JPS5854615B2 - Fine aggregate production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is effective in crushing raw stone and correction crushed stone that has been crushed intermediately in a bed compression type cone crusher equipped with a specified crushing chamber and a mantle with a large eccentricity. A method for producing fine aggregate that enables the direct production of fine particles with an excellent shape from large lumps by introducing a mixing ratio that is similar to the above, and that enables the crushing plant to be constructed in the simplest form due to this direct production. Regarding.

For example, when obtaining aggregate for concrete by crushing lumps such as rocks or ores, it is necessary that the particle shape of the crushed single particles itself be good in order to ensure constant concrete performance. As is well known, this grain shape is specified in detail as the actual area ratio (bulk specific gravity/true specific gravity x α) in JIS and JASS5.

When crushing is performed using a conventional crusher, the maximum gap of the outlet opening formed during the eccentric rotational movement of the crusher is usually set to be approximately equal to or smaller than the target product size. In this case, the crushing capacity is the amount of crushed rock per unit time, that is, the amount of rock passing through the crusher per unit time determined by the outlet gap, eccentricity of the mantle, crushing chamber shape, rotation speed, etc., and the amount of rock that passes through the crusher per unit time after crushing. It is determined by the amount of crushed stone (product) to obtain the desired dimensions.

Therefore, during crushing, efforts are made to make the exit gap smaller than the target product size, thereby making the ratio of product production to the amount of raw ore passing through the crusher as close to 100% as possible. However, in order to increase this ratio as much as possible, it is necessary to make the exit gap small.
However, if this is done, the amount passing through the crusher will inevitably tend to decrease, and the product production will also decrease accordingly.

To explain this using a conventional crusher as an example, the first
In the figure, 1 is a conical cone cape, 2 is a mantle which is also conical and performs an eccentric rotation movement within the cape 1, and a crushing chamber 3 is formed between the inside and outside of these.

Reference numeral 4 indicates an outlet opening through which the crushed material is discharged, and C indicates a gap between the outlets.The supplied raw ore is repeatedly compressed by the rotation of the mantle 2 in the crushing chamber 3, and is thereby compressed between the mantle 2 and the cone. Outlet gap C defined by cape 1
After being crushed to a particle size or size approximately equal to , it is discharged from the machine through the outlet opening 4.

The crushed stone obtained in this way is sorted into products with the desired size and particle size, and other products.At this time, as mentioned above, in order to increase the product production ratio, the outlet opening 4 is made small so that it can pass through the crusher. Although the ratio of product production to volume will increase,
The amount of raw ore passing through the crusher decreases, resulting in a decrease in product production.

At the same time, the crushing chamber performs single-layer, so-called non-layer compression crushing between the inside and outside of the mantle and cone cape.
The product grain shape tends to be flat and cross-sectioned, and for this reason, it is necessary to further pass these crushed stones through a grain shape improving machine such as an impact crusher for the purpose of grain shape improvement.

Since the crusher in this case is of a type that strikes the rock at high speed, its parts are subject to severe wear and tear, which causes major problems in terms of maintenance, operating rates, and production costs of the rock crushing plant.

In addition, when obtaining fine aggregate with a certain particle size range using such a non-layer compression type cone crusher, the outlet gap C needs to be made as small as the desired product size. In order to prevent a decrease in production capacity and further improve the refining performance, it is possible to deal with this by making both walls of the crushing chamber 3 (inner and outer peripheral surfaces of the cone cape 1 and the mantle 2) as parallel as possible. However, in this case, the upper end of the crushing chamber becomes smaller in size, making it impossible to supply very large rough stones.As a result, pre-treatment is required, which naturally reduces the number of related equipment in a series of crushing plants. There was also the problem that the number of units increased, resulting in a complicated plant configuration.

