JP2002160047A - Heat insulating cover material for molten metal, manufacturing method therefor and slag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superb heat insulating cover material for a molten metal, which facilitates recycling of ceramic industry waste, stable supply in a big volume without cost increase and operation without deterioration in working environment, and its manufacturing method as well as slag obtained by applying the cover material to the molten metal. SOLUTION: The heat insulating cover material is obtained by crashing, adjusting and baking the ceramic industry waste.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat insulating material for coating a molten metal, a method for producing the same, and a slag.

[0002]

2. Description of the Related Art Conventionally, in the process of ingot casting or continuous casting of molten steel from a melting furnace such as an open hearth furnace, a converter, and an electric furnace, the temperature of the molten steel in a ladle, a tundish, and the like is maintained. This is because it is necessary to maintain the temperature at 1,500 ° C. for about 3 hours from the ladle to the casting step. As the heat insulating material for such heat insulation, burned rice husk, perlite, vermiculite, pulp sludge incineration ash, water and sewage sludge incineration ash, or a combination thereof is used.

[0003] Among them, burned rice hulls (insulation material of rice husk raw material) has a carbon ratio of 40 to 50%, contains silica and the like, and is superior in heat insulation effect to other materials. However, processing was troublesome, the price was high, and collection in large lots was difficult. In addition, since the burned rice hulls contain many fine powders and grains, they are scattered by the rising air current, which may lower the yield and deteriorate the working environment.

[0004] Here, instead of such burned rice husks, heat insulating materials made of other mineral raw materials have been proposed as described above.
However, most of such heat insulating materials are melted by contact with molten steel when used at a high temperature for a long time, and are inferior in heat insulating properties and have a practical problem.

On the other hand, ceramic waste (hereinafter simply referred to as waste) including building interior and exterior materials such as siding board waste, etc.
They are finely pulverized by these manufacturers and recycled as a bulking material for raw materials. However, in practice, there is a problem that the strength of the finished product is reduced. For this reason, a considerable portion was landfilled at a final disposal site. In particular, siding board waste contains about 3 to 10% of fiber such as organic fiber, so that it is difficult to handle and reuse as resources. For these reasons, there is a demand for exploitation of the above-mentioned waste material recycling applications.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and makes it possible to recycle the above-mentioned waste material, stably supply a large amount without increasing the cost burden. It is an object of the present invention to provide a heat insulating material for molten metal coating, a method for manufacturing the same, and a slag which have good heat insulating properties without deteriorating the working environment.

[0007]

In order to achieve the above-mentioned object, the heat insulating material for coating a molten metal according to the present invention is characterized by being manufactured by crushing and adjusting ceramic waste material and firing it. Another aspect of the present invention is a method for producing a heat insulating material for coating a molten metal, the method including crushing adjustment of ceramic waste material, and firing. The slag obtained after using the above-mentioned heat insulating material for molten metal coating can be reused as a raw material for cement, an aggregate, a soil improvement material and the like.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a heat insulating material for coating a molten metal and a method for producing the same according to the present invention will be described. As described above, the heat insulating material for molten metal coating according to the present invention is produced by crushing and adjusting ceramic waste material and firing it.

The term "molten metal" as used in the present invention refers to a metal that has been melted at a high temperature and introduced into a tribe, tundish, torpedo car, ingot mold, or the like, and most commonly molten iron or molten steel.

In the present invention, specific examples of the ceramic waste include waste materials such as interior / exterior materials for buildings, wall tiles, blocks and the like. As the waste material of the building interior and exterior materials, inorganic interior and exterior materials are suitable, and inorganic panels such as siding boards, cement boards, ALC boards, calcium silicate boards, wood chip cement boards, wood wool cement boards, and cement ceiling boards are preferred. Waste materials can be mentioned.

Among the above, the siding board generally means a plate-like outer wall material. The siding board is manufactured, for example, by mixing other components with cement and molding a cement compound reinforced with fibrous materials. In addition, it is also possible to use an inorganic powdery material instead of cement, further blend and strengthen fibers, blend a binder, and mold the raw material.

The fibers used for reinforcement include inorganic (mineral) fibers such as glass fibers, metal fibers and carbon fibers, organic fibers such as cellulose fibers (pulp fibers, wood, cellulose fibers), PVA fibers, and acrylic fibers. And synthetic fibers such as olefin fibers such as polypropylene and aramid fibers. In the case where cement is used, alkali-resistant fibers are preferred. These fibers can be used alone or in combination of two or more. Here, a method of manufacturing a siding board will be exemplified below.

