JPH1110129A - Manufacture of sand for backfilling material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve resource conservation and nature conservation by a method wherein raw materials such as concrete destruction rubbish or the like are supplied to a crushing separator to be selected by crushing, then the crushed and adjusted raw materials are supplied to a dust precipitator to recover a dust content, and a small particle size aggregate classified through screening equipment is taken out as a recycled sand. SOLUTION: Raw materials are firstly charged into a hopper 1, and supplied to drawing out equipment 2 from a lower end discharge opening of the hopper 1. The raw materials drawn out from the drawing out equipment 2 are sent to a crushing separator 3, and classified by crushing into, for example, a constituent of exceeding 50 mm and a constituent of 50 mm or under. The raw materials exceeding 50 mm selected with the crushing separator 3 are sent to crushing equipment 4 to be crushed further finer, and the crushed raw materials are sent to screening equipment 6. The raw materials are classified into, for example, a constituent of exceeding 10 mm and a constituent of 10 mm or under, and the screened constituent of 10 mm or under is recovered as a recycled sand. Besides, the constituent of 10 mm or over is supplied to secondary crushing equipment 8 with conveyance equipment 7, and crushed further finer to 10 mm or under.

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 sand for backfill material, and more particularly to a method for effectively utilizing waste concrete or asphalt as a raw material and having a small amount of soil and cement as a backfill material. An object of the present invention is to provide a method for producing sand for a backfill material, which can obtain suitably usable high-quality sand.

[0002]

2. Description of the Related Art Conventionally, concrete and asphalt wastes are often disposed of directly in landfills. However, these wastes, which are industrial wastes, have recently become scarce in disposal places, especially in Tokyo and Osaka. It is becoming increasingly difficult to secure industrial waste disposal sites, especially in cities. On the other hand, extraction of masago is limited from the viewpoint of nature protection and environmental conservation.
Sand as backfill material is scarce. Therefore, in recent years, a method for removing foreign matters such as reinforcing bars from concrete waste and crushing the same to obtain fine recycled aggregate has been devised.

[0003]

However, since concrete waste contains cement as a compounding material for concrete, simply crushing concrete waste finely causes cement to remain in recovered recycled sand. When such recycled sand containing a large amount of cement is used as a backfill material, the cement is solidified with the lapse of time, so that there is a problem that it is difficult to perform the excavation work again. In addition, since the concrete waste material that comes with the demolition of buildings contains a lot of soil, simply crushing the concrete waste material into fines will cause the recovered sand to contain a lot of soil. If reclaimed sand with a large amount of soil is used as a backfill material as it is, there is a problem that the backfill material becomes liquefied during rainfall or the like. The present invention has been made in order to solve the above problems, and can be effectively used as a raw material of concrete waste and asphalt waste,
It is an object of the present invention to provide a method for producing sand for a backfill material that can obtain good-quality sand that can be suitably used as a backfill material with little soil or cement content.

[0004]

According to the present invention, at least a step of supplying a raw material cut out from a cutting equipment to a crushing and sorting equipment to crush and sort into a large-grain aggregate and a small-grain aggregate, It is characterized by comprising the steps of supplying the raw material crushed and adjusted by the crushing equipment to the dust collection equipment to collect the dust, and the step of taking out the small-sized aggregate of 10 mm or less separated through the sieving equipment as recycled sand. The above-mentioned conventional problems are completely solved by providing a method for producing backfill material sand.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing recycled sand according to the present invention will be described with reference to the drawings. FIG. 1 is a process explanatory view showing an example of an embodiment of the present invention. Raw materials used in the method for producing recycled sand according to the present invention are concrete waste materials, asphalt waste materials, natural stones, blast furnace slag, cement lumps, and the like. Among them, a major feature is that concrete waste materials and asphalt waste materials can be effectively used as raw materials. Things.

[0006] The above-mentioned raw material is first introduced into a hopper (1), and supplied to a cutting-out facility (2) from a lower end discharge port of the hopper (1). As the cutting equipment (2), a reciprocating feeder (product name) is suitably used, and the raw material discharged from the hopper (1) is continuously cut by a predetermined amount. The raw material cut out from the cutting equipment (2) is sent to a crushing and sorting equipment (3) and crushed and sorted into a component exceeding 50 mm and a component not exceeding 50 mm. Grizzly feeder (product name) as crushing and sorting equipment (3)
Is used, and the soil contained in the raw material is removed in this step.

[0007] 5 selected in the crushing and sorting equipment (3)
The raw material exceeding 0 mm is sent to the crushing equipment (4) and further crushed. Although a jaw crusher is used as the crushing equipment (4), an impeller breaker (trade name) can also be suitably used. The raw material crushed in the crushing equipment (4) is transported by a belt conveyor (5).
To the sieving facility (6). In addition, a belt conveyor is suitably used as the transport equipment in the present invention. However, the present invention is not particularly limited, and any transport equipment can be used as appropriate. The same applies to the transport equipment described below.

