JP2689082B2 - Method for manufacturing fine aggregate for concrete - 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 fine aggregate for concrete from granular slag obtained by treating waste, for example, a residue after treating waste refuse. The present invention relates to a method for manufacturing a fine aggregate for concrete by processing a certain granular slag.

[0002]

2. Description of the Related Art In recent years, the amount of domestic waste such as garbage has increased remarkably, and the total amount of garbage waste treated by local governments nationwide reaches about 50 million tons or more per year.

Under these circumstances, in a waste disposal plant, a large amount of waste waste is incinerated, the incineration ash obtained is melted, and the molten slag is rapidly cooled with water to form granular slag. The process of reducing the volume and making it harmless is carried out. And although this granular slag, which is the residue after treating the garbage waste, has been partially recycled, most of it is disposed of by landfilling, and it is gradually becoming difficult to secure the disposal site. This is the current situation.

On the other hand, there is a shortage of sand (fine aggregate) used in concrete work such as soil work and construction work, and the extraction of sand will lead to environmental damage, and water pollution due to runoff of earth and sand. It may also have an adverse effect on biological resources.

Therefore, the inventors of the present invention have conducted extensive studies to reuse granular slag, most of which has been disposed of by landfill, as fine aggregate for concrete. The surface of the granular slag is glassy and smooth. Yes,
It was found that, compared with the conventionally used fine aggregate, sand, not only the particles are coarse, but also the amount of fine powder is small, and the shapes are often angular and needle-shaped, and the actual volume ratio is also small.

On the other hand, fine aggregate for concrete is generally required to be within the range of standard grain size and to have a shape close to a sphere, and the higher the actual volume ratio, which depends on the quality of the grain size and shape, the better the quality. It is considered to be fine aggregate. Therefore, if the granular slag is used as it is as fine aggregate, the particle size and shape are poor and the actual volume ratio is low, so that the unit water amount increases and bleeding increases significantly, and as a result, good quality concrete cannot be obtained.

The granular slag is crushed by an impact crusher such as a rod mill used for the production of crushed sand and used as a material for an interlocking block, but is typified by a rod mill. With impact-type crushing technology such as that shown in the figure, the particles become finer, but it is difficult to maintain the particle size range suitable for fine aggregates, and since the quality of the particle shape cannot be improved, the actual volume ratio is about 56% to 57%. Therefore, it was not possible to replace the entire amount of the fine aggregate for concrete. This is because the principle of atomizing the particles of the impact type crusher is by breaking the particles, and the cracked surface of the particles that are momentarily atomized remains as a new corner. On the other hand, Japanese Patent Application Laid-Open No. 7-101760
As described in Japanese Patent Publication No. JP-A-2003-242, after the molten slag is crushed into coarse aggregate having a relatively large diameter and fine aggregate having a relatively small diameter, the obtained coarse aggregate and fine aggregate are subjected to polishing treatment. As a result, attempts have been made to use it as aggregate. However, the aggregate containing the coarse aggregate and the fine aggregate disclosed in the invention of the prior application is only slightly increased in the actual volume ratio as compared with the aggregate processed by the impact crusher, so that the conventional It could not replace the used sand (fine aggregate).

[0008]

[Means for Solving the Problems] Therefore, the inventors do not crush the granular slag to instantly pulverize the particles or generate new angles, but rub the particles together to pulverize them by friction between the particles. It was considered to adjust the actual volume ratio by mixing the fine powder generated during the atomization. As a means for applying this principle to make the granular slag finer, for example, a device for reclaiming foundry sand can be used, in which a circular grindstone is rotated and the granular slag is pressed and rubbed together. Therefore, a sliding grinding type casting sand reclaiming device is used in which the granular slag is moved by utilizing centrifugal force under a load and the particles are rubbed together during this movement.

In the method according to the present invention, fine aggregate for concrete is manufactured from granular slag by drastically changing the original operating conditions of the apparatus for reclaiming foundry sand.
Specifically, the granular slag obtained by treating waste is rubbed against each other by using centrifugal force while the material is loaded by its own weight, and gradually pulverized by friction between particles. These particles are processed into a spherical shape within a range of a predetermined coarse particle ratio, and the fine powder generated during this processing is once separated, and then the fine powder is added in a volume ratio of 2 to 2 with respect to the processed slag particles. The fine aggregate for concrete is manufactured by mixing in a ratio of 15% and making the actual volume ratio 66% or more. Further, in this case, the granular slag obtained by treating the waste is rubbed against each other by using centrifugal force while being loaded with its own weight, and the fine powder component generated by the friction between the particles is not separated. The fine aggregate for concrete can also be manufactured by adopting the procedure of increasing the particle size in the slag particles as it is and processing it into a spherical shape so as to have a predetermined ratio.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing a fine aggregate for concrete according to the present invention, granular slag obtained by treating waste is processed into a spherical shape within a range of a predetermined coarse particle ratio and processed. 2 to 15% by volume of fine powder separated at the time of spherical processing is mixed with the slag particles of No. 1 and the actual volume ratio is set to 66% or more, so that not only effective use of resources but also use of concrete It is possible to provide fine aggregates, and while increasing the fine powder of granular slag, it is possible to process the spherical shape while keeping the appropriate particle size by slightly suppressing the change in coarse particle ratio (particle size). It is possible to provide a fine aggregate for concrete that can replace the whole amount of sand (fine aggregate) that has been used conventionally. In addition,
In this case, slag particles tend to bleed more than ordinary fine aggregate (sand), so if the volume ratio of the fine powder mixed with the processed slag particles is 2% or less, the effect cannot be expected. The workability is also poor, and if it exceeds 15%, the unit water volume cannot be reduced even if the actual volume ratio increases. Also, when the actual volume ratio is 66% or less, it approaches the actual volume ratio (about 63% or less) of normal fine aggregate (sand), and the water reduction effect required when using slag particles as fine aggregate is expected. Since it cannot be done, the actual product rate is 6
6% or more is preferable. Furthermore, it is possible to drastically reduce the unit amount of water for which the actual volume ratio is 70% or more, and bleeding is suppressed to the same level as in the case of normal fine aggregate (sand) without considering the water cement ratio. So it can be said to be the best.

[0011]

EXAMPLE Next, an apparatus to which a sliding grinding method is applied is illustrated as a preferred example of the method for producing a fine aggregate for concrete according to the present invention, and will be described in detail below.

In the method of the present invention, the granular slag is moved by utilizing centrifugal force while being loaded by its own weight, and the particles are rubbed against each other to gradually finely granulate to produce a fine aggregate for concrete. This is the basic principle. That is, the sliding mill type fine aggregate manufacturing apparatus used as an example in carrying out the method of the present invention has a cylindrical main body 12 having a discharge port 10 in the vicinity of a funnel-shaped bottom portion as shown in FIG. A large number of fins 14 extending at predetermined intervals along the circumferential direction and in the axial direction are arranged on the inner wall of the cylindrical body 12 at the equal diameter portion, while arranged inside the cylindrical body 12. A disk 18 is fixed to the rotating shaft 16 and the disk 18
The upper side surface is preferably formed as a rough surface 20. Also,
In the vicinity of the lower portion of the discharge port 10, a measuring container 22 for the processed slag (fine-grained and spherical-shaped) and a cylindrical main body 12 are provided.
The fine powder separated from the granular slag at the time of processing (particle size 0.1
A measuring container 26 for dust of 5 mm or less), and the processed slag particles and fine powder in the measuring containers 22 and 26 are mixed by a mixer so that the volume ratio thereof falls within a predetermined range. The mixture is mixed and dropped into the container 28 as fine aggregate for concrete and stored. It is to be noted that reference numeral 30 in FIG. 1 denotes a rotary drive device for the disk 18.

In order to manufacture fine aggregate for concrete from granular slag, a predetermined amount of granular slag A is put into the cylindrical main body 12 to fill it, and a disk is loaded under the weight of the granular slag A. 18 is rotated. When the disk 18 rotates, the granular slag A loaded with its own weight is gradually moved toward the inner wall of the cylindrical body 12 due to a centrifugal force generated in the lower layer portion in contact with the rough surface 20.
After colliding with the inner wall of the container and repeating this, the particles are sequentially discharged from the discharge port 10 to the measuring container 22 through the funnel-shaped bottom portion 12a, but by the time they move in the circumferential direction and are discharged. Fine graining and spheroidizing within a predetermined coarse grain ratio are performed.

That is, when the lower layer portion of the granular slag A charged in the cylindrical main body 12 is moved in the circumferential direction of the cylindrical main body 12 by centrifugal force while being in contact with the upper rough surface 20 of the disk 18, Particles are sequentially rubbed with each other, and even after colliding with the inner wall of the cylindrical body 12, the particles are also rubbed with each other while being held between the side edge of the disk 18 and the plurality of fins 14. By virtue of repeated friction between the various particles, the surface portion including the glassy material is scraped off, and the particles are formed into rounded slag particles while being refined (see FIG. 1b). The surface part scraped by the friction between the particles is a fine powder (dust with a particle size of 0.15 mm or less).
After being separated from the slag particles being processed under the suction action of the suction means 24 and once stored in the measuring container 26,
For example, the volume ratio of slag particles: fine powder is 98 to 85%:
It is mixed in the range of 2 to 15%, and adjusted so that the actual volume ratio of the fine aggregate for concrete as the final product is 66% or more.

The degree of grain refinement and spheroidization when the granular slag A is processed into the fine aggregate B for concrete can be appropriately adjusted by the residence time in the cylindrical body 12, for example, the rough surface 20. Change the roughness, or
It is needless to say that by connecting the cylindrical bodies 12 in series and increasing the number of processing steps, it is possible to adjust the particle size and particle shape to a desired size without increasing the processing time required for processing.

Further, in the fine aggregate manufacturing apparatus shown in FIG. 1, the fine powder suction / storage system (suction means 24, measuring container 26) is closed or omitted, and the particles of the granular slag A are rubbed with each other to rub the particles. It is needless to say that the fine aggregate B can be manufactured by increasing the amount of fine powder generated by the friction and making the particles finer and making these particles spherical within a range of a predetermined coarse particle ratio.

Next, fine aggregate B produced from the granular slag A by the method of the present invention as described above, crushed fine aggregate C obtained by crushing the granular slag A with a rod mill and conventionally used. Comparison with natural fine aggregate (sand) D was performed.

2 to 4, the granular slag A is formed by connecting the apparatus shown in FIG. 1 in series in one stage (B1), two stages (B2), and three stages.
Fine aggregate B obtained by connecting and processing stages (B3) and 4 stages (B4) and the same granular slag A by a rod mill for 30 seconds (C1), 1 minute (C2), 3 minutes (C3 ) And for 5 minutes (C4), the characteristic curve of the crushed fine aggregate C and the relationship between the natural fine aggregate D (sand) are shown.

According to FIG. 2, in the crushed fine aggregate C, as described above, since the fine graining is instantaneously performed, the coarse grain ratio is reduced at once, but since it is an impact type, the circularity coefficient ( In the case of a circle, the change is 1.0, and the smaller the flattened ellipse or the irregular shape becomes, the smaller the change becomes. However, in the fine aggregate B obtained by the method of the present invention, As with the material (sand) D, the degree of rounding of the particles (representative value = circularity coefficient) within the range of a desired coarse grain ratio (eg, 2.3 to 3.1) is better than that of the natural fine aggregate D. It is also shown that a good fine aggregate can be obtained depending on the application.

3 and 4, fine aggregate B obtained by the method of the present invention has a much higher actual volume ratio than crushed fine aggregate C at the same coarse grain ratio or circularity coefficient. doing. From this fact, according to the method of the present invention, it is possible to manufacture fine aggregate having an appropriate grain shape while maintaining an appropriate grain size (coarse grain ratio) as shown in FIG. It shows that the product ratio can be increased.

Next, the fine aggregate B obtained by the method of the present invention is
When the actual volume ratio and the unit water amount in the concrete used as the total amount of fine aggregate are examined in FIG. 5, the natural fine aggregate D
Compared with the standard value (actual volume ratio of 62.5%, 170 kg / m ³ or so), if the fine aggregate B is processed so as to increase the actual volume rate, the unit water volume can be significantly reduced. , Thus showing that good and economical concrete can be formed. Further, in the case of concrete in which the granular slag A was used as it was as the total amount of fine aggregate, the material was significantly separated and the sample collapsed even in the slump test, and it was impossible to use it as fine aggregate.

The fine aggregate B obtained by the method of the present invention is
In the concrete used as the total amount of the fine aggregate, as shown in FIG. 6, the bleeding amount can be improved by increasing the actual volume ratio, so that a good working concrete can be obtained. In the figure, the data of the granular slag A indicates that the total amount of the granular slag A cannot be used as the fine aggregate, and thus the fine aggregate in which the granular slag 6 and the natural fine aggregate are mixed in a ratio of 6 is used. is there.

Furthermore, among the fine aggregate B obtained by the method of the present invention, the fine aggregate B1 (actual volume ratio 6
6.7%), ordinary concrete using natural fine aggregate (bleeding amount: 0.2 to 0.3 cm ³ / cm
^The bleeding amount is slightly larger than that in ² ),
In this case, by setting the water cement ratio to about 50%, the bleeding amount can be made similar to that of normal concrete as shown in FIG. 7, and the fine aggregate B3 (actual volume ratio 72.4%) can be used. Then, the bleeding amount can be further reduced.

[0024]

As described above, according to the method for producing a fine aggregate for concrete according to the present invention, the granular slag obtained by treating waste is subjected to centrifugal force while being loaded by its own weight. The particles are rubbed against each other by means of friction, and gradually pulverized by friction between particles, and these particles are processed into a spherical shape within a range of a predetermined coarse particle ratio, and the fine powder separated during this processing is processed. Since it was mixed back with the slag particles already used, so that the actual volume ratio was more than the specified value,
Compared with the conventional crushing method, not only energy consumption (electric power) can be saved, but also resources can be effectively used. In addition, it is possible to provide fine aggregate according to the use of concrete, and while increasing the fine powder content of granular slag, the change in coarse grain ratio (grain size) is slightly suppressed to maintain an appropriate grain size. Since it is manufactured by processing it into a spherical shape in the state, it is possible to obtain a concrete fine aggregate that can replace the total amount of sand that has been conventionally used.

Furthermore, since the unit water amount can be reduced as compared with ordinary concrete using natural fine aggregate (sand), a concrete having high durability can be obtained, and on the other hand, the amount of cement can also be reduced, so that the concrete at the time of hardening can be reduced. It has various advantages such as suppressing heat generation and improving economic efficiency.

Although the method for producing a fine aggregate for concrete according to the present invention has been described above in relation to an apparatus for carrying it out, the present invention melts incinerated ash such as refuse waste and then rapidly cools it with water. Not only the granular slag obtained by doing, but also the granular slag obtained by treating the sewage sludge as waste can be used as a material without inconvenience, various within the scope not departing from the spirit of the present invention Of course, changes can be made.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an apparatus and a manufacturing principle of an example for carrying out a method for manufacturing a fine aggregate for concrete according to the present invention, in which a
[FIG. 3] is an explanatory view of a manufacturing process, and b is a schematic explanatory view in which particles of the granular slag are slid and rubbed to make them finer and spherical.

FIG. 2 is a characteristic diagram showing the relationship between the circularity coefficient and the coarse grain ratio of fine aggregate B obtained by the method of the present invention and crushed fine aggregate C produced by a rod mill.

FIG. 3 is a characteristic diagram showing the relationship between the actual volume ratio and the coarse grain ratio of the fine aggregate B and the crushed fine aggregate C shown in FIG.

FIG. 4 is a characteristic diagram showing the relationship between the performance ratio and the circularity coefficient of the fine aggregate B and the crushed fine aggregate C shown in FIG.

5 is a characteristic diagram showing the relationship between the actual volume ratio and the unit water amount when the fine aggregate B shown in FIG. 2 is used for the total amount of fine aggregate of concrete.

FIG. 6 is a characteristic diagram showing the relationship between the actual volume ratio and the bleeding amount when the fine aggregate B shown in FIG. 2 is used for the total amount of fine aggregate of concrete.

7 is a characteristic diagram showing that the bleeding amount can be reduced by adjusting the water cement ratio of B1 and B3 in the fine aggregate B shown in FIG.

[Explanation of symbols]

10 discharge ports, 12 cylindrical body, 14 fins, 16
Rotating shaft, 18 disk, 20 rough surface, 22 weighing container,
24 suction means, 26 measuring container, 28 mixing container, 3
0 rotary drive, A granular slag, B fine aggregate, C
Crushed fine aggregate, D Natural fine aggregate (sand),

Claims (2)

(57) [Claims] 1. A granular slag obtained by treating waste is used as a material, and the granular slag is rubbed against each other by utilizing centrifugal force while being loaded by its own weight, and gradually rubbed by the friction between the particles. After finely granulating and processing these particles into a spherical shape within a range of a predetermined coarse particle ratio, and further separating the fine powder generated during this processing once, this fine powder is applied to the processed slag particles. 2-15% by volume
The mixing ratio is set to 66.7% or more, and the method for producing a fine aggregate for concrete is characterized. 2. A granular slag obtained by treating waste is used as a material, and the granular slag is rubbed against each other by using centrifugal force while being loaded by its own weight, and finely divided by friction between the particles. A method for producing a fine aggregate for concrete, characterized in that the particles are gradually made finer while increasing the powder content, and these particles are processed into a spherical shape within a range of a predetermined coarse grain ratio.