JP3313211B2 - Method for producing concrete product using molten slag aggregate and concrete product obtained by the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing aggregate using crushed molten slag obtained by melting solid waste such as sewage sludge, and using the slag as aggregate. The present invention relates to a concrete product using aggregate.

[0002]

2. Description of the Related Art For example, sewage sludge obtained by sewage treatment is either discarded from incinerated ash or melted to form molten slag and reused.

Hitherto, as a recycling system of molten slag, a system has been proposed in which the molten slag is pulverized and reused as aggregate for concrete products. This conventionally-known pulverized aggregate of molten slag is used to pulverize a slag lump, mix the pulverized large and small lump of slag with ordinary aggregate, and use it as an aggregate for concrete.

On the other hand, an interlocking block is known as a paving stone having a curved contact surface. This known interlocking block factory bending strength 50 kgf / cm ^2, compression strength is restricted to 330kgf / cm ^2. When the conventional aggregate of the molten slag is used for the interlocking block, the bending strength and the compressive strength cannot be obtained. For this reason, the aggregate obtained by grinding the molten slag is mixed with the ordinary aggregate. Was usually used.

[0005]

As described above, concrete products are required to have predetermined flexural strength and compressive strength, respectively. However, when the above-mentioned crushed aggregate of molten slag is used, the flexural strength of concrete products is increased. Therefore, the aggregate used could not be composed entirely of the crushed molten slag aggregate. For this reason, in the conventional recycling system, the crushed aggregate of the molten slag is mixed with ordinary aggregate (classified and collected by crushed stone, or classified from river or beach sand) to about 1/3 and used. It was the actual situation. As described above, in the system using the conventional aggregate of the molten slag, the amount of the molten slag used is small, and it cannot be said that the system is a sufficient system for reusing a large amount of the molten slag mass. In addition, even if the crushed aggregate of the molten slag is mixed and used with the ordinary aggregate, a decrease in the strength of the concrete product obtained by this is inevitable.

[0006] In addition, the above-mentioned conventionally-known pulverized aggregate of molten slag does not use the fine powder generated in the pulverizing step, so that there is also a problem that secondary waste called fine powder is generated. If the fine powder is used in the aggregate, the fine powder will not be generated as secondary waste. However, if the fine powder is used in the aggregate, the strength of the concrete product may be reduced. It is necessary to determine the mixing ratio. Extra fine powder is generated depending on the mixing ratio of the fine powder, and this becomes secondary waste.

Therefore, an object of the present invention is to improve the above-mentioned drawbacks, to reduce the reduction in bending strength and compressive strength, and to prevent secondary waste from being generated by reusing molten slag as 100% aggregate. It is an object of the present invention to provide a method of manufacturing a concrete product using aggregate obtained by pulverizing molten slag and a concrete product obtained by the manufacturing method.

[0008]

A feature of the present invention is that a molten slag obtained by melting solid waste in a melting furnace is pulverized, and coarse bone obtained by polishing treatment as a secondary treatment. Material, fine aggregate, water and cement are mixed, and a concrete product is manufactured by vibration molding or press molding, and the fine powder generated in the crushing process and / or the polishing process is melted again in a melting furnace to form molten slag. It is in the place where it is crushed again and used.

Another feature of the present invention is that the molten slag of the sewage sludge is pulverized to obtain a coarse aggregate, a fine aggregate, and an actual rate of the coarse aggregate and the fine aggregate of 60% or more. The coarse aggregate, fine aggregate, water and cement were mixed at a mixing ratio of 0 to 12.0 for coarse aggregate and 7.0 to 20 for fine aggregate.
0, fine powder of 1.0, water of 0.7 to 3.5, and cement of 2.5 to 6.0, and mixing and vibration molding or press molding to produce a concrete product.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a flowchart showing a process of pulverizing molten slag according to one embodiment of the present invention. In the following description, the treatment of the molten slag of sewage sludge is described. However, the molten slag used in the present invention is not limited to the molten slag of sewage sludge, and the waste slag of municipal waste is not limited to the molten slag. It also includes other non-combustible solid waste such as shredder dust, fly ash and asbestos. In converting sewage sludge into molten slag, as a pretreatment, sewage sludge is put into a dryer and dried, then put into a melting furnace, incinerated, melted and directly melted into slag. Includes not only such molten slag but also one in which sewage sludge is incinerated in advance as incineration to form incineration ash, and the incineration ash is melted.

Referring to FIG. 1, a raw material 1 dried by a dryer (not shown) (or once incinerated to form incinerated ash) is introduced into a melting furnace 2 and subjected to a melting treatment.
The molten slag is introduced into the cooling device 3. The molten slag introduced into the cooling device 3 is pulverized by heat shrinkage, and most of the molten slag mass has a diameter of 150 mm or less. This molten slag mass is introduced into the aggregate manufacturing machine 4.

The molten slag mass introduced into the aggregate manufacturing machine 4 is pulverized, polished and discharged as product aggregate 5. The fine powder generated in the aggregate manufacturing machine 4 is sent to the dust collector 7 by the blower 6, is collected as the fine powder 8, and is again supplied to the melting furnace 1.

Here, the aggregate manufacturing machine 5 has a structure as shown in FIGS. That is, the aggregate manufacturing machine 5 is composed of double drums rotating in mutually opposite directions, and has a structure in which the inner rotating drum 22 is provided inside the outer rotating drum 21. Center O of outer rotating drum 21
₁ and the rotation center O ₂ of the inner rotating drum 22 are eccentric to each other, and a liner gap H described later is adjusted by changing the amount of eccentricity. A plurality of liners 23 project from the inner peripheral surface of the outer rotating drum 21,
A plurality of liners 2 are also provided on the outer peripheral surface of the inner rotating drum 22.
4 are protruded. The molten slag mass to be crushed is introduced from a chute 25, and as shown in FIG.
3, 24 crushed. The diameter of the aggregate obtained by pulverizing the molten slag is determined by the gap H between the liners 23 and 24. If the gap H is large, the diameter of the aggregate is large, and if it is small, the diameter of the aggregate is small. Since the liner 23 provided on the outer rotating drum 21 extends halfway along the length of the drum, the aggregate crushed by the liners 23 and 24 is transferred to the agitation polishing space 27 as shown in FIG. It is transported and agitated and polished only by the liner 24 of the rotating drum 22 to form a smooth and round shape as a whole. The polished aggregate is discharged from the end of the drum. A blow duct 26 is provided inside the end of the inner rotating drum 22 so that fine particles are sent from the outlet duct 28 to the dust collector 8 by blowing into the drum by the blower 7. The end of the aggregate manufacturing machine 5 has a closed structure so that the fine powder is not discharged to the outside. In the above-described aggregate manufacturing machine, the inner rotating drum and the outer rotating drum are rotated in opposite directions to improve the pulverizing efficiency. The present invention is not limited to the embodiment, and includes a structure in which the outer rotating drum is fixed and only the inner rotating drum is rotated, a structure in which the outer rotating drum is rotated and the inner rotating drum is fixed, and an outer rotating drum. It includes a structure for rotating the inner rotating drum in the same direction at a different number of rotations, and the like.

Now, in the case of the preferred aggregate shape, it is necessary that the individual aggregates have an overall smooth and round shape without protruding portions. Therefore, in order to express the shape of each aggregate, it is usual to measure the actual product ratio and express the properties of the aggregate. The actual loading ratio indicates the volume per unit weight, and 100% when completely filled without any gap.
Expressed as%. When the actual value is small, the bending strength and the compressive strength of the concrete product obtained by using this aggregate are reduced. The actual percentage of aggregate obtained by crushing molten slag with a normal crusher is 56% to 57%.

On the other hand, as shown in the aggregate manufacturing machine 4, when the aggregate obtained after crushing and passing through the agitation polishing process was measured, the actual product ratio was 63%. The numerical value of 63% of the actual loading rate is improved by 6 to 7 points compared to the actual loading rate of 56% to 57% of the molten slag aggregate obtained by crushing the molten slag with a normal crusher. When this is used as an aggregate of a concrete product, the bending strength and the compressive strength are remarkably improved.

Therefore, an interlocking block was manufactured using the above-described aggregate having an actual loading rate of 63%, and its bending strength and compressive strength were measured. The composition and molding method in that case are as follows. That is, water is 135 kg / m ³ ,
Cement 450 kg / m ^3, relatively large coarse aggregate diameter (5mm larger than the diameter) of 450 kg / m ^3, a relatively small diameter fine aggregate to (0.15 mm diameter ~5mm diameter) 1150 kg
/ M ^3, and the molding method was vibration molding and press molding.

As a result, the bending strength is 61.2 kgf / c.
m ² , and the compressive strength was 482 kgf / cm ² .
This number is practical reference value 50 kgf / cm ² flexural strength of interlocking blocks have become sufficiently high in comparison with the practical standard values 330kgf / cm ² compressive strength,
It does not hinder practical application.

Factors that the aggregate strongly influences the bending strength and compressive strength of the concrete product are the actual product ratio and the mixing ratio. As a result of various experiments performed by the present inventors, if the actual product ratio is 60% or more, the concrete product obtained by using the conventional molten slag aggregate has a strength far exceeding the bending strength and the compressive strength, and there is no problem in practical use. I confirmed that it would be. Also, the mixing ratios of the aggregate, cement and water are not limited to the above mixing ratios. When water is 1.0, coarse aggregate is 0 to 12.0 and fine aggregate is 7. 0-2
It was confirmed that sufficient strength (bending strength and compressive strength) as a concrete product could be obtained even when 0.0 and cement were used at 2.5 to 6.0.

