, J,..., K, K,..., L, L.

The method for removing the residual pig iron has an outer diameter of 16.3 m.
When the blast furnace is applied, six blast holes 8 are formed per half day by one piercing device 7, and the removal of all the remaining pig iron 6 in the furnace can be completed in 7 days.

When there is no space around the lower periphery of the blast furnace 1 for moving the movable carriage 14 over the entire periphery, only the perforator 7 is attached to the outer periphery of the steel shell 2 to form a second blast hole. Is also good. In the above embodiment, the case where the number of the openings 5 is one has been described, but the number of the openings may be two.

[0032]

As is clear from the above, in the method for removing residual iron from the blast furnace according to claim 1, the explosive is charged into the first and second blast holes to blast and remove the residual iron. The removed portion of the residual iron can be generated not only in the direction from the opening toward the back of the blast furnace, but also in the direction along the inner peripheral surface of the steel shell from the opening. Therefore, the construction period can be significantly reduced as compared with the conventional method, that is, the method of forming only the first blast holes.

In the method for removing residual iron from the blast furnace according to the second aspect, the blasting using the second blasting hole is performed prior to the blasting using the first blasting hole. The removal portion of the residual pig iron occurs before the direction toward the inner side of the steel shell from the opening toward the direction along the inner peripheral surface of the steel shell. That is,
The exposed portion of the residual iron spreads in the furnace, and the free surface of the residual iron blasted by the first blast hole is widened. Therefore, many first blast holes can be drilled in parallel, and the blasting efficiency of the first blast holes can be increased. As a result, much residual iron can be removed by one blast. Therefore, the construction period can be further reduced.

In the method for removing residual iron from the blast furnace according to the third aspect, when a certain block is blasted, both ends of the next block in front of the block are simultaneously blasted using the second blast hole. In the same manner as in claim 2, a removal portion of residual iron occurs prior to the direction from the opening toward the back of the blast furnace from the opening toward the direction along the inner peripheral surface of the steel shell, and the The exposed portion of the residual pig iron is widened, and the free surface of the next section blasted by the first blast hole is widened. Therefore, many first blast holes can be drilled in parallel, and the blasting efficiency of the first blast holes can be increased. As a result,
Many blasts can be removed with a single blast. Therefore, the construction period can be further reduced.

[Brief description of the drawings]

FIG. 1 is a process diagram illustrating a method for removing residual iron from a blast furnace according to one embodiment of the present invention.

FIG. 2 is a process diagram illustrating a method for removing residual iron from the blast furnace.

FIG. 3 is a process diagram illustrating a method for removing residual iron from the blast furnace.

FIG. 4 is a process diagram illustrating a method for removing the residual iron from the blast furnace.

FIG. 5 is a diagram showing a perforation apparatus used in the method for removing residual iron from the blast furnace.

FIG. 6 is a sectional view of a blast furnace to be renovated.

FIG. 7 is a process diagram illustrating a conventional method for removing residual iron from a blast furnace.

[Explanation of symbols]

 A, B,..., M block 1 blast furnace 2 iron shell 4 refractory brick 6 residual iron 8 blast hole 61 annular part 62 circular part 81 first blast hole 82, 83 second blast hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tatsuhiro Furonaga 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Inside Okumura Gumi Co., Ltd. (72) Kenji Yoshikawa 2, Matsuzaki-cho, Abeno-ku, Osaka-shi, Osaka Chome No.2-2 Okumura Gumi Co., Ltd. F-term (reference) 4K015 EB01 EC06

Claims (3)

[Claims] 1. A method for removing residual iron in a blast furnace provided with an iron shell on an outer periphery, the method comprising removing a part of the iron shell on a lower outer periphery of the blast furnace to form an opening, and removing the residual iron. A first blasting hole is drilled in the exposed part of the blast furnace, and a second blasting hole is drilled in the residual iron by penetrating an iron shell existing at a position other than the opening in the lower outer periphery of the blast furnace, A method for removing residual iron from a blast furnace, comprising loading an explosive into the first and second blast holes and blasting and removing the residual iron. 2. The method for removing residual iron from a blast furnace according to claim 1, wherein blasting using the second blast holes is performed prior to blasting using the first blast holes. How to remove residual iron from the blast furnace. 3. The method for removing residual iron from a blast furnace according to claim 1, wherein the residual iron is divided into a plurality of pieces in a direction from the opening toward the interior of the blast furnace, and the divided part on the opening side is divided into a plurality of pieces. Blasting by piercing the first blast hole and blasting both ends of the next partition portion located in front of the partition portion by using the second blast hole are simultaneously performed. How to remove residual iron from the blast furnace.