JPH10279940A - Solidifier for water-containing soil and solidification - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soil solidifier that can readily solidify water-containing to fine particles having sufficient strength and is suitable for reusing the soil as a resource for sand substitute and provide a solidification process. SOLUTION: The objective solidifier contains an aqueous solution of poly(meth)acrylic acid and/or its salt and a lime and/or plaster as essential components. In other cases, this solidifier contains particles of a water-soluble poly(meth)acrylic acid and/or its salt and lime and/or plaster as essential components. The poly(meth)acrylic acrylic acid and/or its salt having prescribed properties are admixed to water-containing soil to granulate the mixture and lime and/or plaster is added to the granules whereby the water-containing soil is granulated to particles having a prescribed particle size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a solidifying agent and a method for solidifying hydrous soil.
The present invention relates to a solidifying agent and a solidifying method suitable for solidifying hydrous soil and reusing the soil as a resource such as a substitute for sand.

[0002]

2. Description of the Related Art Generally, for example, in excavation work employing a muddy water shield method or the like, excavated soil generated during excavation is discharged to the outside together with the excavated muddy water by supplying excavated muddy water to an excavation hole. The generated soil is reused after the soil is separated, and the rest is discarded as mud. Accordingly, the muddy water is a slurry containing a large amount of water together with the clay.

[0003] When treating the above-mentioned muddy water as industrial waste, the muddy water is subjected to dehydration press or the like to perform solid-liquid separation so as to be able to carry out dumping or the like, and then obtained as a dewatered cake or the like. It has been practiced to mix a water-absorbing resin, cement, slaked lime, quick lime, etc. with the sludge to be produced, that is, the water-containing soil, and to solidify it.

As such a treatment method, for example, Japanese Patent Application Laid-Open No. 2-94891 discloses a method of adding and kneading a dispersion of an anionic acrylic coagulant, cement and the like to hydrous soil. I have. Further, JP-A-52-61354 and JP-A-64-51198 disclose, in hydrous soil, water-soluble synthetic polymer substances having cohesive properties, and air-hardened cements and hydraulic cements. Are disclosed.

[0005] The solidified hydrous soil is discarded at a predetermined disposal site such as a landfill disposal site. Alternatively, in civil engineering work that requires backfilling of boreholes,
BACKGROUND ART After mixing a water-absorbing resin, cement, and the like into a hydrated soil, the hydrated soil is injected into a wellbore before solidifying.

[0006]

However, since water-containing soil must be treated as industrial waste, it requires a great deal of disposal costs. Also, the number of disposal sites for discarding hydrous soil is decreasing year by year. Therefore, when the water-containing soil is treated by the conventional solidification method, there is also a problem that it is difficult to secure a disposal place. Therefore, a solidification method capable of reusing water-containing soil has been desired. From this point of view, Japanese Patent Application Laid-Open No. 64-51198 does not disclose a solidification method and application suitable for reusing water-containing soil.

Further, Japanese Patent Application Laid-Open Nos.
No. 6-17054 discloses that, to a hydrous soil, a powder of an acrylamide copolymer such as a copolymer of acrylamide and sodium acrylate, and lime are added to improve the soil quality, There is disclosed a method for reusing the same. However, when a copolymer of acrylamide is used, there is a disadvantage that when lime or the like is used, the whole soil becomes strongly alkaline, acrylamide is hydrolyzed, and ammonia is generated.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to easily solidify hydrous soil into fine granules having sufficient strength, for example, as a resource such as a substitute for sand. It is an object of the present invention to provide a solidifying agent and a solidifying method which are suitable for reusing the material.

[0009]

Means for Solving the Problems The present inventors have diligently studied a solidifying agent and a solidifying method for hydrous soil in order to achieve the above object. As a result, poly (meth) acrylic acid and / or a salt thereof having predetermined properties and the like, and lime and / or gypsum are solidified using a solidifying agent as an essential component, thereby solidifying the hydrous soil. The present inventors have found that hydrous soil is finely divided into particles having sufficient strength and a predetermined particle diameter and can be effectively used as, for example, a substitute for sand, and have completed the present invention.