In order to eliminate these conventional problems, this invention uses a layered compression type cone crusher to directly and efficiently produce fine aggregate from large ore. Fine aggregate with excellent granule shape can be obtained directly from raw materials, and the purpose can be completely achieved with just one crusher, so there is no need to install an additional crusher for improvement, and the crushing plant can be constructed in the simplest form. The purpose of this invention is to provide a method for producing fine aggregate that enables
In contrast, a conical mantle is rotated with an eccentric amount e of 0.05H to 0.1H around the lower end of the mantle, and the mantle is rotated approximately in the vertical direction to leave an exit gap C of 0.025H to 0.05H due to the approach of the mantle. A raw stone A is placed in a cone crusher having a cone cape forming a uniform compression crushing chamber.
The crushed stone F for particle size correction, which is a part of the crushed stone crushed by the same crusher, is mixed and continuously supplied so that the crushed stones are packed in layers in a consolidated state, and the rotation of the mantle is In a method of directly producing fine aggregate from rough stones having a maximum size of approximately ioom or more by compressing and crushing stones to be crushed by using the same crusher, at least a part of the crushed stone F for particle size correction mixed with the rough stones A is used. The crushed stone containing fine aggregate is used as it is without being classified or sorted, and the quantitative ratio (F/
The point is to adjust and maintain A) so that it is 0.3 to 3.0.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. FIGS. 2 and 3 show the main parts of the layer compression type cone crusher used in the present invention and the crushing state thereof.

The cone crusher 10 consists of a cone cape 11 in the form of a conical tube, and a mantle 12 that performs an eccentric rotation movement around the center line of the cone cape within the cone cape 11. A crushing chamber 13 formed between the inside and outside of these cone capes has an outlet at its lower end. Although it is similar to the conventional cone crusher in that it has an opening 14, in the present invention, raw ores such as rocks supplied into the crushing chamber 13 formed by the mantle 12 and the cone cape 11 are gradually crushed by the rotation of the mantle 12. Under compressive load,
In order to increase the output of the product when it is discharged from the outlet opening 14, on the one hand it is necessary to increase the amount of raw stone passing through it, and on the other hand, on the other hand, it is necessary to increase the product content of the desired particle size with respect to the amount of rough stone passing through it. It is necessary to adjust the two requirements simultaneously, but for the former condition, the exit opening 1
4, the inner and outer widths of the crushing chamber 13 have a uniform shape that is almost parallel in the vertical direction, and the eccentricity e of the eccentrically moving mantle 12 (this is caused by the rotational movement of the mantle 12). By increasing the distance between the inner and outer edges of the mantle 12, the position of the outer circumferential edge of the lower end of the mantle 12 when the gap is at its minimum and the position of the outer circumferential edge when it is at its maximum, the calculated amount of rough stones passing through per unit time (ton/hr) is determined in large numbers.

The latter condition can be solved by providing a crushing mechanism with a sufficient bulk density and a high compression ratio when compressing the rough stone in the crushing chamber 13.

In other words, by setting the gap C of the outlet opening 14 and the corresponding eccentricity e of the mantle 12, the amount of raw ore passing through the crusher (crusher), in other words, the amount of crushed throughput is determined, and this amount of throughput is determined. When the raw stones are continuously supplied to the crushing chamber 13, they fall and flow in a compacted state at each position in the crushing chamber length H direction within the crushing chamber 13.

In this way, in order to maintain the consolidated layered flow state of the raw ore in the crushing chamber 13 and to increase the amount of raw ore passing through the crusher, it is necessary to open the outlet opening 14 in consideration of the relationship with the eccentricity e described later. It is optimal and essential to set the gap C in the range of 0.025) (~0.05H with respect to the length of the crushing chamber, that is, the generatrix length H of the mantle 12; if this lower limit is exceeded, the exit opening 14 If the gap is too small, the amount of rough stone passing through will be reduced, making it difficult to achieve the distant relative of the purpose mentioned above.

Further, if the upper limit is exceeded, a layered consolidated fluid state cannot be obtained, and it becomes difficult to apply a sufficient compressive load to the rough stone due to the eccentric rotation of the mantle 12.

