JP2009148712A - Granule, sintered body, and methods for producing them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which is simple in granulation and high in waste utility (recycling efficiency) when a waste such as incineration ash, sludge, or construction soil is granulated by adding water for recycling. <P>SOLUTION: Granules contain one or more kinds of materials selected from a group consisting of incineration ash, sludge, and construction soil, and a clay mineral which contains smectite as a main component and has a swelling force of at least 10 ml/2 g in an amount of 3-30 pts.mass based on 100 pts.mass of the materials. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a granulated body and a sintered body. In particular, the present invention relates to a granulated body and a sintered body made from waste such as incinerated ash, sludge, or construction generated soil.

  In recent years, the amount of incinerated ash, sludge and construction generated soil has increased. And it is becoming difficult to dispose of it easily. Therefore, recycling of the waste is being tried in various directions. However, since the quality of waste is not stable, it is very difficult to recycle it.

  Now, as reuse (recycling) of incinerated ash and construction generated soil waste, it has been proposed to use it as a civil engineering material such as concrete aggregate or roadbed material in addition to cement raw materials. For example, recycling to aggregate is performed by granulating powder waste and performing steps such as cement solidification and firing. And the said granulation may be granulated just by adding water as it is. However, when the particle size is large or the particle size distribution is narrow, granulation is often difficult. Moreover, fly ash cannot be granulated as it is because the particles are spherical in the coal ash generated from pulverized coal combustion at a coal-fired power plant.

  Waste such as papermaking sludge is generated from the papermaking process and used paper recycling process. Organic substances such as fine fibers that are not recovered in the papermaking process, and inorganic substances such as kaolin, talc, and calcium carbonate that are used as pigments and dyes Consists of And papermaking sludge is often incinerated for weight reduction. The paper sludge thus incinerated (paper sludge incinerated ash) is industrially reused to the extent that it is used as a cement raw material. And most of the remaining amount is landfilled. In addition, industrial use as an aggregate is hardly made.

In addition, from the viewpoint of reducing CO ₂ emissions, biomass power generation using carbon-neutral biogenic raw materials such as paper sludge and wood chips is increasing. And since the quality of incinerated ash discharged by biomass power generation is not stable, recycling is more difficult.

  By the way, in order to recycle the waste, the powder of these wastes is granulated. For this granulation, a roll press, a pan pelletizer, or the like is used. At this time, the properties of the raw material (powder) greatly affect the granulation property. And granulation is often very difficult. In particular, when granulating continuously with a pan pelletizer, it may not be possible to granulate at all depending on the raw material. Even if it can be granulated, the particle size becomes large and there is a problem that it cannot be controlled.

Conventionally, several granulation techniques have been proposed.
For example, there is no need to adjust the particle size of coal ash, coal ash with a relatively large maximum particle size can be used, and a granulated product with high strength can be obtained regardless of the type of granulation method, and the firing temperature range is wide. In order to obtain an easy-to-operate artificial lightweight aggregate, sewage sludge incinerated ash is used as a raw material mixed with coal ash so that the proportion of coal ash is 10% to 80% by weight. A method of manufacturing an artificial lightweight aggregate characterized by the above has been proposed (Japanese Patent Laid-Open No. 11-35356).

  In addition, ash is cemented for the purpose of solidifying the ash and having a sufficient strength that can be effectively used as a construction material such as paving material, and that does not cause a problem of elution of heavy metals at a low cost. And a method of solidifying and molding the resulting mixture, wherein the ash is pulverized, and cement, water and a calcium compound are added to and mixed with the ash or pulverized ash. A characteristic ash solidification molding method has been proposed (Japanese Patent Laid-Open No. 2002-18411).

In addition, in order to utilize the characteristics or functionality of paper sludge ash, finely pulverized paper sludge ash with low moisture absorption for the purpose of establishing a waste recycling system mainly composed of paper sludge ash. A papermaking sludge ash-containing granulated product obtained by granulating a pulverized product with only water injection has been proposed (Japanese Patent Laid-Open No. 2005-103464).
JP-A-11-35356 JP 2002-18411 A JP 2005-103464 A

  By the way, as mentioned above, although various granulation techniques have been proposed, granulation is still difficult in many cases. In particular, even in the case of granulating by adding inorganic fine powder or cement to incineration ash, sludge, or construction generated soil, the amount of addition is not small and waste recycling efficiency is poor.

  Therefore, the problem to be solved by the present invention is that in order to recycle waste such as incineration ash, sludge, or construction generated soil, granulation with the addition of water is easy and To provide technology with high waste utilization (recycling efficiency).

