JPS62138372A - Manufacture of heat retaining heat insulating material - 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] [Industrial Application Field] The present invention is a heat-insulating material, particularly for use in direct or indirect contact with molten metal, such as ingot seals, ingot bases, riser sleeves, gutters, and ingot substrates. This invention relates to a method of manufacturing a heat-insulating material.

[Conventional technology]

As the heat-retaining insulation material mentioned above, it is known that an inorganic and/or organic binder is added to ceramic fibers, this is made into a water-dispersed slurry, formed into a predetermined shape by a method such as vacuum forming, and dried. .

However, the conventional ceramic fiber-containing heat-insulating materials manufactured in this manner, which contain organic binders, are exposed to high temperatures during use and generate smoke, odor, irritating gases, etc., deteriorating the working environment.

On the other hand, products made by bonding ceramic fibers with only a mix binder require a large amount of binder to provide strength, and the surface is coated with a coating material to prevent this inorganic binder from reacting with molten metal. 0 In addition to heat-retaining insulation materials containing ceramic fibers, there are also materials made by adding organic or inorganic binders to refractory powder, and molded hydrated powders such as calcium silicate and hardened by hydration. However, they are both heavy and inconvenient to handle, and hydration-cured products have problems such as decomposition of hydrates at the temperature during use and deterioration of strength.

[Problem that the invention seeks to solve]

The present invention does not generate smoke, odor, irritating gas, etc. that worsen the working environment, is lightweight and has sufficient strength, and does not cause any inconvenience even if it comes into direct contact with molten metal. The purpose of the present invention is to provide a method for manufacturing a heat insulating material.

[Means for solving problems]

In order to achieve the above object, the present invention adds 10 to 70% by weight of an organic material that carbonizes when heated to a ceramic fiber, molds it into a desired shape, and then bakes it in a non-oxidizing atmosphere to add the organic material to the ceramic fiber. Provided is a method for producing a heat-insulating material, which is characterized by carbonizing the material.

As the ceramic fiber, in addition to aluminosilicate fiber, one type or a mixture of several types such as high alumina fiber and Zirr-ya fiber can be used.

Further, as the organic material that is carbonized by heating, organic fibers such as polyacrylonitrile fibers and regenerated cellulose fibers; organic binders such as carboxymethyl cellulose (CMC) and phenol formaldehyde can be used.

[Effect]

Organic materials that are carbonized by heating can be heated and fired at an appropriate temperature in a non-oxidizing atmosphere, such as a vacuum, a reducing atmosphere, or an inert gas atmosphere, to eliminate carbonization, smoke, odors, irritating gases, etc. It becomes a carbonaceous substance that does not generate any carbon and remains between the ceramic fibers, giving strength to the heat-insulating material and providing good releasability to molten metal.

Therefore, if the content of the organic material in the mixture of ceramic fibers and organic material is less than 10% by weight, the return of the heat-retaining and insulating material to the molten metal increases, resulting in poor release properties. In order to improve the ability to release hot water, carbonaceous materials such as carbon fibers are used in addition to organic materials that carbonize when heated.
It can also be used within the range of ~70% by weight. In addition, when the content of organic materials exceeds 70% by weight, the amount of ceramic fibers forming the skeleton decreases relatively, and as the carbonaceous content decreases due to repeated use of the thermal insulation material at high temperatures, it becomes difficult to maintain the shape. Become.

The table below lists the experimental results showing the relationship between the content of organic materials, the strength of the thermal insulation material, and the releasability of molten aluminum.

〔Example〕

Example 1 Polyacrylonitrile fibers were added in a range of 0 to 75% by weight to an equal amount tR compound of aluminosilicate ceramic fiber for 1260 t:'' and high alumina ceramic fiber for 1600 C, and this was dispersed in water. The slurry was formed into a board by vacuum forming. After drying, the formed product was heated and fired in a vacuum furnace at 100 Orr for 1 hour.

Table 1 shows the test results regarding the heat shrinkage rate, strength, and releasability of molten aluminum of the obtained thermal insulation material.

Table 1 Example 2 100 parts by weight of aluminosilicate ceramic fiber, 50 parts by weight of silica powder as an inorganic filler, and 25 parts by weight of organic material phenol formaldehyde were mixed to form a water-dispersed slurry, which was then plated using a paper machine and pressed. After being pressurized with a rock so that the bulk density after drying becomes 0.65 mm, it is dried and heated to 1000 mm in a vacuum oven.
It was heated and baked at t: for 1 hour. When the obtained heat-insulating material was immersed in molten aluminum, it did not emit smoke or get wet with aluminum, and exhibited extremely good properties.

Example 3 100 parts by weight of aluminosilicate ceramic fiber, 5 parts by weight of colloidal silica as an inorganic binder, 5 parts by weight of CM0 as an organic binder, 20 parts by weight of fine wood chips
Parts by weight and 15 parts by weight of polyacrylonitrile fibers were mixed to form a water-dispersed slurry, which was formed into a gutter shape by vacuum forming. After drying, it was heated and baked in a vacuum oven at 1000 U for 1 hour.

When molten aluminum was transferred through the resulting gutter, no smoke was generated and the water heated well.

〔Effect of the invention〕

According to the present invention, almost no combustible organic matter is present in the heat-retaining insulation material, so there is no generation of smoke, odor, irritating gas, etc. during high-temperature use, and there is no risk of deterioration of the working environment. In addition, since the structure has a structure in which the spaces between the ceramic fibers are filled with carbonaceous material, the molten metal heats up extremely well even without being covered with a coating material, making it possible to produce a lightweight and sufficiently strong heat-retaining insulation material at a low price. can be provided to

Applicant: Isolite Pubhook Fireproof Co., Ltd. Masao Yamamoto\1-1

Claims (1)

[Claims] (1) Heat retention characterized by adding 10 to 70% by weight of an organic material that carbonizes when heated to ceramic fibers, molding it into a desired shape, and then firing it in a non-oxidizing atmosphere to carbonize the organic material. Method of manufacturing insulation material.