JP3025829B2 - Refurbishment method of blast furnace hearth - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of refurbishment of a blast furnace for disassembling and repairing a bottom brick of a blast furnace, and more particularly, to a method of refining a bottom furnace brick of a blast furnace by blasting the bottom brick. The present invention relates to a method for repairing a blast furnace furnace bottom that has been improved so as to avoid impact on bricks.

[0002]

2. Description of the Related Art FIG. 4 is a vertical sectional view showing an internal state of a blast furnace after blowing. As shown, the blast furnace 20
As is well known, bricks 22 are constructed on the side walls and the furnace bottom on the inner surface of the steel shell 21 which defines the appearance of the steel shell 21. Normally, carbon bricks 25 having high thermal conductivity are vertically stacked in a disc shape on the furnace bottom 24 for the purpose of improving cooling, and further, a carbon brick 26 having high heat insulation properties is flatly stacked in a disc shape thereon. ing.

[0003] The blast furnace 20 on which the bricks 22 are constructed as described above.
The hot metal produced in the furnace is tapped by a tapping gutter (not shown) from a taphole (not shown) opened on the furnace side near the furnace bottom 24. The opening position of this tap hole is set higher than the furnace bottom 24 because the tapping gutter is provided at an angle, so that the hot metal remains in the furnace bottom 24 after blowing, and
Or the solid metal lump 28 is solidified.

In the refurbishment work of the blast furnace performed every about 10 to 20 years, the residual iron 27 and the mixed iron ingot 28 are dismantled and removed, and the bricks 22 constructed inside the blast furnace 20 are dismantled and reconstructed. Is done. A blasting method is usually employed for dismantling the residual iron 27, the mixed iron lump 28 and the hearth brick 22 '.

Conventionally, in this blasting method, a part of the steel shell 21 on the furnace side is cut with a gas burner or the like, and the residual iron 27 or the mixed iron ingot 28 on the furnace bottom 24 is cut from the side by a punch or jet lance for about 50 to 50 minutes. After forming a blast hole (not shown) having a diameter of 80 mm, blasting is performed in the blast hole, and the residual iron 27 and the mixed
Crush. Thereafter, the crushed pieces of the residual iron 27 and the mixed iron ingot 28 and the broken pieces of the bricks at the same time are scraped out and removed.
6 and the carbon brick 25 were mechanically broken, or the hearth bricks 22 'were blasted and dismantled.

[0006]

By the way, the conventional blasting method uses the remaining iron 27, the mixed iron ingot 28 and the carbon brick 2
Not only 6 but also the carbon brick 25 was crushed and dismantled and removed. Recently, the operating technology and refractory technology have progressed and developed, and the blast furnace 20 has been blown off intact without breaking the bottom brick 22 ', especially the carbon brick 25 at the bottom.
From the viewpoint of quality, the conventional blasting method is a demolition method that damages the entire furnace bottom brick 22 ', although the carbon brick 25 can sufficiently withstand reuse. In addition, there is a problem that the carbon brick 25 must be newly constructed.

The carbon brick 25 has a size of 40 to 5
Because it is expensive at 100,000 yen / ton, and about 1700-1800 ton is used for the bottom 24 of the blast furnace 20,
There was a problem that the repair cost increased.

In view of the above problems, an object of the present invention is to provide a method for repairing a blast furnace hearth in which carbon bricks constructed on the blast furnace bottom can be reused and repair costs can be greatly reduced. It is in.

[0009]

According to a first aspect of the present invention, there is provided a method for repairing a furnace bottom of a blast furnace according to the first aspect of the present invention. Blast holes are formed in the solidified residual iron and mixed iron ingot,
After scraping and removing crushed pieces of iron and mixed iron ingots and brick pieces by blasting the blast furnace, in the refurbishment method of the blast furnace bottom where the furnace bottom brick is reconstructed, After a slit is formed along the furnace radial direction in the hearth brick located below the mixed iron ingot, the blast hole is blasted.

[0010] The method for repairing the furnace bottom of the blast furnace according to the second aspect of the present invention is a method for repairing residual iron or mixed iron ingot that has solidified on the furnace bottom where the furnace bottom brick composed of carbon bricks has been constructed on carbon bricks. After forming a blast hole and blasting it, scraping and removing crushed pieces of iron and mixed iron crushed pieces and brick pieces,
In the refurbishment method of the blast furnace hearth where the furnace bottom brick is reconstructed,
After the blast furnace is blown out, after forming a slit along the furnace radial direction in the above carbon-inside brick located below the residual iron or the mixed iron ingot, the blast hole is blasted and the residual iron or mixed iron above the slit is blasted. After crushing the lump and the carbon brick, removing the crushed pieces and the brick pieces of the residual iron and the mixed iron lump, a new carbon brick was constructed on the carbon brick left under the slit. Things.

Further, the method for repairing the furnace bottom of the blast furnace according to the third aspect of the present invention is a method for repairing residual iron or mixed iron ingot that has solidified on the furnace bottom where the furnace bottom brick composed of carbon bricks has been constructed on carbon bricks. A blast hole is formed, and after blasting the blast hole to scrape out and remove crushed pieces and brick pieces of crushed residual iron and mixed iron lump, the blast furnace is blown in the blast furnace bottom refurbishment method of reconstructing the furnace bottom brick. After stopping, after forming a slit along the furnace radial direction in the above carbon internal brick located below the residual iron or mixed iron ingot, the blast hole is blasted and the residual iron, mixed iron ingot and carbon above the slit are blasted. After crushing the internal brick and removing the crushed pieces and brick pieces of the remaining iron and mixed iron lump, the carbon internal brick left under the slit is mechanically broken and a new carbon is installed on the exposed carbon brick. The brick was constructed That.

[0012] The method for repairing the furnace bottom of the blast furnace according to the fourth invention is a method for refining residual iron or mixed iron lump remaining on the furnace bottom where the furnace bottom brick composed of carbon in-built bricks is constructed on carbon bricks. A blast hole is formed, and after blasting the blast hole to scrape out and remove crushed pieces and brick pieces of crushed residual iron and mixed iron lump, the blast furnace is blown in the blast furnace bottom refurbishment method of reconstructing the furnace bottom brick. After stopping, after forming a slit along the furnace radial direction in the carbon brick located below the residual iron or mixed iron ingot, blast the blast hole to set up the residual iron, mixed iron ingot, and carbon inside the slit. After crushing bricks and carbon bricks, removing these crushed pieces of iron and mixed iron lump and brick pieces, a new carbon-inside brick is constructed on the carbon bricks left under the slit.

[0013] Still further, according to a fifth aspect of the present invention, there is provided a method of repairing a blast furnace furnace bottom, wherein the solidified residual iron or mixed iron ingot remains in the furnace bottom where the furnace bottom brick composed of carbon bricks is constructed on carbon bricks. A blast hole is formed in the blast furnace, and after scraping and removing crushed pieces of iron and mixed iron lump and brick pieces by blasting the blast hole, the blast furnace is refurbished to rebuild the furnace bottom brick. After blowing, a slit is formed along the furnace radial direction in the carbon brick located below the residual iron or mixed iron ingot, and then the blast hole is blasted to cause residual iron, mixed iron ingot, and carbon inside the slit. After crushing the construction brick and carbon brick, removing the crushed pieces and brick pieces of the remaining iron and mixed iron lump, a new carbon brick is laid flat on the carbon brick left under the slit, and a new carbon Like installing an internal brick One in which the.

[0014]

According to the construction of the blast furnace hearth repair method according to the first aspect of the invention, when the blast furnace is blown off, the bottom brick remains in a substantially healthy state below the residual iron or the mixed iron ingot. Then, after forming a slit in the furnace bottom brick along the furnace radial direction, the blasting hole is blasted, so that the slit forms a free surface completely cut off from the residual iron or the mixed iron lump, and the free surface is formed. The blasting impact is absorbed by the surface, and the residual iron, the mixed iron lump and the hearth brick above the slit are crushed.

The above-mentioned furnace bottom brick is composed of a carbon brick placed on the bottom and an internal carbon brick placed thereon. Therefore, if a slit is formed in the carbon brick, the remaining pig iron, the mixed metal lump and the carbon brick above the slit are crushed, and the carbon brick and the carbon brick remaining below the slit can be diverted. On the other hand, when the slit is formed in the carbon brick, the remaining pig iron, the mixed metal lump, the carbon internal brick and the carbon brick above the slit are crushed, and the carbon brick remaining under the slit can be diverted.

