JP4342782B2 - Aggregate production method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an aggregate production method and apparatus for producing aggregate used for concrete or the like by crushing quarrying, and more particularly to an aggregate production method and apparatus using a roller mill.
[0002]
[Prior art]
With the recent depletion of natural aggregates (gravel, sand) and restrictions on collection, demand for artificial aggregates (crushed stone, crushed sand) produced by crushing quarry is increasing. In the production of aggregates by crushing such raw materials, for example, the mill body into which raw materials and rods (steel bars) are charged is rotated, and the rods are dropped to give impact and friction to the raw materials. Conventionally, a rod mill for crushing has been widely used. However, in the case of the above-mentioned rod mill, since it is impact crushing with a rod, the vibration and noise are large, and the obtained crushed stone and crushed sand are not as good as natural ones, and the running cost is high. It was not satisfactory.
In view of this, roller mill type crushers that can obtain crushed sand with good grain shape with low vibration, low noise, and low running cost are attracting attention. A method for producing crushed sand using such a roller mill type crusher has been proposed in, for example, Japanese Patent Application Laid-Open No. 7-51591. In this crushed sand production method, a relatively fine raw material having a particle size of about 30-0 mm or about 5-2.5 mm is charged into a roller mill to obtain crushed sand as a product.
[0003]
[Problems to be solved by the invention]
However, the aggregate production method using the conventional roller mill has been used only for the purpose of taking out only the crushed sand as a product, so that the product yield remains as low as about 50 to 60%, and the raw material size is large. The value was low. Therefore, when trying to use raw materials with a large size for rationalization of the plant, there is a problem that the yield deteriorates and conversely the efficiency deteriorates.
Further, for example, in addition to the crushed sand product, when the crushed stone product is further taken out, for example, a plant as shown in FIG. 4 is set up.
In the plant A0 shown in FIG. 4, first, a raw material having a maximum size of about 300 mm supplied from the surge pile 51 is crushed to a maximum size of about 80 to 60 mm by a secondary cone crusher 52 and classified by a sieve 53, and a relatively large size crushing is performed. The material is crushed again by the third cone crusher 54 to obtain a crushed material of about 20-0 mm. Since the crushed material by the cone crusher generally has a poor particle shape (angular), a part of the sieve 53 below the sieve 53 (and a part thereof may be used as a roadbed material) and the third cone crusher 54 Part of the obtained crushed material is trimmed by the granulator 55, and then a crushed stone product of 20-5 mm is taken out. The remaining crushed material that has not been sent to the granulator 55 is crushed by the roller mill 56, and the fine powder is washed away by the wet classifier 57, and the product crushed sand is taken out.
As described above, when taking out the crushed sand product and the crushed stone product using the above-described conventional aggregate production method using a roller mill, the crushed stone product and the crushed stone product from the maximum 80-60 mm obtained by the secondary corn crusher, In order to obtain a crushed sand product, a very large plant equipped with three crushers, a tertiary corn crusher, a granulator, and a roller mill, is required.
The present invention has been made in view of the above circumstances, and its object is to produce an aggregate production method capable of efficiently producing a crushed sand product and a crushed stone product while rationalizing the configuration of the plant, and It is to provide such a device.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the method of the present invention simultaneously produces crushed sand and crushed stone by repeatedly crushing a raw material composed of secondary crushed material in a crushed stone plant with a roller mill until it falls below the upper limit of a predetermined size range. a aggregate production method, a crushing step of crushing the raw material was charged into the roller mill, the crushed product obtained in the above crushing step, and crushed stone of a given size range that the lower limit 5 mm, the predetermined size Classification into crushed material larger than the upper limit of the range and crushed material less than 5 mm smaller than the lower limit of the predetermined size range, re-entering the crushed stone larger than the upper limit of the predetermined size range into the roller mill, and lower limit of 5 mm and the crushed stone acquisition step of taking intact without further grinding the crushed stone of a predetermined size range which, by a predetermined classification means, after being classified by the crushed stone acquisition step Serial and a crushed sand acquisition step of removing the fine powder taken out crushed sand smaller ground product than the lower limit of the predetermined size range, separately without mixing with the crushed stone a crushed sand with retrieved by the crushed stone acquisition step removed by the classification means It is configured as an aggregate production method characterized by being stored.
With this configuration, for example, a crushed stone product and a crushed sand product can be taken out simultaneously using only a roller mill using secondary crushed material as a raw material, the plant configuration can be streamlined, and both products can be combined. Therefore, it is possible to increase the production yield.
