JPH10120471A - Repairing material for lining torpedo car by vibrating darby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a repairing material for lining a torpedo car by a vibrating darby, excellent in adhesiveness, causing neither peel nor wear, exhibiting wear and tear mainly composed of dissolution loss, capable of extremely prolonging the life of a furnace. SOLUTION: This repairing material comprises an aluminous aggregate, 5-20wt.% of a silicon carbide having <=0.5mm particle diameter, 3-10wt.% of mixed powder of silica flower and calcined alumina having the ratio of the calcined alumina to the silica flower of 0.05-1 and 0.5-3wt.% of a coal-based pitch raw material having the ratio to the mixed powder of 0.1-1 and <=0.5mm particle diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repair material for a mixed iron car lining used for repairing a mixed iron car lining with a vibrating iron.

[0002]

2. Description of the Related Art In recent years, repair of bricks for lining of mixed-iron cars has been carried out by vibrating irregularly shaped refractories kneaded in a non-fluid state as a measure to improve the working environment with low durability and dust generation by spraying repair. A method of constructing a refractory while applying vibration with a trowel to impart thixotropic properties has been adopted. Initially, repair materials used for this purpose were mainly clay-bonded materials, but there was a problem that the strength change after heat load was large and the corrosion resistance was likely to deteriorate due to the formation of low-melting glass with low adhesive strength. Was. Therefore, Japanese Patent Publication 2-1084
Japanese Patent Application Laid-Open No. 4-107204 discloses an improvement in workability by using ultrafine silica powder for aggregate and silicon carbide fine powder as disclosed in Japanese Patent Application Laid-Open No. 4-107204. A system that improves workability by adding a system-based shape preservative has been developed.

[0003]

On the other hand, the demand for high corrosion resistance has become severe, and in a vibrating iron material using silica flour as fine powder, an improvement in corrosion resistance cannot be expected due to the formation of a low melting point glass phase by silica. Poor construction fillability in the part,
Due to the strength properties and expansion during hot, adhesion to the base material brick is not enough, and from the drying to the operation time, peeling from the base material surface may occur, compared to the sprayed material However, the durability of the furnace was not sufficient, the construction required a long time and required heavy work, and the improvement of workability and work environment could not be expected so much, and the life of the furnace could not be extended significantly.

[0004] The present invention has excellent adhesiveness, does not suffer from delamination wear, exhibits wear mainly due to erosion, shortens the working time and eliminates heavy reinforcing work, and contributes to prolonging the life of the furnace. The purpose of the present invention is to provide a repair material for lining a mixed iron car using a trowel.

[0005]

According to the present invention, a repair material for lining a mixed iron wheel using a vibrating iron according to the present invention includes alumina aggregate and a particle size of 0.5.
5 to 20% by weight of silicon carbide having a diameter of not more than 5 mm, 3 to 10% by weight of a mixed powder of silica flour and calcined alumina having a calcined alumina to silica flour ratio of 0.05 to 1, A material containing 0.5 to 3% by weight of a coal-based pitch raw material having a ratio of 0.1 to 1 with respect to.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a repair material for a vibrating trowel mainly using an alumina-based aggregate. In order to prevent a decrease in corrosion resistance rather than an improvement in workability due to silica, the amount of silica is reduced and an alternative material is used. However, the use of a large amount of calcined alumina increased the material viscosity, and markedly deteriorated the ironing property and the elongation of the material. However, by controlling the calcined alumina / silica flower ratio, it was found that vibration propagation was significantly improved without ironing, and that it was possible to shorten the construction time and improve the corrosion resistance by densifying the structure. .

[0007] Alumina aggregates include, for example, electrofused alumina, sintered alumina, bauxite, sand shale, chamotte, etc., having an Al ₂ O ₃ content of 50% by weight or more in order not to impair the fire resistance. Can be used.

