JP2636725B2 - Aggregation treatment method of dredged slurry - 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 agglomerating dredged slurry, and more particularly to a method for producing a dredged slurry having a high water content of 100% by weight or more based on solid content at low cost. Also, the present invention relates to a method for efficiently performing agglomeration treatment.

[0002]

2. Description of the Related Art In dredging work, a large amount of dredging slurry is generated, and it is necessary to solidify the generated dredging slurry to some extent, whether it is discarded or backfilled.

[0003] Conventionally, industrial waste soil or construction waste soil of clay-based slurry is solidified in accordance with the water content thereof (in this specification, the water content means the ratio of the weight of water to the weight of solids). However, for those having a relatively low water content of 40% or less, quick lime (CaO) is added and the water content is adjusted and the solidification treatment by the pozzolanic reaction is performed. Further, those having a water content of 40 to 100% are subjected to solidification treatment by adding cement or cement and a polymer absorbent and / or quicklime.

However, a slurry having a high water content of 100% or more requires a large amount of a solidifying material to be added by the above-described method, which increases the processing cost.
It is the present condition that after drying in the sun for a long period of time, the water content is reduced and then treated.

[0005] The dredging slurry generated during dredging is also
Since the slurry is a high water content slurry having a water content of 100% or more, solidification requires long-term solar drying.

[0006]

As described above, since the dredged slurry is a slurry having a high moisture content, the solidification of the dredged slurry has the following problems.

That is, in order to prevent an increase in the amount of solidified material such as quicklime and the like, and to avoid a rise in cost, it is necessary to dry in the sun for a long period of time. There are problems such as the need to secure space for solar drying.

On the other hand, in order to increase the processing efficiency without performing sun drying, it is necessary to add a large amount of a solidifying material, resulting in an increase in processing cost.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a low-cost and efficient method for agglomerating a dredged slurry having a high water content of 100% or more. .

[0010]

According to a first aspect of the present invention, there is provided a method for agglomerating a dredged slurry, comprising: adding a fluidized bed boiler ash and a water-soluble polymer absorbent to a dredged slurry having a water content of 100% by weight or more based on solid content. and added a method for processing crumb of the dredging slurry, 160-20 wt% of a fluidized bed boiler ash to said dredging slurry, a water-soluble polymer absorber 13
０．０５0.05% by weight.

According to a second aspect of the present invention, there is provided a method for agglomerating dredged slurry, comprising: adding a fluidized bed boiler ash, a water-soluble polymer absorbent to a dredged slurry having a water content of not less than 100% by weight based on solid content;
Cement or a method by adding the lime to process crumb of the dredging slurry, a fluidized bed boiler ash 160-20 wt%, a water-soluble polymer absorbing material 3 against the dredged slurry 0.05 wt%, cement or is characterized by the addition of quick lime 15% by weight or less.

That is, the water-soluble polymer absorbent material is effective for solidifying the dredged slurry because it absorbs water in the dredged slurry and gels. However, it is necessary to add a large amount to a high water content slurry. And cause a rise in cost.

The present inventor studied the reduction of the amount of the water-soluble polymer absorbent added to the dredged slurry with a high water content, and as a result,
The present inventors have found that the amount of water-soluble polymer absorbent added can be reduced by adding a fluidized bed boiler ash to the dredged slurry to reduce the water content per volume, and completed the present invention.

Hereinafter, the present invention will be described in detail.

In the method of the present invention, the water content is 100%
More high water content dredged slurry to the fluidized bed boiler ash and the water-soluble polymer absorber, or even cement or the addition of quicklime.

[0016] In the present invention, a fluidized bed boiler ash, flow
The water content of the dredged slurry after adding and mixing the moving bed boiler ash is 1
It is preferably added so as to be not more than 00%, preferably about 40 to 100%, and the amount of addition is appropriately determined according to the water content of the dredging slurry to be treated. The addition amount is as follows.

[0017] When adding a fluidized bed boiler ash and the water-soluble polymer absorbent material dredged slurry, its amount is 160 to 20 wt% of a fluidized bed boiler ash respect dredged slurry, a water-soluble polymer absorber 13-0.05% by weight
You.

When the fluidized bed boiler ash, the water-soluble polymer absorbent, cement or quick lime are added to the dredged slurry, the fluidized bed boiler ash is added to the dredged slurry in an amount of 1%.
60 to 20% by weight, water-soluble polymer absorbent is 3 to 0.05
Wt%, less than 15 wt% cement, preferably 8-4%
15% by weight or less, preferably 8 to 4% by weight
% By weight .

In the present invention, a fluidized bed to dredged slurry
And the addition amount of the boiler ash is smaller than the above range fluidized bed Boi
The effect of reducing the required amount of the water-soluble polymer absorbent, cement, and quick lime due to the addition of the ash cannot be sufficiently obtained, and if the amount is too large, it may be difficult to aggregate the particles to a predetermined strength. When the proportion of the water-soluble polymer absorbent is less than the above range, the particles cannot be sufficiently aggregated, and when the proportion is too large, the cost of adding the water-soluble polymer absorbent is undesirably high.