That is, in order to solve the above-mentioned problems, the solidifying agent for hydrous soil according to the first aspect of the present invention comprises an aqueous solution of poly (meth) acrylic acid and / or a salt thereof, and lime and / or gypsum. It is characterized as being an essential component. In order to solve the above problems, the solidifying agent for hydrous soil according to the second aspect of the present invention comprises water-soluble poly (meth) acrylic acid and / or its salt particles, lime and / or gypsum as essential components. It is characterized by becoming.

[0011] According to the above configuration, the solidified hydrous soil (hereinafter, referred to as solidified material) is refined into particles having sufficient strength and a predetermined particle diameter (hereinafter, simply referred to as finely divided). ) Is done. Thereby, the solidified material can be effectively used as a substitute for sand, for example. That is,
The solidified material can be reused as a resource. Also,
Because the solidified material can be reused, environmental protection, resource saving, and extension of the disposal place can be achieved.
The disposal cost of the hydrated soil can be reduced.

According to a third aspect of the present invention, in order to solve the above-mentioned problems, an aqueous solution of poly (meth) acrylic acid and / or a salt thereof is mixed with the water-containing soil, and the mixture is mixed. After granulation, lime and / or gypsum are added to the granulated material. According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, water-soluble poly (meth) acrylic acid and / or a salt thereof are mixed with water-containing soil, and the mixture is granulated. After that, lime and / or gypsum are added to the granulated material.

According to the above method, the solidified product can be finely divided. Thereby, the solidified material can be effectively used as a substitute for sand, for example. That is,
The solidified material can be reused as a resource. Also,
Because the solidified material can be reused, environmental protection, resource saving, and extension of the disposal place can be achieved.
The disposal cost of the hydrated soil can be reduced.

Hereinafter, the present invention will be described in detail. The hydrated soil to be solidified by the solidifying agent and the solidification method according to the present invention may be any hydrated soil. In particular, clay and silt which could not be reused in the past can be granularly solidified. As the water-containing soil, for example, the soil generated during excavation in excavation work employing the underground continuous wall method, mud shield method, or the like is separated into earth and sand and muddy water, and the muddy water is dewatered and pressed to form a solid. After liquid separation, sludge obtained as a dewatered cake, etc .; muddy water generated during construction work is allowed to stand in a sedimentation tank, and sludge obtained as a sediment;
Soft soil and the like can be mentioned.

The hydrated soil is JIS A
1203 (water content test method)
The water content ratio represented by “(water (g) / solid content (g)) × 100” is
Those in the range of 20% to 200% are preferred. 200 moisture content
%, The water content (hereinafter, referred to as water content) is large, so that a large amount of the solidifying agent must be used, which increases the cost of the solidifying agent, which is not preferable. In addition,
The source of the hydrated soil is not limited to the above example. Further, the hydrous soil may contain bentonite and the like in addition to clay and silt.

The poly (meth) acrylic acid and / or its salt used in the solidifying agent and the solidifying method according to the present invention comprises:
(1) a state of an aqueous solution, and (2) particles having water solubility. In the present invention, “poly (meth) acrylic acid” refers to at least one selected from the group consisting of a homopolymer of acrylic acid, a copolymer of acrylic acid and methacrylic acid, and a homopolymer of methacrylic acid. Shall refer to the polymer of the species.

The poly (meth) acrylic acid may be water-soluble, but is preferably a linear polymer. The poly (meth) acrylic acid salt is not particularly limited as long as it is a water-soluble poly (meth) acrylic acid salt. For example, alkali metal salts such as sodium salt and potassium salt; Ammonium salt;
Amine salts and the like.

The neutralization ratio of the poly (meth) acrylate is not particularly limited, but is preferably 90% or less.
% Or less, more preferably 40% or less, and 20% or less.
% Is most preferred. If the degree of neutralization of the poly (meth) acrylate exceeds 90%, the solidified product may not be able to be refined. Then, of the poly (meth) acrylic acid and / or the poly (meth) acrylate having a neutralization ratio of 90% or less, the complete acid type (that is, the neutralization ratio is 0%).
%) Is most preferred.

The weight average molecular weight (Mw) of poly (meth) acrylic acid and / or a salt thereof (hereinafter, referred to as poly (meth) acrylic acid (salt)) is preferably in the range of 50,000 to 6,000,000, and 200,000 to 2,000,000. Is more preferable. And the weight average molecular weight (Mw) is 500,000-2,000,00
Most preferred is a poly (meth) acrylic acid (salt) having a neutralization ratio of 0 or less and 40% or less. If the weight average molecular weight (Mw) of the poly (meth) acrylic acid (salt) is less than 50,000, it is not preferable because the solidified product cannot be finely divided. When the weight average molecular weight (Mw) of poly (meth) acrylic acid (salt) exceeds 6,000,000, mixing poly (meth) acrylic acid (salt) in particles with hydrous soil produces a thickening effect. It is not preferable because the water cannot be mixed uniformly, and when poly (meth) acrylic acid (salt) in the form of an aqueous solution is mixed with hydrous soil, the viscosity of the aqueous solution becomes too high, and both are mixed uniformly. Is not preferred because

When poly (meth) acrylic acid (salt) is used in the form of an aqueous solution, the viscosity of the aqueous solution is preferably in the range of 5 cP (centipoise) to 5,000 cP, more preferably 10 cP to 5,000 cP.
More preferably, it is within the range of 1,000 cP. The viscosity of the aqueous solution is 5 cP
If it is less than 10%, it is not preferable because the solidified product cannot be refined. In addition, the viscosity of the aqueous solution is 5,000
If it exceeds cP, it is not preferable because the aqueous solution cannot be uniformly mixed with the hydrous soil and the solidified product cannot be refined. Depending on the weight average molecular weight (Mw) of the poly (meth) acrylic acid (salt) to be used, the viscosity of the aqueous solution is set within the above range by adjusting the concentration of the aqueous solution to 0.5% by weight to 50% by weight. , Preferably in the range of 1.0% to 15% by weight.

When poly (meth) acrylic acid (salt) is used as particles, the average particle diameter of the particles is from 0.01 mm to
It is preferably in the range of 2 mm, more preferably in the range of 0.02 mm to 1 mm, and even more preferably in the range of 0.05 mm to 0.5 mm.
If the average particle size is more than 2 mm, the amount used must be increased in order to make the solidified product finer, which increases the cost and is not preferable. Furthermore, the average particle size is 0.01
If less than mm, poly (meth) acrylic acid (salt)
When handling, dust is easily generated and the poly (meth) acrylic acid (salt) is easily absorbed by moisture. Therefore,
The workability is lowered, and when added to the hydrous soil, the flour is generated. In order to reduce the grain size, the amount used must be increased.

The amount of the poly (meth) acrylic acid (salt) to be used per 100 parts by weight of hydrous soil is preferably in the range of 0.01 to 5 parts by weight, more preferably in the range of 0.05 to 1 part by weight. . If the amount of the poly (meth) acrylic acid (salt) is less than 0.01 part by weight, it is not preferable because it is difficult to make the solidified product into fine particles. Further, even if the amount of poly (meth) acrylic acid (salt) used is more than 5 parts by weight, the effect is hardly different from the case where it is used within the above range. Therefore, the excessively used poly (meth) acrylic acid (salt) is not preferable because it is wasted. When the poly (meth) acrylic acid (salt) is used in the form of an aqueous solution, the above-mentioned amount used means the poly (meth) acrylic acid (salt) in the aqueous solution
(Pure content). Poly (meth) acrylic acid (salt)
It is particularly preferable to use the compound in the form of an aqueous solution, since the amount used can be reduced, and the particle size obtained by finer granulation becomes smaller.

