JPH05213657A - Production of calcium silicate formed body - Google Patents

Abstract

PURPOSE:To produce a lightweight calcium silicate formed body having high strength and excellent dimensional stability without any problem involving the lightweight filler. CONSTITUTION:A slurry A obtained by heat-treating a slurry consisting of a calcareous material with the molar ratio of Ca/(Si+Al) controlled to 1.0 to 5.0, an amorphous silicate material and water under reduced pressure and further adding a siliceous material to control the molar ratio to 0.6 to 1.1 and a slurry B obtained by hydrothermally synthesizing a slurry consisting of a calcareous material with the molar ratio of Ca/(Si+Al) controlled to 0.8 to 1.1 are mixed in the area enclosed by the coordinates a, b, c and d in the figure, 1-10% of a reinforcing fiber and clay material are further added, and the admixture is formed and subjected to a hydrothermal reaction at 140-220 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a calcium silicate compact.

[0002]

2. Description of the Related Art Most of the calcium silicate compacts used as building materials are manufactured by hydrothermal reaction after molding filler such as calcareous raw material, siliceous raw material, reinforcing fiber and lightweight aggregate. Has been done. However, in this method, in order to reduce the bulk specific gravity to 0.45 to 0.55, a considerable amount of a lightweight filler is required, so that there is a problem that the bending strength is lowered. Further, since the amount of pores is large, the rate of dimensional change due to water absorption is large, and it is difficult to use it as a building material unless waterproof treatment is performed.

Therefore, an object of the present invention is to solve the above-mentioned problems caused by a lightweight filler, and to provide a method for producing a calcium silicate compact which is lightweight, has high strength and is excellent in dimensional stability.

[0004]

That is, the method for producing a calcium silicate compact according to the present invention comprises a calcareous raw material and an amorphous silicic acid having a Ca / (Si + Al) molar ratio of 1.0 to 5.0. A slurry consisting of raw materials and water is heat-treated under normal pressure,
Further, a slurry (A) having a Ca / (Si + Al) molar ratio within the range of 0.6 to 1.1 by adding a siliceous raw material, and Ca /
A slurry (B) obtained by hydrothermally synthesizing a slurry composed of a calcareous raw material, a siliceous raw material, and water having a (Si + Al) molar ratio in the range of 0.8 to 1.1 is represented by coordinates a, shown in FIG. Mix in a ratio within the range surrounded by b, c and d, and further 1 to 10% based on the weight of the solid content in the slurry.
Is added and molded, and the hydrothermal reaction is performed at a temperature in the range of 140 to 220 ° C.

Further, in the method for producing a calcium silicate compact according to the present invention, the Ca / (Si + Al) molar ratio is 1.0 to 5.0.
The slurry consisting of the calcareous raw material, the amorphous silicic acid raw material and the water within the range of is heat treated under normal pressure, and the siliceous raw material is further added to adjust the Ca / (Si + Al) molar ratio to 0.6 to 1.1. Slurry obtained by hydrothermally synthesizing the slurry (A) within the range and a slurry consisting of a calcareous raw material, a siliceous raw material and water within a Ca / (Si + Al) molar ratio of 0.8 to 1.1. (B) is mixed at a ratio within a range surrounded by coordinates a, b, c and d shown in FIG. 1, and further, 1 to 10% of reinforcing fiber and 10% based on the weight of solid content in the slurry.
It is characterized in that the following clay minerals are added, molded, and hydrothermally reacted at a temperature within the range of 140 to 220 ° C.

[0006]

The calcareous raw material used in the method of the present invention includes slaked lime, quick lime, etc., the siliceous raw material is silica sand, calcined diatomaceous earth, etc., and the amorphous raw material is diatomaceous earth,
Examples thereof include silica fume and nip seal.

