JPS60141666A - High strength lightweight refractory heat insulating block and manufacture - 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 relates to a new M high-strength lightweight fireproof insulation block and a method for manufacturing the same.

Fireproof insulation materials, which are mainly used in heating furnaces and other equipment to save energy by strengthening insulation, utilize the insulation properties of air by creating pores and air layers within their structure to reduce thermal conductivity. Generally, fireproof insulation bricks, ceramic fiber insulation materials, lightweight castable refractories, etc. are used. Among these, fireproof insulation bricks have drawbacks such as insufficient strength and a low maximum operating temperature of usually around 1600°C. Insulating materials made from ceramic fibers processed into blankets, felts, blocks, etc. are lightweight and have great heat insulating properties, but because the fibers used are amorphous, the temperature increases over time and when used. At the same time, crystals precipitate and become coarse, resulting in loss of flexibility and pulverization, or shrinkage, which causes major drawbacks such as not being able to withstand long-term use at high temperatures. In addition, splashes from hot metal, scale from steel ingots, mineral dust, etc. can adhere to the surface and cause deterioration, and if the gas flow in the furnace is fast, the fibers on the surface can be blown away and damaged. There are also drawbacks.

In addition, lightweight castable refractories contain static aggregate and lime (Cab), so they cannot withstand long-term use at high temperatures, are complicated to construct, and use a large amount of water, so after construction. There are drawbacks such as the need for a large amount of time and a heat source for drying.

The present inventor has developed a specific fire-resistant insulation material that does not have the above-mentioned drawbacks, that is, it is lightweight, has a high maximum operating temperature, has sufficient strength, has little deterioration during use, and is stable for a long period of time. Rod-shaped or () string-shaped molded bodies are arranged irregularly or (
and) A new coal block, which is a sintered body that is regularly arranged and sintered, has been developed and a separate application is being filed. As a result of continued research, the present inventor has discovered that by covering the molded body before firing with a covering material, the strength of the molded body itself improves after firing, and the bonding strength between the molded bodies can be strengthened. The present inventors have discovered that the strength of the block obtained is further increased, and deterioration during use is further reduced, and the present invention has been completed.

That is, the present invention is a rod-shaped or (and) string-shaped molded article containing a refractory raw material and a binder and having a cross-sectional diameter of 0.3 to 5 m+Il, the surface of which is coated with a coating material. contains irregularly or (and) regularly arranged, integrated, high-strength, lightweight fire-resistant and heat-insulating blocks, as well as fire-resistant raw materials and a binder, and has a cross-sectional diameter of 0.3 to 5 mm. A rod-shaped or (and) string-shaped molded body, or a dried or calcined product whose surface is covered with a coating material, or a dried or calcined product placed irregularly in a molding frame or (and) The present invention relates to a method for producing a high-strength, lightweight, fire-resistant and heat-insulating block, which is characterized by filling the blocks in a regular array, and then baking and integrating them.

The high-strength, lightweight, fireproof, heat-insulating block of the present invention is the above-described specific rod-shaped or (and) string-shaped molded body whose surface is covered with a coating material (hereinafter referred to as a coated rod-shaped or string-shaped molded body). ) are arranged irregularly or (and) regularly and are sintered and integrated, and because it has a large number of voids in its structure, it is lightweight and has excellent heat insulation properties.
However, it has high strength.

Here, sintering covered rod-shaped or (and) string-shaped molded bodies arranged irregularly or (and) regularly means, for example, (1) having a fixed or various shapes (length, length, etc.); (2) coated rod-shaped molded bodies of a certain shape and diameter may be irregularly intertwined and sintered, or (2) coated rod-shaped molded bodies of a certain shape may be irregularly entangled. The coated rod-like molded body of a certain shape, which has a different shape, is alternately intertwined with one or more layers in which the coated rod-shaped molded body is irregularly entangled, or ) may be continuously or discontinuously overlapped and sintered in the order of (3) a layer in which coated rod-shaped molded bodies of a fixed or various shapes are arranged in a fixed direction and a layer in a different direction ( For example, layers arranged in the right angle direction) may be alternately overlapped and sintered, or coated rod-shaped molded bodies of (4)-4 or of various shapes and coated rod-shaped bodies of fixed or various shapes may be sintered. (5) Covered string-like molded bodies of fixed or various shapes may be irregularly or regularly folded and sintered. (6) A layer in which a coated string-like molded body of a fixed or various shapes is folded irregularly or regularly and a coated rod-shaped molded body of a fixed or various shapes. This indicates that the molded body may be sintered with irregularly intertwined or regularly arranged layers alternately overlapping each other.

The high-strength, lightweight, fireproof, heat-insulating block of the present invention is manufactured, for example, as follows.

First, a refractory raw material, a binder, water, etc. are kneaded and extruded into a rod or string shape using an extrusion molding machine i or the like. The rod-shaped molded body may be obtained by appropriately cutting a string-shaped molded body base material or a product obtained by drying or calcining the same, or may be obtained by cutting a regular molded body into a rod shape. The cross section of the rod-shaped molded body or string-shaped molded body may be any shape such as circular, oval, square, rectangular, polygonal, etc., and may be solid or hollow, but the diameter thereof is about 0.3 to 5 mm. It is better to

In addition, the diameter in the present invention is of course the diameter of a platform with a circular cross section, but the diameter in cases other than circular is the following formula). The diameter is Q
If the size is smaller than 3mm, it is difficult to manufacture, and the structure of the block after firing tends to be dense, reducing the insulation effect.If the size exceeds 511, the structure of the block after firing becomes sparse, resulting in poor strength. This is not preferable because it tends to decrease.

Further, the rod-shaped molded body or string-shaped molded body may be linear or curved, or may be twisted. Rod-shaped and string-shaped are originally continuous concepts, so in the present invention, the length of the rod-shaped molded product is not limited at all, but for convenience of handling, the length is usually 3 to 300 II.
I! It is often a degree.

The refractory raw material used above is not particularly limited and may be acidic, neutral, or basic, such as alumina, mullite, clay shale, zircon, zirconia,
Spinel, magnesia, clay, dolomite, silica, chamotte, chromium, lime, etc. can be mentioned, and one or more of these can be used in combination to meet the required usage conditions (e.g. maximum usage temperature, required strength, etc.). , reactivity with heated objects such as furnace walls, etc.). Carbon, silicon carbide, nitride, etc. may be used in combination as a refractory raw material. These refractory raw materials are used after appropriately adjusting the particle size according to a conventional method. The binder is not particularly limited, and examples include organic binders such as methyl cellulose, polyvinyl alcohol, dextrin, sodium lignin sulfonate, pitch, tar, and resin, sodium silicate, potassium silicate, aluminum phosphate, and phosphoric acid. Examples include inorganic materials such as magnesium, and at least one of these is used.

The above-mentioned refractory raw material and binder are kneaded according to a conventional method, adding water or the like if necessary, and then formed into a rod or string shape as described above.

Next, the obtained rod-shaped molded body or (and) 1 m-shaped molded body is used as a raw material or after drying or calcining, the surface thereof is coated with a coating material.

As the coating material in the present invention, at least one of metal powder, inorganic material, and organic material is used in the form of powder, solution, or suspension depending on its properties. In the above, metals include, for example, AQ, Si, Fe, Cr.
, Cu, Ti, etc. In addition to the various refractory raw materials mentioned above, examples of inorganic materials include micro silica, alumina sol, silica sol, alumina cement, bittern, silicates such as sodium silicate and potassium silicate, aluminum phosphate, and phosphoric acid. Examples of organic materials include phosphates such as magnesium, sodium birophosphate, and sodium hexametaphosphate, and examples of organic materials include pitch, tar, sodium ligninsulfonate, and phenol resin.

When the coating material is used in powder form, the particle size is not particularly limited and may be determined as appropriate. In addition, examples of solvents used when making the coating material into a solution or suspension include water, alcohols, petroleum nitrate, butyl acetate, toluene, glycerin, triheromethane, and glycol. One type or a mixture of two or more types are used. The concentration of the solution or suspension may be appropriately determined depending on the properties of the solute or suspended component, the coating method, and the like.

The method of coating the rod-shaped or string-shaped molded body with the coating material is not particularly limited, but may be carried out, for example, as follows. That is, when coating a rod-shaped or string-shaped molded body base, it is usually coated by appropriately adhering a powder coating material, or by dipping, spraying, etc. with a solution or suspension coating material. Good. Further, when coating a dried or calcined rod-shaped or string-shaped molded article, it is sufficient to coat it with a coating material in the form of a solution or suspension by dipping, spraying, or the like.

In the above, when a coating material in the form of a solution or suspension is used, drying or calcining is normally performed as appropriate after coating.

Further, when a powder coating material is coated on a substrate, it may be left as is or may be dried or calcined as appropriate. Further, the coating may be applied once, but may be applied multiple times as necessary. Further, the amount of coating is not particularly limited, and may be appropriately determined depending on the type of coating material, the required strength of the block, etc.

Next, the rod-shaped or (and) string-shaped molded body coated as described above is filled into a molding frame made of refractory material, etc., and usually 1
000~2000℃ preferably 1350~1900℃
It is baked at a temperature of ℃ to integrate it.

When filling the molded frame with the coated rod-shaped molded bodies and/or string-shaped molded bodies, they are filled irregularly or (and) regularly arranged. At this time, if necessary, vibration may be applied, or it may be pressed with an appropriate pressure after filling.

Further, the firing may be performed while the mold is filled in the mold, or the mold may be removed from the mold. The firing temperature should be set in consideration of the composition of the raw materials used and various properties such as strength required for the block after firing, and to ensure that the block does not change in quality or shrink in structure during use as a heat insulating block. , Within the above range, select a temperature that is approximately equal to or higher than the operating temperature. The firing time may also be determined as appropriate. The molding frame used above can be of any shape, including rectangular parallelepiped, plate-shaped, cubic, prismatic, cylindrical, cylindrical, etc.
Blocks with irregular shapes such as spherical shapes or a combination of these can be manufactured depending on the purpose of use.

The high-strength pumice fireproof insulation block of the present invention is characterized by the following characteristics: the refractory raw material used, the type of covering material, the length of the covered rod-shaped molded body or (and) the string-shaped molded body, the shape and diameter of the cross section, the arrangement method,
By selecting and combining various firing temperatures, etc., the strength of the product, the ω (bulk specific gravity) of the voids, the density, the maximum use temperature, etc. can be adjusted as appropriate depending on the purpose of use.

The high-strength, lightweight, fire-resistant insulation block of the present invention has a novel structure not previously known, is lightweight and has high strength, can have a high maximum operating temperature, is easy to construct, and is easy to use. It is stable for a long time with little deterioration. Therefore, the high-strength, lightweight fireproof insulation block of the present invention can be suitably used as a fireproof insulation material for, for example, tundish covers, various molten metal container covers such as ladles, various gutter covers, heating furnaces, soaking furnaces, electric furnaces, etc. .

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A particle-sized refractory raw material consisting of 97 parts by weight of chamotte containing 71% by weight of alumina and 29% by weight of silica and 3 parts by weight of kaolin clay was kneaded with 30 parts by weight of a liquid binder (15% by weight aqueous solution of methylcellulose). After that, an extrusion molding machine is used to make a circular cross section with a diameter of 2u+ and a length of 10
A rod-shaped molded body of ~120 mm was obtained. This particle size is 1o
The product was placed in a container containing μm microsilica powder to obtain a rod-shaped molded product whose surface was coated with microsilica powder. A molding frame (400'x400xl 50 ([11111] made of high alumina bricks) assembled on a firing trolley.
Filled in a tunnel kiln at a maximum temperature of 1600℃.
When fired at .degree. C. for 6 hours, a block was obtained in which the individual coated rod-shaped compacts were irregularly intertwined and sintered to form an integrated block. The physical properties of this block are shown in Table 1. Table 1 shows that the high-strength, lightweight fireproof and heat-insulating block of the present invention is lightweight and has high strength. For comparison,
Examples of commercially available products (Company A: alumina-silica-based ultra-light fireproof insulation bricks) are also listed in Table 1.

Example 2 In Example 1, the rod-shaped molded body whose surface was coated with microsilica powder was immersed in a 60% aqueous solution of bittern at 110°C.
A block was obtained in the same manner as in Example 1, except that a rod-shaped molded body whose surface was coated by drying for 20 hours was used. The physical properties of this block are shown in Table 1. From Table 1, it can be seen that this material is also light, durable, and has high strength.

Table 1

Claims (1)

[Claims] ■ A rod-shaped or (and) string-shaped molded article containing a refractory raw material and a binder and having a cross-sectional diameter of 0.3 to 5I, the surface of which is covered with a coating material. A high-strength, light-weight, fire-resistant and insulating block made of irregularly or (and) regularly arranged sintered blocks. ■ A rod-shaped or (and) string-shaped molded body containing a refractory raw material and a binder and having a cross-sectional diameter of 0.3 to 5 ml1, or a dried or calcined product whose surface is coated with a coating material. Or manufacture of a high-strength, lightweight fireproof and heat-insulating block characterized by drying or calcining the same and filling it in a forming frame in an irregularly or (and) regularly arranged arrangement, and then baking and integrating it. Law.