Production Method 1 Water is added to the compounded raw materials to form a slurry. The slurry is formed to a predetermined thickness by a papermaking method, and then the strip is formed into a roll, cut into a predetermined size, compressed and pressed. Obtain a siding board by curing. Examples of the compounding raw materials include the following compositions. (1) A cement compound containing cement, quartz sand and pulp fiber. The mixing ratio is preferably 30 to 50% by weight of cement, 30 to 50% by weight of silica sand, and 3 to 10% by weight of pulp. (2) A composition in which a coloring pigment is further added to cement, silica sand, and pulp fiber.

Production Method 2 Water is added to the mixture containing the mineral fiber, the inorganic powder, and the powdered synthetic resin binder as required, and the mixture is evenly dispersed to obtain a sediment. Then, the sediment is pressed and cut to an appropriate length to obtain a product. As a component, an inorganic foam or the like can be further added. Examples of the mineral fiber include rock wool, slag wool, mineral wool, and glass fiber. These mineral fibers can be used alone or in combination of two or more.

Examples of the inorganic powder include calcium carbonate, silica sand, microsilica, slag, aluminum hydroxide and the like. These inorganic powders can be used alone or in combination of two or more. Examples of the powder synthetic resin binder include powder synthetic resins such as melamine resin and phenol resin.
These powdery synthetic resin binders can be used alone or in combination of two or more.

In the present invention, in order to obtain a heat insulating material for coating a molten metal, the above-mentioned ceramic waste material is crushed and adjusted. That is, in the present invention, the crushing of the ceramic waste material is preferably adjusted to 1 mm or more and 100 mm or less. More preferably,
Adjust the crushing to 2 mm or more and 10 mm or less. Preferably, 2 mm or more and 5 mm or less are optimal. The crushing adjustment can be performed by a general-purpose crushing (crushing) device such as a jaw crusher, a roll crusher, and a pin mill.

In the present invention, after the crushing adjustment, the ceramic waste material is fired. The firing is performed in a device such as an electric furnace or a rotary kiln. When organic fibers are contained, it is preferable to carry out in a reducing atmosphere in order to keep the carbonized state.
The firing temperature is preferably 500 ° C. or more and 1,000 ° C. or less. More preferably, it is carried out at a temperature of 800 ° C. or more and 1,000 ° C. or less.

By performing firing as described above,
The heat insulating material for coating a molten metal of the present invention can be obtained. By firing, for example, even in the case of a siding board containing organic fibers, such organic components are volatilized or partially carbonized. Thereby, danger such as ignition and white smoke is eliminated, and a good heat retaining effect is obtained.

As described above, the heat insulating material for coating a molten metal according to the present invention can solidify molten steel in a favorable solidified state, for example, by applying it to molten steel from a blast furnace or an electric furnace tribe. In addition, the air does not scatter due to the ascending airflow during use, and does not deteriorate the working environment. Further, the heat insulating material for coating a molten metal according to the present invention is advantageous in terms of cost since it uses waste material. Note that both the firing step and the step of applying to molten metal such as molten steel can be performed at a high temperature, and can be performed without generating harmful substances such as dioxin.

The heat insulating material for coating a molten metal according to the present invention, when applied to molten metal such as molten steel, floats at a high temperature around 1600 ° C. This enables a large volume reduction of the waste material itself. The waste material after being applied to the molten metal has a use as a slag as a raw material for cement, aggregate, soil improvement material, etc., and can be recycled.

[0021]

EXAMPLE 1 A method for producing a heat insulating material for coating a molten metal according to the present invention was carried out using an electric furnace. (1) Waste material to be treated: Waste material of the siding board obtained in the following manufacturing process was treated. First,
As the same siding board, a slurry is prepared by adding water to a cement composition consisting of 40% by weight of cement, 45% by weight of silica powder, 5% by weight of pulp fiber, and 1% by weight of polypropylene fiber, and is formed into a 15 mm thickness using a dewatering press method. The cured product was steam-cured for 6 hours, and the product was prepared by performing a saturated wet heat curing using an autoclave.

(2) Crushing adjustment This siding board was crushed and adjusted to 2 mm or more and 5 mm or less. The crushing adjustment was performed by a roll crusher.

(3) Sintering The siding board waste crushed and adjusted was fired at 800 ° C. in a reducing atmosphere in an electric furnace.

By performing the above firing, a heat insulating material for coating the molten metal was obtained. The organic fibers partially volatilized and were partially carbonized and remained. When this heat retaining material for coating a molten metal was applied to molten steel from a molten steel electric furnace, it was confirmed that the molten steel exhibited a favorable solidification state and had a heat retaining effect. Further, the heat insulating material did not scatter due to the rising air current during use, and did not deteriorate the working environment.

