JPS61219774A - Lightweight refractory structural 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 [Field of Industrial Application] The present invention relates to a lightweight fire-resistant structural material that is lightweight and has excellent heat insulation properties and volumetric stability in an environment at high temperatures of 1000° C. or higher.

[Conventional technology]

Generally, diatomite bricks, castable refractories made of alumina cement mixed with lightweight aggregate, cellular concrete, etc. are known as structural materials.

However, in an atmosphere of 1000°C or higher, especially 1500°C or higher, siliceous bricks lack heat insulation and fire resistance, and castable refractories, even though they have sufficient fire resistance, lack heat insulation and become bulky. The specific gravity was also heavy, at 19/cyr' or more.

In aerated concrete, the use was of an inner cone, which caused explosion and melting.

[Problem that the invention seeks to solve]

The present inventors have conducted extensive studies on the development of a lightweight fire-resistant structural material that is lightweight, has excellent heat insulation and volume stability, and has good workability in high-temperature atmospheres of 1000°C or higher, especially 1500°C or higher, and found that a specific composition They found that it would be better to mix fine powder refractory aggregate and air bubbles with alumina cement to increase the overall porosity to 50% or more, and have completed the present invention.

Means for Solving Problems C] That is, 1. The present invention provides a composite material comprising an alumina cement hydrate, a finely divided refractory aggregate with a maximum particle size of 1n or less and an average particle size of 88μ or less, and air bubbles with a diameter of 30 or less. A hardened product having a porosity of 50% or more, the alumina cement hydrate contains Ca
O”At20350~70 parts by weight, ?2 Ca07
kl, gos 10-40 parts by weight, CaO・2 Atz
This is a lightweight fireproof structural material characterized by being a hydrate of alumina cement consisting of 0 to 50 parts by weight of Os and 0 to 60 parts by weight of amorphous material.

The present invention will be explained in more detail below.

The alumina cement used in the present invention is CaO・At8
0350-70 parts by weight, i2Ca07 At2031
The alumina cement consists of 0 to 40 parts by weight, 2030 to 50 parts by weight of Ca02At, and 0 to 60 parts by weight of amorphous material.Alumina cements other than these have lower strength and fire resistance at high temperatures.

The fine powder refractory aggregate is preferably one that exhibits little volumetric expansion or contraction due to thermal changes, such as α-kL203, MgO・M,
08.3 Ata03-2810. ．． 8102 and Cr
2O3 etc. can be used. The particle size structure is such that the maximum particle size is 1 μm or less and the average particle size is 88 μm or less; otherwise, the insulation properties will be poor, the bulk specific gravity will become large, and cracks will occur due to expansion and contraction due to thermal changes.

The bubbles have a diameter of 6 mm or less, and if the bubbles are larger than that, the insulation and strength will be reduced. The amount of air bubbles is the amount that makes the porosity 50% or more, and if it is less than 50%, the insulation properties will be poor.The method of mixing air bubbles is as follows: (1) Add a predetermined amount of combustible material to alumina cement and Or a method of adding 710 to fine refractory aggregate, adding water to make a slurry, hardening it, and heating to remove combustible substances. (2) Add water to the mixture with alumina cement and/or fine refractory aggregate. There are methods such as making a slurry and curing it after adding and mixing a foaming agent or blowing agent.Flammable substances include 1F plastic cellulose, charcoal, etc. -In case the foaming agent or blowing agent contains albumin, vitamin Examples include foaming agents of type B, protein-based foaming agents such as amylase, and foaming agents of metal powder-alkali metal #X.Protein-based foaming agents are preferred from the viewpoint of ease of controlling the size and amount of pores.

Foaming methods include mechanical methods such as shaking, stirring, and air supply, physical methods such as reducing solubility and heating, heating of carbonates,
There are chemical methods such as acid addition and fermentation.
(October 1, 2017). Note that a normal mortar mixer is sufficient for mixing the alumina cement, fine powder refractory aggregate, and air bubbles, which preferably have closed cells, and curing after molding can be done in water, air drying, Curing is performed using steam, high temperature and high pressure, or a combination of these.

〔Example〕

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

CaO"At20B, 12CaO"7Al2O3, Ca
After adding and mixing the alumina cement shown in Table 1 consisting of O"2At203 and amorphous and fine powder refractory aggregate, water was added to form a slurry. To this slurry, a predetermined amount of air bubbles with a particle size of 6 km or less (the blending amount is shown in Table 2). The lightweight fire-resistant structural materials shown in Table 3 were obtained by force-pounding, uniformly dispersing and curing (shown in Table 3).

Note that the physical properties were measured by the missing method.

Bulk specific gravity: According to JIS R2614, after drying at 400°C, it was left to cool indoors and the IT per volume was measured.◇ Porosity: According to JI8R2205.

Thermal conductivity; conforms to JI8R2618.

Linear change rate; Residual sg tension wheel measured before and after firing at 1600°C according to JIS R2554. Strength: Strength after firing at 1200°C for 6 hours was measured according to JIS R2521.

Fire resistance: According to RRS R2575.

Table 1 Alumina cement (parts by weight) [Effects of the invention] The fireproof structure of the present invention has a temperature of 1000'O or more, especially 15
It is lightweight, has excellent heat insulation and volume stability, and is easy to process in high-temperature atmospheres of 00℃ or higher.
If used as a heat insulating material, a sound insulating material, and a fireproof structural material in steel-related or non-ferrous steel-related places exposed to high temperatures, extremely good effects can be achieved. Furthermore, since it has good heat insulation properties, energy saving can be made more efficient.

Claims (1)

[Claims] Alumina cement hydrate, a hardened product with a total porosity of 50% or more, comprising fine powder refractory aggregate with a maximum particle size of 1 mm or less and an average particle size of 88 μ or less, and air bubbles with a diameter of 3 mm or less, the alumina cement Hydrate is CaO・Al_2O_
3 50-70 parts by weight, 12CaO・7Al_2O_3
10~40 parts by weight, CaO・2Al_2O_3 0~
A lightweight fireproof structural material characterized by being a hydrate of alumina cement consisting of 50 parts by weight and 0 to 60 parts by weight of amorphous cement.