[0020] For cement or quick lime is added for increased crumb intensity is determined in accordance with the strength required, be added more than the above range, the significant improvement in strength It is not admitted, and the cost rises, which is not preferable.

In the above range, the proportion of each additive to be added is appropriately determined according to the degree of water content of the dredged slurry and the treatment method after agglomeration (whether discarded or reused for landfill). It is preferable to determine.

In the method for treating a dredged slurry of the present invention, the order of addition of each additive is not particularly limited, and all the additives can be added simultaneously at the same time. It is desirable to carry out the procedure, but the order of addition is not limited at all.

After adding and mixing a predetermined amount of fluidized bed boiler ash to the dredged slurry, a predetermined amount of a water-soluble polymer absorbent is added and mixed. After adding and mixing a predetermined amount of the fluidized bed boiler ash dredging slurry, adding and mixing water-soluble polymer absorber, further cementite <br/> down bets or admixing quicklime. After adding and mixing a portion of the predetermined amount of the fluidized bed boiler ash dredging slurry, adding and mixing water-soluble polymer absorber, balance and cement the fluidized bed boiler ash or admixing the lime.

The general composition of the fluidized-bed boiler used in the present invention is as follows. Fluidized bed boiler ash is industrial waste
It is generated in large quantities in various places as a product, and is available at low cost
can do.

[0025]

[Table 1]

[0026]

[Action] flow fluidized bed boiler ash, low specific gravity, high water absorption, it is possible to effectively reduce the moisture per volume of the high water content dredging slurry. In particular, fluidized bed boiler ash contains CaO
Is contained in a large amount, which is effective for water content adjustment and solidification by the pozzolanic reaction, and contains CaSO ₄ , which is effective for generating ettringite to develop agglomeration strength.

On the other hand, as described above, the water-soluble polymer absorbent
Absorbs the water in the dredged slurry and gels and solidifies
You.

By adding a fluidized bed boiler ash together with such a water-soluble polymer absorbent, the water content of the dredged slurry is reduced, and an appropriate amount of the water-soluble polymer absorbent or water-soluble polymer absorbent is added. cement by preparative or the quicklime, it is possible to crumb to the desired strength and.

According to the method of claim 2, the strength of agglomeration can be increased, which is effective for reclaiming landfills.

[0030]

The present invention will be described more specifically with reference to the following examples.

Examples 1 to 3 and Comparative Examples 1 to 4 Each additive was added to a high water content dredging slurry having a water content of 154% at the ratio shown in Table 3 and mixed. 3 is shown.

The composition of the fluidized bed boiler ash used is as shown in Table 2. The order of addition was the same as that described above.

The agglomerated strength was shown by relative evaluation with reference to that obtained in Comparative Example 1.

[0034]

[Table 2]

[0035]

[Table 3]

As is evident from Table 3, according to the method of the present invention, high-moisture-content dredging can be carried out at low cost with less addition of a water-soluble polymer absorbent, cement and quick lime without performing sun drying. Agglomeration of the slurry can be performed.

On the other hand, in Comparative Examples 1 and 2 using no fluidized-bed boiler ash , a large amount of a water-soluble polymer absorbent or cement is required for agglomeration. Also, fluidized bed boiler
In Comparative Examples 3 and 4 in which the same amount of the water-soluble polymer absorbent and cement as in Examples 1 and 2 were used without using ash , it was impossible to aggregate.

[0038]

As described above in detail, according to the method for treating a dredged slurry of the present invention, a dredged slurry having a high water content of 100% or more can be obtained at a low cost and easily available in a fluidized bed.
By using boiler ash , the agglomeration treatment can be performed efficiently at low cost without adding a large amount of expensive additives.

According to the method of claim 2, it is possible to increase the agglomeration strength and to obtain the agglomerates having a desired strength.

Claims (2)

(57) [Claims] 1. A method for adding a fluidized bed boiler ash and a water-soluble polymer absorbent to a dredged slurry having a water content of 100% by weight or more with respect to solid content, and subjecting the dredged slurry to an agglomeration treatment. 160 to 20% by weight of the fluidized bed boiler ash and 13 to 0.
A method for agglomerating dredged slurry, comprising adding 0.05% by weight. 2. A crumb of the water content fluidized bed boiler ash 100% or more by weight of dredging slurry, and a water-soluble polymer absorbing material, the dredging slurry cement or by adding the lime to the solid content adding a method of treating, 160-20 wt% of a fluidized bed boiler ash to said dredging slurry, a water-soluble polymer absorber 3 to 0.05% by weight, cement or 15% by weight of quicklime or less A method for treating dredged slurry.