Further, according to the construction of the blast furnace hearth repair method according to the second aspect of the present invention, as described above, when the blast furnace is blown off, the bottom brick is substantially sound under the residual iron or the mixed iron ingot. It remains in a state. Next, after a slit is formed along the furnace radial direction in the carbon-containing brick, the blasting hole is blasted, so that the blasting impact is absorbed by the slit, and the residual iron, mixed iron lump and carbon inside the slit are absorbed above the slit. The brick will be crushed. Then, when the crushed pieces and the brick pieces of the residual iron and the mixed iron lump are removed, the carbon built-in brick and the carbon brick which can be diverted remain under the slit.

Therefore, if a new carbon brick is constructed on the carbon brick left under the slit, the material cost can be reduced by reusing the carbon brick,
The construction cost is reduced.

Further, according to the construction of the method for repairing the furnace bottom of the blast furnace according to the third invention, the blast furnace is blown off and a slit is formed in the carbon-inside brick along the furnace radial direction, as in the second invention. After forming the blast, the blasting holes are blasted, so that the blasting impact is absorbed by the slits, the residual iron, the mixed iron lump and the carbon-internal brick above the slits are crushed, and the crushed pieces of the residual iron and the mixed iron lump and the bricks When the pieces are removed, carbon internal bricks and carbon bricks which can be diverted remain under the slits.

Although the carbon-inside bricks left under the slits can be basically diverted, the carbon-inside bricks left under the slits are used in the third aspect of the present invention because they are easily deteriorated by heat history. A new carbon brick is constructed on the exposed carbon brick that has been mechanically broken. Therefore, reuse of carbon bricks not only reduces material costs and construction costs, but also ensures higher safety and reliability.

According to the construction of the blast furnace bottom repair method according to the fourth aspect of the present invention, as described above, when the blast furnace is blown off, the bottom brick is substantially sound under the residual iron or the mixed iron ingot. It remains in a state. Next, after a slit is formed in the carbon brick along the furnace radial direction, the blasting hole is blasted, so that the blasting impact is absorbed by the slit, and residual iron, mixed iron lump, and carbon inside the slit are absorbed above the slit. Bricks and carbon bricks will be crushed. Then, when the crushed pieces and brick pieces of the residual iron and the mixed iron lump are removed, carbon bricks that can be diverted remain under the slits. In this case, in order to increase the amount of reuse of the carbon brick, it is preferable to form the slit near the upper surface of the carbon brick.

Accordingly, if a new carbon brick is constructed on the carbon brick left under the slit, the material cost is reduced and the construction cost is reduced by reusing most of the carbon brick. . In addition, since the carbon brick is more excellent in the machinability than the carbon brick made of Hi-alumina brick or the like, the construction cost is also reduced from this point.

Further, according to the construction of the method for repairing the furnace bottom of the blast furnace according to the fifth invention, the blast furnace is blown off and a slit is formed in the carbon brick along the furnace radial direction as in the fourth invention. After being formed, the blasting holes are blasted, so that the blasting impact is absorbed by the slits, and the residual iron, the mixed iron lump, the carbon built-in brick and the carbon brick above the slits are crushed, and the crushed pieces of the residual iron and the mixed iron lump are formed. When the brick pieces are removed, carbon bricks that can be diverted remain under the slit. According to the fifth aspect of the present invention, a new carbon brick is laid flat on the carbon brick left under the slit, and a new carbon brick is constructed thereon. Therefore, the slit is laid flat from the upper surface of the carbon brick. It is preferable to form at a position corresponding to the thickness.

Therefore, by reusing most of the carbon brick, not only the material cost and the construction cost are reduced, but also the construction cost is reduced due to the excellent machinability of the carbon brick. , So that higher safety and reliability are ensured.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the blast furnace furnace repairing method according to the present invention will be described below in detail with reference to the accompanying drawings. A first embodiment of the blast furnace hearth repair method according to the present invention will be described. As shown in FIG. 1, carbon bricks 3 are vertically stacked in a disc shape on a furnace bottom 2 of a blast furnace 1, and a carbon built-in brick 4 made of a Hi alumina brick or the like is disc-shaped thereon. They are stacked flat. The thickness of the carbon brick 3 is about 1500-
1800 mm, and the thickness of the carbon internal brick 4 is about 5
100 to 700 mm or small bricks are constructed. In the furnace bottom 2, when blown off, the residual iron 5 and a part of the mixed iron lump (not shown) are solidified.

Next, blast holes 6 are formed in the residual iron 5 and the mixed iron ingot solidified at the furnace bottom. Specifically, a part of the steel shell (not shown) on the furnace side is cut with a gas burner or the like, and the remaining iron 5 or the mixed iron lump on the furnace bottom 2 is punched from the side by a punch or a jet lance (not shown). A blast hole 6 having a diameter of about 50 to 80 mm is formed.

After the slit 7 is formed in the carbon brick 4 along the furnace radial direction, the blast hole 6 is blasted. Specifically, this slit 7 is formed at a position of about 150 to 200 mm from the lower surface of the brick 4 built in carbon.

The slit 7 is formed by a slot drilling machine for tunnel excavation (not shown) in which a rod having a bit at the tip is rotated by a motor and the trailing end is hit with a hammer, or as shown in FIG. Like wire saw 8
Is adopted. When a slot opening machine is used, a part of the steel shell on the furnace side is cut with a gas burner or the like, and a continuous hole is formed at a predetermined position of the carbon brick 4 from a side at a predetermined position. .

On the other hand, when the wire saw 8 is used,
As shown in FIG. 2, first, part A of the steel shell on the furnace side is cut with a gas burner or the like, and the wire 9 is inserted into the inside. Next, the cut A portion of the steel shell is welded, the B portion and the C portion, the D portion, and the E portion of the steel shell are sequentially cut along the circumferential direction, and the wire 9 is inserted therein. Then, the driving device 10 is rotated to gradually form the slits 7 gradually toward the central portion of the carbon brick 4. Since the carbon built-in brick 4 is softer than the residual pig iron 5, continuous cutting by the wire saw 8 is advantageous in construction. In addition, as said wire 9, for example,
Adopt diamond wire.

If the slit 7 is formed on the entire surface in the furnace radial direction, the disassembled material above the slit 7 falls due to its weight. Therefore, the cutting is stopped before the slit 7 is crushed, and every time the slit 7 is formed to some extent. The blast hole 6 is charged and blasted. Then, the remaining pig iron 5, the mixed iron lump and the carbon built-in brick 4 above the slit 7 are crushed.

Next, crushed pieces of the residual iron 5 and the mixed iron lump,
At the same time, the broken brick pieces are scraped out with a bulldozer or the like and removed. If the carbon built-in brick 4 above the slit 7 is not broken, it is mechanically broken with a bulldozer or the like and scraped off. The above method is repeated to remove the remaining iron 5 and the crushed pieces and the brick pieces of the mixed iron lump above the slit 7 over the entire furnace bottom.

After that, about 150 to
Approximately 500 new on 200 mm carbon brick 4
The refurbishment of the furnace bottom 2 is completed by stacking the carbon in-built bricks 4 of ~ 700 mm.

Next, the operation of the first embodiment will be described. When the blast furnace 1 is blown off and the carbon brick 3 and the carbon-containing brick 4 remain in a substantially healthy state under the residual iron 5 or the mixed pig iron lump, the carbon brick 3 is placed along the furnace radial direction along the furnace radial direction. When the blast hole 6 is blasted by forming a slit 7, the slit 7 forms a free surface completely cut off from the residual iron 5 or the mixed metal lump,
The blasting impact is absorbed by this free surface.

Thereafter, a new carbon brick 4 of about 500-700 mm is newly constructed on the carbon brick 4 of about 150-200 mm, so that the carbon brick 3 can be reused without fail. Material cost can be reduced. Also, since it is not necessary to perform the removal work and the installation work of the carbon brick 3, the construction cost can be reduced, and the repair period of the blast furnace can be significantly shortened, so that the repair cost can be greatly reduced as a whole. it can. Further, since the free surface is formed by the slit 7 and blasting is performed, the amount of charge can be reduced.