Slurry (A) used in the method of the present invention
Is Ca / (Si + Al) for calcareous raw material and amorphous silicic acid raw material.
The mixture was added at a molar ratio of 1.0 to 5.0, and water was added to the mixture, which was then heat-treated under normal pressure.
The a / (Si + Al) molar ratio was set to 0.6 to 1.1. Here, if the Ca / (Si + Al) molar ratio of the slurry (A) is less than 0.6 or exceeds 1.1, the strength and dimensional stability of the obtained calcium silicate compact will be reduced.
The molar ratio is preferably in the range of 0.8 to 1.0. The heat treatment is performed at 70 to 95 ° C., preferably 8
It is performed in a temperature range of 0 to 90 ° C.

Slurry (B) used in the method of the present invention
Is a mixture of a calcareous raw material and a siliceous raw material at a Ca / (Si + Al) molar ratio of 0.8 to 1.1, and water added thereto, which is hydrothermally synthesized by a conventional operation. The amount of unreacted lime in the slurry (B) is preferably 5% or less. Here, if the Ca / (Si + Al) molar ratio of the slurry (B) is less than 0.8, the amount of unreacted siliceous raw material increases, which is unsuitable for reducing the weight of the calcium silicate compact, that is, reducing the specific gravity. If the molar ratio exceeds 1.1, the amount of unreacted lime exceeds 5%, which is not preferable. In addition, slurry (B)
By using, it contributes to the low specific gravity, high strength, and improvement in dimensional stability of the calcium silicate compact.

The mixing ratio of the slurry (A) and the slurry (B) is such that the calcareous raw material of the slurry (A) and the amorphous silicic acid raw material of C are mixed.
It is within the range surrounded by the coordinates a, b, c and d in FIG. 1, which shows the relationship between the a / (Si + Al) molar ratio and the ratio (%) of the slurry (B).

Here, on the left side of the line connecting the coordinates a and b in FIG. 1, since the slurry (A) becomes too bulky in the heat treatment under normal pressure, the specific gravity becomes too low, and the ratio of the slurry (B) is high. Therefore, high strength and dimensional stability cannot be obtained. Further, on the right side of the line connecting the coordinates c and d in FIG. 1, gelation is small even if the slurry (A) is heat-treated under normal pressure, and it is necessary to add a large amount of the slurry (B) to reduce the specific gravity. However, drainage is lowered, productivity is deteriorated, and there is a problem in cost.

After mixing the slurry (A) and the slurry (B) in the above mixing ratio, 1 to 10% of reinforcing fibers are added based on the weight of the solid content of the slurry. As the reinforcing fiber, cellulose, vinylon, PAN, carbon fiber, glass fiber or the like can be used.

In the method of the present invention, clay mineral is added to the above slurry based on the weight of the solid content of the slurry.
It can also be added in an amount of 0% or less, preferably 5 to 10%. If the amount of the clay mineral added exceeds 10%, the lightness and strength of the obtained calcium silicate compact will decrease. It is preferable to use sepiolite or talc as the clay mineral. In addition, sepiolite has an excellent moisture absorbing / releasing property and improves the humidity control effect. This is because sepiolite has a low specific gravity, high porosity, and good dimensional stability due to moisture absorption and desorption. In addition, talc improves the machinability, reduces the weight of the calcium silicate compact and makes the machinability particularly excellent.

After adding reinforcing fibers and, if desired, clay mineral to the slurry, the slurry is molded into a predetermined shape, and the temperature is 140 to 220 ° C.
The hydrothermal reaction is carried out in the temperature range. In the hydrothermal reaction, if the temperature is lower than 140 ° C., unreacted substances increase, which is not preferable, and if the temperature exceeds 220 ° C., the strength of the obtained calcium silicate compact decreases, which is not preferable.

[0014]

EXAMPLES The method of the present invention will be further described below with reference to examples. Example Preparation of Slurry (A) Raw materials were mixed at a Ca / (Si + Al) molar ratio shown in Table 1 below, treated under the heating conditions shown in Table 1, and then a siliceous raw material was added secondarily to give Ca / A slurry (A) was obtained by adjusting the (Si + Al) molar ratio.

[0015]

[Table 1]

Preparation of Slurry (B) Slurry (B) was prepared by hydrothermally synthesizing the slurry at the Ca / (Si + Al) molar ratio and conditions shown in Table 2 below.

