JP2915399B1 - Bentonite spraying waterproofing method - Google Patents

Abstract

An object of the present invention is to provide a spraying waterproofing method that can efficiently and efficiently blow bentonite without using an organic binder. SOLUTION: In a dry process, the residue of 2.36 mm sieve is 5% by weight or less and the passing amount of 250 μm sieve is 10% by weight.
In the following, granular bentonite having a swelling force of 10 ml / 2 g or more and water or smectite slurry are jetted from separate nozzles, and the two are mixed on the flight space to the adherend and on the adherend to apply the bentonite. A method of spraying on the kimono surface. For 1 part by weight of the granular bentonite,
Use 0.5-1.1 parts by weight of water or 0.4-1.2 parts by weight of smectite slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for spraying and waterproofing bentonite, and more particularly, to a waterproofing layer which does not use any organic matter and which has a corrosion resistance to microorganisms and a soil. The present invention relates to a method of spraying and waterproofing bentonite, which is useful in the case of applying water resistance to an adhered substance to be heated to a high temperature.

[0002]

2. Description of the Related Art A method is known in which granular bentonite is coated on the surface with a spray gun to waterproof the surface (Japanese Patent Application Laid-Open No. 49-28591). This method is used when the surface to be waterproof does not like to have a curved surface or a seam, when it has a complicated shape, in a narrow place where it is difficult for people to enter, or in a place where the working environment is bad due to dust accumulation. This is particularly effective when the sheet-based waterproofing method is difficult or undesirable.

[0003] However, in the above method, since an organic liquid binder is used as a means for adhering the dried bentonite particles to the surface of the adherend, the material cost is increased, and when the temperature is increased, the organic binder is not used. There is a drawback that the agent burns or decomposes, generating odor or smoke.

[0004] In recent years, the generation rate of refuse has been increasing year by year, and the amount of refuse incinerated by incinerators has also increased. However, in order to burn refuse as completely and efficiently as possible while maintaining incineration conditions above a certain level. In addition, it is legally required to periodically clean garbage incinerators. In this cleaning, it is particularly necessary to manually clean the space between the cooling pipe and the refractory brick, which is extremely complicated.In addition, since the inside of the refuse incinerator where ash dust and the like cannot be avoided, workers are inferior. Must be exposed to harsh working conditions,
There was a drawback that the downtime of the furnace had to be long due to poor cleaning efficiency.

Therefore, in order to reduce the number of workers, shorten the cleaning period and improve the use efficiency of the furnace, it is not necessary to expose the workers to a poor working environment. Instead, a new method of washing the furnace with water has been considered. However, if washing water enters between the metal cooling pipe and the refractory brick, the water that has become acidic by dissolving the ash will corrode the pipe. It is necessary to seal between

However, it is cumbersome to perform the above-mentioned sealing by hand, and when an organic sealing material is used, the material cost is increased and cracks may be formed between the refractory brick and the cooling pipe. In addition, when used after cleaning, there is a drawback that the sealing material incompletely burns, polluting the atmosphere and generating offensive odor. Although such disadvantages are improved by employing a waterproofing method in which the bentonite is sprayed on the sealing, the waterproofing method is not a complete solution due to the use of an organic binder.

[0007]

The inventors of the present invention have conducted intensive studies on a method of spraying bentonite particles without using an organic binder. As a result, bentonite of a specific particle size having a constant water content and swelling power, It was found that the bentonite particles can be efficiently sprayed onto the surface of the adherend by spraying the water or smectite slurry onto the adherend while being mixed in the air, and reached the present invention. Accordingly, a first object of the present invention is to provide a spray waterproofing method capable of efficiently and efficiently blowing bentonite without using an organic binder. A second object of the present invention is to provide a method of spraying and waterproofing bentonite, which is effective even for adherents that are heated to a high temperature.