  While studies for solving the above-mentioned problems are being intensively promoted by the present inventors, when smectite clay is used, granulation becomes easy and the shape of the aggregate deteriorates due to abrasion, etc. even in the firing process. It has been found that this can be suppressed.

The present invention has been made based on the above findings.
That is, the above problem is
One or more materials selected from the group of incinerated ash, sludge and construction generated soil;
A clay mineral containing smectite as a main component and having a swelling power of 10 ml / 2 g or more,
The clay mineral is solved at a ratio of 3 to 30 parts by mass with respect to 100 parts by mass of the material.

In addition, the above problem is
One or more materials selected from the group of incinerated ash, sludge and construction generated soil;
A clay mineral having a swelling power of 10 ml / 2 g or more mainly composed of smectite,
Containing an organic binder,
The clay mineral is 3 to 30 parts by mass and the organic binder is 0.1 to 10 parts by mass with respect to 100 parts by mass of the material.

In addition, the above problem is
One or two or more materials selected from the group of incinerated ash, sludge, and construction generated soil, and a clay mineral having a swelling power of smectite as a main component and having a swelling power of 10 ml / 2 g or more, per 100 parts by mass of the material Then, the clay mineral is solved by a method for producing a granulated product, which comprises granulating a mixture containing 3 to 30 parts by mass.

In addition, the above problem is
One or more materials selected from the group of incinerated ash, sludge, and construction generated soil, clay minerals having a swelling power of 10 ml / 2 g or more mainly composed of smectite, and an organic binder The granulated product is produced by granulating a mixture of 3 to 30 parts by mass of the clay mineral and 0.1 to 10 parts by mass of the organic binder with respect to 100 parts by mass. Solved by the method.

In addition, the above problem is
This is solved by a sintered body characterized in that the granulated body is fired.

In addition, the above problem is
It solves by the manufacturing method of the sintered compact characterized by baking said granulated body at 650-1300 degreeC.

  3 to 30 clay minerals having a swelling power of 10 ml / 2 g or more containing smectite as a main component with respect to 100 parts by mass of one or more kinds of waste selected from the group of incinerated ash, sludge and construction generated soil Since it was used at a ratio of part by mass, granulation was very easy. Further, even when the granulated body is baked to improve the strength, it is difficult to cause shape deterioration such as wear in the baking process.

  The present invention is a granulated body (granulated product). This granulated body contains one or more materials (waste) selected from the group of incinerated ash, sludge, and construction generated soil. In particular, a kind selected from the group of incineration ash such as paper sludge incineration ash having a coarse particle size that is difficult to granulate alone, sludge such as purified water sludge generated from water and sewage, and construction generated soil such as construction sludge Contains two or more materials (waste). And the clay mineral whose swelling power which has a smectite as a main component is 10 ml / 2g or more is included. Although there is no particular restriction on the upper limit of the swelling power, the upper limit of the swelling power of clay minerals mainly composed of smectite that we have is usually about 30 ml / 2 g. In addition, a preferable example as a clay mineral which has a smectite as a main component is bentonite. And the ratio of the said material (waste) and clay mineral is 3-30 mass parts (especially 4 mass parts or more. 20 mass parts or less) with respect to 100 mass parts of materials (waste). is there. Preferably, the organic binder is contained at a ratio of 0.1 to 10 parts by mass (particularly 0.2 parts by mass or more and 5 parts by mass or less) with respect to 100 parts by mass of the material (waste).

  Moreover, this invention is a manufacturing method of a granulated body (granulated material). This manufacturing method is a method of granulating a mixture containing the above material (waste) and the above clay mineral in the above-described ratio. Preferably, in addition to the material (waste) and the clay mineral, an organic binder is used. In particular, the organic binder is used at a ratio of 0.1 to 10 parts by mass (particularly 0.2 parts by mass or more and 5 parts by mass or less) with respect to 100 parts by mass of the material (waste). In granulation, in particular, granulation is performed by adding water. The addition of water may be performed simultaneously with the mixing of the above components, but is usually granulated by adding water to the mixture.

  Moreover, this invention is a sintered compact. This sintered body is obtained by firing the granulated body (granulated product).

  Moreover, this invention is a manufacturing method of a sintered compact. This sintered body fires the granulated body (granulated material). The temperature at the time of firing is 650 to 1300 ° C. (particularly 800 ° C. or more and 1200 ° C. or less).

