JPS5930776A - Vibration molding material for hot repair of blast furnace tap trough - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for repairing locally eroded areas of a blast furnace tapwater in a hot state (7
The present invention relates to a vibratory molding material for hot repair in the form of clay, which is used when performing repair work at a temperature of 00°C to 1200°C.

Conventionally, materials used for constructing blast furnace tap troughs include stamp materials, vibration molding materials, pouring materials, and the like.

Stamp materials must be compacted by manually operating a rammer, etc., but if the base material has high residual heat, the work environment is extremely difficult due to high heat dust, and construction work cannot be done in a warehouse. Therefore, corrosion resistance and adhesive strength with the base material are low, which is a problem. Furthermore, the construction work itself was impossible when the base material was hot at 300°C or higher. On the other hand, vibration-forming materials are made of clay-like material, and appropriate excitation force is applied to the materials. It is constructed using degeneration.

In this case, it is possible to perform construction work in a hot state, but the moisture in the input material rapidly evaporates and decreases near the boundary with the base material, making it impossible to obtain a sufficient construction material and the structure becomes porous, resulting in poor corrosion resistance. There was a tendency for the adhesive force with the base material to decrease.

The pouring material is in powder form and is added water and kneaded before use. In this case, since construction is carried out in a muddy state, the de-framing time is shortened by providing self-hardening properties. Although it is possible to perform construction work on these poured materials in a hot state, the poured material hardens without being sufficiently filled near the boundary with the base material, resulting in an insufficient construction material and a porous structure. However, it shows the same tendency as vibration molding.

As a result of various studies in order to improve the above-mentioned drawbacks, the present inventors have found that by using a certain amount of secondary particles formed by mixing and granulating carbonaceous resin, carbon powder, and refractory powder, We have now completed the present invention by discovering that it is possible to improve the corrosion resistance even in hot conditions without impairing workability, and also has high adhesion to the base material.

The water required to impart thixotropy to vibration-formed materials can be reduced by 30q6 to 50% compared to the water required for poured materials, and therefore the filling properties of the construction body are clearly better with vibration-formed materials. The present inventors have confirmed that the effect of adding secondary particles is also effective for vibration molded materials.

The refractory aggregate used in the present invention is one or more of sintered or fused alumina, dexide, shale, sillimanite, chamotte, lowite, clay, spinel, zircon, zirconia, and silicon carbide. be.

On the other hand, the secondary particles are 10 to 70 parts by weight of one or more types of fine powder of 0.3 cm or less made of the same material as the above-mentioned refractory aggregate, 20 to 70 parts by weight of carbonaceous resin, and 5 to 5 parts by weight of carbon powder. It is a granulated product consisting of 70 parts by weight.

If the proportion of the refractory powder constituting the secondary particles is less than 10 parts by weight, the carbon source material is too large (it becomes porous after firing), reducing corrosion resistance; No carbon bond is obtained, and no improvement in adhesion to the base material can be expected.

The carbonaceous resin may be one or more of coal pitch, asphalt, petroleum pitch, phenol resin, or furan resin, but the proportion thereof is preferably at least 20 parts by weight, and if it is less than this, the amount of softening and melting will be small and the construction will be difficult. The properties are insufficient, and sufficient carbon bonds cannot be obtained. Also,
If it exceeds 70 parts by weight, the amount of volatile components increases, the connective tissue becomes porous, and corrosion resistance and adhesiveness are reduced.

Although it is better to use one type of carbonaceous resin, it is better to use two or more types with different softening points. The reason is that workability is maintained by the softening and melting of the low-melting point carbonaceous resin before the material moisture at the boundary part decreases due to the heat of the base material and construction becomes difficult. The higher the value, the more it softens and melts and maintains workability. On the other hand, experiments have shown that it is easier to form carbon bonds when two or more types have different softening points.

An example of a combination of different softening points is coal pitch with a softening point of 220°C and petroleum pitch with a softening point of 220°C.

Carbon powder includes phosphorous graphite, earthy graphite, quiche graphite, crystalline carbon powder such as electrode scrap, petroleum coke, pitch coke, various car blacks, retort carbine,
One or more types selected from amorphous carbon powder such as anthracite and charcoal are used.

If the proportion of carbon powder is less than 5 parts by weight, it is not effective in improving corrosion resistance, and if it exceeds 70 parts by weight, the proportion of carbonaceous resin, which is a combined material, decreases accordingly, making it difficult to obtain carbon bonding.

The size of the above secondary particles may be 5W or less, but preferably 3W or less. This is because if the length is 5 m or more, the structure after the volatile matter has dispersed becomes porous as a whole, which reduces the strength of the structure and reduces the corrosion resistance. Therefore, the mixing ratio of secondary particles is 5 to 20 parts by weight, preferably 8 to 15 parts by weight. If it is less than 5 parts by weight, the amount of softening, melting, and diffusion will be small, and the workability will not be improved sufficiently.
In addition, the carbon bond strength is not sufficiently developed. On the other hand, if it is more than 20 parts by weight, a large amount of volatile matter will scatter, and the porosity of the constructed body will increase, resulting in a decrease in corrosion resistance.