In addition, when crushing the raw ore that flows and falls in a compacted layer within the crushing chamber 13 in this manner, sufficient bulk density and high compression ratio are given to the raw ore within the crushing chamber 13 when compressed by the swirling motion of the mantle 12. For this purpose, it is necessary to make the eccentric rotational momentum of the mantle 12, that is, the amount of eccentricity e, larger than that of the conventional one, and the amount of eccentricity e allowed by the minimum amount and the mechanical structure of the crusher. is mantle 1
2 bus length and crushing chamber length) 0.05H to 0.
It is necessary to set it within the range of 1H.

In this way, in order to determine the gap C and the eccentricity e of the outlet opening 14, and to effectively propagate the compressive load between the laminar tiles on the raw stone in the crushing chamber 13, it is necessary to
It is necessary to form a fluid state in which the rough stones are densely packed in the crushing chamber 13, and for this purpose, by supplying a sufficient amount of rough stones to the crushing chamber 13, the filling state of the rough stones in the crushing chamber 13 can be maintained. As a result, the compressive work due to the eccentric rotational movement of the mantle 12, in other words, the compressive load on the rough stone, is propagated between the layers of rough stones, and as a result, the rough stones with low strength are broken and crushed. Room 13
By repeating this process, the product is crushed to the required particle size.

This crushing mechanism will be explained in more detail with reference to FIG. 3, which shows that the rotating motion of the mantle 12 relative to the cone cape 11 is a linear motion, and that the crushing chamber 13 is partially cut in the axial direction. Although this is an action diagram divided into multiple regions I to ■ in the length H direction, the mantle 12 has an eccentric amount e.
When the raw stone in the chamber 13 gradually increases its bulk density and starts to move forward from a position away from the cone cape 11, it shows a tendency to flow in the circumferential direction within the chamber 13. Due to the extremely large amount of raw stones supplied, a kind of restraint occurs in the circumferential direction, and most of the compression work by the mantle 12 becomes a compressive load on the raw stones, which is propagated between the rough stones. become,
In this respect, it is meaningful to set the gap C of the outlet opening 14 large to increase the supply amount of raw stone.

In this way, the bulk density of the rough stones increases due to the rotational movement of the mantle 12, and when the compressive load is propagated between the rough stones, the destruction of the rough stones progresses from the one with the lowest fracture strength, and the destroyed rough stones are in the area that receives the compressive load. Acts as a load propagation member at , and the rough stone is compressed in a layered manner until the mantle 12 reaches the position closest to the cone cape 11 with the eccentricity e shown by the imaginary line in the figure, that is, a debris compression crushing action occurs. This layer compression and crushing proceeds simultaneously in each region shown in 1 to 3 in the chamber 13.

According to this type of waste compression crushing method, there is no restriction on the size of the raw material, such as the upper limit of 50 to 60M, as in conventional non-layer compression type crushers, and the size of the raw material is limited to the size of the stone crushing plant. The primary crushed product in, i.e. 100-250
Although it is possible to use particles with a diameter of about In order to satisfy this requirement, the size of the raw material, that is, the raw stone, must be as small as possible, approximately 30 to 4077 ff or less.

However, in order to obtain fine aggregate of about 13-5M, 30-4M
Using as a raw stone a grain with a size of about 0w1 that is already fine to some extent requires a dedicated crushing process and has the disadvantages of using a raw material that already has a high commercial value. A large lump (maximum size of about 100 to 250 m) is used as raw material, that is, raw stone, and 30 m is used directly from it.
If fine aggregate of 71 gIl or less can be produced, it will be extremely advantageous in terms of simplifying the stone crushing plant equipment and reducing production costs.

This invention focuses on the above points and uses the layer compression type cone crusher 11 to directly obtain fine aggregate from large aggregates.
It was configured to perform crushing treatment as shown in the figure.

This will be explained below along with the crushed particle size distribution table shown in FIG.

The illustrated surge pile 15 has 17
Raw stones with a particle size of 0M or less are temporarily stored, and are distributed as shown below.