Next, a description will be given of a second embodiment of the blast furnace hearth repair method according to the present invention. In the refurbishment method of the blast furnace furnace bottom of the second embodiment, similarly to the first embodiment, after forming a slit 7 in the carbon inner brick 4 along the furnace radial direction, the blast hole 6 is blasted. To crush the remaining iron 5 above the slit 7, the mixed iron lump and the carbon brick 4, and to divert the carbon brick 4 of about 150 to 200 mm under the slit 7.
And the carbon brick 3 is left.

In particular, in the second embodiment, after the remaining iron 5 and the crushed pieces of the mixed iron ingot and the brick pieces are scraped out with a bulldozer or the like and removed, the carbon built-in brick 4 left under the slit 7 is removed. Break mechanically. In general, the carbon brick 4 is hardened like basalt due to the heat history, but the thickness of the carbon brick 4 left under the slit 7 is about 150.
Since it is about 200 mm, it can be easily broken by hitting with a pick hammer or the like.

Then, the brick pieces having broken the carbon built-in brick 4 are scraped out and removed, and the carbon built-in brick 4 of about 500 to 700 mm is newly piled on the exposed carbon brick 3 to flatten the furnace bottom 2. The renovation work is completed.

The second embodiment has basically the same operation and effect as the first embodiment. In particular, in the second embodiment, the carbon of about 150 to 200 mm left under the slit 7 is used. The internal brick 4 is mechanically broken. Although the thin carbon brick 4 can basically be diverted, it is easily deteriorated due to the heat history. Therefore, in this embodiment, about 50 new carbon bricks 4 are added to the exposed carbon brick 3 by breaking the carbon brick 4.
A carbon brick 4 of 0 to 700 mm is constructed. Therefore, by reusing the carbon brick 3, not only the material cost and the construction cost of the carbon brick 3 can be reduced and the repair cost of the blast furnace can be significantly reduced, but also the carbon built-in brick 4 which is easily deteriorated is removed. By doing so, high safety and reliability can be ensured. Before destroying the carbon-inside brick 4 that has been left thin, the carbon-inside brick 4 is used to drive the carbon brick 3 from the running of the bulldozer.
Is protected, so that the damage can be prevented.

Next, a description will be given of a third embodiment of the blast furnace hearth repair method according to the present invention. The blast furnace bottom repair method of the third embodiment is similar to the first and second embodiments.
After the blast furnace 1 has been blown off, the residual iron 5
A blast hole 6 is formed in the molten iron mass.

After the slit 17 is formed in the carbon brick 3 along the furnace radial direction, the blast hole 6 is blasted. As described above, when the slits 17 are formed in the carbon brick 3, compared with the case where the slits 7 are formed in the carbon brick 4 as in the first and second embodiments, the cutability is good and the smoothness is improved. Since a surface is easily formed, a post-process can be easily performed. Specifically, the slit 17 is formed in the carbon brick 3
Is formed at a position of about 150 to 200 mm from the upper surface of the substrate. As described above, a slot opening machine (not shown) for tunnel excavation or a wire saw 8 as shown in FIG. 2 is used for forming the slit 7. In order to prevent the slit 17 from being crushed, the blast hole 6 is charged and blasted every time the slit 17 is formed to some extent. Then, the remaining iron 5 above the slit 17, the mixed iron lump, the carbon brick 4
And the carbon brick 3 is crushed.

Next, crushed pieces of the residual iron 5 and the mixed iron lump,
At the same time, the broken brick pieces are scraped out with a bulldozer or the like and removed. If the carbon brick 4 and the carbon brick 3 above the slit 17 are not broken, they are mechanically broken with a bulldozer or the like, or the blast holes 6 are formed in the carbon brick 4 to reduce the charge amount. To blast and crush and remove.

When the crushed pieces and the brick pieces are removed, the carbon bricks 3 of about 1300 to 1650 mm left under the slit 17 are exposed, and the carbon bricks 4 of about 500 to 700 mm are newly piled on the bricks. As a result, the repair work on the hearth 2 is completed.

Although the third embodiment has basically the same operation and effect as the first and second embodiments, particularly in the third embodiment, the slit 17 is formed in the carbon brick by the furnace diameter. It is formed along the direction. Accordingly, the blasting impact is absorbed by the slit 17, so that the remaining pig iron 5, the mixed metal lump, the carbon-internal brick 4, and the approximately 150 to 200
mm carbon brick 3 is crushed, but the carbon brick 3 of about 1300-1650 mm below the slit 17 is not crushed. When the remaining iron 5 and the crushed pieces and brick pieces of the mixed iron lump are removed, about 1
The carbon brick 3 of 300 to 1650 mm remains. In the third embodiment, the reason why the slit 17 is formed at a position of about 150 to 200 mm from the upper surface of the carbon brick 3 is to increase the amount of reuse of the carbon brick 3.

Therefore, about 130
Approximately 500 new on carbon brick 3 of 0-1650 mm
Because the carbon brick 4 of ~ 700mm is piled up flat,
Most of the carbon brick 3 can be reused, and the material cost of the carbon brick 3 can be reduced. Also,
Since it is not necessary to perform the removal work and the installation work of the carbon bricks 3, the construction cost can be reduced, and the repair period of the blast furnace can be significantly shortened, so that the repair cost can be largely reduced as a whole. Further, the slit 17
As a result, a free surface is formed and blasting is performed, so that the amount of charge can be reduced. Since the carbon brick 3 has better machinability than the carbon brick 4 made of Hi alumina brick or the like, the construction cost can be reduced from this point as well.

Next, a description will be given of a fourth embodiment of the blast furnace hearth repair method according to the present invention. The refurbishment method of the blast furnace bottom of the fourth embodiment is similar to that of the third embodiment.
After forming a slit 17 along the furnace radial direction, the blast hole 6 is blasted. However, in the fourth embodiment, the slit 17 is set to about 500 m from the upper surface of the carbon brick 3.
It is formed at a position of about 700 mm. Therefore, the slit 17
Pig iron 5, mixed iron lump, carbon brick 4 and about 5
The carbon brick 3 of 00 to 700 mm is crushed, and the carbon brick 3 of about 800 to 1100 mm that can be diverted remains under the slit 17.

In particular, in the fourth embodiment, the remaining iron 5 and the crushed pieces and the brick pieces of the mixed iron ingot are scraped out with a bulldozer or the like and then removed to remove about 800 to 800 mm remaining under the slit 17.
Approximately 500-7 new on 1100mm carbon brick 3
The refurbishment work of the furnace bottom 2 is completed by flat-laying the 00 mm carbon bricks 3 and further flatly laminating about 500 to 700 mm of carbon built-in bricks 4 thereon.

The fourth embodiment has basically the same operation and effect as those of the first to third embodiments. However, in the fourth embodiment, in particular, about 800 to 110
About 500-700m newly on 0mm carbon brick 3
m carbon bricks 3 are stacked flat, and about 50 new
Since the carbon bricks 4 of 0 to 700 mm are laid flat, most of the carbon bricks 3 are reused,
Not only can the material cost and construction cost of the carbon brick 3 be reduced to significantly reduce the cost of refurbishment of the blast furnace, but also the carbon brick 4 that is easily deteriorated is removed and a carbon brick of about 500 to 700 mm is used as a safety margin. By removing the upper portion of 3 and newly stacking the carbon brick 3 of about 500 to 700 mm, extremely high safety and reliability can be secured.

Although the above embodiment has been described taking the blast furnace 1 as an example, it goes without saying that the blast furnace 1 can be applied to other types of blast furnace as long as the furnace bottom brick structure has the same structure.

[0048]

As described above, according to the blast furnace hearth repair method according to the present invention, the carbon bricks installed in the blast furnace bottom can be reused, and the repair cost can be greatly reduced. The effect is excellent.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view showing a state in which a slit is formed in a carbon brick in first and second embodiments of the blast furnace furnace repairing method according to the present invention.

FIG. 2 is a schematic plan view showing a state in which a slit is formed by a wire saw in the method of repairing the furnace bottom of the blast furnace of the present embodiment.

FIG. 3 is a schematic sectional side view showing a state in which a slit is formed in a carbon brick in third and fourth embodiments of the blast furnace furnace repairing method according to the present invention.

FIG. 4 is a schematic side sectional view showing an internal state of the blast furnace after blowing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blast furnace 2 Furnace bottom 3 Carbon brick 4 Carbon brick inside brick 5 Residual iron 6 Blast hole 7 Slit 8 Wire saw 9 Wire 10 Driving device A, B, C, D Steel shell cutting position 17 Slit 20 Blast furnace 21 Steel shell 22 Brick 22 ' Hearth brick 23 Side wall brick 24 Hearth 25 Carbon brick 26 Carbon built brick 27 Residual iron 28 Mixed iron lump

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C21B 7/00, 7/06 F27D 1/16

Claims (5)

(57) [Claims] Claims 1. A blast hole is formed in a solidified residual iron or mixed iron ingot at a furnace bottom where a furnace bottom brick composed of carbon-inside brick is constructed on a carbon brick, and the blast hole is blasted and crushed. After scraping off and removing crushed pieces and brick pieces of residual iron and mixed iron ingot, in the blast furnace bottom rehabilitation method of reconstructing the furnace bottom brick, after the blast furnace is blown, it is located under the residual iron or mixed iron ingot. A method of repairing a blast furnace hearth, wherein a slit is formed in the furnace bottom brick in a furnace radial direction, and then the blast hole is blasted. 2. A blast hole is formed in the solidified residual iron or mixed iron ingot at the hearth where the hearth brick composed of carbon-inside brick is constructed on the carbon brick, and the blast hole is blasted and crushed. After scraping off and removing crushed pieces and brick pieces of residual iron and mixed iron ingot, in the blast furnace bottom rehabilitation method of reconstructing the furnace bottom brick, after the blast furnace is blown, it is located under the residual iron or mixed iron ingot. After forming a slit along the radial direction of the furnace on the carbon-containing brick, the blasting hole is blasted to crush the residual iron, the mixed iron lump and the carbon-containing brick above the slit. A method for refurbishment of a blast furnace furnace, characterized in that after removing crushed pieces and brick pieces, a new carbon built-in brick is constructed on the carbon built-in brick left under the slit. 3. A blast hole is formed in the solidified residual iron or mixed iron ingot at the hearth where the hearth brick composed of carbon-inside brick is constructed on the carbon brick, and the blast hole is blasted and crushed. After scraping off and removing crushed pieces and brick pieces of residual iron and mixed iron ingot, in the blast furnace bottom rehabilitation method of reconstructing the furnace bottom brick, after the blast furnace is blown, it is located under the residual iron or mixed iron ingot. After forming a slit along the radial direction of the furnace on the carbon-containing brick, the blasting hole is blasted to crush the residual iron, the mixed iron lump and the carbon-containing brick above the slit. A blast furnace furnace characterized in that after removing crushed pieces and brick pieces, the carbon built-in brick left under the slit is mechanically broken and a new carbon built-in brick is constructed on the exposed carbon brick. Bottom repair method. 4. A blast hole is formed in solidified residual iron or mixed iron lump at a furnace bottom where a furnace bottom brick composed of carbon-inside brick is constructed on a carbon brick, and the blast hole is blasted and crushed. After scraping off and removing crushed pieces and brick pieces of residual iron and mixed iron ingot, in the blast furnace bottom rehabilitation method of reconstructing the furnace bottom brick, after the blast furnace is blown, it is located under the residual iron or mixed iron ingot. After forming a slit in the carbon brick along the furnace radial direction, the blasting hole is blasted to crush the residual iron, the mixed iron ingot, the carbon built-in brick, and the carbon brick above the slit. A method for refurbishment of a blast furnace bottom, characterized in that after removing crushed pieces and brick pieces of the above, a new carbon-inside brick is constructed on the carbon brick left under the slit. 5. A blast hole is formed in the solidified residual iron or mixed iron ingot at the hearth where the hearth brick made of carbon-inside brick is constructed on the carbon brick, and the blast hole is blasted and crushed. After scraping off and removing crushed pieces and brick pieces of residual iron and mixed iron ingot, in the blast furnace bottom rehabilitation method of reconstructing the furnace bottom brick, after the blast furnace is blown, it is located under the residual iron or mixed iron ingot. After forming a slit in the carbon brick along the furnace radial direction, the blasting hole is blasted to crush the residual iron, the mixed iron ingot, the carbon built-in brick, and the carbon brick above the slit. A blast furnace characterized in that after removing crushed pieces and brick pieces of the above, a new carbon brick is laid flat on the carbon brick left under the slit, and a carbon built-in brick is newly constructed thereon. Furnace bottom repair method.