JP2003293015A - Method for plugging opening hole part in furnace using bar-like formed body made of inorganic fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for plugging an opening hole part in a furnace with which filling of the opening hole part in the furnace is surely performed and a repairing effect in the furnace with the filling material can remarkably be improved and this plugging is made to contribute to the extension of service life of the furnace, etc., and to the reduction of a cost of a refractory. <P>SOLUTION: The plugging of the opening hole part is performed by filling a refractory including bar-like refractory composed of inorganic fibers into the opening hole part in the furnace or charging the bar-like refractory into the filling material to charge this refractory together with the filling material into the opening hole part or filling the filling material after charging the bar- like refractory. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for closing the opening of a kiln used for melting and refining metals such as steel, waste treatment, glass and cement production, high temperature treatment, and more particularly, for blast furnaces. The present invention relates to a filling method for tap holes.

[0002]

2. Description of the Related Art Various furnaces are used for melting and refining metals such as steel. In order to put molten metal in and out of these kilns, an opening is provided in each of the kilns. The openings are opened and closed in various ways as needed to control the flow of molten metal. In a blast furnace, which is a facility for producing hot metal by reducing iron ore, every time hot metal accumulates at the bottom of the furnace, the hot metal and slag are periodically discharged from a horizontal hole-like opening called a tap hole at the bottom of the side wall. . When the discharge is completed, a filler or a clay-like material called mud is filled to close the tap hole. This filling material closes the taphole and at the same time rises on the side wall in the furnace and spreads to the surroundings, and also functions to repair and protect the periphery of the taphole. However, in some cases, the raised portion may be missing and the repair protection effect may not be obtained.

As one of the measures for suppressing the loss of the refractory and the destruction due to thermal stress, there is a method of disposing inorganic fibers such as carbon fibers in the refractory or outside thereof. For example, a high heat-resistant high-strength pipe for molten metal in which carbon fiber bundles are arranged in a refractory matrix is disclosed in JP-A-59-156971, and a refractory having through holes therein has a bundle of carbon fibers or a mesh. A winding method is described in Japanese Patent Laid-Open No. 2-133166. Further, there is a method of impregnating or coating a carbon fiber with a thermosetting resin in order to firmly bond the fibers or the fibers and the refractory to each other.
No. 069 publication.

[0004]

All of these methods use carbon fiber threads, strings, tapes, tows, bundles, and nets, cloths, felts, papers and mats made of these. Hereinafter, these are referred to as a bundle of carbon fibers. These converging bodies have the disadvantage that they have no shape-retaining property or are poor in shape, and it is difficult to install them on the surface of refractory or in the desired shape. Further, as a result of this, sagging tends to occur because it is difficult to install linearly on the surface of the refractory or on the inside of the refractory without such shape retention or poor shape retention. For this reason, even if carbon fiber having high strength and high elastic modulus is used, the refractory in which it is installed cannot be prestressed, and therefore a sufficient destruction preventing function cannot be obtained. In addition, since the carbon fiber bundles are liable to be frayed, the carbon fiber bundles may not be useful because they are scattered during the manufacturing process or construction process of the refractory or the filler.

In addition, since these converging bodies have large voids between individual fibers, when impregnated or applied with a resin or the like, a large amount of the resin is likely to be absorbed, and the fibers are present everywhere in the resin mass. It becomes an organization that does. At a high temperature, which is equivalent to the temperature at which the refractory material is used, such a material becomes very porous due to volatile components in the resin, and not only has low strength, but also the fibers and carbon originating from the resin are easily oxidized.

The present invention ensures the filling of the kiln furnace opening,
An object of the present invention is to provide a method for closing the opening of a kiln, which can dramatically improve the in-furnace repair effect by the filling material and can contribute to extending the life of the kiln and the like and reducing the cost of refractory materials.

[0007]