[0008]

SUMMARY OF THE INVENTION The above objects of the present invention are attained when a 2.36 mm sieve residue is 5% by weight or less in a dry system.
A granular bentonite having a 50 μm sieve passing amount of 10% by weight or less and a swelling force of 10 ml / 2 g or more, and water or smectite slurry are jetted from separate nozzles,
Mix both in the flight space to the adherend and on the adherent,
A method of spraying bentonite onto the surface of an adherend, wherein 0.5 to 0.5 parts by weight of the granular bentonite is used.
Achieved by a bentonite spraying and waterproofing method characterized by using 1.1 parts by weight of water or 0.4 to 1.2 parts by weight of smectite slurry.

Since bentonite used in the present invention is used as a waterproofing agent, it is basically preferable that it has a large swelling force. Therefore, granular bentonite is an alkaline clay mainly composed of the clay mineral montmorillonite, and unlike clay minerals such as kaolinite and pyrophyllite, 40 to 12 per 100 g of clay.
It has a large cation exchange capacity of 0 meq. The exchangeable cations are usually sodium, calcium and magnesium ions.

[0010] Granular bentonite is, specifically, a water content of about 15 to 40% by weight mined from a bentonite deposit.
The raw ore containing is coarsely crushed to a diameter of 20 mm or less, then dried by a rotary drier until the water content becomes 4 to 9% by weight, and then sorted by a vibrating screen machine using a particle size screen,
The commercialized crushed granules are used. Bentonite, which mainly contains calcium ions as exchangeable cations, has a swelling power of 10 ml / 2 g or less. Then, by reacting with soda ash and activating it, the swelling power becomes 10 ml / 2 g or more, and it can be used.

Further, water is added to bentonite powder which has been dried by a rotary dryer and then pulverized by a roller mill, and granulated by an extrusion granulator and then dried, or bentonite raw ore is disc-pelleted. Granular bentonite products produced by a granulator such as Fuji Paudal Co., Ltd.) and dried can also be used.

In the present invention, since no organic adhesive is used in particular, in order to mix the particulate bentonite with water during the flight and adhere to the surface of the adherend, water is required during the flight of the particulate bentonite. It is necessary that it absorbs and swells and at least its surface becomes tacky. If the granular bentonite is too coarse, the bentonite particles that have collided with the surface of the adherend will be rebounded and fall off easily.In addition, even if the surface has adhesiveness, it will not be able to withstand its own weight and will fall and will adhere to the surface. Can not stay. Also, if the granular bentonite is too fine, the bentonite hardly adheres to the surface to be adhered and becomes dust and the working environment deteriorates, and the self-healing ability when the waterproof layer is perforated due to an unexpected reason becomes insufficient. There are cases.

Accordingly, the granular bentonite used in the present invention needs to have a 2.36 mm sieve residue of 5% by weight or less and a 250 μm sieve passing amount of 10% by weight or less in a dry system. The tests for sieve residue and sieve passing are based on the Japan Bentonite Industry Association Standard Test Method (JBAS).

The water content of the granular bentonite is 4.0 to 9.0 in order to be injected quantitatively from the nozzle and to quickly absorb water in the air and to develop self-adhesion in the granular bentonite in a short time. % By weight. Outside this range, the water absorption rate of the granular bentonite decreases. Further, if the water content is more than 9% by weight, the water tends to stay at the outlet of the hopper of the spraying machine or in the transport hose, and it is difficult to quantitatively escape from the nozzle. The water content is 4.0% by weight.
If it is less than 30, the bentonite rubs against each other in the hopper of the spraying machine or in the transport hose to form fine particles, thereby increasing the amount of dust generated.

On the other hand, the swelling power of granular bentonite is 10 m.
l / 2g or more, especially 15 ml / 2
It is preferable that it has a swelling force of at least g. When the swelling force is less than 10 ml / 2 g, the waterproofing effect of the waterproof layer is not sufficient, and the self-healing ability when the waterproof layer has a hole due to an unexpected cause is reduced. The water content is a value measured according to JBAS-101-77, and the swelling power is a value measured according to JBAS-104-77.