As the lime according to the present invention, various known limes can be employed. Specific examples of the lime include quick lime and slaked lime, but are not particularly limited. Examples of the gypsum include anhydrous gypsum and hemihydrate gypsum, but are not particularly limited. These limes and gypsums may be used alone or as a mixture of two or more.

The total amount of lime and gypsum used per 100 parts by weight of hydrous soil is preferably in the range of 1 to 35 parts by weight, more preferably in the range of 2 to 25 parts by weight.
If the total amount of lime and gypsum is less than 1 part by weight, the strength (described later) of the solidified product becomes insufficient, which is not preferable. Also, reduce the total amount of lime and gypsum
If the amount is more than 35 parts by weight, the strength of the solidified product may decrease, which is not preferable.

As described above, the solidifying agent according to the present invention comprises:
Poly (meth) acrylic acid (salt) with specified properties
And lime and / or gypsum as essential components. Next, a solidification method for solidifying hydrated soil using the solidifying agent having the above-described configuration will be described below.

First, the poly (meth) acrylic acid (salt) is mixed with the hydrous soil in the form of particles or an aqueous solution. As a mixer used when mixing the hydrous soil and the poly (meth) acrylic acid (salt), a device capable of stirring and mixing without kneading the both is preferable. An apparatus in which the shape of the stirring blade is formed in a rod shape, a fishing hook shape, or the like is preferable so that the stirring blade can be agitated while applying a shearing force to both shafts. In other words, the shape of the agitating blade, which extends in the direction perpendicular to the moving direction of the stirring / mixing as much as possible, can prevent the particle diameter from becoming coarse due to kneading, and can prevent the stirring blade from adhering to the agitating blade and the inner wall of the apparatus. This is desirable because it can prevent

Examples of such a device include a planetary forced mixer (planetary mixer). The water-containing soil is mixed with the poly (meth) acrylic acid (salt) using the above mixer, and the shear force generated by the stirring blade is used to make the particle diameter in the range of 0.1 mm to 50 mm, preferably 0.3 mm. It can be refined (granulated) to a particle size in the range of mm to 10 mm. The method of mixing the water-containing soil with the poly (meth) acrylic acid (salt) is not particularly limited.

Next, lime and / or gypsum are added to the obtained granules and mixed. The mixer used for mixing both is not particularly limited, but a device capable of stirring and mixing without kneading the both is preferable. When mixing using such a mixer, the above-mentioned hydrated soil is mixed with poly (meth) acrylic acid (salt).
And so that the shearing force is not applied as much as the mixing method at the time of mixing, and the rotational speed of the stirring blade is relatively reduced,
It is preferable to stir so that lime and / or gypsum adhere to (glide) the surface of the granulated material. As a result, a finely divided product in which lime and / or gypsum adheres almost uniformly to the surface of the granulated product is obtained. In addition, a part of lime and / or gypsum may enter the inside of the granulated material. The method of mixing the granulated material with lime and / or gypsum is not particularly limited.

The obtained granulated material may be immediately backfilled, but then left at room temperature for about 3 to 7 days to cure lime and / or gypsum, That is, the solidified material has a predetermined strength. The strength of the solidified product is measured using a 90% modified CBR (California Bearin) measured based on JIS A 1211 (CBR test method).
g Ratio) value is 5% to 60%. The strength is determined by the viscosity and water content of hydrous soil, or poly (meth) acrylic acid (salt).
It can be arbitrarily adjusted depending on the amount of lime and / or gypsum added. The larger the 90% corrected CBR value, the higher the strength.