The raw ore having the above distribution is supplied to the cone crusher 10 at a rate of 240 t/h as shown in FIG.

G shown here is the sum of the return amount F and the raw ore amount A, and is essentially the rough supply amount.

This crusher 10 is of the above-mentioned waste compression crushing type,
By performing compaction-like compression crushing here, 347
It is discharged to the outside of the machine through an exit gap C that varies in the range of E1 to 73.

This discharged amount is B in the figure, and this B has a particle size distribution of 50M or less as shown in the fifth figure.

This amount of B is divided into C and D by a divider 1T provided in the next stage.
C is divided into 2571g11. Sieve classifier 1
8 or as a return portion.

Here, it is clear that C and D show the same particle size distribution, but the division ratio is C:D 2:1, that is, C
The amount is about 273 (381 t/l'1) of the discharged amount, and the D amount is about 1/3 (173 t/h).

In this way, the amount of C is passed through a vibrating sieve of 2571 gl1 by the classifier 18, and is classified into a portion H shown in the figure and a return portion E.

The crushed stone valve H weighing less than 251g11 is distributed evenly as shown in Figure 5, and is actually passed through the classifier 18 at the next 13 stations at a rate of 240t/h to be sieved into hl and h2 to become products.

In this way, a large amount of fine aggregate was returned in order to directly obtain it, and this is shown in the figure and E.

D is taken out at a rate of 173 t/h if the product contains fine aggregate as it is, and the overall distribution is less than 50 μg, and E is 141 t/h if it is in the range of 50 to 2511 g
h, and the combined form of these, ie, F shown in the figure, is supplied to the cone crusher 10 again as a particle size correction amount (314 t/h).

Therefore, in reality, this return amount, the so-called correction valve, is 314 tons.
/h, and the new supply amount A is assumed to be 240t/h, and this ratio, expressed as F/A, is approximately 1.31.

This ratio means that the return will increase by about 31%, but you can easily set and maintain this ratio as follows.

That is, assuming that the new supply amount A is constant, for example, here, F/A=
In order to obtain a ratio of 1.31, the crushed material is first returned in its entirety by the divider 1γ, and the amount of recycled crushed stone E increases with time, resulting in a state of F/A=131.

At this point, by returning the divider 1T to a constant ratio and adjusting it, an amount of crushed material equal to the amount of raw ore A can be taken out to the product side, and the return circuit will operate while maintaining the above-mentioned constant ratio.

This is as shown by the equation A=H=240 t/h.

This ratio needs to be 0.3 or more in order to achieve the desired purpose, and if it exceeds 3.0, the return amount will be excessive and the actual product production will be too low, so it is preferable to avoid F/A. =i, preferably in the range of o to 2.0 in order to more fully achieve the intended purpose.

Therefore, when the waste is compressed and crushed at a ratio of F/A = 1.31 as described above, a considerable amount of the crushed stone valves and product fine aggregate that have been crushed will be mixed into the rough stone, and Consolidation-like crushing is performed when the density is highest, and the interparticle density as a whole can be considered as a small lump, so the compressive force is transmitted accurately and the crushing of large lumps proceeds efficiently. becomes.

At the same time, materials that are flat, long, easily broken, or weak are crushed relatively early, resulting in a decrease in the number of grains with poor shape and an increase in the number of grains with good shape.

In this way, a specific amount of crushed stone is recycled for particle size correction, essentially density correction, but the present inventors had considered a circuit with a similar correction purpose prior to the above-mentioned preferred example. As shown in Fig. 6, the crushed stone from the crusher 10 is passed through the classifiers 18 of each stage of 20 ya or more, 13 or more, 5 or more, and the crushed stone is crushed with a core of about 20 to 13'IMl. Appropriate amounts of product J and appropriate amounts of fine aggregate products of about 13 to 5 liters are added to the reflux crushed stone F, respectively, to the amount of raw ore A at the above ratio. It was said that a similar effect could be expected by mixing, but in this case, the splitter 11 is used to take out the crushed stone at each stage as a product in addition to the return, so depending on the amount taken out, the amount returned may be excessive. If the gap is set to a certain value because the relationship between the outlet gap and the product consistency is constant regardless of the amount of supply to the crusher, Naturally, the range for correcting the particle size itself is also limited by this, resulting in a disadvantage.