Here, it is desirable that the selection of the raw material and the classification level in the crushed stone obtaining step are set so that the lower limit value of the maximum dimension of the raw material is not less than the maximum particle size of the crushed stone obtained in the crushed stone obtaining step.
In order to achieve the above object, the apparatus of the present invention is capable of simultaneously breaking crushed sand and crushed stone by repeatedly crushing a raw material consisting of secondary crushed material in a crushed stone plant with a roller mill until it falls below the upper limit of a predetermined size range. a aggregate production apparatus for producing a crushing means for crushing the raw material was charged into the roller mill, the crushed product obtained in the above pulverizing means, and crushed stone of the predetermined size range of the lower limit 5 mm, Classifying the crushed material larger than the upper limit of the predetermined size range and the crushed material of 5 mm or less smaller than the lower limit of the predetermined size range, re-injecting the crushed material larger than the upper limit of the predetermined size range into the roller mill, and and crushed stone acquisition means for retrieving it without further grinding crushed stones of the predetermined size range to limit the 5 mm, by a predetermined classification means, the crushed stone get hands Remove the fines smaller crushed than the lower limit of the classified the predetermined size range stage and a crushed sand acquiring means for taking the crushed sand, and the said crushed stones taken out of crushed sand extracted by the classifying means in the crushed stone acquisition step It is constituted as an aggregate production device characterized by being stored separately without mixing .
All the above-mentioned aggregate production methods can be realized on this device.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments and examples of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. It should be noted that the following embodiments and examples are examples embodying the present invention, and do not limit the technical scope of the present invention.
FIG. 1 is a block diagram showing a schematic configuration of the plant A1 according to the embodiment of the present invention, FIG. 2 is a side sectional view showing a detailed configuration of the roller mill 8 in the plant A1, and FIG. It is the graph which showed the relationship between the power basic unit, crushed sand, and the production ratio of 20-5 crushed stone.
[0006]
A plant A1 according to the present embodiment embodies the aggregate production apparatus according to the present invention as a crushed stone plant that produces a 20-5 mm crushed stone product and a crushed sand product, and has an overall configuration as shown in FIG. Have Moreover, the roller mill 8 which is a main component of the plant A1 is configured as shown in FIG.
First, the configuration and crushing operation of the roller mill 8 will be briefly described with reference to FIG.
The roller mill 8 has a right cylindrical housing 21. A table 22 having a vertical rotation axis is disposed in the housing 21. The table 22 is rotationally driven by a motor 24 via a speed reducer 23 provided below the table 22.
On the table 22, a plurality of rollers 25 are arranged at intervals in the circumferential direction with their circumferential surfaces being close to the table 22. The roller 25 is pivotally supported by the arm 26 with its rotating shaft directed in the radial direction of the table 22. The arm 26 is formed integrally with a swing lever 27 having a horizontal rotation shaft 28, and a hydraulic cylinder 29 is connected to the lower end of the swing lever 27. Accordingly, the roller 25 is swung around the horizontal rotation shaft 28 according to the expansion and contraction of the hydraulic cylinder 29. When the hydraulic cylinder 29 is reduced, the roller 25 is pressed toward the upper surface of the table 22.
A throwing chute 30 is provided in the upper part of the housing 21 so as to coincide with the rotational axis of the table 22. The quarry, which is the material to be crushed (raw material), is input into the input chute 30 as indicated by an arrow Y1, and is supplied to the central portion of the table 22 that is rotationally driven. The object to be crushed supplied to the central portion of the table 22 moves in the radial direction of the table 22 by centrifugal force, and is caught in the gap between the table 22 and the roller 25.
The crushed material crushed between the table 22 and the roller 25 is further transported outward by the centrifugal force of the table 22 and exceeds the dam 22a protruding upward along the outer periphery of the table 22. It falls on the casing 31. The crushed material dropped on the casing 31 is scraped off by a scraper 22b attached to the table 22 and discharged from a discharge chute (not shown) provided on the casing 31.
[0007]
Then, the whole structure of plant A1 and the flow of a process are demonstrated using FIG. This plant A1 is the same as the above plant A0 after replacing the three crushers of the tertiary cone crusher 54, the granulator 55, and the roller mill 56 in the plant A0 shown in FIG. 4 with one roller mill 8. (Production of crushed stone product and crushed sand product).