Since the solidified product obtained as described above has a predetermined particle size and strength, it can be reused as a resource such as a substitute for sand without performing operations such as pulverization and sieving. Can be achieved. That is, in civil engineering work in which excavation holes need to be backfilled, backfilling can be performed using the solidified material without separately preparing sand or the like. In addition, the solidified material is used as a backfill material for use in a buried pipe or structure, a barrier layer material as artificial sand, a vegetation base material for spraying a slope to process the slope, a soil improving material. , A water retention material, a water permeable material, a filtration material and the like. Further, since the solidified material can be reused, environmental conservation, resource saving, life extension of a disposal place can be achieved, and disposal cost of hydrous soil can be reduced.

[0031]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 Water containing soil was obtained by dewatering and pressing mud generated by excavation using the mud shield construction method. The water content of the hydrous soil was 84%. Then, as the mixer, a planetary mixer equipped with a hook-type stirring blade in the shape of a fishing hook was used.

Into the mixer, 5 kg of the above hydrated soil was charged,
While stirring the hydrated soil at 160 rpm, the weight average molecular weight
(Mw) 800,000, neutralization rate 0%, particle size 0.05mm ~ 0.25
25 g of particulate polyacrylic acid in the range of mm was added and mixed little by little to the hydrous soil to make it fine. The ratio of polyacrylic acid to hydrous soil, that is, the amount used is 0.5% by weight.

Next, while the obtained granulated material was stirred at 160 rpm, 750 g of quicklime as lime was added and mixed little by little to the granulated material. The proportion of quicklime to hydrous soil is 15% by weight.

By the above operation, a finely divided product in which quicklime was almost uniformly attached to the surface of the granulated product was obtained. The obtained finely divided product had a particle size in the range of 0.3 mm to 10 mm and an average particle size of 1 mm. Thereafter, the granulated product is cooled at room temperature for 7 minutes.
Left for days. Thus, a solid was obtained. The 90% modified CBR value of the solid was 8%. Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 2 5 kg of hydrated soil having a water content of 84% was charged into the same mixer as that of Example 1, and the weight-average molecular weight (Mw) of the hydrated soil was stirred at 160 rpm. But
500 g of a 5% by weight aqueous solution of polyacrylic acid having a neutralization ratio of 0% at 800,000 was added and mixed little by little to the hydrous soil to make fine particles. The viscosity of the aqueous solution was 40 cP. Also,
The ratio of polyacrylic acid to hydrous soil, that is, the amount used is 0.5% by weight.

Next, while the obtained granulated material was stirred at 160 rpm, 750 g of quicklime as lime was added and mixed little by little to the granulated material. The proportion of quicklime to hydrous soil is 15% by weight.

By the above operation, a finely divided product in which quicklime was substantially uniformly adhered to the surface of the granulated product was obtained. The obtained finely divided product had a particle size in the range of 0.3 mm to 5 mm and an average particle size of 1 mm. Thereafter, the granulated product is cooled at room temperature for 7 minutes.
Left for days. Thus, a solid was obtained. The 90% modified CBR value of the solid was 7%. Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 3 Into the same mixer as in Example 1, 5 kg of hydrous soil having a water content of 78% was charged, and while stirring the hydrous soil at 160 rpm, the weight average molecular weight (Mw) was increased. But
125 g of particulate polyacrylic acid having a neutralization rate of 800,000, a neutralization rate of 0%, and a particle diameter in the range of 0.05 mm to 0.25 mm was added and mixed little by little to the hydrous soil to make it fine. The ratio of polyacrylic acid to the hydrous soil, that is, the amount used is 2.5% by weight.

Next, while the obtained granulated product was stirred at 160 rpm, 750 g of slaked lime as lime was gradually added to and mixed with the granulated product. The proportion of slaked lime to hydrous soil is 15% by weight.

