JPS597661B2 - Method for producing inorganic cured body - Google Patents

Description

[Detailed description of the invention] This invention relates to a method for producing an inorganic cured body.

Conventionally, calcium aluminate trisulfate high
Drate (3Cao-Al2o3・3caso4・31
~32H20 (hereinafter abbreviated as TSH) was produced in the following manner.

That is, calcium aluminate monosulfate hydrate (3CaO・A1203・caso4・12
H2o (hereinafter abbreviated as MSH), gypsum (CaSO4.
2H20) and water were added, mixed, shaped, and then cured to produce the product.

However, the MSH used in this reaction has traditionally been composed of Ca(OH)2, AI(OH)3, and CaS04-2.
It was produced by blending H20 in a molar ratio of 1:3:1 and hydrothermally synthesizing it at 180°C in an autoclave in the presence of water.

MSH produced in this manner lacked reactivity because it had a perfect crystal structure.

Therefore, the method for manufacturing a TSH cured body using this has a problem in that the reaction rate is low and curing is slow.

Therefore, an object of the present invention is to provide a method for producing an inorganic cured product with high rapid curing properties.

In summary, the production method of the present invention involves hydrothermally reacting a CaO component raw material, an A1203 component raw material, and a CaSO4 component raw material at 183° C. or higher in the presence of water to synthesize MSH. : Add MSH KCaSO + ingredients and water to TS
It is characterized by obtaining H.

Here, the CaS04 component raw material also includes dihydrate gypsum, hemihydrate gypsum, and anhydrous gypsum.

Since the reaction takes place at high temperatures, the presence or absence of water of crystallization does not seem to matter much.

Next, this invention will be explained in detail.

In the synthesis of MSH, when the temperature is raised above 183° C., MSH with collapsed crystals is obtained.

At the same time, aluminum calcium hydrate (
CaO whose main components are 3CaO・Al203・6H2o
-Al203 hydrate) is produced as a by-product.

In this case, the crystal shape of MSH is shifted and aluminum lucium hydrate is produced as a by-product, resulting in MSH
becomes activated and becomes highly reactive.

Note that the preferred reaction temperature in this synthesis reaction is 183
-190°C, most preferably 185-187°C
It is.

If the temperature is less than 183°C, activation of MSH will be insufficient, and if it exceeds 190°C, the amount of MSH produced will be extremely small.

In the synthesis of MSH, if the amount of water is small, the result will be block-like, and if the amount of water is increased, the result will be a slurry.

The block-shaped material is dried and ground to obtain raw material MSH.

Use the slurry as is.

A TSH cured body is manufactured using this.

When using powdered MSH in the production of TSH,
For example, 1 part of MSH is mixed with 202 parts of CaSO4.2H in powder form, water is added to the mixture at a mixing ratio of 1:1, the mixture is kneaded, and then cast.

Next, it is cured at 50° C. and then dried to produce a cured TSH body.

In the production of TSH, when slurry MSH is used, it is produced, for example, in the following manner.

(1) 2 parts of CaS04/2H20 for 1 part of MSH
1.5 parts of CaSO4.2H20, and add 1.0 parts of water to make a water mixing ratio of 1:1.

When the amount of water in the obtained slurry is large, the amount of water is adjusted by filtering.

The cake-like substance thus obtained was heated to 50°C and 100°C.
% humidity and drying to produce a TSH cured body.

(2) Add CaSO4.2H20 to MSH, and then add water to adjust the solid content concentration to 5-10%, then adjust the pH of this slurry to 11.5-12.5, and then filter it to make a cake. Obtain a similar substance.

A TSH cured body is produced by treating this in the same manner as in (1).

In this case, since the pH of the slurry is adjusted, the reaction rate becomes even higher.

As described above, since the production method of the present invention uses active MSH, the reaction rate of the TSH conversion reaction is extremely high, and an inorganic cured product with high rapid hardening properties can be obtained.

Furthermore, the strength of the obtained inorganic cured body is improved by 10% compared to that using unactivated MSH.

Next, examples will be described.

Example 1 A cured TSH body was produced using active powder MSH in the following manner.

This active powder MSH is obtained by drying and pulverizing MSH synthesized at 185° C. and at a water mixing ratio of 1.2.

Add 1.7 parts of CaSO4.1/2H20 (hemihydrate gypsum) to 1 part of active powder (based on weight, the same applies hereinafter), add water to make the hot water ratio 1:1, cast, and then heat at 50°C and 100°C. % humidity.

Curing began to occur within 5 minutes after casting and the curing reaction was complete in 35 minutes.

After the reaction was completed, it was dried at 40°C to obtain a cured TSH body.

This cured product has a specific gravity of approximately 0.7 and a bending strength of 20 kg/
It was cwt.

Comparative Example 1 A TSH cured body was obtained in the same manner as in Example 1 except that non-activated powder MS {(synthesized at 18Q° C.) was used.

In this case, it took 50 minutes to complete the curing reaction.

The obtained TSH cured body has a specific gravity of about 0.7 and a bending strength of 1.
It was 8 kg/ca.

Example 2 A TSH cured body was produced using activated slug IJMSH in the following manner.

This active slurry MSH was synthesized at 185°C and a hot water ratio of 1.8 and was used as is.

The solid content concentration (MSH+CaS04
- 2H20/total amount) was 5%.
After adding 2H20 and Ca(OH)2 saturated solution, the solids were well dispersed to obtain a dispersed slurry.

Next, this is filtered to create a cake-like substance with a solid content of approximately 50%, which is cured at 50°C in an atmosphere with 100% humidity.
An SH cured product was obtained.

Examples 3 to 6 TSH cured bodies were obtained in the same manner as in Example 2, except that the pH and curing temperature of the dispersed slurry were adjusted as shown in the following table.

Example 7 Everything was carried out in the same manner as in Example 1, except that 1.7 parts of CaSO4 ・1/2 H2 0 used as the CaS04 component raw material was used and 16 parts of CasO4 (anhydrous gypsum) was used. .

The obtained cured product had a specific gravity of 0.68 and a bending strength of 18.5 kg/crA.

Comparative Examples 2 to 4 TSH cured products were prepared in the same manner as in Example 2, except that unactivated slurry'JMSH (synthesized at 180°C) was used and the pH of the dispersed slurry and curing temperature were adjusted as shown in the following table. I got it.

The manufacturing conditions of Examples 2 to 6 and Comparative Examples 2 to 4 and the performance of the obtained TSH cured bodies are shown in the following table.

In addition, at reaction rate 1, it takes 3 hours to complete the reaction, and at intensity 1, it is 13 kg/crA.

Claims (1)

[Claims] I CaO component raw material, A1203 component raw material, and SaS0
Calcium aluminate monosulfate hydrate is synthesized by subjecting the four component raw materials to a hydrothermal reaction at 183°C or higher in the presence of water, and the CaS04 component and water are added to this calcium aluminate monosulfate hydrate to synthesize calcium. A method for producing an inorganic cured product, which comprises obtaining aluminate trisulfate hydrate.