JPH06141671A - Inorganic porous material - Google Patents

Abstract

PURPOSE:To provide the inorganic porous soil jor agricultural and horticultural uses capable of being utilized as siliceous fertilizer, soil-improving agent, slope face-greening soil, seedling-cultivating soil, horticultural soil, etc., by quickly reducing the strong alkalinity of ALC, while holding the excellent properties of the ALC. CONSTITUTION:This method for producing the inorganic porous material having a pH of <=9.6 is characterized by subjecting an inorganic porous material and ALC containing quartz and a pH of <=9.6 to a carbonization treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic porous material which can be used as a horticultural soil, a soil improving agent and the like.

[0002]

2. Description of the Related Art Light-weight cellular concrete (hereinafter abbreviated as ALC) whose main component is porous calcium silicate hydrate
Is widely used as a building material and heat insulating material, and the end material has appropriate strength due to containing quartz, and the small apparent specific gravity obtained from being a porous body, water permeability, water retention, air permeability, etc. From the characteristics of, crush and for example garden soil,
It is used as a soil conditioner.

[0003]

However, ALC has a pH value.
Since it has a strong alkalinity of 10 or more, when ALC powder is used as a siliceous fertilizer or a soil conditioner, if it is used locally or mixed in a large amount, the alkali will adversely affect the soil and the growth of plants. Since it is inhibited, it must be used with extreme caution.

Therefore, a method of reducing the alkalinity of ALC by performing an acid treatment using hydrochloric acid, nitric acid or the like can be considered, but such a method may decompose the quartz, so that it has an appropriate strength. Easy to lose. Therefore, the present invention is to provide a low-alkali inorganic porous material without losing the characteristics of ALC such as strength, small apparent specific gravity, water permeability, water retention, and air permeability.

[0005]

The present invention has a pH of 9.6.
It is a method of obtaining an inorganic porous body having a pH of 9.6 or less by carbonating an inorganic porous body containing quartz and a lightweight cellular concrete below. The pH referred to here is 25 g after adding 100 g of ion-exchanged water at 25 ° C. to 1 g of the obtained inorganic porous material and stirring for 3 minutes.
The value measured with a pH meter in a constant temperature bath at ℃.

The ALC used in the present invention is, for example, a slurry obtained by mixing a siliceous raw material and a calcareous raw material, and curing the slurry as it is under high temperature and high pressure steam, or generating bubbles such as a foaming agent and a foaming agent in the slurry. An artificial mineral obtained by curing a slurry-like material mixed with an agent in a mold and then curing it at high temperature and high pressure steam may be mentioned. The ALC component is xonotlite, tobermorite, gyrolite, foshaygit, hellebrandite, or the like, and any one of these components may be a single component or a mixture of two or more types. , CSH gel, unreacted siliceous raw material and the like may be contained, but quartz must be contained together with these components. The quartz is made of quartz by a physical X-ray diffractometer.
When the diffraction intensity of one surface (2θ = 3.34) is measured in cps unit, it is necessary that a peak be present.

As the ALC, it is possible to use a defective product generated in the manufacturing process of the ALC, an ALC scrap produced during the construction of a building, a house or the like. The shape such as the particle size of ALC is not particularly limited and may be selected depending on the use of the inorganic porous body. The carbonation treatment of the present invention can employ a known method and is not particularly limited, and examples thereof include a method of bringing ALC into contact with a carbon dioxide gas atmosphere, or a method in which carbon dioxide gas is dissolved in water. A method of introducing ALC and the like can be mentioned.
It is necessary to perform carbonation treatment until the pH of the LC becomes 9.6 or less.

ALC has a pH of 10.3 or higher. AL
C degree of carbonation during carbonation, that is, A after carbonation treatment
The relationship between the calcium carbonate content with respect to the calcium content in LC and pH is as shown in FIG. The pH drops sharply up to a certain degree of carbonation, and when the pH reaches about 9.6, the pH hardly drops even if carbonation is further performed.

Further, if the carbonation treatment is carried out until the pH becomes 9.6 or less, the carbonation degree advances to 40%, and the substantial pH of the inorganic porous material of the present invention is also reduced. pH is 9.
If the value exceeds 6, the degree of carbonation is not sufficient,
The use of the inorganic porous material of the present invention is extremely limited.

[0010]

FIG. 1 shows that if the inorganic porous material obtained by the above method maintains the shape of the original porous material of ALC, the characteristics of ALC can be fully utilized when the inorganic porous material is used. preferable. The inorganic porous material of the present invention is
It can be used as horticultural soil, soil conditioner, slope greening soil, planting soil, nursery soil, and horticultural soil.

[0011]

With the above-mentioned constitution, the carbon dioxide gas contacting with ALC is carbonated in ALC and the calcium content becomes calcium carbonate, so that the pH is substantially lowered. Even if a porous body is used, it does not have a bad influence.

[0012]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples. The pH, the crystallinity of quartz and the carbonation degree shown in Examples and Comparative Examples were measured by the following methods. pH 1 g of the obtained inorganic porous material was added with ion-exchanged water 10 at 25 ° C.
After adding 0 g and stirring for 3 minutes, p in a constant temperature bath at 25 ° C.
It was measured with an H meter.

Presence of Quartz Crystals The physical intensity of the obtained inorganic porous material was measured by a physical X-ray diffractometer to measure the diffraction intensity of 101-face (2θ = 3.34) of quartz in cps unit. Carbonation degree The obtained inorganic porous material was reacted with hydrochloric acid, and the carbonation degree was measured by the amount of carbon dioxide gas generated. (The state where the calcium component in ALC was completely calcium carbonate was defined as 100% carbonation.)