The use of silicon carbide is effective in bringing the thermal expansion characteristics of the repaired article closer to the base material brick to be repaired, and in preventing silicon slag from infiltrating since silicon carbide has the property of being hardly wetted by slag. If the content is less than 5% by weight, this effect is small and the corrosion resistance is deteriorated. On the other hand, 20% by weight
When the amount exceeds the range, a large amount of silicon dioxide, which is an oxidation product of silicon carbide, is generated, the amount of total silica in the matrix is increased, and as a result, the calcined alumina / silica flour ratio is changed, and the amount of liquid phase generated is increased. Corrosion resistance deteriorates.
A particle size of 0.5 mm or less is good for maintaining slag resistance and controlling generation of silicon dioxide (SiO ₂ ), and a particle size range of 0.075 to 0.005 mm is more preferable.

[0009] Silica flour has an almost spherical microscopic shape, and its particles are negatively charged on the particle surface, and are extremely excellent in dispersion during kneading due to electric repulsion. However, use of silica flour alone causes oversintering, shrinkage, and easy peeling. However, when used in combination with a small amount of calcined alumina, the calcined alumina reacts with the silica flour to promote the formation of mullite and suppress shrinkage, thereby preventing delamination wear. Therefore, the calcined alumina / silica flower ratio is preferably 0.05 or more.
On the other hand, the amount of calcined alumina was increased and calcined alumina /
When the silica flour ratio is larger than 1, shrinkage is prevented by the mullite generation effect, but when vibrating with a vibrating iron at the time of construction, the viscosity of the material becomes high, and the propagation of vibration inside the material becomes worse. In addition, the filling property of the material on the back side is inferior, and the adhesiveness is deteriorated. For this reason, it is easy to peel off from drying to operation. As a result, the service life during operation is rather deteriorated. Therefore, the calcined alumina / silica flower ratio is desirably 1 or less. If the calcined alumina used has a particle size range of 5 μm or less, the reaction with the silica flour is effectively promoted.

[0010] The pitch is heated and melts and softens when it reaches a specific temperature, which is effective in forming a bond on the bonding surface. When heated further, volatile components are scattered and carbonized. There are coal pitch and petroleum pitch as pitch,
Petroleum-based pitch has a lower residual coal ratio, more volatile components, and a smaller amount of β-resin that is effective in improving strength, as compared with coal-based pitch. That is, in the case of petroleum-based pitch, the use of coal-based pitch is preferable because the explosion phenomenon is likely to occur due to volatile components derived from the pitch during drying, and even if it does not explode, the durability and the adhesive strength are reduced.

When a coal-based pitch raw material having such characteristics is blended (hereinafter referred to as pitch raw material), the pitch raw material in the material is softened during drying, and the softened pitch raw material is uniformly dispersed in a matrix by a capillary phenomenon. And carbonize.
Therefore, the matrix has a form in which carbon is uniformly dispersed, thereby suppressing slag infiltration and significantly improving corrosion resistance. Furthermore, it moves to the bonding interface with the base material and carbonizes there. At this time, a carbon bond is generated in a form connecting the base material and the repair material. The conventional alumina-silicon carbide vibrating iron repair material is physically bonded, whereas the pitch raw material is chemically bonded.

That is, the pitch raw material is required to have a function of strengthening the matrix and bonding at the bonding interface with the base material.
If the amount exceeds the weight percentage, the voids after the volatile components of the pitch material are scattered become excessive, and the oxidation resistance is remarkably deteriorated. Further, the volatile components generated during drying are increased, so that the explosion phenomenon is easily caused. Therefore, the use of the pitch material is preferably 0.5 to 3% by weight.

As described above, the use of the pitch raw material has the effect of uniformly dispersing carbon in the matrix, thereby suppressing oversintering. In the case where a large amount of silica flour is used as in the present invention, the use of the pitch raw material is difficult. Plays an important role and is effective in the matrix and at the adhesive interface. However, excess pitch material in the matrix softens during drying and moves freely in the matrix,
Breaks the matrix bond, causing strength degradation. Furthermore, the volatile matter generated by the decomposition flows out to the outside through the strength-deteriorating layer, thereby causing an explosion. Therefore, as the optimum value of the amount of the pitch raw material used in the matrix, the ratio of the coal-based pitch raw material to the total amount of the calcined alumina and the silica flour is preferably in the range of 0.1 to 1. When this value is smaller than 0.1, the pitch in the matrix and the pitch of the bonding interface are insufficient, and the corrosion resistance and the bonding strength are reduced. On the other hand, when this value is larger than 1, the corrosion resistance and the explosion resistance are remarkably reduced.