The water used for imparting self-adhesiveness to the granular bentonite may be any water that does not swell its swelling ability when the granular bentonite is wet.
Medium water such as rainwater or tap water can be used. The amount of water used must be 0.5 to 1.1 parts by weight, and particularly preferably 0.6 to 1.0 part by weight, based on 1 part by weight of granular bentonite.

Water for imparting self-adhesiveness to the granular bentonite may appropriately contain sodium silicate from the viewpoint of assisting the adhesion of the bentonite. If the content of sodium silicate is increased, the material cost increases. Therefore, it is sufficient to use the necessary minimum according to the application and the shape of the adhered substance. Although it depends on the amount of sodium silicate to be used, the amount of water is reduced to 0.5 to 4.0 parts by weight by adding 1.0 to 4.0 parts by weight of sodium silicate to 100 parts by weight of water.
It can be slightly (about 0.2 to 0.3 parts by weight) less or more than 1.1 parts by weight. In particular, when a lot of acidic substances are present on the surface of a substance to be adhered, such as in an incinerator, sodium silicate also has a function of neutralizing the substance, so that its usefulness is enhanced.

When the smectite slurry is used together with the granular bentonite, the viscosity of the smectite slurry is set in the range of 13 to 30 cP (20 ° C.) in order to stably atomize and facilitate the adhesion of the granular bentonite. It is particularly preferable to set the range of 15 to 25 cP. The viscosity of the smectite slurry is a value measured in a 20 ° C. environment using a fan rotation viscometer 35SA (manufactured by Valoid) conforming to the rules of the Petroleum Institute of America.

The wet sieve residue of the smectite slurry is preferably not more than 5% by weight of the 75 μm sieve residue. The amount of use of such a smectite slurry is 0.3 to 1.2 with respect to 1 part by weight of granular bentonite.
It is necessary to be a part by weight, but in particular, 0.4 to 0.1 part by weight.
It is preferably 9 parts by weight.

The smectite used in the present invention is as follows:
A layered silicate clay mineral represented by the general formula
Selected from the group having exchangeable cations and water molecules
At least one. General formula: X_m(Y²⁺, Y³⁺)_2-3Z₄O₁₀(OH)₂・
nH₂OX: K, Na, 1 / 2Ca, 1 / 2Mg Y²⁺: Mg, Fe²⁺, Mn²⁺, Ni²⁺, Zn
²⁺, 2Li⁺  Y³⁺: Al³⁺, Fe³⁺, Cr³⁺  Z: Si, Al m: 0.25 to 0.6 n: Remarkably fluctuates depending on the type of interlayer ion and relative humidity
You.

Such a smectite usually contains at least one of montmorillonite, saponite and hectorite as a main component, and may be a natural or synthetic product or a mixture thereof. Such smectite is generally marketed as a dry powder product having a water content of 10% by weight or less, and is used as a viscosity modifier for cosmetics, pharmaceuticals and the like.

The amount of water required to form a slurry by adding water to smectite has a preferable range according to the type of smectite used. In the present invention, the viscosity of a slurry in which smectite is dispersed in water with a mixer,
When using a fan rotational viscometer 35SA manufactured by Valoid Co., it is added so as to have a pressure of 13 cP to 30 cP.

As in the case of using water, sodium silicate can be appropriately added to the smectite slurry. The amount of the smectite slurry can be adjusted to 0.2 to 1.3 parts by weight with respect to 1 part by weight of granular bentonite by adding sodium silicate. When using smectite, it is preferable to use 0.3 to 0.7 parts by weight of sodium silicate per 100 parts by weight of water.
When the surface of the adherend is acidic, it is particularly preferable to contain sodium silicate.

In the present invention, the above-mentioned granular bentonite is sprayed from an air gun, and water or a smectite slurry containing sodium silicate as required is sprayed from another air gun or another nozzle of the same air gun. Then, both are mixed in the flight space up to the surface of the adherend and the surface of the adherend to impart self-adhesiveness to the granular bentonite and form a bentonite waterproof layer on the surface of the adherend.