In the plant A1 shown in FIG. 1, the raw material having a maximum of about 300 mm supplied from the surge pile 1 through the feeder 2 is first crushed by the secondary cone crusher 3 to a maximum of 80 to 40 mm. A part of the obtained crushed material is sieved with a sieve 4 as necessary, and the sieved material is taken out as a roadbed material 5 and the rest is put into a hopper 6. A maximum of 80 to 40 mm of crushed material charged into the hopper 6 is charged into the above-described roller mill 8 through the feeder 7 based on a predetermined charging amount. The roller mill 8 is operated at a predetermined power unit, and the input raw material is crushed. Here, an example of the crushing means is constituted by the hopper 6, the feeder 7 and the roller mill 8. The crushed material discharged from the roller mill 8 is processed by one of the two classifiers 21 and 22 surrounded by a one-dot chain line in FIG. 21 is a dry classifier using the air separator 10, and 22 is a wet classifier using the wet classifier 12. In practice, usually only one of these is installed.
When the dry classifier 21 is used, the crushed material discharged from the roller mill 8 is classified by the classifier 9 (an example of the crushed stone obtaining means), and those having a size of 20 mm (an example of the upper limit of the predetermined range) or more are again classified into the hopper. 6, 20 to 5 mm (an example of the predetermined range) is taken out as a crushed stone product of 20-5 mm, and 5 mm (an example of the lower limit of the predetermined range) or less is put into the air separator 10. In the air separator 10 (an example of the crushed sand acquisition means), fine powder (about -75 μm) is removed from the crushed material by air and is taken out as a crushed sand product.
On the other hand, when the wet classifier 22 is used, the crushed material discharged from the roller mill 8 is classified by the classifier 11 (an example of the crushed stone obtaining means), and those exceeding 20 mm (an example of the upper limit of the predetermined range) are again used. It is thrown into the hopper 6 and 20 to 5 mm (an example of a predetermined range) is taken out as a crushed stone product of 20-5 mm, and a piece of 5 mm (an example of the lower limit of the predetermined range) or less is put into a wet classifier 12. . In the wet classifier 12 (an example of the crushed sand acquisition means), fine powder (about -75 μm) is removed from the crushed material as turbid water using water, and the crushed sand product is taken out.
Here, the lower limit of the maximum raw material size is preferably equal to or greater than the maximum particle size of the crushed stone product. If the lower limit of the maximum raw material size is less than or equal to the maximum particle size of the crushed stone product, the specified particle size standard is not satisfied. Note that the upper limit of the maximum raw material size may be set to a size that can be bitten by the roller.
[0008]
Subsequently, the ratio of crushed stone and crushed sand taken out as a product will be described.
The ratio of the 20-5 mm crushed stone product and the crushed sand product finally taken out can be adjusted by changing the power unit of the roller mill 8 based on the amount of raw material input. This is because, for example, when the power unit is lowered, the production rate of crushed sand is lowered and the production rate of crushed stone is raised. Fig. 3 shows the change in the production amount with respect to the total amount of each of the crushed sand product and the 20-5 mm crushed stone product when the power unit is changed for the three types of raw materials 40-0, 40-20, and 80-0. It is a thing. For example, in the case of 40-0 raw material, when the power unit is 1 kWh / ton, the production ratio of crushed stone and crushed sand is 1: 1 (both are about 44%), and the ratio of crushed sand increases as the power unit increases. However, the ratio of crushed stone is decreasing. The trend does not change for other raw materials. According to FIG. 3, in the case of this plant A1, the ratio of 20-5 mm crushed stone product to crushed sand product is produced in the range of 1: 1 to 1: 3 by adjusting the power unit in the range of 1 to 8 kWh / ton. You can see that it is possible.
The power unit of the roller mill 8 can be changed by adjusting the pressure applied by the roller 25, the rotational speed of the table 22, the height of the dam 22a, the feed amount of the raw material, and the like. That is, the production ratio of the crushed stone and the crushed sand can be adjusted by adjusting at least one of the pressure applied by the roller 25, the rotational speed of the table 22, the height of the dam 22a, and the feed amount of the raw material. Is possible.
[0009]
Next, the product yield in the roller mill 8 of the plant A1 will be verified. As is apparent from FIG. 3, the yield of the product combining crushed sand and crushed stone (sum of the crushed sand product rate and 20-5 product rate) is 87 to 88%, 76 to 89%, and 74 to 85%, respectively.
As described above, in the plant A1 according to the present embodiment, the crushed stone product and the crushed sand product can be taken out using only the roller mill using the secondary crushed material as a raw material, and the combined yield of both products is high. Therefore, efficient aggregate production can be performed while rationalizing the plant configuration. Moreover, it is possible to easily change the production ratio of the crushed stone and crushed sand by changing the power unit.