As mentioned above, by adding secondary particles, it is possible to obtain a vibration-formed material that does not reduce workability when constructing a tap trough with high residual heat, has high corrosion resistance, and has good adhesion to the base material. It is characterized by 5 parts of secondary particles made by mixing and granulating carbonaceous resin, carbon powder, and refractory powder with 80 to 95 parts by weight of refractory aggregate whose particle size has been adjusted in advance. -20 parts by weight of vibration molding for hot repair of blast furnace tap troughs.

As the binder, commonly used binders can be used, such as alkyl sulfonates, lignin sulfonates, silicates, phosphates, alumina sol, silica sol, and the like. Table 1 shows examples of the manufacturing method and blending ratio of secondary particles in the present invention.

The method for producing secondary particles is to simply add and mix non-basic fireproof powder and carbon powder to a carbonaceous resin heated and melted at 250 to 350°C, and then punch a large number of holes in the bottom of the container.
The mixture is dripped through a quake-sized pore and cooled and solidified in a water tank placed below.

Using the blending ratio shown in Table 2, preheat to room temperature 300
℃, materials with the respective mixing ratios were put on one side of the construction body with the conventional product mixing ratio heated and kept at 1000°C, and left for 15 minutes at room temperature and 300°C, and 5 minutes at 100°C, and then 2G each. The work was carried out by applying vibrations using an excitation force of 1, and its workability and various physical properties were investigated.

In addition, as an object to be adhered, 160x40X according to the conventional blending ratio
The 40-horse construction body was fired at 1400℃ in advance, and the materials with the respective mixing ratios were applied to one side of the 40'' throat by applying vibration (5 minutes, 2G).
The O2 erosion index, which measures the adhesive strength based on the bending strength, was determined by the drum rotation erosion method, and the test piece used was one previously fired at 1400°C. Incidentally, the firing of the samples and the hot bending strength measurements were all carried out in a reducing atmosphere.

Examples using the product of the present invention are explained in Figures 1 to 3. ◎ After tapping is completed and the taphole is closed, repairs must be carried out within 80 minutes until the next time of tapping. be.

As a repair process, the taphole is closed (the mud gun is held in the taphole),
The pig iron storage condition, pig iron storage amount 3, and slag level 4 are investigated (required time: 5 minutes), the repair area is determined, and the slag 5 is scraped out to the core set level (Fig. 2).

2) Next, the deposit 10 and the dismantled object 7 are removed while the mud gun is being held (required time: 15 minutes).

In this case, the hot metal 3 is covered with the slag 5, a heat insulating board 6 made of a galvanized iron plate is placed on top of the slag 5, and the surface deposits 10 and the protrusions 7 are chipped off, as shown in Fig. 3. have a constant slope interval.

3) Core setting and molding process (required time: 20 minutes) In this process, the core 1 is set, and the repair material 8, which is the product of the present invention, is added and filled by shaking the rod-shaped pipe lake 11. Adjust the shape of the gutter.

4) Holding and drying process (time required: 25 minutes) The Higuchi body is heated to a high temperature (
700 to 1200°C), self-thermal drying is sufficient, but to accelerate drying, heating is performed from inside the core using a drying burner 12.

5) Demolding and tapping preparation process (required time: 5 minutes) After filling the gutter material, the sheath 1 is taken out in about 5 minutes, the heat shield plate 6 is collected, and the preparation for tapping is completed.

By implementing the above, as shown in Table 3, it is possible to incorporate a hot repair process two or more times between full-scale repair and full-scale repair, and the conventional full-scale repair cycle average of 70 days can be changed to 105 days and 1
．． It is a hot repair vibratory molding material that has a significant elongation of 5 times and has a great industrial effect in terms of reducing material consumption.

[Brief explanation of drawings]

Figure 1 is a schematic cross-sectional view of the gutter showing the state of iron removal after tap plugging, Figure 2 is a schematic cross-sectional view of the gutter showing the state of heat shielding before the core is set, and Figure 3 is the schematic cross-sectional view of the gutter showing the condition of the iron removal after the tap is blocked. I set it up and put in the repair material that I invented.
FIG. 2 is a schematic cross-sectional view of a gutter showing a state of vibration caused by a metaphorical break. 1... Core 2... Running refractory 3
... Hot metal 4 ... Slag 5 ... Heat shield plate 6 ... Scraping out, remaining slag 7 ... Projection 8 ... Repair material (invention) 9 ... Weight 10 ... With surface Kimono 11... Rod-shaped vibrator 12... Dry parna

Claims (1)

[Claims] A blast furnace tapping trough consisting of 5 to 20 parts by weight of secondary particles made by mixing and granulating carbonaceous resin, carbon powder, and refractory powder to 80 to 95 parts by weight of refractory aggregate whose particle size has been adjusted in advance. Vibration molding material for hot repairs.