The shape, arrangement, and the like of the air gun and its nozzle can be appropriately designed. In the present invention,
Since granular bentonite comes in contact with water or smectite slurry in the air and its surface swells and has caking properties, any shape of adherend can be used even though no organic adhesive is used. A waterproof bentonite waterproof layer can be easily formed on the surface. Further, even if the formed waterproof layer is later pierced, the bentonite swells and self-repairs when it comes into contact with water, so that the waterproofness is not impaired. In addition, in this invention, waterproofness means the case where a water permeability is 1 * 10 < ^-7 > cm / second or less. The details of the permeability test are described in 1990 (company).
It is described in "Method and Explanation of Soil Testing" issued by the Japan Society of Geotechnical Engineers (currently the Japan Geotechnical Society).

The waterproofing method of bentonite according to the present invention includes waterproofing of existing pipes, waterproofing of underground concrete structures such as underground concrete outer walls of buildings, box culvert outer walls of common trenches, and concrete outer walls of underground parking lots. It can be applied not only to sealing at the bottom of artificial ponds and artificial brooks, when washing incinerators, etc., but also to extinguish fires in case of fire. Also, when the bentonite waterproof layer is exposed on the surface, it is useful for waterproofing for about 10 days when using smectite slurry together with granular bentonite, for about 1 to 2 days when using only water, and sodium silicate. Is added to the smectite slurry and used to provide a waterproof effect for a long time.

[0027]

The waterproofing method of bentonite according to the present invention is inexpensive because it does not use any organic materials, and has no burnable material. It is particularly effective as a construction method.

[0028]

The present invention will be described in more detail with reference to the following examples.
However, the present invention is not limited by this. Ma
The adhesion rate and water stoppage in Examples and Comparative Examples were as follows.
This is the value obtained as follows.Adhesion rate and water stoppage  From the surface to which the plywood is installed vertically,
Spray at 1,500 g / min at a distance of 1 m
With a 2.5 cm bentonite layer on the plywood surface
I wore it. Attach amount to spray amount at this time
Rate. In addition, 2.5 cm of bentonite was adhered.
Wash the adhered surface for 20 minutes, and
The presence / absence is visually determined.
Valued.

Examples 1 and 2 and Comparative Examples 1 and 2. As granular bentonite, paragranular (swelling force 30 ml / 2 g, 2.36 mm sieve residue 0%, 250% swelling force) commercialized as crushed granules from bentonite produced in Wyoming, USA
1.2% by μm sieve, 7.1% by weight of water, 100 parts by weight (manufactured by Paramount Technical Products, Montmorillonite) were used.

On the other hand, tap water and Super Clay (trade name of Montmorillonite as a main component, manufactured by Toyshun Yoko Co., Ltd.) and Hectabrite DP (American)
The mixture was stirred for 5 minutes with a hand mixer UM15 type (manufactured by Hitachi Koki Co., Ltd., rotation speed: 1,100 rpm) using a trade name of Colloid Co., Ltd. and containing hectorite as a main component to obtain a smectite slurry. Next, the granular bentonite and smectite slurry are waterproofed with bentonite.
Spray at the rate in Table 1 until the layer thickness is 2.5 cm
I did. The ratio of the amount of adhesion to the amount of spray (referred to as the adhesion ratio) and the water stoppage are as shown in Table 1.

[0031]

[Table 1]

Examples 3 and 4 and Comparative Examples 3 and 4 The above-mentioned paragranular granite was used, and only tap water was used without using a smectite slurry.
And spraying was performed in the same manner as in Example 1. When the adhesion rate and the water stoppage of the granular bentonite were evaluated in the same manner as in Example 1, the results shown in Table 2 were obtained.

[0033]

[Table 2]

Embodiment 5 FIG. In the spray mixing ratio used in Example 1, the gap between the cooling pipe of the incinerator and the refractory brick was about 1 cm.
When it was buried, no water leakage was seen and it was completely waterproof. It was also confirmed that no odor or smoke was generated even when the incinerator was heated.