[0010]
【Example】
In the said embodiment, although the example which applied this invention to the crushed stone plant was shown, it cannot be overemphasized that it can apply similarly to a gravel plant.
Further, the product to be produced is not limited to 20-5 mm crushed stone with respect to crushed sand, and any product can be handled.
[0011]
【The invention's effect】
As described above, the present invention is an aggregate production that simultaneously produces crushed sand and crushed stone by repeatedly crushing a raw material consisting of secondary crushed material in a crushed stone plant with a roller mill until it falls below the upper limit of a predetermined size range. an apparatus comprising: crushing means for crushing the raw material was charged into the roller mill, the crushed product obtained in the above pulverizing means, and crushed stone of the predetermined size range of the lower limit 5 mm, the upper limit of the predetermined size range Classify into larger crushed material and crushed material of 5 mm or less smaller than the lower limit of the predetermined size range, re-inject the crushed material larger than the upper limit of the predetermined size range into the roller mill, and set the lower limit to 5 mm. and crushed stone acquisition means for retrieving it without further grinding the crushed stone of a predetermined size range, by a predetermined classification means, the classified the predetermined service by the crushed stone acquiring means And a crushed sand acquiring means for taking the crushed sand by removing fines smaller crushed than the lower limit of the size range, separately from the reservoir without mixing with the crushed stone a crushed sand with retrieved by the crushed stone acquisition step removed by the classification means Since it is configured as an aggregate production device characterized by the above, for example, it is possible to take out both crushed stone products and crushed sand products using only a roller mill using secondary crushed material as a raw material, thereby streamlining the plant configuration In addition, it is possible to increase the yield of both products together, thus enabling efficient aggregate production.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a plant A1 according to an embodiment of the present invention.
FIG. 2 is a side sectional view showing a detailed configuration of a roller mill 8 in the plant A1.
FIG. 3 is a graph showing the relationship between the power unit, the crushed sand, and the production ratio of 20-5 crushed stone in the roller mill 8;
FIG. 4 is a block diagram showing a schematic configuration of a conventional plant A0.
[Explanation of symbols]
3 ... Secondary cone crusher 6 ... Hopper 7 ... Feeder 8 ... Roller mill 9 ... Classifier 10 ... Air separator 11 ... Classifier 12 ... Wet classifier

Claims (3)

An aggregate production method for simultaneously producing crushed sand and crushed stone by repeatedly crushing a raw material composed of secondary crushed material in a crushed stone plant with a roller mill until it falls below the upper limit of a predetermined size range ,
A crushing step of crushing the raw material was charged into the roller mill,
The crushed product obtained in the above crushing step, and crushed stone of the predetermined size range of the lower limit 5mm, large crushed than the upper limit of the predetermined size range and a small 5mm below crushed than the lower limit of the predetermined size range If you binary class, and it is taken out crushed stone acquisition step without large crushed than the upper limit of the predetermined size range on again into the roller mill, and further pulverized crushed stone of the predetermined size range to limit the 5mm ,
A crushed sand obtaining step of removing pulverized sand from a crushed material smaller than the lower limit of the predetermined size range classified in the crushed stone obtaining step by a predetermined classification means;
Aggregate production method characterized by comprising pooled separately without mixing with the crushed stone a crushed sand extracted by the classifying means has been removed by the crushed stone acquisition step.   The bone according to claim 1, wherein the selection of the raw material and the classification level in the crushed stone obtaining step are set so that the lower limit of the maximum dimension of the raw material is equal to or greater than the maximum particle size of the crushed stone obtained in the crushed stone obtaining step. Material production method. An aggregate production apparatus that simultaneously produces crushed sand and crushed stone by repeatedly crushing a raw material composed of secondary crushed material in a crushed stone plant with a roller mill until it falls below the upper limit of a predetermined size range ,
A crushing unit for crushing the raw material was charged into the roller mill,
The resulting crushed material in the crushing unit, and crushed stone of the predetermined size range of the lower limit 5mm, large crushed than the upper limit of the predetermined size range and a small 5mm below crushed than the lower limit of the predetermined size range Crushed material larger than the upper limit of the predetermined size range is reintroduced into the roller mill, and the crushed stone obtaining means for taking out the crushed stone in the predetermined size range with the lower limit of 5 mm as it is without further pulverization;
Crushed sand acquisition means for removing fine powder from crushed material smaller than the lower limit of the predetermined size range classified by the crushed stone obtaining means and taking out crushed sand by predetermined classification means,
Aggregate production apparatus characterized by being stored separately without mixing with the crushed stone retrieved the crushed sand extracted by the classifying means in the crushed stone acquisition means.

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