JP2967818B1 - Mud soil treatment method, mud soil treatment equipment, cement raw material, and embankment material - Google Patents

Abstract

An object of the present invention is to provide a technology capable of efficiently treating muddy soil so that it can be easily handled. Also,
The purpose is to provide technology that can effectively use muddy soil. SOLUTION: The method for treating muddy soil, comprising a step of adding a silica-based waste material to the muddy soil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for treating muddy soil discharged by, for example, dredging in a harbor of a seaside power plant.

[0002]

The seaside power plant requires a large amount of seawater as cooling water, and this cooling seawater is taken into the facility from an intake (concrete pit) facing the intake channel. ing. However, muddy soil tends to accumulate at this intake, and if left as it is for a long period of time, the required flow rate cannot be secured. Therefore, it is necessary to periodically remove the muddy soil accumulated at the intake.

Incidentally, a large amount of muddy soil generated by this muddy soil removing operation is finally disposed of as industrial waste, but generally has a high water content of 60 to 80% or more. It is extremely difficult to handle. Moreover,
In recent years, the acceptance conditions of final disposal companies have become strict (water content of 40% or less), and it is not possible to receive them as they are.

Therefore, usually, the muddy soil is subjected to a dehydration treatment by a method called filter cloth dehydration to reduce its water content to 60% or less. However, this dehydration method has very poor processing efficiency. Therefore, an object of the present invention is to provide a technique capable of efficiently treating muddy soil in a form that is easy to handle. Another object of the present invention is to provide a technology capable of effectively utilizing muddy soil.

[0005]

Means for Solving the Problems The present inventor, while proceeding with research for solving the above-mentioned problems, wonders if it is possible to use silica-based waste materials, which are similarly difficult to dispose, for treating muddy soil. Was. That is, the piping of the power plant is covered with a silica-based heat insulating material manufactured by mixing calcium silicate, lime, and water, and subjecting it to high-pressure steam curing (autoclave treatment) in order to enhance heat insulation. I have.
The silica-based heat insulating material is replaced with a new one at the time of periodic inspection. Therefore, a large amount of silica-based waste material is periodically discharged from the power plant. The present inventor has noted that this silica waste material is rich in voids and has a high water adsorption property, and in addition to the muddy soil deposited in the water inlet, the water contained in the muddy soil is removed from the silica waste material. It was thought that if it was adsorbed on the soil, the water content of the muddy soil would be sufficiently reduced, and it would be in a form that was extremely easy to handle. As a result of further research based on this technical concept, the use of silica-based waste material has enabled us to treat muddy soil very efficiently, that is, to treat muddy soil in a form that can be easily handled. I found what I could do. In addition, by using such a method, a large amount of silica-based waste materials that have been poorly handled can be treated simultaneously with the muddy soil, similarly to the case of the muddy soil, so that the effect of two birds per stone can be obtained.

[0006] In addition, the present inventor has been pursuing research for effectively utilizing muddy soil, and as a result, as described above, dewatered muddy soil obtained by adding silica-based waste material to I thought about using it as a cement raw material. Then, it was confirmed that there was no problem in cement production even when a mixture of muddy soil and silica-based waste material was used as a cement raw material. Furthermore, as a result of repeated studies on effective utilization methods other than cement raw materials, the present inventor has found that a mixture of muddy soil and silica-based waste material can be used as an embankment material necessary for forming a road, for example. I found it. By the way, this is also
This is because the silica-based waste material sufficiently adsorbs the water content of the muddy soil, and the handling property of the muddy soil is improved so that the waste material can be used as a banking material.