As described above, according to the present invention, 100% of the molten slag can be used, and no fine powder is used. Compressive strength is obtained, and it is a revolutionary system for recycling molten slag.

[0024]

As described above, according to the present invention, the following effects can be obtained. 10 molten slag of sewage sludge
Since 0% can be reused, the system is good. Since the fine powder generated by the pulverization is returned to the melting furnace and used as aggregate, secondary waste associated with the pulverization is not generated. Further, since fine powder is not used, the strength of concrete products is not reduced, and the system is optimal. . When an interlocking block is manufactured as a concrete product, its bending strength and compressive strength exceed predetermined values, and there is no practical problem, and it is useful as an application. When the aggregate manufacturing machine shown in FIG. 2 is used, the step of stirring and polishing the aggregate is easily performed inside the same manufacturing machine, so that there is no operation that is particularly difficult to improve the actual product rate.

[Brief description of the drawings]

FIG. 1 is a flowchart showing one embodiment of the present invention.

FIG. 2 is a sectional view showing an embodiment of an aggregate manufacturing machine.

FIG. 3 is a sectional view taken along the line AA of the aggregate manufacturing machine of FIG. 2;

FIG. 4 is a sectional view taken along the line BB of the aggregate manufacturing machine of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Raw material 2 Melting furnace 3 Cooling apparatus 4 Aggregate manufacturing machine 5 Product aggregate 6 Blower 7 Dust collector 8 Fine powder 21 Outer rotating drum 22 Inner rotating drum 23 Liner 24 Liner 25 Chute 26 Ventilation duct 27 Stirring polishing space 28 Exit duct

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toru Okui 4-33 Kitahamahigashi, Chuo-ku, Osaka-shi, Osaka Investigator, Obayashi Corporation Examiner Tatsuo Takeshige (56) References JP-A-6-279084 (JP, A (58) Fields surveyed (Int. Cl. ⁷ , DB name) C04B 18/00-18/30

Claims (7)

(57) [Claims] 1. A melting step of producing solid slag by melting solid waste in a melting furnace, and crushing the molten slag to obtain a coarse aggregate having a relatively large diameter, a fine aggregate having a relatively small diameter, and a fine powder. Grinding process, a polishing process of polishing the coarse aggregate and fine aggregate obtained by the grinding process, the coarse aggregate obtained by the polishing process, fine aggregate, water and cement Mixing, shaping process of shaping concrete product by vibration or press forming, fine powder collecting process of collecting fine powder generated in the crushing process and polishing process, and returning the collected fine powder to the melting furnace to re-melt A method for producing a concrete product using an aggregate obtained by pulverizing molten slag, comprising a fine powder remelting step. 2. The sewage according to claim 1, wherein the polishing treatment is performed such that the actual volume ratio of the coarse aggregate and the fine aggregate obtained by the pulverization process is 60% or more. A method for producing a concrete product using aggregate obtained by pulverizing molten slag of sludge. 3. The mixing ratio of coarse aggregate, fine aggregate, water and cement in the forming step is 0-12.
The molten slag according to claim 1 or 2, wherein the fine aggregate is 7.0 to 20.0, the water is 0.7 to 3.5, and the cement is 2.5 to 6.0. A method for producing a concrete product using an aggregate obtained by pulverizing pulp. 4. Aggregate obtained by pulverizing molten slag, polishing as a secondary treatment and removing fine powder, water and cement are mixed, and manufactured by vibration molding or press molding. Concrete products using aggregates obtained by crushing molten slag. 5. The concrete product using aggregate obtained by pulverizing molten slag according to claim 4, wherein the actual volume ratio of the aggregate obtained by the polishing treatment is 60% or more. 6. The aggregate obtained by said polishing treatment is divided into a coarse aggregate having a relatively large diameter and a fine aggregate having a relatively small diameter, and said coarse aggregate, fine aggregate, water and cement are mixed. The mixing ratio is 0 to 12.0 for coarse aggregate, 7.0 to 20.0 for fine aggregate, and 0.1 for water.
The concrete product using aggregate obtained by pulverizing molten slag according to claim 4 or 5, wherein 7 to 3.5 and cement to 2.5 to 6.0. 7. The actual aggregate rate of the coarse aggregate having a relatively large diameter and the fine aggregate having a relatively small diameter is 63%.
The mixing ratio of water and cement is 4.5 for coarse aggregate, 11.5 for fine aggregate, 1.35 for water and 4.5 for cement, and the concrete product is an interlocking block. A concrete product using an aggregate obtained by crushing molten slag according to claim 4. [0001]