JP3163236B2 - Method for solidifying hydrous mud - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for solidifying hydrous mud generated during civil engineering work such as earth pressure shield construction.

[0002]

2. Description of the Related Art Various types of solidifying agents and solidification methods have been proposed for hydrous mud generated during civil engineering works and the like because it has high fluidity and is difficult to transport as it is by a dump truck or the like. For example, a method of adding a lime or cement-based solidifying agent to hydrous mud and solidifying by using the hydraulic properties of these solidifying agents (see JP-A-61-216994), adding a superabsorbent resin to hydrous mud, and Method of increasing the strength of hydrous mud by lowering the water content ratio
-155488), and a method of adding a high-molecular-weight acrylic coagulant to coagulate earth and sand (see Japanese Patent Application Laid-Open No. 2-219890).

[0003] However, the solidification method using quick lime or cement system has the following problems. (1) The solidification time is long, and it takes several hours to several days to solidify. (2) The pH of the solidified mud shows strong alkalinity. The method of using the superabsorbent resin is as follows: (1) It is not economical because it needs to be added in a large amount. (2) Adhesion between the absorbed resin and the mud is not expected, and bleeding is likely to occur. In particular, moisture flows out of the solidified mud due to vibration during transportation by a dump truck or the like. The method using an acrylic coagulant is as follows: (1) The cohesion of earth and sand is strong and has adhesiveness, but the solidified material is sticky and the thread adheres to a drawing device or the like, so that workability is extremely poor.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and provides a method for solidifying hydrous mud which can be solidified in a short time with a small amount of addition, does not have stickiness or stringiness of a solidified product, and does not cause bleeding. The purpose is to provide.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the use of a water-insoluble acrylic polymer obtained under specific polymerization conditions is extremely effective in solving the above problems. The present invention has been completed.

That is, the present invention relates to acrylamide 50
From 100 to 100 mol%, from 0 to 50 mol% of acrylic acid and / or methacrylic acid or a salt thereof and from 0 to 10 mol% of another monovinyl compound copolymerizable therewith, with respect to 100 parts of the total amount of vinyl monomer. A method for solidifying hydrous mud, comprising polymerizing in the presence of 3 to 100 ppm of a monomer having two or more groups, and adding 0.1 to 5 kg of the obtained water-insoluble polymer to 1 m ³ of hydrous mud. ,.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer to be added to the hydrous mud according to the present invention comprises 50 to 100 mol% of acrylamide, 0 to 50 mol% of acrylic acid and / or methacrylic acid or a salt thereof, and other copolymerizable with them. Is a water-insoluble polymer obtained by polymerizing a monomer comprising 0 to 10 mol% of a monovinyl compound in the presence of 3 to 100 ppm of a monomer having two or more vinyl groups with respect to a total amount of 100 parts.

The salts of acrylic acid and methacrylic acid include alkali metal salts, ammonium salts and amine salts. Other monovinyl monomers copolymerizable with acrylamide, acrylic acid and / or methacrylic acid or salts thereof include water-soluble monovinyl monomers such as 2-acrylamido-2-methylpropanesulfonic acid and vinylsulfonic acid and salts thereof. Compound,
Hydrophobic monovinyl compounds such as methyl acrylate, methyl methacrylate and styrene are exemplified.

The monomer having two or more vinyl groups is
For example, a compound having two or more active carbon-carbon double bonds in the same molecule, specifically, a polyhydric alcohol represented by methylenebisacrylamide, diethylene glycol diacrylate, and triethylene glycol dimethacrylate Examples include polyacrylates and methacrylates and polyallyl ethers of polyhydric alcohols such as glycerin triallyl ether.

Regarding the monomer composition, acrylamide is 5
It is used in an amount of 0 to 100 mol%, but if the amount is 50 mol% or less, the function as a solidifying agent cannot be sufficiently exhibited. Acrylic acid and / or methacrylic acid or a salt thereof is 0 to 50 mol%, and other monovinyl compounds copolymerizable with acrylamide, (meth) acrylic acid and the like are 0 to 10 mol%.
Mol% range.