Further, it was confirmed that the suspended slag applied to the molten steel can be recycled as a raw material for cement or an admixture for cement.

Example 2 A method for producing a heat insulating material for coating a molten metal according to the present invention was carried out using an electric furnace. (1) Waste material to be treated: Waste material of the siding board obtained in the following manufacturing process was treated. As a siding board, 40% by weight of cement and 35 of silica powder
Wt%, fly ash 10 wt%, perlite 8 wt%, pulp fiber 6 wt%, polypropylene fiber 1 wt%
Water was added to the cement composition, and the mixture was kneaded, and the die was controlled to have a thickness of 12 mm by an extruder, steam-cured for 6 hours was added thereto, and saturated wet heat curing with an autoclave was performed to produce the mixture. Was prepared.

(2) Crushing Adjustment This siding board was crushed and adjusted to 2 mm or more and 5 mm or less. The crushing adjustment was performed by a ball crusher.

(3) Firing In an electric furnace, the crushed and adjusted siding board waste was fired at 850 ° C. in a reducing atmosphere.

By performing the above firing, a heat insulating material for coating the molten metal was obtained. When this heat retaining material for coating a molten metal was applied to molten steel from a molten steel electric furnace, it was confirmed that the molten steel exhibited a favorable solidification state and had a heat retaining effect. Further, the heat insulating material did not scatter due to the rising air current during use, and did not deteriorate the working environment.

Further, it was confirmed that the suspended slag applied to the molten steel can be recycled as a cement raw material or a cement admixture.

The heat insulating material for coating a molten metal and the method for producing the same according to the present invention have been described with reference to the embodiments and examples. However, the technical scope of the present invention is not limited to these, and those skilled in the art Changes, additions, and modifications obvious to
All are included in the technical scope of the present invention.

[0032]

As is clear from the above description, according to the present invention, it is possible to recycle ceramic waste materials, and to stably supply large quantities without increasing the cost burden. Without deteriorating the work environment,
Provided are a heat insulating material for coating a molten metal having a good heat insulating property, a method for producing the same, and a slag obtained by applying to the molten metal.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ichiro Ishiki 3-8-1 Nishikanda, Chiyoda-ku, Tokyo F-term (reference) Asanouchi Co., Ltd. 4E004 MB14

Claims (13)

[Claims] 1. A heat insulating material for molten metal coating obtained by crushing, adjusting and firing ceramic waste material. 2. A ceramic waste material is crushed and adjusted to 1 mm or more and 100 mm or less, and then 500 ° C. or more and 1,000 mm or less.
The heat insulation material for molten metal coating according to claim 1, wherein the heat insulation material is obtained by firing at a temperature of not more than ℃. 3. The heat insulation material for molten metal coating according to claim 1, wherein the ceramic waste material is a waste material of interior and exterior materials for buildings. 4. The heat insulating material for covering a molten metal according to claim 3, wherein the building interior / exterior material is a siding board. 5. The method according to claim 1, wherein the siding board is cement,
The heat insulating material for molten metal coating according to claim 4, which is a siding board obtained by adding water to a cement composition containing silica sand and organic fibers to form a slurry, and forming the slurry. 6. The insulating material for molten metal coating according to claim 4, wherein the siding board is a siding board obtained by molding a compound containing an inorganic powder, a fiber, and a binder. . 7. A method for producing a heat insulating material for molten metal coating, comprising crushing, adjusting and firing ceramic waste material. 8. Crushing of ceramic waste material to 1 mm or more and 100 mm or less, and then 500 ° C. or more and 1,000 mm or less.
8. The method according to claim 7, further comprising firing at a temperature of not more than ℃.
3. The method for producing a heat insulating material for molten metal coating according to item 1. 9. The method for producing a heat insulating material for coating a molten metal according to claim 7, wherein the ceramic waste material is a waste material of interior and exterior materials for buildings. 10. The method according to claim 9, wherein the building interior / exterior material is a siding board. 11. The siding board according to claim 10, wherein the siding board is obtained by adding water to a cement composition containing cement, silica sand, and organic fibers to form a slurry, and molding the slurry. Heat insulator for metal coating. 12. The heat insulating material for molten metal coating according to claim 10, wherein the siding board is a siding board obtained by molding a compound containing an inorganic powder, a fiber, and a binder. . 13. A slag obtained by applying the heat insulating material for coating a molten metal according to claim 1 to a molten metal.