As the particle size of the pitch raw material, a commercially available particle size can be used. However, when the particle size is large, the effect of adding the pitch raw material is reduced.
The use of a particle size range of 5 to 0.075 mm is preferred;
It goes without saying that a material having a diameter of less than 075 mm can be used.

In addition to the above-mentioned raw materials, 1 to 4% by weight of alumina cement which is usually used as a shape-retaining material,
0.1% by weight of a dispersant such as sodium phosphate, aluminum phosphate and aluminum lactate can be used.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.

Table 1 shows the composition of the repairing material for the mixed iron wheel lining for shaping with a vibrating iron according to the present invention, and Table 2 shows the composition of the conventional repairing material for the mixed iron wheel lining.

In order to form a construction body of 100 × 100 × 50 mm on the surface of the Al ₂ O ₃ —SiC—C mixed-iron car brick cut out in a parallel shape, after placing a metal frame of the same shape on the brick surface, , And were molded with a vibrating iron. After holding this in an atmosphere of 110 ° C. for 24 hours, the adhesive shear strength was measured.

The corrosion resistance index is determined by forming a construction body having a thickness of 100 mm in a rotary erosion furnace and inserting a blast furnace slag into the construction body.
The temperature is maintained at 500 ° C. for 10 hours, and after cooling, A
The erosion of l ₂ O ₃ -SiC-C bricks were calculated as 110. The smaller the corrosion resistance index, the higher the corrosion resistance.

The flexural strength, compressive strength and apparent porosity of a sample molded to 40 × 40 × 160 mm were 100
After being kept in an atmosphere of ° C for 24 hours, it was cooled and measured. The spall resistance was measured by the following procedure. 40x
A sample molded to a size of 40 × 160 mm was fired at 1500 ° C. for 2 hours in a reducing atmosphere, and the elastic modulus at that time was E.
_Set to ₀ . This is placed in hot metal maintained at 1500 ° C for 90 minutes.
After immersion for 2 seconds, water cooling for 30 seconds and air cooling for 15 minutes are repeated twice. Thereafter, the measured elastic modulus and E _2. The spall resistance was measured from changes in E ₀ and E ₂ .
The samples show raised E ₂ / E ₀ as an evaluation of the spalling resistance. The smaller this number is, the larger the change in elastic modulus is, and the poorer the spalling resistance is. Spalling resistance favorable are the ones E ₂ / E ₀ is close to 1. The explosion temperature was cast into 100φ × 100, and after curing and de-framing, it was charged into a furnace holding a predetermined atmosphere, and the explosion temperature was taken as the explosion temperature. The higher the temperature, the higher the explosion resistance. Regarding the workability, も の indicates good, △ indicates good, and X indicates poor.

In the same manner as in the Examples and Comparative Examples, 3% by weight of alumina cement and 0.1% by weight of a dispersant were externally added (indicated by ten).

[0022]

[Table 1] Examples 1 to 6 had the same configuration except that the alumina aggregate was properly used in various ways. A repair material using a raw material having a low content of Al ₂ O ₃ tends to be slightly inferior to the other bricks in corrosion resistance as compared with other bricks, but good results were obtained in all other properties.

In Example 7, when the amount of alumina-based aggregate was increased and silicon carbide was used at 5% by weight of the lower limit value, the effect of preventing slag infiltration by silicon carbide was reduced. Therefore, in comparison with corrosion resistance, bricks were slightly inferior. All properties were good.

In Example 8, silicon carbide was added at an upper limit of 20% by weight.
In this example, the alumina aggregate was reduced and the others were the same as in Example 1. Although the corrosion resistance was lower than that in Example 1,
The rate of decrease was not large, and was good in other characteristics.

In the ninth embodiment, the lower limit of the pitch is 0.5% by weight, the pitch / (calcined alumina + silica flour) ratio is the lower limit of 0.1, and the raw material of the aggregate is changed. Under the same conditions, although the strength and corrosion resistance tended to slightly decrease, the level of the decrease was not so large as to be problematic, and other characteristics showed good numerical values.