In order to solve such a problem, the gist of the present invention is as follows. (1) A method for closing a kiln opening, which is characterized by filling a kiln opening with a refractory containing a rod-shaped molded body made of inorganic fibers. (2) A method for closing an opening of a kiln, which comprises filling a filling material into the opening of the kiln and then charging a rod-shaped molded body made of an inorganic fiber into the refractory. (3) A method for closing a kiln opening, wherein a rod-shaped molded body made of inorganic fiber is charged while filling the kiln opening with a filler. (4) A method of closing an opening of a kiln, which comprises charging a rod-shaped molded body made of an inorganic fiber into the opening of the kiln and then filling the filling material. (5) As the rod-shaped molded body, a molded body obtained by bundling or twisting inorganic fibers, or by bundling the inorganic fibers with inorganic fibers or organic fibers is used. ) A method for closing a kiln furnace opening according to any one of 1) to 4). (6) As the rod-shaped molded body, a molded body obtained by bundling or twisting inorganic fibers with a binder, or further by bundling the inorganic fibers with an inorganic fiber or an organic fiber is used. ~ The method for closing a kiln furnace opening according to any one of (4). (7) The above (6), wherein the binder is a resin
The method for closing the opening of the kiln described in. (8) The method for closing an opening of a kiln according to (7), wherein the resin is a phenol resin. (9) The method for closing a kiln furnace opening according to any one of (1) to (8), wherein the inorganic fiber is a carbon fiber.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a rod-shaped molded body made of an inorganic fiber is used instead of the conventional converging body. In the invention according to the above (1), the kiln opening is filled with a refractory containing a rod-shaped molded body made of inorganic fibers. This is schematically illustrated in FIG. 1, which is a state in which the filler 2 in which the rod-shaped compact 1 is dispersed and contained therein is filled in the tap hole of the blast furnace.

In the invention according to the above (2), the opening of the kiln is filled with the filler, and then the rod-shaped compact is inserted,
In the invention according to (1), the rod-shaped molded body is inserted into the opening together with the filler, and in the invention according to (4), the rod-shaped molded body is inserted into the opening and then the filler is filled. FIG. 2 schematically shows these, and the rod-shaped molded body 1 is present in the filler 2 filled in the tap hole of the blast furnace.

Since the rod-shaped molded body has a shape-retaining property, even if the filler containing the same is filled or the rod-shaped molded body is installed together with the filler, the rod-shaped molded body does not sag inside and the desired shape is obtained. Can be placed at. In addition, the fibers forming the rod-shaped molded body do not fray. The rod-shaped molded product referred to here is one that does not deform and fall even if a sample having a length of about 300 mm is horizontally spread with a span of about 200 mm without applying tension.

The diameter of the rod-shaped body is 1 mm to 50 mm. If it is less than 1 mm, the strength as a rod is insufficient, and if it exceeds 50 mm, the durability of the entire refractory may be deteriorated due to oxidation or melting damage of the rod. The cross-sectional shape is not particularly limited, and may be, for example, a circle, an ellipse, a polygon, a star shape, or a flower shape.

The length of the rod-shaped molded body is about 10 m in the shortest case when manufacturing a filler having the rod-shaped molded body therein.
m, up to about two-thirds of the nozzle diameter of the filling device in the longest case. If it is less than 10 mm, the reinforcing effect and cross-linking effect of the rod-shaped molded body are insufficient, and if it exceeds 2/3 of the minimum size, the nozzle of the filling device may be clogged with material.
In the case of charging after filling, the length of the rod-shaped molded body is preferably approximately the same as the taphole depth. The taphole depth is the distance traveled before the cone of the opener penetrates, and is the length of the taphole.

When filled by the method of the present invention, since the rod-shaped molded body is present in the refractory, the entire refractory can be strengthened by the rod-shaped molded body, and is less likely to be broken by thermal stress or other external force. . Furthermore, even if cracks occur, the progress of cracks and even greater breakage or breakage can be effectively suppressed by the crosslinking effect due to the pull-out resistance of the rod-shaped molded body. The material in which the rod-shaped molded body is present is press-fitted with a closing device in the same manner as a normal closing material.

When the rod-shaped refractory material is charged after the filling material is filled, the rod-shaped refractory material itself needs to have a strength of 10 mm.
A thicker one or more is desirable. Push it in before the filler is cured. It is also possible to load the rod while filling the filler. In this case, the positional relationship between the rod-shaped refractory material and the filling device poses a problem, so that the device needs to be devised. The rod-shaped refractory can be charged and then filled.
It should be noted that the charging direction of the rod-shaped refractory material may be parallel to the axis of the opening, that is, the longitudinal direction of the tapping hole. When it is desired to fill and close the opening in a wide area and close the opening, a rod-shaped refractory may be installed obliquely or nearly parallel to the opening axis to fill the material. Further, these methods may be used in combination with a refractory having a rod-shaped refractory therein, and one rod may be used for one block or two or more rods may be used.

In the invention according to the above (5), the rod-shaped molded product is a molded product obtained by bundling or twisting inorganic fibers, or further bundling them with inorganic fibers or organic fibers.

As the inorganic fiber, carbon fiber, glass fiber,
For example, inorganic fibers such as alumina, alumina-silica, alumina, mullite, zirconia, magnesia-silica, magnesia-silica-calcia can be used. As described above, the carbon fiber has high strength and heat resistance, and is not easily attacked by hot metal or molten slag, and is therefore excellent for plugging the tap hole. On the other hand, since inorganic fibers such as alumina-silica, alumina, mullite, zirconia, and magnesia-silica do not disappear by oxidation,
It is effective when oxidation is a concern. It is also possible to use an organic fiber such as polyurethane for binding. It is also possible to use two or more of these fibers in combination.

Further, in the invention according to (6), a molded body is used in which the inorganic fibers are bundled or twisted with a binder, or the inorganic fibers or organic fibers are further bundled and bundled.

As the binder, organic substances such as various resins,
Inorganic substances such as cement, water glass and clay can be used,
As mentioned above, phenolic resins are one of the preferred binders. A suitable solvent may be used together with the binder. Further, the binder may contain powders of B ₄ C, SiC, glass, metal and the like. These have the effect of increasing the strength of the rod at high temperatures and suppressing the oxidation of carbon fibers and residual carbon. Volatile components in the binder become gas when the refractory receives heat, and may damage the refractory. In order to avoid this, the rod may be subjected to heat treatment or the like as necessary to remove the volatile matter.

When a resin is used as the binder in the invention according to (7), the resin is first impregnated between the fibers and the fibers are bound from the outside with another fiber or pulled out through a die or the like. Therefore, the excess resin is extruded and removed from between the fibers, and a rod-shaped molded body with a small amount of resin can be obtained. Therefore, the strength of the rod-shaped body is high and it is difficult to oxidize. Further, if a rod-shaped molded body is prepared by bundling with resin while applying tension to the fibers, a rod-shaped molded body with pretension can be prepared. When a refractory is created using this, combined with the fact that there is no bending as described above, it is possible to obtain a prestressed filled construction body, which is extremely effective in suppressing damage and fracture. Demonstrate.

When the phenol resin used in the invention according to (8) is heat-treated in a non-oxidizing atmosphere, carbon remains. This carbon, that is, residual coal, binds particles such as other refractory aggregates constituting the refractory, and also functions as a kind of refractory material itself, so that it is a resin suitable for use in refractory materials. Therefore, it is also very suitable as a resin for bundling inorganic fibers.

The carbon fiber used as the inorganic fiber in the invention according to (9) above has high strength and high heat resistance. The disadvantage is that it disappears upon oxidation. When carbon fibers are bundled with a phenol resin, the fibers originating from the resin are integrated with each other and the specific surface area can be reduced. Therefore, oxidation resistance can be enhanced.

The rod-shaped molded body may be linear or not, and may be corrugated, bent at both ends, or not uniform in thickness. If the rod-shaped molded body has branches, protrusions, or irregularities, it will be difficult to pull it out. When the inorganic fibers are twisted together or bound with the inorganic fibers in the production of the rod-shaped molded body, irregularities are formed on the surface, which is advantageous because the pull-out resistance increases. By devising a twisting method, or by taking measures such as binding with a thick bundle of fibers, a bar having a larger surface irregularity can be produced. It is also possible to create a bar with branches by twisting short bars or binding them with fibers.

As the filler which is a refractory material as a base material, all the commonly known refractory materials can be used. For example, various alumina-silica-based raw materials such as magnesia, calcia, spinel, chrome ore, chromia, alumina, mullite, silica, silica, chamotte, shale, bauxite, clay, andaleusite, sillimanite, and kyanite, zircon, zirconia. , Carbides and boride such as SiC, B ₄ C, nitrides such as Si ₃ N ₄ , various metals such as firelen and Si, scaly graphite, coke, earth graphite, artificial graphite, various carbons such as pitch The source is aggregate,
These are refractory materials in which pitches, tars, resin binders and various additives are added as necessary, and kneaded as necessary. When carbon fiber is used as the material of the rod-shaped molded body, it is better to use a carbon-containing refractory material from the viewpoint of suppressing its oxidation.

Although the method of the present invention has been described with reference to the taphole filling method of the blast furnace, the present invention is not limited to the blast furnace and can be applied to the filling and closing of all kiln furnace openings.

[0025]

[Example] [Example 1] Carbon fiber (PAN-based, strength about 5
000MPa, elastic modulus of about 24tf / mm ² ) coated with a phenol resin and bundled, and a bundle of the same fiber was spirally wound around the periphery to make a thickness of 4mm. It was created. The ratio of carbon fiber to phenol resin in the rod-shaped molded body was 40:60 (volume ratio). A large number of this was cut into a length of 40 mm and prepared. 2% by mass of this rod-shaped compact was mixed and added to a blast furnace taphole filling material (mud material) using a phenol resin as a binder and used for filling. In the tap hole on the opposite side of the same blast furnace, a normal product without addition of a rod-shaped body was used and the results were compared.

The mud not only closes the taphole but also serves as a repair material in the furnace. As a repair, the thickness of the mud attached to the furnace wall is evaluated as the taphole depth (the taphole length). A state where a crack occurs in the attached mud and the hot metal penetrates from the crack is called "hole breaking". When the attached mud material is completely separated from the wall or disappears due to melting damage, the tap hole depth becomes smaller.

[0027] Assuming that the average taphole depth of the tapholes filled with the normal material without addition of the rod-shaped body is 100, the average tapholes of the tapholes continuously filled with the mud material with the rod-shaped body for half a year. The depth was 125. In addition, the frequency of occurrence of hole breakage was reduced to about 70 when the case without insertion was 100, and the carbon fiber bundle of the rod-shaped compact suppressed the generation of cracks in the mud adhering to the furnace wall and its growth. It is thought that it was done.

Example 2 A thick rod-shaped compact made of carbon fiber was inserted into the mud material filled in the taphole. First, a wire having a diameter of 6 mm was prepared in the same manner as in Example 1, and further 19 wires were combined to form a thick bar having a diameter of 20 mm and a length of 5 m. This rod was pierced one by one before the mud material filled in the taphole was not cured. The taphole depth was 5.5 m on average. This operation was continued with the same taphole for about half a year, and compared with the taphole on the opposite side of the same blast furnace which did not perform this operation. Assuming that the average taphole depth when the rod-shaped compact was not charged was 100, the average taphole depth was half a year after the start of piercing and was 120.
Also, since the frequency of hole breakage decreased from 100 to 85, it is considered that the crack generation and growth of the mud adhered to the furnace wall was suppressed by the sticking of the rod and the peeling was reduced in this case as well. To be

[0029]

EFFECTS OF THE INVENTION According to the present invention, the filling of the opening of the kiln can be ensured, and the effect of in-furnace repair by the filling material can be dramatically improved, which contributes to the extension of the life of the kiln and the cost reduction of refractory materials. You can

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a blast furnace tap hole filled with a filler containing a rod made of an inorganic fiber.

FIG. 2 is a schematic sectional view showing a blast furnace tap hole in which a rod made of inorganic fiber is pierced into a filler.

[Explanation of symbols]

1: a rod-shaped molded body made of carbon fiber, 2: Filling material

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masanori Shimada             2-6-3 Otemachi, Chiyoda-ku, Tokyo New Japan             Steelmaking Co., Ltd. F-term (reference) 4G033 AA02 AA03 AA04 AA06 AA07                       AA08 AA09 AA10 AA15 AA16                       AA17 AA19 AB07 AB10 AB12                       AB24 BA04                 4K055 AA00 AA01 AA09 JA15

Claims (9)

[Claims] 1. A method for closing an opening of a kiln, which comprises filling a refractory containing a rod-shaped molded body made of an inorganic fiber into the opening of the kiln. 2. A method of closing a kiln opening, which comprises filling a kiln opening with a filler and then charging a rod-shaped molded body made of an inorganic fiber into the refractory. 3. A method for closing a kiln opening, which comprises charging a kiln opening with a filler while filling the kiln opening with a filler. 4. A method for closing an opening of a kiln, which comprises charging a rod-shaped molded body made of an inorganic fiber into the opening of the kiln and then filling the filling material. 5. The rod-shaped molded body is formed by bundling or twisting inorganic fibers, or by bundling the inorganic fibers with inorganic fibers or organic fibers. The method for closing a kiln furnace opening according to any one of 1. 6. The rod-shaped molded body is formed by bundling or twisting the inorganic fibers with a binder, or by bundling the inorganic fibers with an inorganic fiber or an organic fiber. The method for closing a kiln furnace opening according to any one of 1 to 4. 7. The method for closing an opening of a kiln according to claim 6, wherein the binder is a resin. 8. The method for closing an opening of a kiln according to claim 7, wherein the resin is a phenol resin. 9. The method for closing an opening of a kiln according to claim 1, wherein the inorganic fiber is a carbon fiber.