JPH0451514B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] This invention relates to a vibration-formed refractory, particularly a vibration-formed refractory for use in a tilting trough of a blast furnace tap trough. [Conventional examples and their problems] Stamped materials, poured materials, etc. have conventionally been used as lining materials for blast furnace tap troughs. Stamp materials are used in the stamp construction method, which uses an air rammer to push the raw material into a predetermined shape, but the construction process involves long hours of work in high-temperature dust and is accompanied by vibrations. Environmentally undesirable. For this reason, pouring materials have come to be mainly used instead of stamping materials. However, it is necessary to increase the fluidity of pouring materials to improve workability, and for this purpose, 5 to 8% moisture is added. Porosity after time drying is 15%
As mentioned above, the porosity after firing at 1400℃ for 2 hours increases to more than 20%, making it difficult to obtain a dense construction body with low porosity, and as a result, it is difficult to reduce the amount of wear and tear. . In general, the tilting trough in a blast furnace tap trough is exposed to harsh conditions such as falling hot metal, repeated heating and cooling due to receiving and resting, but troughs made of poured material are The disadvantage is that the service life is short, about 20 days, for some reason. Therefore, JP-A No. 51-1487714 discloses a refractory for vibration molding in which alumina, silicon carbide, carbon, and metal silicon or silicon nitride are used as refractory raw materials, and in particular, alumina fine powder is blended into a part of the above alumina. Furthermore, Japanese Patent Application Laid-open No. 73671/1983 discloses a monolithic refractory material for blast furnace tap troughs containing metal fibers for the purpose of improving the structural strength of a construction body. However, the refractory for vibration molding described in the above-mentioned JP-A-51-1487714 and the above-mentioned JP-A-56-1989
Both of the monolithic refractory materials for blast furnace tap troughs described in Publication No. 73671 have a porosity of around 25%, so they cannot be said to be dense construction bodies as described above, and slag etc. This results in easy corrosion, and its corrosion resistance is inadequate. [Means for Solving the Problems] The present invention was proposed in view of the above-mentioned conventional circumstances, and it improves the fluidity of a vibration-molded refractory blended with known metal fibers such as steel or stainless fibers. Vibration molded refractories that reduce the amount of added water without causing damage, make the structure denser, improve corrosion resistance against hot metal and molten slag, and improve abrasion resistance and spalling resistance due to falling hot metal. The purpose is to obtain. In order to achieve the above object, the present invention employs the following means. That is, in a vibration-molded refractory made by adding 2 to 5 parts by weight of steel or stainless steel fiber to 100 parts by weight of a refractory raw material whose main components are alumina aggregate, ultrafine alumina powder, silicon carbide, carbon material, etc. To the above vibration molded refractory, 0.01 to 0.1 parts by weight of potassium soda tartrate,
It is a vibration molded refractory obtained by adding 0.01 to 0.1 parts by weight of a polyalkylaryl sulfonate and 0.01 to 0.1 parts by weight of oxalic acid, and mixing 3 to 5 parts by weight of water with the refractory raw material. [Operation] In this invention, the refractory raw materials used are alumina aggregate, silicon carbide, clay, alumina cement, ultrafine alumina powder, hydrophilic carbon, and metallic silicon. Examples of alumina aggregates include fused alumina, sintered alumina, clay shale, and bauxite.The amount used is 50 to 80% by weight of the refractory raw material, and the particle size is adjusted as appropriate to enable dense packing. It is used as Silicon carbide is effective in preventing erosion of slag and hot metal, and silicon carbide with a particle size of about 0.3 mm or less is used in an amount of 5% to 15% by weight based on the total amount of refractory raw materials.
If it is less than 5% by weight, it will not be effective in preventing erosion, and if it exceeds 15% by weight, the fluidity required for construction will not be obtained even if vibration is applied, and construction workability will deteriorate.
Undesirable. Clay has the effect of increasing strength in the intermediate temperature range (800-1200°C). There are no particular restrictions on the clay that can be used, but for example, diyodia kaolin, Motoyama Kibushi clay, etc. can be used. The particle size of clay is
The thickness is 5 μm or less, and the mixing ratio is 1 to 5% by weight based on the total amount of the refractory raw material. 1% clay by weight
If it is less than 5% by weight, the strength cannot be increased, and if it exceeds 5% by weight, fluidity cannot be obtained and workability is deteriorated, which is not preferable. Alumina cement is 1-5% by weight as a binder
Mixed. If the amount used is less than 1% by weight, it is not preferable because the time required for curing the construction body becomes longer. Moreover, if it exceeds 5% by weight, it is undesirable because it becomes easily eroded by hot metal and slag. Ultrafine alumina powder starts sintering in the intermediate temperature range, and has the role of increasing the strength and densification of the constructed body in the high temperature range. The particle size is about 20μm or less,
It is used in an amount of 5 to 10% by weight based on the total amount of refractory raw materials.
If the amount of ultrafine alumina powder is 5% by weight or less, sufficient strength and denseness of the constructed body in the above-mentioned high temperature range cannot be obtained. Also, if it is mixed in at 10% by weight or more,
The necessary fluidity cannot be obtained during construction. Hydrophilic carbon is carbon whose surface has been treated with hydrophilic organic substances such as dextrin and polyvinyl alcohol.It is effective in preventing erosion of hot metal and has been hydrophilically treated, so it can be used with water, such as potassium soda tartrate, etc. Contributes to reducing the amount of addition.
Furthermore, it also contributes to increased strength in the temperature range of 400 to 800°C. This hydrophilic carbon has a particle size of about 1 mm or less, and is added in an amount of 1 to 5% by weight based on the total amount of the refractory raw material. If the amount used is less than 1% by weight, there will be no effect of preventing hot metal erosion, and if it is less than 5% by weight, surface oxidation will increase during drying before use and during use, resulting in increased wear. Metallic silicon contributes to an increase in strength at 1000 to 1400℃, but the effect is small below 1% by weight, and 3