In the sieving equipment (6), the raw material is separated into components exceeding 10 mm and components not exceeding 10 mm,
The sieved component of 10 mm or less is recycled sand (RC-
Collected as 10).

[0009] 10m separated by the sieving equipment (6)
The components of m or more are supplied to the secondary crushing facility (8) by the transport facility (7). Secondary crushing equipment (8) is 10m
m and further crush the crushed material to 10 mm or less, and remove cement hydrate, pitch, etc. coated on the crushed material. Super sander (trade name),
Super rounder (trade name), single toggle crusher, cone crusher, roll crusher, impact crusher, hammer crusher, ball mill, rod mill, roller mill, jet mill and the like are preferably used. The secondary crushing equipment (8) is connected to a dust collecting equipment (9) including an air separator and the like, and collects cement powder and the like as dust. The raw material from which the dust content has been recovered is supplied again to the sieving equipment (6) by the transport equipment (10), and the components of 10 mm or less separated by the sieving equipment (6) are recovered as recycled sand (RC-10). .

According to the manufacturing method described above, the crushing and sorting equipment (3) removes soil from the raw material in advance, and the secondary crushing equipment (8) and the dust collecting equipment (9) remove excess cement. Therefore, it is possible to finally obtain good-quality reclaimed sand containing less soil and cement.

FIG. 2 is a process explanatory view showing another example of the embodiment of the present invention, and will be described below with reference to this figure. The raw material is first introduced into the hopper (11), and the hopper (1
It is supplied to the cutting-out facility (12) from the lower outlet of 1). As the cutting equipment (12), a reciprocating feeder (product name) is suitably used, and the raw material discharged from the hopper (11) is continuously cut by a predetermined amount. The raw material cut out from the cutting equipment (12) is crushed and sorted (1).
It is sent to 3) and crushed and sorted into components exceeding 50 mm and components not exceeding 50 mm. A grizzly feeder (trade name) is used as the crushing and sorting equipment (13), and the soil contained in the raw material is removed in this step.

The raw materials exceeding 50 mm selected in the crushing and sorting equipment (13) are sent to the primary crushing equipment (14), where they are further crushed. Although a jaw crusher is used as the primary crushing equipment (14), an impeller breaker (trade name) can also be suitably used. The raw material crushed in the primary crushing facility (14) is transferred to a first sieving facility (1) by a transport facility (21) comprising a belt conveyor.
It is sent to 5). A magnetic separation device (22) is provided above the transfer equipment (21) to remove iron scraps (23).

In the first sieving facility (15), the raw material crushed in the primary crushing facility (14) is separated into a component exceeding 30 mm and a component having a size of 30 mm or less.
Is sent to the secondary crushing equipment (16) by the transport equipment (27) and further crushed. Impeller breaker (trade name) as secondary crushing equipment (16)
Is preferably used. The raw material crushed by the secondary crushing equipment (16) is supplied again to the first sieving equipment (15) via the transport equipment (17) and (21), and the raw material crushed by 30 mm
And components of 30 mm or less
Those exceeding mm are sent again to the secondary crushing facility (16) via the transport facility (27). In other words, this process is repeated until the crushed material exceeding 30 mm separated by the first sieving equipment (15) has a size of 30 mm or less.

[0014] The components having a size of 30 mm or less sieved by the first sieving equipment (15) are supplied to the quantitative switching device (2).
According to 4), it is divided into those sent to the transport equipment (25) and those sent to the transport equipment (29). The crushed product sent to the transport equipment (29) is recovered as it is as a reclaimed crusher run (RC-30) of 0 to 30 mm.
On the other hand, the crushed material sent to the transport equipment (25) is supplied to the second sieving equipment (18), and is separated into components of 10 mm or less and components of 10 mm to 30 mm. And the component of 10 mm or less separated by this second sieving equipment (18) is recovered as recycled sand (RC-10).

The 10-30 mm component separated in the second sieving facility (18) is supplied to a tertiary crushing facility (19) by a transport facility (30). Third crushing equipment (1
9) is a method for further crushing a crushed material exceeding 10 mm to a size of not more than 10 mm and removing cement hydrate, pitch, etc. coated on the crushed material. Super sander (trade name), super rounder (product) Name), single toggle crusher, cone crusher, roll crusher, impact crusher, hammer crusher, ball mill, rod mill, roller mill, jet mill, etc. are preferably used. The tertiary crushing equipment (19) is connected to a dust collecting equipment (28) including a bag filter and the like, and excess cement is collected as dust. In addition, dust collection equipment (2
As 8), a classifier such as an air separator may be used. The remaining raw material is again supplied to the second sieving equipment (18) by the transport equipment (20), and the components of 10 mm or less separated by the second sieving equipment (18) are recovered as recycled sand (RC-10). .