[0014]

[Reference Example] ALC mill ends generated at a building construction site were collected, crushed by a crusher, the reinforcing bars in the inside were pulled out, and then coarsely crushed by a hammer mill. The coarsely pulverized product thus obtained was sieved to obtain a powdery ALC having a diameter of 2.0 mm or less, which was dried at 110 ° C. until a constant weight was obtained.

The powdery ALC was composed of siliceous calcium containing tobermorite as a main component, and Ca / Si was 0.58 by X-ray diffraction and fluorescent X-ray analysis. Also,
The apparent specific gravity was about 0.65, and the water retention rate was about 75%. Table 1 shows the pH, X-ray diffraction intensity of the 101st surface, and carbonation degree of this powder.

[0016]

Example 1 80 g of distilled water and 20 g of the powdery ALC obtained in the reference example were put into a three-necked flask equipped with a thermometer, a gas blowing tube, and a reflux condenser, and carbon dioxide gas was blown into the magnetic stirrer to saturate it. After that, the temperature of the solution adjusted to about 4.4 was raised to 30 ° C. with a stirrer in the reference example, and carbon dioxide was supplied at a flow rate of 500 cc / min to give
The reaction was carried out at 0 ° C. under stirring for 5 hours. Reaction product to ALC
The powder was filtered off and dried at 110 ° C. to obtain the inorganic porous material of the present invention. PH of this inorganic porous material, 101
Table 1 shows the X-ray diffraction intensity and the carbonation degree of the surface.

The apparent specific gravity was 0.63 and the water retention rate was 75%, which were almost the same as those of the reference example. Furthermore, an appropriate amount of the inorganic porous material obtained in this example was placed in a petri dish having a diameter of 10 cm, water was added in an appropriate amount, 50 seeds of Komatsuna were seeded, and the seeds were placed in a room at room temperature (20 ° C.) for 10 days to obtain a germinated state. The subsequent growth situation was observed. As a result, the germination rate after 3 days was about 90%, after 7 days it had grown to 3.5 cm, and after that it had grown satisfactorily.

[0018]

Example 2 An inorganic porous material of the present invention was obtained by the same method as in Example 1, except that the carbonation treatment was performed at 60 ° C. About the obtained inorganic porous body, pH, 101
Table 1 shows the results of measuring the X-ray diffraction intensity and the carbonation degree of the surface.
Shown in.

[0019]

[Example 3] In Example 1, the carbonation treatment was carried out at 60 ° C.
An inorganic porous material of the present invention was obtained by the same method except that the reaction time was 3 hours. Table 1 shows the results of measuring the pH, the X-ray diffraction intensity of the 101 plane, and the carbonation degree of the obtained inorganic porous body. The apparent specific gravity was 0.66 and the water retention rate was 81%, which was not much different from that of the reference example.

[0020]

[Example 4] Powder A obtained in Reference Example in an autoclave
After 20 parts of LC and 15 parts of distilled water were introduced and degassed, carbon dioxide gas was introduced under a gauge pressure of 1.2 kg / cm ² and reacted for 1 day, followed by drying at 110 ° C. to give the inorganic porous material of the present invention. Got the body For the obtained inorganic porous material, p
Table 1 shows the results of measuring the X-ray diffraction intensity of H, the 101st plane, and the carbonation degree.

Furthermore, the growth of Komatsuna was observed in the same manner as in Example 1. As a result, the germination rate after 3 days was 90.
% After about 7 days, the growth was 3.1 cm after 7 days, and the growth was good thereafter.

[0022]

[Comparative Example 1] In Example 1, the carbonation treatment was carried out at 30 ° C.
An inorganic porous material was obtained by the same method except that the reaction time was 3 hours. For the obtained inorganic porous material, p
Table 1 shows the results of measuring the X-ray diffraction intensity of H, the 101st plane, and the carbonation degree. Furthermore, the growth of Komatsuna was observed in the same manner as in Example 1. As a result, the germination rate after 3 days was about 90%, after 7 days it had grown to 3.1 cm, after which the leaf tips were rounded and growth almost stopped.

[0023]

[Comparative Example 2] In Example 1, the carbonation treatment was carried out at 80 ° C,
An inorganic porous material was obtained by the same method except that the reaction time was 1 hour. For the obtained inorganic porous material, p
Table 1 shows the results of measuring the X-ray diffraction intensity of H, the 101st plane, and the carbonation degree.

[0024]

[Comparative Example 3] In Example 1, the carbonation treatment was conducted at 30 ° C.
An inorganic porous material was obtained by the same method except that the reaction time was 1 hour. For the obtained inorganic porous material, p
Table 1 shows the results of measuring the X-ray diffraction intensity of H, the 101st plane, and the carbonation degree.

[0025]

[Table 1]

[0026]

INDUSTRIAL APPLICABILITY The inorganic porous material of the present invention has a suitable strength due to having quartz, and the strong alkalinity of ALC is reduced by a simple method in a short time without losing the characteristics of ALC. Thus, it becomes possible to provide an inorganic porous material that can be used for a wide range of applications such as garden soil and fillers.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between carbonation degree and pH value.

Claims (2)

[Claims] 1. An inorganic porous material having a pH of 9.6 or less and containing quartz. 2. A method for obtaining a quartz-containing inorganic porous body having a pH of 9.6 or less by carbonating a lightweight cellular concrete.