[0007] The present invention has been made based on such findings, and an object of the present invention is a method for treating muddy soil, in which silica-based waste used as a heat insulating material is added to the muddy soil. The problem is solved by a muddy soil treatment method characterized by comprising a step. In the muddy soil treatment method of the present invention, the silica-based waste material is powder or has an average particle size of 30 m.
m or less, and particularly preferably one crushed to an average particle size of about 10 mm.
That is, the silica-based waste material is collected in various sizes and shapes at the time of removal, but it is pulverized into a powder or has an average particle size of 30 mm or less, particularly, an average particle size of 10 mm.
After crushing to a certain degree, it is preferable to add to the muddy soil. As a result, the water absorption area of the silica-based waste material increases, so that the water in the muddy soil is more quickly adsorbed to the silica-based waste material, and the treatment efficiency is further improved. The upper limit of the average particle diameter of the silica-based waste material is 30 mm as described above, but there is no particular lower limit. In other words, the lower limit is a dimension corresponding to the particle size of the fine powder.

Further, as a method of adding silica waste material to the muddy soil, there is a method of adding a silica-based waste material to a bed of a transport vehicle as a means of transporting the muddy soil.
First, a method of providing a layer of silica-based waste material and loading muddy soil on the silica-based waste material on the carrier can be mentioned.
By doing so, the addition of silica-based waste materials to the muddy soil and the work of loading them on the transport vehicle can be performed at the same time, and the labor required for the treatment is greatly reduced. In this case, the muddy soil and the silica-based waste material are appropriately stirred by, for example, vibration of a carrier while the transport vehicle travels to the destination, and at the time of arrival at the destination, a good mixing state is obtained.

When the muddy soil and the silica waste material are mixed using the carrier of the transport vehicle as described above,
Silica waste material (silica waste material laid on the bottom of the loading platform)
It is preferable to further provide a silica waste material on the muddy soil loaded on the above. This allows the moisture in the muddy soil to be absorbed more rapidly. The muddy soil layer and the silica-based waste material layer may be further alternately and repeatedly provided.

Another object of the present invention is to provide an apparatus for treating muddy soil, comprising: a muddy soil supply means for supplying muddy soil ;
A silica-based waste material supply means for supplying the silica-based waste material that has been used as the waste material, a muddy soil supplied from the muddy soil supply means, and a silica-based waste material supplied from the silica-based waste material supply means. And a mud soil treatment device characterized by comprising a tank.

[0011] Alternatively, the present invention is to provide an apparatus of the muddy soil, and mud-like soil supply means for supplying muddy soil, warmth
A silica-based waste supply means for supplying the silica-based waste used as the material, a muddy soil supplied from the muddy soil supply means, and a silica-based waste supplied from the silica-based waste supply means. The problem is solved by a muddy soil treatment apparatus comprising a tank and stirring means for stirring the muddy soil and the silica-based waste material charged into the tank.

The tank referred to here, particularly the tank in the above-mentioned muddy soil treatment apparatus, may mean a carrier of a transport vehicle. And for the same reason as in the case of the above-mentioned muddy soil treatment method, between the silica-based waste material supply means and the tank, a pulverization means for pulverizing the silica-based waste material supplied from the silica-based waste material supply means into powder, Or an average particle size of 30 mm or less,
In particular, it is preferable that crushing means for crushing to an average particle diameter of about 10 mm is further provided.

[0013] Further, the above-mentioned problems are caused by muddy soil and heat insulating material.
This problem is solved by a cement raw material characterized by containing a silica-based waste material used as a raw material. That is,
The problem is solved by a cement raw material characterized by containing the composition obtained by the above muddy soil treatment method. Further, the above problem is solved by an embankment material characterized by containing muddy soil and silica waste used as a heat insulating material . That is, the problem is solved by an embankment material characterized by containing the composition obtained by the above muddy soil treatment method.

[0014] The muddy soil referred to in the present specification does not mean only muddy soil or sludge deposited at the intake of a seaside power plant, but means any muddy material containing water.
Particularly, dredged soil (silt) discharged when dredging in the harbor facing the intake of the seaside power plant is naturally included in the muddy soil to be treated by the present invention.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A muddy soil treatment method described below as a first embodiment of the present invention relates to the treatment of muddy soil containing water (sludge). (Silica-based heat insulating material) It is characterized by comprising a step of adding waste material and dewatering. In particular, in the present embodiment, the silica-based waste material has an average particle diameter of 30 mm or less, particularly an average particle diameter of 10 mm.
After crushing to the extent, it is added to the muddy soil.

A muddy soil treatment apparatus described below as an embodiment of the present invention is also used for treating muddy soil containing water (sludge), and supplies muddy soil. Clay-based soil supply means, silica-based waste material supply means for supplying silica-based waste material, muddy soil supplied from the muddy soil supply means, and silica-based waste material supplied from the silica-based waste material supply means are supplied. It has a mixing tank (tank) and a stirring means for stirring the muddy soil and the silica-based waste material charged in the mixing tank. In addition, the muddy soil treatment apparatus of the present embodiment, the silica-based waste material supplied from the silica-based waste material supply means between the silica-based waste material supply means and the mixing tank, the average particle size of 30 mm or less, particularly the average particle size A crushing means for crushing to about 10 mm is further provided.

The cement material (the same applies to the embankment material) described below as an embodiment of the present invention is:
It has a muddy soil (sludge) and a silica-based waste material as components, and is characterized by adding a silica-based waste material to the muddy soil and adsorbing water contained in the muddy soil to the silica-based waste material. . Next, an embodiment of the present invention will be described in more detail with reference to FIG. 1 showing a schematic structure of a muddy soil treatment apparatus.

As can be seen from FIG. 1, the muddy soil treatment apparatus of the present embodiment comprises a muddy soil supply means 2 for supplying muddy soil to a mixing tank 1 and a silica Waste material supply means 3, crushing means 4 interposed between the silica waste material supply means 3 and the mixing tank 1, and a stirring means 5 having a part (stirring blade 5 a) provided in the mixing tank 1. Consists of

Among these components, the mixing tank 1 is provided with a discharge port 1a at the lower portion for discharging the mixture to the outside. That is, the mixture obtained by stirring the muddy soil and the silica waste material put into the mixing tank 1 by the stirring means 5, that is, the cement raw material (or embankment material) is discharged from the outlet 1a, and It is to be loaded on a transport means waiting below, for example, a carrier of a transport vehicle (truck).

On the other hand, a muddy soil supply means 2 for supplying muddy soil
Since the muddy soil treatment apparatus of this embodiment performs the treatment of the muddy soil containing water, the hopper portion 2a contains a large amount of water (water content of 60 to 80).
% Or more) of the muddy soil is contained therein, and the muddy soil can be charged into the mixing tank 1 by a required amount. The silica-based waste material supply means 3 for supplying the silica-based waste material also has a hopper 3 similar to the muddy soil supply means 2.
A contains a silica-based (silica-based heat insulating material) waste material, and is configured so that it can be supplied into the mixing tank 1 by a required amount.

However, as described above, in this embodiment,
Crushing means 4 between mixing tank 1 and silica-based waste material supply means 3
Is interposed. Therefore, the silica-based waste material stored in the hopper portion 3a of the silica-based waste material supply means 3 remains in a roughly crushed state, in other words, a state recovered at the site. The crushing means 4 converts the coarsely crushed silica waste material to an average particle size of 30 mm or less, particularly an average particle size of 1 mm.
It plays a role of crushing to about 0 mm. In some cases, instead of the crushing means 4, a crushing means for crushing the silica-based waste material into powder may be provided.

The stirring means 5 is for stirring and uniformly mixing the muddy soil and the silica waste material charged into the mixing tank 1. Actually, as described above, the stirring blade 5a disposed in the mixing tank 1 rotates at a predetermined speed, and the muddy soil and the silica-based waste material are mixed. Thus, the cement raw material (or embankment material) having muddy soil and silica-based waste material as main components, that is, adding silica-based waste material to muddy soil, and adsorbing water contained in muddy soil to silica-based waste material The cement raw material (or embankment material) thus obtained is obtained.

Now, the procedure for converting the muddy soil into a cement raw material (or embankment material) using the above-mentioned muddy soil treatment apparatus is described. A predetermined amount of muddy soil is put into the tank 1. On the other hand, the silica-based waste material is also introduced into the mixing tank 1 from the silica-based waste material supply means 3 by the crushing means 4 to have an average particle diameter of
After crushing to the extent, a predetermined amount is introduced.

When the muddy soil and the silica-based waste material are supplied into the mixing tank 1, the stirring means 5 is operated, that is, the stirring blades 5a are rotated to mix the muddy soil and the silica-based waste material. Thereby, the water contained in the muddy soil is adsorbed by the silica-based waste material, and the muddy soil is sufficiently dehydrated. After stirring for a certain time, the mixture of the muddy soil and the silica-based waste material is discharged from the discharge port 1a of the mixing tank 1. In this way, a cement raw material (or embankment material) mainly composed of muddy soil and silica-based waste material is obtained.

As described above, in the present embodiment, the silica-based waste material also used in the seaside power plant is used for the treatment of the muddy soil accumulated at the intake of the seaside power plant. That is, the water contained in the muddy soil is adsorbed on the silica waste material. For this reason, the water content of the muddy soil is sufficiently reduced, and the muddy soil is in a form that is extremely easy to handle, that is, a form that can be easily handled. In addition, this can solve the problem of a large amount of silica-based waste material that has conventionally been difficult to dispose of. Furthermore, since the mixture of the muddy soil and the silica waste material becomes a clay substitute (or embankment material) for the cement material, the muddy soil and the silica waste material can be effectively used.

Next, a second embodiment of the present invention will be described. Hereinafter, a muddy soil treatment method described as a second embodiment of the present invention has the same basic technical idea as that of the above-described first embodiment, but includes a method of transporting muddy soil to a carrier of a transport vehicle. The method is characterized in that silica-based waste material is laid to a predetermined thickness, and muddy soil is loaded on the silica-based waste material laid on the carrier, whereby the silica-based waste material is added to the muddy soil. In particular, the method for treating muddy soil of the present embodiment is to further lay silica-based waste material to a predetermined thickness on muddy soil loaded on silica-based waste material.

FIG. 2 shows an outline of the muddy soil treatment process.
The second embodiment of the present invention will be described in detail with reference to FIGS. As described above, the muddy soil treatment method of the present embodiment does not use a mixing tank or a stirring means to mix the muddy soil and the silica-based waste material, and instead uses a transport vehicle as a transporting means. (Track).

That is, first, as shown in FIG. 2A, a silica-based waste material is laid on a carrier K of a transport vehicle T (a hatched portion in the figure). However, the laying thickness of this silica waste material is about 10 cm. When the laying of the silica-based waste material is completed, subsequently, as shown in FIG.
The muddy soil is loaded thereon (dots in the figure). Although not shown, mud soil is supplied using the same mud soil supply means as in the first embodiment.
The loading thickness of the muddy soil is seven times the laying thickness of the silica waste material, that is, about 70 cm.

When a predetermined amount of the muddy soil is thus loaded on the carrier K of the transport vehicle T, then, as shown in FIG. 2C, a silica waste material is further laid thereon (FIG. 2C). ). However, the laying thickness of this silica waste material is also about 10 cm. After the above operation is completed, the transport vehicle T departs for the destination cement factory (or road construction site), but before reaching the destination, the moisture of the muddy soil becomes silica. Adsorbed to waste materials. Further, the muddy soil and the silica-based waste material loaded on the cargo bed are appropriately stirred by vibrations during traveling or the like. By this, by the time the transport vehicle T arrives at the cement factory (or the road construction site), the muddy soil is sufficiently dehydrated and becomes ready for handling. In other words, a cement raw material (or embankment material) mainly composed of muddy soil and silica-based waste material can be obtained. However, in some cases, the muddy soil and the silica-based waste material may be loaded on the carrier K of the transport vehicle T, and then may be forcibly stirred using a heavy machine such as a backhoe. Alternatively, the carrier K of the transport vehicle T
Before loading on a mixture, muddy soil and an appropriate amount of silica-based waste material may be mixed, and the mixture may be subjected to a stirring treatment using a heavy machine such as a backhoe.

In the second embodiment, the silica-based waste material is doubly arranged so as to sandwich the muddy soil from above and below, but the present invention does not necessarily have to adopt such a form. For example, the silica-based waste material may be a lower layer alone, or a layer of silica-based waste material and a layer of muddy soil may be provided alternately and repeatedly.

[0031]

According to the present invention, the muddy soil can be efficiently treated so as to be easily handled. Further, muddy soil and silica-based waste material can be effectively used.

[Brief description of the drawings]

FIG. 1 is a schematic structural diagram of a muddy soil treatment device (first embodiment).

FIG. 2 is a schematic diagram of a muddy soil treatment process (second embodiment).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mixing tank (tank) 1a Discharge port 2 Mud soil supply means 2a Hopper part 3 Silica-based waste material supply means 3a Hopper part 4 Crushing means 5 Stirring means 5a Stirring blade T Transport vehicle K Carrier

Continued on the front page. (72) Inventor Shigeru Sakuma 4-6-14 Shibaura, Minato-ku, Tokyo Tokyo Electric Engineering Co., Ltd. 11 TEPCO Environmental Engineering Co., Ltd. Fukushima Daini Atomic Energy Office (56) References JP-A-8-229593 (JP, A) JP-A-6-285498 (JP, A) JP-A 7-136693 (JP, A) JP 6-49188 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) C02F 11/00-11/20 E02F 7/00 B09B 3/00 B09B 5/00

Claims (11)

(57) [Claims] 1. A method for treating muddy soil, comprising a step of adding a silica waste material used as a heat insulating material to the muddy soil. 2. The method for treating muddy soil according to claim 1, wherein the silica-based waste material is powder or crushed to an average particle size of 30 mm or less. 3. A layer of silica-based waste material is provided on a carrier of a transport vehicle as a means of transporting the muddy soil, and the muddy soil is loaded on the silica-based waste material on the carrier, whereby silica is added to the muddy soil. The method for treating muddy soil according to claim 1, wherein a waste material is added. 4. The method for treating muddy soil according to claim 3, wherein a silica-based waste material is further provided on the muddy soil loaded on the silica-based waste material. 5. An apparatus for treating muddy soil, comprising: muddy soil supply means for supplying muddy soil; silica-based waste material supply means for supplying silica-based waste material used as a heat insulating material; A muddy soil treatment apparatus comprising: a muddy soil supplied from a soily soil supply means; and a tank into which silica-based waste material supplied from the silica-based waste material supply means is charged. 6. An apparatus for treating muddy soil, comprising: a muddy soil supply means for supplying muddy soil; a silica-based waste material supply means for supplying silica-based waste material used as a heat insulating material; A tank into which the muddy soil supplied from the soil-supplying means and the silica-based waste material supplied from the silica-based waste material supplying means are charged; and a stirrer for stirring the muddy soil and the silica-based waste material charged into the tank. And a means for treating muddy soil. 7. A method according to claim 1, wherein the means for supplying silica-based waste material is provided between the tank and the tank.
The crushing means for crushing the silica-based waste material supplied from the silica-based waste material supply means into a powdery form, or a crushing means for crushing the silica-based waste material to an average particle diameter of 30 mm or less, is further provided. 7. The muddy soil treatment device according to 6. 8. A cement raw material comprising muddy soil and silica-based waste used as a heat insulating material . 9. A cement raw material comprising the composition obtained by the method for treating muddy soil according to any one of claims 1 to 4. 10. Muddy soil and used as heat insulating material
Fill material characterized by containing a silica-based waste. An embankment material comprising the composition obtained by the method for treating muddy soil according to any one of claims 1 to 4.