If it exceeds % by weight, the necessary fluidity cannot be obtained even if vibration is applied, resulting in poor construction workability, which is undesirable. In this invention, in order to reduce the amount of water added, 0.01 to 0.1 part by weight of potassium soda tartrate, 0.01 to 0.1 part by weight of polyalkylaryl sulfonate, and 0.01 part by weight of oxalic acid are added to 100 parts by weight of the above refractory raw material. ~0.1 part by weight is added. As the polyalkylaryl sulfonate, a dispersant containing a β-naphthalene sulfonic acid sodium formalin condensate as a main component, etc. can be used. By adding these three substances, the amount of water added can be reduced to three times the amount of refractory raw material.
~5 parts by weight (conventionally 5 to 8 parts by weight) is sufficient, and therefore the construction body can be finished precisely. It is not preferable that the amounts of the three substances added are outside the above ranges, since fluidity deteriorates when the amount of water added is small. Furthermore, if the amount of the three substances added is greater than the above range, the curing time will be too long, and
If the amount is too low, the porosity of the constructed body will increase, resulting in poor durability. By finely finishing the refractory as described above, it is possible to reduce the amount of wear and tear on the refractory at high temperatures. Because thermal spalling due to impact, heating, and cooling is large, measures to prevent peeling and cracking are required. It is also necessary to take measures to prevent explosions during heating. Therefore, in this invention, steel fibers or stainless steel fibers are added to the above raw materials. The amount of this fiber added must be 2 to 5 parts by weight based on the amount of the refractory composition.
If the amount of steel fiber is less than 2 parts by weight, sufficient tensile strength cannot be obtained, and if it is more than 5 parts by weight, kneading in a mixer becomes difficult, which is not preferable. This invention combines each of the above-mentioned components in a predetermined amount,
3 to 5 parts by weight of water of the refractory raw material is added. If the water content is less than 3 parts by weight, fluidity necessary for construction cannot be obtained. Furthermore, when the water content exceeds 5% by weight, the porosity increases, and therefore the erosion of hot metal and slag becomes more intense. After adding water and kneading the refractory as described above, the construction frame is fixed to the tilting trough of the blast furnace tap trough, etc.
Vibration filling using a normal vibration construction method provides fluidity equivalent to that of conventional pouring material, and therefore fills gaps sufficiently. [Example] Based on the above description, each component was blended as shown in the Example column of Table 1, and for comparison, a blend related to the conventional pouring method was blended as shown in the Comparative Example column. Sodium aromatic sulfonate was added as a water reducing agent to the same fire-resistant raw materials as in the Examples section above, and the mixture was mixed as shown in the Comparative Examples section, molded using each method to prepare test pieces, and various tests were carried out. I went. Table 2 shows the measurement results of the bulk specific gravity, room temperature bending strength, compressive strength, and hot bending strength of the examples and comparative examples, and the porosity and slag corrosion resistance index of the examples, comparative examples, and comparative examples. It is shown in Table 3. Furthermore, the second
“〇〇℃×△△hr” written in the bulk specific gravity, room temperature bending strength, compressive strength, and porosity columns of Tables and Table 3
indicates the measurement result after firing for △△ hours at a temperature of 〇〇°C. In other words, since the porosity has decreased moisture, after drying (110℃ x 24hr) and after firing (800℃ x 2hr or
1400°C x 2 hours) are both smaller than those of the comparative example, and therefore the bulk specific gravity is larger. Furthermore, by incorporating steel fiber, we were able to obtain dramatically large values for room temperature bending strength, compressive strength, and hot bending strength. In addition, the slag corrosion resistance index in Table 3 is determined by performing a high frequency slag erosion test on the test pieces in the example column and the comparative example column at 1650°C for 2 hours using ordinary steel and 200 g of converter slag. quantity
100 and expressed as a relative index. This result shows that the examples according to the present invention are excellent in corrosion resistance. In addition, when refractories with the composition shown in Table 1 were installed and used in tilting troughs using the respective construction methods, the service life of the comparative example was 20 days, while the service life of the example was 35 days. The durability has been significantly improved. The water-reducing function of the water-reducing agent according to the present invention is particularly excellent, and even when the added water content is 4% by weight, the workability during kneading is good and the resulting construction material is dense.
In particular, it exhibits a remarkable water-reducing function in vibration-molded refractories containing metal fibers.

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[Table] * Bulk specific gravity, room temperature bending strength, compressive strength, hot bending strength [Effects of the invention] As explained above, this invention uses potassium soda tartrate and polyalkylaryl sulfonic acid for refractory raw materials. Since salt and oxalic acid are mixed in to suppress the moisture content to 3 to 5% by weight of the refractory raw material, the heating drying time can be shortened and the density of the construction body can be increased. A construction body with high erosion resistance against slag can be obtained.
In particular, when steel or stainless fiber is added to improve strength, the amount of added moisture can be reduced without reducing fluidity, resulting in a dense construction body.

Claims (1)

[Claims] 1. Vibration made by adding 2 to 5 parts by weight of steel or stainless steel fiber to 100 parts by weight of a refractory raw material whose main components are alumina aggregate, ultrafine alumina powder, silicon carbide, carbon material, etc. In the molded refractories, 0.01 potassium soda tartrate is added to the above vibration molded refractories.
~0.1 part by weight, polyalkylaryl sulfonate
1. A vibration-molded refractory characterized by adding 0.01 to 0.1 parts by weight of oxalic acid and 0.01 to 0.1 parts by weight of oxalic acid, and mixing water with 3 to 5 parts by weight of a refractory raw material.