By the above operation, a granulated product in which slaked lime adhered to the surface of the granulated product almost uniformly was obtained. The obtained finely divided product had a particle size in the range of 0.3 mm to 10 mm and an average particle size of 1 mm. Thereafter, the granulated product is cooled at room temperature for 7 minutes.
Left for days. Thus, a solid was obtained. The 90% modified CBR value of the solid was 8%. Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 4 5 kg of hydrated soil having a water content of 78% was charged into the same mixer as that of Example 1, and the weight-average molecular weight (Mw) of the hydrated soil was stirred at 160 rpm. But
625 g of a 10% by weight aqueous solution of polyacrylic acid having a neutralization rate of 0% at 800,000 was added and mixed little by little to the hydrous soil to obtain fine granules. The viscosity of the aqueous solution was 630 cP. The ratio of polyacrylic acid to the hydrated soil, that is, the amount used is 1.25% by weight.

Next, while the obtained granulated product was stirred at 160 rpm, 750 g of slaked lime as lime was gradually added to and mixed with the granulated product. The proportion of slaked lime to hydrous soil is 15% by weight.

By the above operation, a finely divided product having slaked lime adhered to the surface of the granulated product almost uniformly was obtained. The obtained finely divided product had a particle size in the range of 0.3 mm to 7 mm and an average particle size of 1 mm. Thereafter, the granulated product is cooled at room temperature for 7 minutes.
Left for days. Thus, a solid was obtained. The 90% modified CBR value of the solid was 9%. Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 5 5 kg of hydrated soil having a water content of 50% was charged into the same mixer as that of Example 1, and the weight-average molecular weight (Mw) of the hydrated soil was stirred at 160 rpm. But
250 g of a 10% by weight aqueous solution of polyacrylic acid having a neutralization ratio of 800,000 and 0% was added and mixed little by little to the hydrous soil to make fine particles. The viscosity of the aqueous solution was 630 cP. The ratio of polyacrylic acid to the hydrous soil, that is, the amount used is 0.5% by weight.

Next, while the obtained granulated product was stirred at 160 rpm, 750 g of slaked lime as lime was gradually added to and mixed with the granulated product. The proportion of slaked lime to hydrous soil is 15% by weight.

By the above operation, a finely divided product having slaked lime adhered to the surface of the granulated product almost uniformly was obtained. The obtained finely divided product had a particle size in the range of 0.3 mm to 5 mm and an average particle size of 1 mm. Thereafter, the granulated product is cooled at room temperature for 7 minutes.
Left for days. Thus, a solid was obtained. The 90% corrected CBR value of the solid was 10%. Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

[0048]

[Table 1]

Example 6 Instead of the polyacrylic acid used in Example 1, the weight average molecular weight (Mw) was 800,00.
0, The same operation as in Example 1, except that sodium polyacrylate having a neutralization ratio of 40% and a particle size in a range of 0.05 mm to 0.25 mm was used at 0.5% by weight with respect to the hydrated soil. By performing the above operation, a finely divided product was obtained. The obtained finely divided product had a particle size in the range of 0.5 mm to 15 mm and an average particle size of 1 mm. Also, 90% modified CBR of solidified material
The value was 6%. Table 2 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 7 Instead of the polyacrylic acid used in Example 1, the weight average molecular weight (Mw) was 220,00.
0, the same operation as that of Example 1 except that 0.5% by weight of particulate polyacrylic acid having a neutralization ratio of 0% and a particle size in a range of 0.05 mm to 0.25 mm was used relative to the hydrated soil. By performing the operation, a finely divided product was obtained. The obtained finely divided product has a particle size in the range of 0.5 mm to 8 mm and an average particle size of 2 mm
Met. The 90% modified CBR value of the solidified product is 6%
Met. Table 2 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 8 Instead of the polyacrylic acid used in Example 1, the weight average molecular weight (Mw) was 1,400,0
In addition to using 0.5% by weight of particulate polyacrylic acid having a neutralization rate of 0% and a particle diameter in the range of 0.1 mm to 0.45 mm with respect to the hydrous soil, instead of the quicklime used in Example 1, Fine granules were obtained by performing the same operation as in Example 1 except that anhydrous gypsum was used in an amount of 15% by weight with respect to the hydrous soil. The obtained finely divided product has a particle size of 1
It was in the range of mm to 25 mm, and the average particle size was 3 mm.
The 90% corrected CBR value of the solidified product was 7%.
Table 2 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 9 Instead of the aqueous solution of polyacrylic acid used in Example 2, the weight average molecular weight (Mw) was
1,400,000, except that a 5% by weight aqueous solution of sodium polyacrylate (viscosity: 2,000 cP) with a neutralization ratio of 40% was used so that the amount of sodium polyacrylate was 0.5% by weight based on the hydrous soil. By performing the same operation as that of Example 2, a finely divided product was obtained. The obtained finely divided material has a particle diameter in a range of 2 mm to 30 mm, and has an average particle diameter of
It was 10 mm. The 90% corrected CBR value of the solidified product is
8%. Table 2 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 10 Instead of the polyacrylic acid aqueous solution used in Example 2, the weight average molecular weight (Mw) was
1,400,000, except that a 5% by weight aqueous solution of sodium polyacrylate (viscosity: 4,500 cP) with a neutralization ratio of 100% was used so that the amount of sodium polyacrylate was 0.5% by weight based on hydrous soil. By performing the same operation as that of Example 2, a finely divided product was obtained. The obtained finely divided product has a particle size in the range of 5 mm to 50 mm, and has an average particle size.
It was 11 mm. The 90% corrected CBR value of the solidified product is
9%. Table 2 shows the main solidification conditions, the particle size of the finely divided material, and the like.