[0017]

[Table 2]

Table 3 below shows the production conditions and formulation of the calcium silicate compact according to the method of the present invention, and various characteristics of the obtained calcium silicate compact. A press was used to form the slurry, and the dimensions were 150 × 80 × 10 mm. In addition, in FIG. 2, Ca / (S of the calcareous raw materials and the amorphous silicic acid raw materials of the slurries (A) in Examples 1 to 7 are shown.
The relationship between the (i + Al) molar ratio and the slurry (B) ratio is shown.

[0019]

[Table 3]

In Table 4 below, the production conditions and formulation of the calcium silicate compact according to the method of the present invention and various characteristics of the obtained calcium silicate compact are described. A press was used to form the slurry, and the dimensions were 150 × 80 × 10 mm. In addition, in FIG. 3, Ca / of the calcareous raw materials and the amorphous silicic acid raw materials of the slurries (A) in Comparative Examples 1 to 10 is shown.
The relationship between the (Si + Al) molar ratio and the slurry (B) ratio is shown.

[0021]

[Table 4]

[0022]

According to the method of the present invention, by using two kinds of slurries together as described above, it is possible to provide a calcium silicate compact which is lightweight, has high strength and is excellent in dimensional stability.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a Ca / (Si + Al) molar ratio of a calcareous raw material of a slurry (A) and an amorphous silicic acid raw material and a ratio (%) of a slurry (B).

FIG. 2 is a diagram showing a relationship between a Ca / (Si + Al) molar ratio of a calcareous raw material of a slurry (A) and an amorphous silicic acid raw material and a ratio of a slurry (B) in Examples 1 to 7.

FIG. 3 is a diagram showing the relationship between the Ca / (Si + Al) molar ratio of the calcareous raw material of the slurry (A) and the amorphous silicic acid raw material and the ratio of the slurry (B) in Comparative Examples 1 to 10.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noriaki Koga 6-1 Kashiwara, Ishioka-shi, Ibaraki Asuka Central Research Institute Co., Ltd. (72) Yutaka Suyama 6-1 Kashiwara, Ishioka-shi, Ibaraki Ask Central research institute

Claims (2)

[Claims] 1. A Ca / (Si + Al) molar ratio of 1.0 to 5.0.
The slurry consisting of the calcareous raw material, the amorphous silicic acid raw material and the water within the range of is heat-treated under normal pressure, and the silicic raw material is further added to adjust the Ca / (Si + Al) molar ratio to 0.6 to 1.1. Slurry obtained by hydrothermally synthesizing the slurry (A) within the range and a slurry composed of a calcareous raw material, a siliceous raw material and water having a Ca / (Si + Al) molar ratio within the range of 0.8 to 1.1. (B) is mixed in a ratio within a range surrounded by coordinates a, b, c and d shown in FIG. 1, and 1 to 10% of reinforcing fiber is added based on the weight of the solid content in the slurry. , And performing a hydrothermal reaction at a temperature in the range of 140 to 220 ° C., a method for producing a calcium silicate compact. 2. A Ca / (Si + Al) molar ratio of 1.0 to 5.0.
The slurry consisting of the calcareous raw material, the amorphous silicic acid raw material and the water within the range of is heat treated under normal pressure, and the siliceous raw material is further added to adjust the Ca / (Si + Al) molar ratio to 0.6 to 1.1. Slurry obtained by hydrothermally synthesizing the slurry (A) within the range and a slurry consisting of a calcareous raw material, a siliceous raw material and water within a Ca / (Si + Al) molar ratio of 0.8 to 1.1. (B) is mixed at a ratio within a range surrounded by coordinates a, b, c and d shown in FIG. 1, and further, 1 to 10% of reinforcing fiber and 10% based on the weight of solid content in the slurry.
A method for producing a calcium silicate compact, which comprises adding and molding the following clay mineral and performing a hydrothermal reaction at a temperature within a range of 140 to 220 ° C.