The amount of the monomer having two or more vinyl groups is in the range of 3 to 100 ppm, preferably 5 to 60 ppm, based on the total amount of the above-mentioned other monomers, and the optimum addition amount is determined depending on the polymerization conditions employed. If the addition amount exceeds 100 ppm, the solidification performance of the water-containing mud is reduced, and it is necessary to increase the usage amount. On the other hand, 3pp
If it is less than m, the effect of the present invention cannot be obtained because the treated soil becomes sticky.

The polymerization method for obtaining the polymer of the present invention may be any of aqueous solution polymerization, precipitation polymerization (dispersion polymerization), reverse-phase suspension polymerization and reverse-phase emulsion polymerization. preferable. As the reverse phase emulsion polymerization, for example,
JP-B-34-7679, JP-B-52-18224, JP-B-52-39417
The method described in each publication can be adopted.

Specifically, a water-in-oil emulsion prepared by mixing, emulsifying and dispersing an aqueous phase containing a monomer and a hydrophobic liquid with an emulsifying surfactant is used as a polymerization initiator for producing free radicals. Polymerization in the presence gives a reversed-phase emulsified polymer.

Examples of polymerization initiators include redox initiators in combination with peroxides such as persulfates and alkyl peroxides and sulfites, ferrous salts, amine compounds, azobisisobutyronitrile, 2,2 2′-azobis- (2-amidinopropane) dihydrochloride, 2,2′-azobis- (2,
An azo-type thermal decomposition initiation system such as 4-dimethylvaleronitrile) is used. Further, polymerization can be carried out by irradiating light in the presence of a photosensitizer such as benzophenone or benzoin ethyl ether.

[0015] The water-insoluble polymer of the present invention, as shown in the Examples below, has a unique characteristic in the thread length and the polymer liquid filter passing rate as compared with the conventional water-soluble coagulant and the superabsorbent resin. It is. That is, the conventional water-soluble coagulant has a thread length of about 40 mm and a polymer liquid filter passing rate of about 100%, and the conventional superabsorbent resin has a thread length of 0 mm and a polymer liquid filter passing rate of about 100%. In contrast to 1%, the polymer of the present invention has a polymer liquid filter passage rate of about 3% or less and is substantially water-insoluble,
Moreover, the thread length is about 4 to 10 mm, and the properties are clearly different from those of the former two. Therefore, the effect obtained by the present invention is presumed to be based on such a difference in the properties of the polymer.

The hydrous mud which is the object of the present invention generally includes excavated soil excavated by civil works such as a shield method having a water content of 30% or more, or sludge deposited on rivers and ports. In addition, various sludges requiring solidification treatment are mentioned.

The method of adding the polymer to the hydrous mud may be to add the polymer powder or liquid as it is, or to dissolve the polymer powder or liquid once in water and then add it. Well, there is no particular limitation.

The amount of the polymer added is 0.1 to 5 kg / m ³ ,
Preferably, it is in the range of 0.2 to ³ kg / m3. If the addition amount is less than 0.1 kg / m ³ , the solidification is insufficient or not solidified, and if it exceeds 5 kg / m ³ , no further effect is obtained and it is not economical.

When the polymer of the present invention is used for solidifying hydrous mud, conventionally used solidifying agents such as cement, lime, gypsum and water glass can be used in combination, if necessary. .

[0020]

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

A. Production of Polymer Example 1 426.0 50% aqueous solution of acrylamide in 67.3 parts of water
Parts (3.0 mol) and 72.0 parts (1 mol) of acrylic acid,
An aqueous phase was prepared by adding 88.9 parts of 45% sodium hydroxide and 0.0029 parts of methylene bisacrylamide (MBAA). Next, the aqueous phase was added to Idemitsu Petrochemical
306.9 parts of IP-Solvent 2028 and 10.2 parts of Kao-made Leodol MS-60 and Leodol SP-O10 2
An oil phase containing 0.4 parts was added and stirred in a Waring blender for 1 minute to obtain a water-in-oil emulsion. The resulting emulsion was charged into a 1500 ml separable flask equipped with a stirrer, a nitrogen gas blowing tube, a thermometer and a gas outlet tube, and then benzoin ethyl ether (0.05 part in 1 ml of methanol) was added. After blowing nitrogen gas into this emulsion to remove dissolved oxygen,
The polymerization temperature was reduced to 40 ° C. on a water bath, and the mixture was irradiated with light from an ultraviolet lamp to carry out polymerization until the residual monomer became 1% or less. The above-mentioned water-in-oil emulsion obtained by polymerization was added to Kao's Emulgen 9 as a reversal surfactant.
10 20.4 parts and 10.2 parts of Emulgen 906 were added to obtain a polymer. The effective component of the reverse emulsion polymer product was 30%, the product viscosity was 420 cp, and the spinning length was 9.5 mm. This was designated as Sample-1, and the results are shown in Table 1.
Shown in

Incidentally, the measurement of the spinning length and the passing ratio of the polymer liquid filter was carried out by the following methods. [String length] 300 g of a 0.1% aqueous polymer solution was placed in a 300 ml glass beaker, and a glass rod having a 6.6 mm diameter rounded tip was held at a position 10 mm from the liquid surface of the polymer liquid. Was measured at a speed of 500 mm / min until the yarn was cut.

[Polymer liquid filter passage rate] 0.1%
300 ml of the polymer solution is placed in a plastic cylindrical container (diameter 60 mm, length 300 mm) provided with a 1 μm pore size Nuclepore filter (manufactured by Nucleopore Corp) at the lower port, pressure-filtered at a pressure of 2 kg / cm ² , and the filtrate [ A (g)]
Was evaporated in a dryer at 90 ° C. to remove the residual amount [B (mg)]
Was measured and calculated by the following equation. Polymer liquid filter passage rate (%) = (B / A) × 100

Example 2 The same operation as in Example 1 was carried out except that the amount of MBAA added was changed in Example 1, and Sample-2 and Comparative Sample-1 were used.
~ 3. Table 1 shows the results.

[0025] * Equivalent to conventional water-soluble coagulant ** Equivalent to conventional superabsorbent resin

The polymers of the present invention (Samples 1 and 2)
A polymer prepared without adding a cross-linking agent (Comparative sample-1 equivalent to a conventional water-soluble coagulant) and the amount of the cross-linking agent added is less than the lower limit of the present invention, as compared with the case where the filter hardly passes through a filter having a pore size of 1 μm. (Comparative sample-2)
Is almost passed through the filter, the polymer of the present invention is different from the conventional water-soluble coagulant,
A polymer prepared in such a manner that the amount of the cross-linking agent added exceeds the upper limit of the present invention (Comparative Sample-3, corresponding to a conventional superabsorbent resin) has a spinning length of 0 mm and shows no spinnability at all. It is clear that the polymer of the present invention exhibits considerable spinnability and is different from conventional superabsorbent resins.

Example 3 A 55% aqueous solution of acrylamide in 39.7 parts of water was 559.4.
Part (3.94 mol), 4.3 parts (0.06 mol) of acrylic acid, 5.3 parts of 45% sodium hydroxide and 0.00 of diethylene glycol dimethacrylate (DEDMM).
An aqueous phase was prepared by adding 43 parts. Next, to this aqueous phase was added an oil phase containing 2028285.3 parts of IP-solvent manufactured by Idemitsu Petrochemical, 9.5 parts of Reodol MS-60 manufactured by Kao, and 19.0 parts of Reodol SP-O10. After stirring for minutes, a water-in-oil emulsion was obtained. The resulting emulsion was 1500 m equipped with a stirrer, a nitrogen gas blowing pipe, a thermometer and a gas outlet pipe.
A 1-separable flask was charged, and then 0.05 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) (in 1 ml of toluene) was added. After nitrogen gas was blown into this emulsion to remove dissolved oxygen, polymerization was carried out on a water bath at a polymerization temperature of 40 ° C. until the residual monomer became 1% or less. 19.0 parts of Kao Emulgen 910 and Emulgen 906 as surfactants for reversal were added to the water-in-oil emulsion obtained by the above polymerization.
9.5 parts were added to obtain a polymer. The reverse phase emulsion polymer product had an effective content of 30%, a product viscosity of 350 cp, and a string length of 5.3 mm. This was designated as Sample-3, and the results are shown in Table 2.