[0054]

[Table 2]

Example 11 Instead of the aqueous solution of polyacrylic acid used in Example 2, the weight average molecular weight (Mw) was
90,000, 30% by weight of polyacrylic acid with a neutralization rate of 0%
An aqueous solution (viscosity 800 cP) was used so that the amount of polyacrylic acid was 3.0% by weight with respect to the hydrous soil, and instead of quicklime used in Example 2, anhydrite was used at 15% by weight with respect to the hydrous soil. Except for using, the same operation as in Example 2 was performed to obtain a finely divided product. The obtained finely divided material has a particle diameter in a range of 2 mm to 35 mm,
The average particle size was 4 mm. Also, 90% correction of solidified material
The CBR value was 5%. Table 3 shows the main solidification conditions, the particle size of the finely divided product, and the like.

Example 12 Instead of the water-containing soil used in Example 1, 5 kg of water-containing soil having a water content of 84% was used, and instead of the polyacrylic acid used in the same Example, the weight average molecular weight (Mw ) Is 2,000,000, neutralization rate is 0%,
Except for using 0.2% by weight of particulate polyacrylic acid with a particle diameter in the range of 0.1mm to 0.5mm based on hydrous soil,
By performing the same operation as in Example 1, a finely divided product was obtained. The obtained finely divided product had a particle size in the range of 3 mm to 45 mm and an average particle size of 8 mm. The 90% corrected CBR value of the solidified product was 9%. Table 3 shows the main solidification conditions, the particle size of the finely divided product, and the like.

Example 13 The proportion of the amount of quicklime used in the hydrous soil in Example 1 was from 15% by weight to 5% by weight.
By performing the same operation as that of Example 1 except that it was changed to, a finely-granulated product was obtained. The obtained finely divided product has a particle diameter in the range of 0.3 mm to 10 mm, and an average particle diameter of 1 mm.
Met. The 90% modified CBR value of the solidified product is 4%
Met. Table 3 shows the main solidification conditions, the particle size of the finely divided product, and the like.

