JP2590726B2 - Method for producing agglomerated material for clayey soil - 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 producing an agglomerated material for a clay soil, and more particularly to an agglomeration of a clay soil using a fluidized bed boiler ash as an agglomerated material for a clay soil. The present invention relates to a method for manufacturing a material.

[0002]

2. Description of the Related Art In recent years, it has been desired to effectively reuse various industrial wastes for the purpose of saving resources and reducing the amount of wastes.

[0003] Conventionally, pulverized coal boiler ash among boiler ash, which is waste from a combustion furnace, has been used as a cement raw material.

[0004]

However, fluidized-bed boiler ash has a high SO ₃ content and generates a low-melting compound in a cement kiln and / or a preheater, which hinders operation. Can not be done, and most are discarded at present.

[0005] On the other hand, clay soil discharged in large quantities from construction sites and mining sites is sometimes used as a cement raw material, but its viscosity makes it difficult to handle. I have.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and is directed to agglomeration of clayey soil in which a fluidized bed boiler ash is effectively used as an agglomerating agent for improving the handling property of clayey soil. An object of the present invention is to provide a method for manufacturing a material.

[0007]

According to a first aspect of the present invention, there is provided a method for producing an agglomerated material for a clayey soil, wherein the fluidized bed boiler ash is classified into coarse particles and fine particles, and the coarse particles are aggregated in the clayey soil. It is characterized by being recovered as a chemical material.

According to a second aspect of the present invention, there is provided a method for producing an agglomerated material for a clayey soil according to the first aspect, wherein the collected coarse particles are subjected to a surface peeling treatment, and then classified into coarse powder and fine powder. It is characterized in that it is recovered as an aggregate for clayey soil.

According to a third aspect of the present invention, there is provided a method for producing an agglomerated material for a clayey soil according to the first aspect, wherein the collected coarse particles are subjected to a surface peeling treatment, and then classified into a coarse powder and a fine powder. The method is characterized in that the fine powder is recovered as an agglomerated material for clayey soil.

Hereinafter, the present invention will be described in detail.

In the method according to the first aspect, the fluidized-bed boiler ash is classified and divided into coarse particles and fine powder. Here, the classification means is not particularly limited, but since there is a specific gravity difference between the coarse and fine powder components to be classified, performing air classification using this specific gravity difference is a simple and advantageous method. .

By this classification, the fluidized-bed boiler ash becomes C
It is separated into coarse particles and fine powders rich in aO (quick lime).

In the method of the first aspect, of the classified coarse particles and fine powder, the coarse particles containing a large amount of CaO are recovered as agglomerating material for clayey soil.

The coarse particles obtained by the classification generally have an average particle size of 80 to 110 μm, and the fine powder has an average particle size of 25 to 110 μm.
50 μm.

The fine powder obtained by this classification contains a large amount of CaSO ₄ and can be recovered and used as a cement raw material or the like.

In the method according to the second or third aspect, the coarse particles collected by the classification are subjected to a surface peeling treatment by, for example, being treated with a cylindrical rotating body (rod mill) containing a rod or a vibration mill, and then subjected to air. Classification into fine powder of the exfoliated material and coarse powder from which the surface layer has been exfoliated by classification or sieving.

Among the classified coarse powder and fine powder, the coarse powder is Ca
The powder contains a lot of O, and the fine powder contains a lot of CaSO ₄ (anhydrite).

In the method according to the second aspect, the coarse powder containing a large amount of CaO is recovered as a flocculant for clayey soil. Also,
The method according to claim 3, wherein the coarse powder containing a large amount of CaO,
The fine powder containing a large amount of O ₄ is recovered as an agglomerator for clayey soil.

The coarse powder obtained by subjecting the above coarse particles to a surface peeling treatment and classification generally has an average particle diameter of 70 to 100 μm, and the fine powder has an average particle diameter of 20 to 60 μm.

The agglomerated material of the clay soil produced according to the present invention is added to and mixed with the clay soil at a predetermined ratio, thereby effectively aggregating the clay soil and improving its handleability. can do.

The addition ratio of the agglomerated material according to the present invention to the clayey soil varies depending on the water content and the composition of the clayey soil to be treated. If the clay soil is 25 to 50% by weight, it is preferable to add approximately 5 to 100% by weight of coarse particles obtained by classifying the fluidized-bed boiler ash. In addition, when adding coarse powder obtained by subjecting the coarse particles to a surface peeling treatment and classification, it is preferable to add about 5 to 70% by weight based on the clay soil.

Further, when both the coarse powder and the fine powder obtained by subjecting the coarse particles to the surface peeling treatment and classification are added, the coarse powder is added in an amount of about 4 to 50% by weight to the clayey soil. Is 1 to
It is preferable to add about 30% by weight.