In the tenth embodiment, the amount of pitch used is
%, And the pitch / (calcined alumina + silica flower) ratio was set to the upper limit of 1, but no problem was observed.

In Examples 11 and 12, aggregates and the like were used in Example 1.
In this example, the ratio of calcined alumina / silica flour was set to the lower limit of 0.05 and the upper limit of 1, respectively. When the ratio is 0.05, the strength is improved, but the corrosion resistance is slightly lowered. However, the strength is not so significant that there is no problem in other characteristics. In addition, when the ratio was 1, all the characteristics showed good values and there was no problem.

[0028]

[Table 2] Comparative Example 1 is a conventionally used alumina-silicon carbide vibrating trowel repair material. It is characterized by the use of refractory clay as a raw material for ultra-fine powder and no use of pitch.
The strength is also inferior to the comparative alumina-silicon carbide mixed iron car lining brick.

Comparative Example 2 is an example in which silicon carbide was not used. In this case, the oxidation of the pitch was large, so that the corrosion resistance was significantly deteriorated, and the spalling resistance was also greatly deteriorated.

Comparative Example 3 is an example in which the amount of silicon carbide is larger than the specified amount.
₂ ) is produced in large quantities and forms a low-melting glass phase, so that the corrosion resistance is significantly poor.

Comparative Example 4 is an example in which the particle size of silicon carbide is out of the specified range and large, but has no effect on suppressing slag infiltration into the matrix, resulting in poor corrosion resistance.

Comparative Example 5 is an example in which the pitch amount is smaller than the specified value, and is better in corrosion resistance and other characteristics than Comparative Example 1, but is clearly inferior to the product of the present invention except for the apparent porosity.

Comparative Example 6 is an example in which the pitch amount was larger than the specified value, but the corrosion resistance was significantly inferior, the apparent porosity and other characteristic values were poor, and cracks were generated when the sample was dried. Gender was found to be inadequate.

Comparative Examples 7 to 10 are examples in which the calcined alumina / silica flower ratio was changed, and were out of the specified values, resulting in inferior corrosion resistance, spall resistance or strength.

Comparative Example 11 is a case where a petroleum-based pitch was used in place of the coal-based pitch of Example 2. The workability was good, but the explosion temperature was low due to the influence of volatile components, and the results were inferior to Example 2 in adhesive strength, bending strength and compressive strength.

As described above, Examples of the present invention shown in Table 1 are superior in each characteristic value as compared with Comparative Examples shown in Table 2,
It turns out that workability is also excellent.

Further, when the repair material according to the present invention was used for repairing the lining of a 350 t mixed iron wheel,
After using 150 charges at 0 to 150 mm, a residual of 70% or more was confirmed.

[0038]

According to the repairing material of the mixed iron wheel lining by the vibrating trowel of the present invention, the adhesiveness is good, there is no exfoliation wear, the corrosion resistance is excellent, and the furnace life can be greatly extended. In terms of workability, the construction time can be shortened compared to before,
In addition, it has become possible to eliminate heavy muscle work. As a result, the overall cost of mixed-iron cars was reduced.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minoru Kataoka 1-1, Higashihama-cho, Yawatanishi-ku, Kitakyushu-shi, Fukuoka Kurosaki Ceramics Co., Ltd. 1-1, Higashihama-cho, Yawata Nishi-ku Kurosaki Ceramics Co., Ltd., Amorphous Business Division, Yawata Irregular Form Factory (72) Inventor Junji Yamada 1-1, Tobata-cho, Tobata-ku, Kitakyushu-shi Inventor Saburo Matsuo 1-1 Niwahata-cho, Tobata-ku, Kitakyushu Nippon Steel Corporation Yawata Works (72) Inventor Hisato Yoshimoto 1-1 Niwahata-cho, Tobata-ku, Kitakyushu Nippon Steel Corporation Yawata Works

Claims (1)

[Claims] An alumina aggregate, 5 to 20% by weight of silicon carbide having a particle size of 0.5 mm or less, and a silica flour and a calcined alumina having a calcined alumina to silica flour ratio of 0.05 to 1. And 3 to 10% by weight of the mixed powder with 0.5 to 3% by weight of a coal-based pitch raw material having a ratio of 0.1 to 1 to the mixed powder.