Example 14 Fine granules were obtained by performing the same operation as in Example 5 except that quicklime was used in an amount of 25% by weight based on the hydrous soil instead of slaked lime used in Example 5. Compound was obtained. The obtained granulated product has a particle size
It was in the range of 0.3 mm to 5 mm, and the average particle size was 1 mm. The 90% corrected CBR value of the solidified product was 15%. Table 3 shows the main solidification conditions and the particle size of the finely divided material.
Shown in

[0059]

[Table 3]

Comparative Example 1 Instead of the polyacrylic acid used in Example 1, the weight average molecular weight (Mw) was 780,00.
0, water-containing soil containing a particulate acrylate / acrylamide copolymer (weight ratio of acrylate / acrylamide = 30/70) with a neutralization ratio of 100% and a particle size in the range of 0.05 mm to 0.25 mm The same operation as in Example 1 was performed except that 0.5% by weight was used. However, a finely divided product could not be obtained. Table 4 shows the main solidification conditions.

Comparative Example 2 The weight average molecular weight (Mw) was 1,300,0 instead of the polyacrylic acid used in Comparative Example 1.
00, a water-containing soil containing a particulate acrylate / acrylamide copolymer (weight ratio of acrylate / acrylamide = 30/70) having a neutralization ratio of 100% and a particle size in the range of 0.07 mm to 0.4 mm. The same operation as in Example 1 was performed except that 0.5% by weight was used. However, a finely divided product could not be obtained. Table 4 shows the main solidification conditions.

[0062]

[Table 4]

[0063]

As described above, the solidifying agent for hydrous soil according to claim 1 of the present invention comprises poly (meth) acrylic acid and / or
Alternatively, the composition comprises an aqueous solution of a salt thereof, lime and / or gypsum as essential components. As described above, the solidifying agent for hydrous soil according to claim 2 of the present invention comprises water-soluble poly (meth) acrylic acid and / or a salt thereof and lime and / or gypsum as essential components. It is.

As a result, the hydrated soil after solidification is refined into particles having a sufficient strength and a predetermined particle size, so that the hydrated soil can be effectively used as a resource such as a substitute for sand. (Reuse). In addition, since the solidified material can be reused, environmental preservation, resource saving, life extension of the disposal site can be achieved, and the effect of reducing the disposal cost of the hydrous soil can also be achieved.

In the method for solidifying hydrous soil according to claim 3 of the present invention, an aqueous solution of poly (meth) acrylic acid and / or a salt thereof is mixed with hydrous soil as described above, and the mixture is granulated. Thereafter, lime and / or gypsum are added to the granulated product. The method for solidifying hydrous soil according to claim 4 of the present invention comprises mixing water-soluble poly (meth) acrylic acid and / or a salt thereof into hydrous soil and granulating the mixture as described above. A method of adding lime and / or gypsum to the granulated product.

Thus, the solidified hydrous soil can be refined into particles having a sufficient strength and a predetermined particle size, so that the hydrous soil can be effectively used as a resource such as a substitute for sand. This has the effect that it can be utilized (reused) for In addition, since the solidified material can be reused, environmental preservation, resource saving, life extension of the disposal site can be achieved, and the effect of reducing the disposal cost of the hydrous soil can also be achieved.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C09K 17/48 C09K 17/48 P E21D 9/06 301 E21D 9/06 301U // C09K 103: 00 (72) Inventor Satoshi Yamada Nippon Shokubai Co., Ltd., located at 992 Nishioki, Okihama-shi, Abashiri-ku, Himeji-shi, Hyogo

Claims (4)

[Claims] 1. A solidifying agent for hydrous soil, comprising, as essential components, an aqueous solution of poly (meth) acrylic acid and / or a salt thereof, and lime and / or gypsum. 2. A water-soluble poly (meth) acrylic acid and / or
Or a solidifying agent for hydrous soil, comprising particles of a salt thereof and lime and / or gypsum as essential components. 3. A method comprising mixing an aqueous solution of poly (meth) acrylic acid and / or a salt thereof with a hydrous soil, granulating the mixture, and adding lime and / or gypsum to the granulated material. How to solidify hydrated soil. 4. A method comprising mixing particles of water-soluble poly (meth) acrylic acid and / or a salt thereof with a hydrous soil, granulating the mixture, and adding lime and / or gypsum to the granulated material. Method for solidifying hydrous soil.