Furthermore, since the method uses reflux while taking out the product as shown in the figure, it is inevitable to use multiple dividers 1 here.
1... Therefore, there is a problem in terms of maintenance as a plant.

According to the method of the present invention, intermediate crushed stone containing fine aggregate is crushed in advance by layer compression crushing of raw stone using a crushing chamber having a shape specified as described above and a mantle that rotates greatly. By refluxing a suitable amount of the aggregate and mixing it with the raw ore, compacted bed compression crushing is performed, eliminating the trouble and difficulty in producing fine aggregate associated with conventional non-bed compression crushing type crushers. It is possible to obtain fine aggregate directly and easily from large blocks of raw stone, and in particular, because the waste is compacted by mixing it with recycled crushed stone containing fine aggregate, it is possible to obtain a good grain shape. Fine aggregate can be obtained efficiently, and the type and number of crushers can be minimized, making the circuit configuration of the stone crushing plant extremely simple and eliminating the need for conventional grain shape improvement machines such as impact crushers. Therefore, overall plant maintenance, availability, production costs and
It is extremely advantageous in terms of

For example, as in the conventional system shown in Fig. 7, the primary crusher 2
The raw stone that has been primarily crushed by 0 is placed in a surge bin or pile 15.
This is stored in the primary sieve machine 21 via the feeder 16.
This stone is further crushed by a secondary crusher (non-layer compression crusher) 22, and then passed through an impact crusher 23 for improving particle shape to be sorted.
Next, it is crushed by LaTsunya 24 and then again by impact type crusher 23.
Compared to the method in which the particle shape is improved by refluxing to
circuit configuration, operational complexity and effort, production cost, operating rate, etc.
It is advantageous in all respects, and there is no problem that it is difficult to obtain fine aggregate with a good grain shape depending on the material used, and the present invention makes it possible for the first time to economically produce fine aggregate with excellent shape and specifications. As a result, it has great utility value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main part of a conventional non-bed compression type cone crusher, FIG. 2 is a sectional view of the main part of the bed compression type cone crusher used in the present invention, and FIG. 3 is an explanatory diagram of the state of compressing and crushing debris. Fig. 4 is a circuit diagram showing an example of the operation of the method of the present invention, Fig. 5 is a particle size distribution table thereof, Fig. 6 is an example circuit diagram showing a comparative example for the present invention, and Fig. 1 is a circuit diagram of a conventional method of a stone crushing plant. It is a circuit diagram. 10... Cone crusher, 11...
Corncafe, 12... Mantle, 13...
...Crushing chamber, 14...Exit opening, C...
・・Exit gap, H・・Generator length, e・・・・
・Eccentricity, A...Rough supply amount, F...
Return portion for particle size correction.

Claims (1)

[Claims] 1 The lower edge of the mantle is 0.05H- for the generatrix length H.
A conical mantle rotates with an eccentricity e of 0.1H, and the distance between 0.025H and 0.05H due to the approach of the mantle
In a cone crusher having a cone cape forming a compression crushing chamber that is substantially uniform in the vertical direction so as to leave an exit gap C of F is mixed and the stones to be crushed are continuously supplied so as to be packed in layers in a consolidated state, and the stones to be crushed are compressed and crushed into waste by the rotation of the mantle, and the maximum size is approximately 100M. In the method of directly producing fine aggregate from the raw stone described above, the crushed stone containing the product fine aggregate crushed by the same crusher is classified and sorted as at least a part of the crushed stone F for grain size correction to be mixed with the raw stone A. In addition to using it as is, crushed stone F and raw stone A for particle size correction are used.
A method for producing fine aggregate, which comprises adjusting and maintaining a quantitative ratio (F/A) of 0.3 to 3.0.