On the other hand, the raw material having a size of 50 mm or less selected by the crushing and sorting equipment (13) is supplied to the third sieving equipment (26) by the transfer equipment (31), and the components exceeding 30 mm are supplied by the third sieving equipment (26). And components of 30 mm or less. A magnetic separation device (32) is provided above the transfer equipment (31) to remove iron scraps (23).
Is removed.

The component exceeding 30 mm separated in the third sieving facility (26) is sent to the secondary crushing facility (16) via the transport facility (27) and is finely crushed again. 21) to the first sieving facility (15). Third sieving equipment (26)
The raw material having a size of 30 mm or less sieved is recovered as a 0-30 mm regenerated crusher run (RC-30).

According to the above-mentioned method for producing recycled sand, soil is removed from the raw material in advance by the crushing and sorting equipment (13).
Since excess cement is removed by the tertiary crushing equipment (19) and the dust collecting equipment (28), high quality reclaimed sand containing less soil and cement can be finally obtained.

In the present invention, only concrete waste material or a mixture of concrete waste material and asphalt waste material is suitably used as a raw material, but a mixture of concrete waste material and asphalt waste material is preferably used.
This is because, when only the waste concrete material is used as the raw material, the ratio of the cement component remaining in the obtained reclaimed sand increases, and it becomes easy to solidify. When a mixture of the concrete waste material and the asphalt waste material is used, the ratio of the asphalt waste material to the whole is set to 80% or less, preferably 50% or less. This is because if the proportion of the asphalt waste material is too large, it is difficult to remove the pitch of the asphalt, and the obtained reclaimed sand contains oil.

[0020]

EXAMPLES The effects of the present invention will be further clarified by showing test results of sand obtained by the method for producing sand for backfill material according to the present invention. (Embodiment) Recycled sand (RC-10) was finally obtained by using a concrete waste material brought in from a site as a raw material and using a production method including the steps shown in FIG. (Comparative Example) Recycled sand (final material) was finally produced by using a concrete waste material brought in from the site as a raw material, and comprising a process in which the crushing and sorting equipment, the tertiary crushing equipment, and the dust collecting equipment were removed from the process shown in FIG. RC-10) was obtained. Table 1 shows the test results of the recycled sand obtained in the examples and comparative examples.

[Table 1]

The test method is based on the plasticity index (JIS A-
1205), mass per unit volume (JIS A-1104), specific gravity and water absorption (JIS A-1110).

As shown in Table 1, the sand obtained in the examples had a plasticity index of NP (measurable). This shows that the obtained sand contains almost no soil. Further, the sand obtained in the example had a unit volume mass of 1.56, which was larger than 1.36 of the comparative example, and showed a value very close to the unit volume mass of natural sand of about 1.6. This is considered to be because the cement content was removed by the tertiary crushing equipment and the dust collecting equipment in the example, whereas the cement content was not completely removed in the comparative example. In addition, in terms of water absorption and specific gravity, the sand obtained in the example was superior to the comparative example, indicating that good quality sand was obtained.

[0023]

As described above, the present invention provides at least a step of supplying a raw material cut out from a cutting equipment to a crushing and sorting equipment to crush and sort into a large-grain aggregate and a small-grain aggregate, A step of supplying the raw material crushed and adjusted by the crushing equipment for adjustment to a dust collection equipment to collect dust, and a step of taking out small-sized aggregates of 10 mm or less separated through a sieving equipment as recycled sand. Therefore, the following effects can be obtained.

That is, concrete waste material discharged as a result of demolition of a building or asphalt waste material discharged as a result of repairing a pavement road can be effectively used as a raw material. High quality sand suitable for use as backfill material can be obtained, saving resources,
It can contribute to natural environment conservation.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a preferred embodiment of a method for producing sand for backfill material according to the present invention.

FIG. 2 is a flowchart showing another embodiment of the method for producing sand for backfill material according to the present invention.

[Explanation of symbols]

 2 Cutting out equipment 3 Crushing and sorting equipment 4 Crushing equipment 6 Sieving equipment 8 Dust collection equipment 12 Cutting out equipment 13 Crushing and sorting equipment 14 Crushing equipment 16 Sieving equipment 18 Dust collection equipment

Claims (1)

[Claims] At least a step of supplying a raw material cut out from a cutting equipment to a crushing and sorting equipment to crush and sort into a large-grain aggregate and a small-grain aggregate, and crushing and adjusting by a crushing equipment for particle size adjustment. The process of supplying the raw materials to the dust collection equipment to collect the dust, and the 10m separated through the sieving equipment
removing small-grain aggregates having a particle size of m or less as reclaimed sand.