Example 4 Samples-3 to 5 and Comparative sample-4 were obtained in the same manner as in Example 3, except that the monomer composition and the amount of DEGDM added were changed. Table 2 shows the results.

[0029] AA / Aa-Na: Acrylic amide / sodium acrylate AA / Aa-NH ₄ / AMPS-Na: Acrylic amide / ammonium acrylate / 2-acrylamito-2-methylfluorobenzene sodium sulfonate

B. Example 5 Addition to hydrous mud Example 5 Hydrous mud having the following composition and physical property values was prepared by adding 1600 g of Toyoura standard sand, 1067 g of SAM clay and 1067 g of water.
g was kneaded with a mortar mixer according to JIS R5201 for 3 minutes.

Silt clay content 40% Water content 40% Specific gravity 1.79 Flow value 300 or more

A predetermined amount of the polymer shown in Table 3 (inverted emulsion polymer as it is) was added to 1,000 ml of the wet mud, kneaded with a mortar mixer according to JIS R5201 for 3 minutes, and the solidified mud was evaluated. Table 3 shows the results.

[Evaluation method] (1) Flow value The solidification state of the water-containing mud was measured in accordance with "Physical test method of mortar" specified in JIS-R5201.
If the flow value is less than 110, transport by a dump truck or the like is possible, and the range of 110 to 120 can be transported somehow, but if it exceeds 120, transport becomes impossible.

(2) Breathing A load of 7.5 kg was applied to 100 g of the water-containing mud for 1 minute, and the amount of water (ml) oozing out during the load was measured. This value is preferably as small as possible, but there is no particular problem as long as it is about 3 ml or less.

(3) Stickiness and Stringing Test The solidified hydrous mud after completion of the flow test was evaluated for stickiness and stringiness. 〇: No stickiness and no stringiness X: Solid and stringiness

[0036]

Example 6 According to Example 5, a hydrous mud having the following composition and physical properties was prepared. Silt clay content 45% Water content 50% Specific gravity 1.70 Flow value 300 or more To 1000 ml of this water-containing mud, a predetermined amount of the polymer described in Table 4 (as it is with the inverse emulsion polymer) is added and JI is added.
Evaluation was performed after kneading with a mortar mixer of SR5201 for 3 minutes. Table 4 shows the results.

[0038]

[0039]

According to the present invention, hydrous mud can be solidified in a short time with a small amount of polymer added, and the solidified mud is free from stickiness, stringing, and no bleeding. Thus, it is possible to provide a method for solidifying hydrous mud which has very good workability.

Continuation of the front page (56) References JP-A-4-45850 (JP, A) JP-A-54-45262 (JP, A) JP-B-6-91998 (JP, B2) (58) Fields investigated (Int) .Cl. ⁷ , DB name) C02F 11/00-11/20 E02D 3/12 C07K 17/00-17/52

Claims (4)

(57) [Claims] 1. A monomer comprising 50 to 100 mol% of acrylamide, 0 to 50 mol% of acrylic acid and / or methacrylic acid or a salt thereof, and 0 to 10 mol% of another monovinyl compound copolymerizable therewith. Polymerization is carried out in the presence of 3 to 100 ppm of a monomer having two or more vinyl groups with respect to 100 parts in total, and the resulting water-insoluble polymer is used in an amount of 0.1 to 5 k / m3 of hydrous mud
g. A method for solidifying hydrous mud, characterized by adding g. 2. The method for solidifying hydrous mud according to claim 1, wherein the polymerization is carried out by a reversed-phase emulsification method. 3. The water-insoluble polymer whose dispersion liquid has spinnability.
The method for solidifying the hydrous mud according to the above. 4. Breathing of solidified hydrous mud is 3 m.
The method for solidifying hydrous mud according to any one of claims 1 to 3, which is 1 or less.