Embodiments 6 and 7 Sodium silicate No. 3 (manufactured by Central Glass Co., Ltd.) was added to water, and the mixture was stirred by the hand mixer used in Example 1, and then stirred while adding the super clay little by little to obtain a smectite slurry containing sodium silicate. The results of spraying in the same manner as in Example 1 with the composition shown in Table 3 were as shown in Table 3, and in each case, the water stopping performance and the adhesion rate were good.

[0036]

[Table 3]

Embodiment 8 FIG. Except that the spray composition used in Example 3 was used, the procedure was exactly the same as that in Example 5. In this case, too, it was confirmed that the waterproofness between the refractory bricks of the cooling pipe of the incinerator was sufficient. Was.

Embodiment 9 FIG. Table 4 shows the results of spraying and evaluation in the same manner as in Example 3 except that various granular bentonite having a particle size distribution shown in Table 4 was used. Column A in Table 4 shows the results of Example 3. Further, all of the granular bentonite of A to E are paragranular, and F and G are granular bentonite whose swelling force is adjusted. As is evident from the results in Table 4, in the case of the present invention of A, C, E and G, it was proved that not only the water stopping property was good but also the adhesion rate was as good as 85% or more.

[0039]

[Table 4]

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kaneo Ichinohe 1-18-1 Toranomon, Minato-ku, Tokyo Inside Toyojun Yoko Co., Ltd. (72) Inventor Junzo Fujinawa 1-16-1 Toranomon, Minato-ku, Tokyo Toyojun Yoko Co., Ltd. (72) Inventor Shintaro Ichiyasu 1-18-1 Toranomon, Minato-ku, Tokyo Japan Co., Ltd. Toyojun Yoko Co., Ltd. (72) Inventor Toshihisa Yanagida 1472 Ukitacho, Edogawa-ku, Tokyo Co., Ltd. Shinwa Corporation (56) References JP-A-49-39620 (JP, A) JP-A-49-28591 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B05D 1/00-7 / 26 C09K 3/10

Claims (6)

(57) [Claims] In the dry method, granular bentonite having a 2.36 mm sieve residue of 5% by weight or less, a 250 μm sieve passing amount of 10% by weight or less, and a swelling force of 10 ml / 2 g or more, and water or smectite slurry are separately separated. A method of spraying bentonite onto the surface of the adherent by mixing the two in the flight space up to the adherend and the adherend, and spraying the bentonite on 1 part by weight of the granular bentonite. A method of spraying and waterproofing bentonite, comprising using 1.1 to 1.1 parts by weight of water or 0.4 to 1.2 parts by weight of smectite slurry. 2. The method for spraying and waterproofing bentonite according to claim 1, wherein sodium silicate is further contained in the water or the smectite slurry. 3. The method for spraying and waterproofing bentonite according to claim 1, wherein the viscosity of the smectite slurry at 20 ° C. is 13 to 25 cP. 4. A layer in which smectite is represented by the following general formula:
Silicate clay minerals, with exchangeable cations and
At least selected from clay minerals with water molecules
The ben according to any one of claims 1 to 3, wherein
Tonite spray waterproofing method. General formula: X_m(Y²⁺, Y³⁺)_2-3Z₄O₁₀(OH)₂・
nH₂OX: K, Na, 1 / 2Ca, 1 / 2Mg Y²⁺: Mg²⁺, Fe²⁺, Mn²⁺, Ni²⁺, Z
n²⁺, 2Li⁺  Y³⁺: Al³⁺, Fe³⁺, Cr³⁺  Z: Si, Al m: 0.25 to 0.6 n: Remarkably fluctuates depending on the type of interlayer ion and relative humidity
You. 5. The waterproofing method according to claim 4, wherein the smectite used in the slurry is a clay mineral mainly composed of at least one selected from the group consisting of montmorillonite, hectorite and saponite. . 6. The sprayed and waterproofed bentonite according to claim 1, wherein the granular bentonite contains 4.0 to 9.0% by weight of water and has a swelling power of 15 ml / 2 g or more. Construction method.