This will be described in more detail.
First, the above-mentioned raw materials (the above-mentioned waste powder and clay mineral having a swelling power of 10 ml / 2 g or more (for example, bentonite having a swelling power of 10 ml / 2 g or more)) containing smectite as a main component are prepared. And water is added to these raw materials, and a granulated material with a diameter of several mm to several tens of mm is created. This granulated product is sintered at a temperature of 650 ° C. or higher to obtain an artificial aggregate or the like.

  For the granulation, for example, a roll press, a pan pelletizer, an Eirich mixer or the like is used. That is, water or an aqueous solution is added to the raw material, and granulation is performed using the granulator. When granulation is performed using a pan pelletizer, the granulated product has a spherical shape, and a granulated product of an arbitrary size can be obtained by controlling the granulation. Therefore, granulation using a pan pelletizer is preferred.

  Incineration ash, sludge, and construction waste soil are used as the raw material for granulated materials. Only one of these may be selected and used, or two or more may be selected and used. However, it is usually preferred that one type is selected and used.

  Examples of the incineration ash include pulverized coal combustion ash, fluidized bed combustion coal ash, coke ash, waste incineration ash, sewage sludge incineration ash, paper sludge incineration ash, and waste plastic incineration ash from coal-fired power plants. The papermaking sludge incineration ash is ash obtained by incinerating sludge generated in the papermaking process or recycling of used paper. And as a main component, inorganic components, such as Ca and Al, are included. In addition, incineration ash generated from biomass power generation using biomass fuel such as firewood, charcoal, waste material, and food pomace is also included. Incinerated ash, which is an organic raw material, such as paper sludge incinerated ash, is a preferred raw material because it has fine pores (pores) inside and has high water absorption (porous) characteristics. That is, since the granulated and fired product of the organic raw material incinerated ash becomes a highly water-absorbing aggregate, it is preferable to use the incinerated ash of the organic raw material as the granulated material.

  Examples of the sludge include purified water sludge and sewage sludge. Preferably, purified water sludge is used.

  Examples of construction generated soil include construction residual soil, contaminated soil, and dredged soil. Among these, it is preferable that the content of silt / clay having a particle diameter of 75 μm or less is 70% or more. The reason is that if the amount of sand is too much, it becomes difficult to control the particle size when granulating.

  The above-mentioned various incineration ash, sludge and construction generated soil are pulverized and used as a raw material for the granulated body as necessary.

A raw material having high water retention (powder: powder) usually has good granulation properties.
However, when a raw material in which the amount of the 88 μm residue exceeds 30% is used, the granulation property is extremely deteriorated. The reason for this is thought to be that the lack of small particles that complement each other, resulting in poor adhesion strength between the particles and difficulty in granulation.
Therefore, it was considered that the granulation property would be improved when such a raw material was mixed with clay mineral.

  However, it has been found that any clay mineral can be used. That is, as a result of the present inventors' research, it has been found that it is important to be a clay mineral mainly composed of a smectite mineral. Moreover, it has been found that it is important that the clay mineral has a swelling power of 10 ml / 2 g or more. In addition, the clay mineral having a swelling power of 11 ml / 2 g or more was preferred. And when the above conditions were not met, the features exhibited by the present invention could not be obtained. And it is important that the clay mineral having such characteristics is used in an amount of 3 parts by mass or more with respect to 100 parts by mass of the waste. Preferably it is 4 parts by mass or more. More preferably, it is 5 parts by mass or more. From the viewpoint of granulation properties, there is no particular restriction on the upper limit value. However, an increase in the amount of clay minerals means that the amount of waste used is relatively reduced (the waste recycling efficiency is reduced). Therefore, from the viewpoint of increasing the waste recycling efficiency, the clay mineral is set to 30 parts by mass or less. Preferably it is 20 mass parts or less. Furthermore, it is 15 parts by mass or less.

  In addition to the clay mineral having the above characteristics, it is preferable to use an organic binder (for example, a lignin-based substance). That is, when a solution containing an organic binder (in particular, a water-soluble organic binder such as lignin) is added and granulated, the granulation property is further improved. And the strength after granulation also improved. In addition, the wear resistance was further improved. A preferable amount of the organic binder is 0.1 to 10 parts by mass with respect to 100 parts by mass of the material (waste). More preferably, it was 0.2 mass part or more. And it was 5 mass parts or less.

  It is also conceivable to use cement in addition to the organic binder.

  In order to further improve the mechanical strength of the granulated product, firing is performed. For firing, a tunnel kiln, a roller house kiln, a fluidized bed, or a rotary kiln can be used. In addition, it is preferable to use a rotary kiln from the viewpoint of ease of manufacture. And if it bakes at the temperature of 650-1200 degreeC with such a baking kiln, a strong sintered body (aggregate) can be obtained.

Hereinafter, the present invention will be described with specific examples.
[Example]
Table-1
Sample Waste raw material Clay mineral A Clay mineral B Organic binder No1 Paper sludge incineration ash 0 parts by mass 0 parts by mass 0 parts by mass No2 Papermaking sludge incineration ash 0 parts by mass 5 parts by mass 0 parts by mass No3 Papermaking sludge incineration ash 3 parts by mass 0 Mass part 0 parts by mass No4 Papermaking sludge incineration ash 5 parts by mass 0 parts by mass 0 parts by mass No5 Papermaking sludge incineration ash 10 parts by mass 0 parts by mass 0 parts by mass No6 papermaking sludge incineration ash 12 parts by mass 0 parts by mass 0 parts by mass No7 Papermaking sludge Incinerated ash 5 parts by mass 0 parts by mass 1 part by mass No8 Paper sludge incinerated ash 0 parts by mass 5 parts by mass * 0 parts by mass No9 Silt dry powder product 0 parts by mass 0 parts by mass 0 parts by mass No10 silt dry powder product 5 parts by mass 0 parts by mass Part 0 part by mass No11 purified water sludge dry powder product 0 part by mass 0 part by mass 0 part by mass No12 purified water sludge dry powder product 5 parts by mass 0 part by mass 0 part by mass Paper sludge ash is d50% = 47.2μm
* Silt (construction mud) dry powder product is 82% silt and clay
* Clean water sludge dry powder product is 75% silt and clay content
* Clay mineral A is bentonite with a swelling power of 13ml / 2g (Akagi manufactured by Hojun Co.)
* Clay mineral B is bentonite with a swelling power of 8ml / 2g (Harjun made by Hojun Co.)
* The clay mineral B of No. 8 was kaolinite having a swelling power of 2 ml / 2 g. The waste raw material dry powder and bentonite were used as the main raw materials in the ratio shown in Table 1, and granulated with a 800 mm diameter pan pelletizer. That is, the above raw materials were put into a pan pelletizer. Further, while spraying water or an organic binder (lignin) aqueous solution with a watering device, the mixture was rotated and granulated. In addition, if necessary, the material was continuously operated and granulated while adding raw materials.

  At this time, since it investigated about granulation property, the result is shown in Table-2.

  After granulation, it was baked at temperatures of 600 ° C., 700 ° C., 1000 ° C., and 1200 ° C. in an electric furnace. And since the crushing strength of this baked product was investigated, the result is shown in Table-2.

Table-2
Sample Granulation Crushing strength (N)
600 700 1000 1200
No1 Can't granulate----
No2 Granulated but difficult to control particle size-4 4 10
No3 Granulated but difficult to control particle size 5 8 12 30
No4 Good granulation, particle size controllable 8 15 22 90
No5 Good granulation, particle size controllable 10 19 22 112
No6 Good granulation, particle size controllable 9 18 21 135
No. 7 Very good granulation, particle size controllable 25 35 51 252
No8 Granulated but difficult to control particle size-4 6 65
No9 Granulation somewhat difficult, particle size control not possible----
No10 Good granulation, particle size controllable 10 20 28 190
No11 granulated, but difficult to control particle size 7 10 22 90
No12 Good granulation, particle size controllable 19 25 41 290

According to this, it turns out that what becomes this invention has good granulation property and the intensity | strength of the sintered compact which baked the granulated material is large.

Patent Applicant Taiheiyo Material Co., Ltd.
Representative Katsumi Udaka

Claims (5)

One or more materials selected from the group of incinerated ash, sludge and construction generated soil;
A clay mineral containing smectite as a main component and having a swelling power of 10 ml / 2 g or more,
The granulated body, wherein the clay mineral is in a ratio of 3 to 30 parts by mass with respect to 100 parts by mass of the material. One or more materials selected from the group of incinerated ash, sludge and construction generated soil;
A clay mineral having a swelling power of 10 ml / 2 g or more mainly composed of smectite,
Containing an organic binder,
The granulated product, wherein the clay mineral is 3 to 30 parts by mass and the organic binder is 0.1 to 10 parts by mass with respect to 100 parts by mass of the material. One or two or more materials selected from the group of incinerated ash, sludge, and construction generated soil, and a clay mineral having a swelling power of smectite as a main component and having a swelling power of 10 ml / 2 g or more, per 100 parts by mass of the material Then, the clay mineral is granulated from a mixture containing 3 to 30 parts by mass. A sintered body obtained by firing the granulated body according to claim 1 or 2. A method for producing a sintered body, comprising calcining the granulated body of claim 1 or 2 at 650 to 1300 ° C.