[0023]

In a fluidized-bed boiler, coal becomes porous ash by low-temperature combustion and becomes fine powder in a fluidized bed. On the other hand, limestone is not powdered, and CaSO
₄ (Anhydrite) becomes coarse particles. Accordingly, fluidized bed boiler ash generally comprises coal ash, coarse particles containing a large amount of CaO with CaSO ₄ adhered to the surface, and silica sand when a fluidized medium is used.

In the method according to the first aspect, by classifying such fluidized-bed boiler ash, CaSO ₄ is added to the surface.
Adheres and collects coarse particles containing a large amount of CaO.

Further, CaSO ₄ in the method of claim 2, in which the coarse grains further surface release-treated by stripping the CaSO ₄ component of the surface was peeled off and coarse powder containing a large amount of CaO
And a fine powder containing a large amount of CaO.
Is recovered. In claim 3, the coarse powder and the fine powder containing a large amount of CaSO ₄ are recovered.

The aggregation mechanism of the clayey soil according to the present invention is as follows.

That is, since clay mainly contains Al ₂ O ₃ and SiO ₂ , it can be solidified by the pozzolan reaction (CHS formation reaction) by adding CaO. In addition, by adding CaO and CaSO ₄ , ettringite can be generated and solidified.

For this reason, coarse particles containing a large amount of CaO obtained by the classification of the fluidized-bed boiler ash are used as they are, or coarse particles containing a large amount of CaO obtained by subjecting the coarse particles to a surface separation treatment and classification, or By adding and mixing the coarse powder and the fine powder containing a large amount of CaSO ₄ to the clay soil, the clay soil can be effectively aggregated, and the handling property can be improved.

In particular, according to the method of claim 3, by using coarse powder and fine powder respectively, CaO and CaSO
The excellent addition effect of ₄ is obtained, and more efficient agglomeration can be performed.

[0030]

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

Example 1 100 kg of a fluidized-bed boiler ash having a composition shown in Table 1 generated in the electric power industry was classified by air, and 29 kg of coarse particles (average particle size 110 μm) and fine powder (average particle size) having the composition shown in Table 1 were obtained. 35μ
m) The mixture was classified into 71 kg, and coarse particles were collected.

Example 2 A portion of 10 kg of the coarse particles recovered in Example 1 was subjected to a surface peeling treatment by a rod mill, and then classified by an airflow classifier.
Coarse powder having the composition shown in Table 1 (average particle size: 100 μm) 8.3 k
g and fine powder (average particle size 45 μm) 1.7 kg,
The coarse powder was recovered.

Example 3 The same operation as in Example 2 was performed to collect coarse powder and fine powder, respectively.

[0034]

[Table 1]

The above coarse particles, coarse powder and fine powder were added to a high water content heavy clay (water content 33%) collected from a limestone quarry at a ratio shown in Table 2 and mixed. The agglomeration was carried out and the handling was greatly improved.

[0036]

[Table 2]

[0037]

As described above in detail, according to the method for producing the agglomerated material for clayey soil according to the present invention, the agglomerated material for clayey soil is converted from the fluidized-bed boiler ash conventionally discarded. Can be manufactured. Moreover, the handling property of clay soil can be significantly improved using the obtained aggregated material, and various clay soils can be effectively used. In particular, clay agglomerated using the agglomerated material according to the present invention is suitable for planting soil because it contains lime.

According to the method for producing the agglomerated material of the clay soil of claim 1, the agglomerated material of the clay soil is easily obtained from the fluidized-bed boiler ash, and the separated fine powder is used as a cement raw material or the like. can do.

According to the method for producing an agglomerated material for a clayey soil according to the second aspect, a CaO component as an agglomerated material for a clayey soil is recovered from a fluidized-bed boiler ash to perform favorable agglomerated treatment. I can do it.

According to the manufacturing method of the crumb of material clay soil according to claim 3, and each recovered and CaO component and CaSO ₄ component as crumb of material of clay soil from the fluidized bed boiler ash, Even better agglomeration treatment can be performed.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C09K 103: 00 B09B 3/00 301E

Claims (3)

(57) [Claims] 1. A method for producing an agglomerated material for clayey soil, wherein the fluidized bed boiler ash is classified into coarse particles and fine powder, and the coarse particles are recovered as an agglomerated material for the clayey soil. . 2. The method according to claim 1, wherein the collected coarse particles are subjected to surface peeling treatment, then classified into coarse powder and fine powder, and the coarse powder is recovered as an aggregating material for clayey soil. Method for producing agglomerated materials for clay soil. 3. The method according to claim 1, wherein the collected coarse particles are subjected to a surface peeling treatment, then classified into coarse powder and fine powder, and the coarse powder and the fine powder are recovered as an agglomerated material for clayey soil. A method for producing an agglomerated material for clayey soil, characterized by comprising: