JPS6012986B2 - 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.

Generally, calcium aluminate trisulfate hydrate (*a0, needle 203, length aS04, 31-32
An inorganic cured body made of TSH (hereinafter abbreviated as TSH) is produced as follows. That is, calcium aluminate monosulfate hydrate ($ao・AI2
03・CaS04・12th 20, hereinafter abbreviated as MSH) is synthesized from lime component raw material, alumina component raw material, gypsum component raw material and water, and gypsum (CaS04・2nd 20) is synthesized from this.
TSH is produced by adding and further reacting with water. In this case, if the reaction rate of MSH to TSH reaction can be increased, the demand for mass production can be met. Therefore, an object of the present invention is to provide a method for producing an inorganic cured product that can increase the reaction rate of the TSH conversion reaction. A feature of the present invention is that in a manufacturing method for producing an inorganic hardened body made of calcium aluminate trisulfate hydrate by reacting calcium aluminate monosulfate hydrate, gypsum, and water, the (020) crystal face is 0
02) The purpose is to use a crystal whose crystal plane has a large diffraction X-ray intensity ratio.

Next, this invention will be explained in detail.

However, it has not been clarified that the reaction rate differs depending on the type of gypsum used in the TSH conversion reaction, and it is believed that the reaction rate is the same regardless of the type of gypsum used. It was considered.

However, the inventors conducted further research and investigated the reaction rate of the TSH conversion reaction by reacting various types of gypsum with a certain amount of MSH.
) It has been found that the reaction rate becomes faster when gypsum with a large diffraction X-ray intensity ratio of crystal planes is used. In other words, the X-ray diffraction diagram of gypsum (dihydrate) obtained as various by-products is as shown in Figure 1, and the position of each diffraction plane is common to all gypsums, but the diffraction X-ray intensity differs from that of gypsum. We found that it differs depending on the type.

Crystal planes with particularly remarkable changes in intensity are (020), (002)
), (022, 051), etc. Of these, (020
) and (002) crystal planes each have a large absolute value of the diffraction X-ray intensity, so the absolute value of the intensity change also becomes large. The reaction rate of the TSH conversion reaction was investigated by reacting various kinds of gypsum having different diffraction X-ray intensities on crystal planes with a certain amount of MSH. At this time, the (020) and (002) planes with high diffraction X-ray intensity were selected as the target crystal planes.
Then, the effects of their diffraction X-ray intensity ratio, impurities in the gypsum, and average particle diameter on the reaction rate were investigated. The results are shown in Table 1. Table 1 In Table 1, the recrystallized product refers to a sample of 110q0
After heating for 6 hours to make hemihydrate salt, water was added to make dihydrate salt.

Moreover, the pulverized product is obtained by finely pulverizing the sample using a colloid mill. Furthermore, the relationship between the (002 plane)/(020 plane) diffraction X-ray intensity ratio and the TSH formation reaction rate constant is shown in FIG.

The following can be seen from Table 1 and Figure 2. In other words, the '1' TSH conversion reaction rate is correlated with the (002 sub/(02 tiger) diffraction X-ray intensity ratio, and if gypsum with a diffraction The reaction rate increases.

[2' Even gypsum with a small (002 plane)/(020 plane) diffraction X-ray intensity ratio can be increased by recrystallization, and those with a large ratio have a high TSH conversion reaction rate.

[31 The size of gypsum particles has no relation to the TSH conversion reaction rate o'4} Depending on the impurities in gypsum, TSH
The oxidation reaction rate is not affected.

As mentioned above, in the TSH reaction between MSH and gypsum, the more the (002) crystal plane of gypsum grows and the diffraction X-ray intensity increases, the higher the reactivity becomes;
) It can be said that the larger the crystal plane grows and its diffraction x-ray intensity becomes smaller, the smaller it becomes.

This can be considered as follows. That is, (002)
Since the crystal plane has a higher dissolution rate than the (020) crystal plane, gypsum on which the (002) crystal plane has grown has a high reactivity with MSH. Therefore, it is thought that when gypsum with grown (002) crystal planes is used, the reaction rate of the TSH formation reaction becomes slower. Note that (020) crystal plane has (00
2) Unlike the crystal plane, many molecules are coordinated,
This surface is the barrier surface. Therefore, (020)
Gypsum with grown crystal planes (Samples A, B, C, etc. in Table 1) is divided from the cleavage plane even if the particle size is reduced by crushing, so it is clear that the size of the particle size does not affect the reaction rate. It is. As described above, according to the manufacturing method of the present invention, as gypsum, the (00
2) Because the crystal plane uses a material with a high diffraction X-ray intensity,
The reaction rate of the TSH conversion reaction can be increased.

[Brief explanation of the drawing]

FIG. 1 is an X-ray diffraction diagram of gypsum, and FIG. 2 is a diffraction X-ray intensity ratio curve diagram of the TSH conversion reaction rate constant. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. In a manufacturing method for producing an inorganic hardened body made of calcium aluminate trisulfate hydrate by reacting calcium aluminate monosulfate hydrate, gypsum, and water, (020) crystals as gypsum A method for producing an inorganic cured body, characterized in that an inorganic cured body is used that has a large diffraction X-ray intensity ratio of the (002) crystal plane to the (002) crystal plane. 2. The method for producing an inorganic cured body according to claim 1, wherein the diffraction X-ray intensity ratio is selected to be 0.1 or more.