JPS63221852A - Method of crushing raw material stone - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) This invention provides a method for crushing raw material stone such as blast furnace slag to make the particle size of the product stone as uniform as possible when obtaining product stone by crushing raw material stone. Concerning a crushing method.

(Prior art) For example, when blast furnace slag, which is a raw material stone, is crushed into product stone and used as a roadbed material, the particle size of the product stone must be 25 mm or less and within the range specified by JIS standards. , and it is required to get it close to the median value.

Conventionally, the above-mentioned crushing and sizing of blast furnace slag have been carried out by the following methods. This will be explained with reference to FIGS. 8 to 13.

In FIG. 8, first, a raw material stone M having a large particle size is roughly crushed by a coarse crusher C. This coarsely crushed raw material stone MQ1 is composed of stones with different particle sizes, and is then crushed by a cone crusher 41, which is a crusher, thereby obtaining intermediate raw material stone Mo2. Further, this intermediate raw material stone Mo2 is sorted by particle size using a sieve 42 to obtain an intermediate product GO1. This is stored in each store or stockyard 43. Then, a predetermined amount is placed from each of these hoppers or the stockyard 43 onto a driving belt conveyor 44, thereby conveying it to a product yard 45 while blending a product layer G that conforms to the JIS standard.

In the above case, the cone crusher 41 is constructed as shown in FIG. That is, the upper body 47 for forming the crushing chamber 46 is provided in a fixed state. This upper body 47
A concave ring 48 whose axis is vertical is attached to the inner wall of the housing. On the other hand, a cone head mantle 49 is provided which rotates eccentrically around a vertical axis. A crushing gap 50 is formed between the concave ring 48 and the cone head mantle 49, through which the raw stone Moi supplied from the upper input port passes and is crushed. In the above case, the cone head mantle 49 is supported by a hydraulic cylinder (not shown) so as to be able to rise and fall.

The raw material stone Mol supplied from the upper input port is pinched between the inner circumferential surface, which is the crushing surface of the concave ring 48 and the outer circumferential surface, which is the crushing surface of the cone head mantle 49, which face each other in the crushing gap 50. Shattered.

In the above configuration, when the supply amount of the raw material stone M and the gap dimensions of the crushing gap 50 are constant, for example, the raw material stone M has a grain size of 25 mm or less (hereinafter referred to as small diameter stone), When the mixing rate of grains with a grain size of 25 mm or more (hereinafter referred to as large grain stones) changes, the grain size of the intermediate raw material stone Mo2 changes as follows.

That is, 1. For example, as shown in FIG.
ol is concave ring 48 and cone head mantle 4
9, many large-diameter stones are thrown into the crushing chamber 46 formed between these two stones 48 and 49, and the load inside the crushing chamber 46 increases. Therefore, the oil pressure in the hydraulic cylinder supporting the cone head mantle 49 (hereinafter referred to as crushing pressure) is, for example, 24 Kg/am2.
The pressure rises to a high level. When the crushing pressure increases in this way, the pressurizing force between the raw stones Mo1 in the crushing chamber 46 and the crushing gap 50 increases, and as a result, the grain size of the intermediate raw stones Ma2 becomes fine.

Also, as shown in Figure 11, there are many small-sized stones.

That is, when there are few large-sized stones, the load on the crushing chamber 46 is small, and the crushing pressure is, for example, 15 kg.
/cts2. When the crushing pressure decreases in this way, the inside of the crushing chamber 46 and the crushing gap 5
The pressing force between the raw stones Mat at 0 becomes lower,
As a result, the grain size of the intermediate raw material stone Mo2 becomes coarse.

FIG. 12 shows the above-mentioned crushing characteristics in a table. Moreover, FIG. 13 is a graph showing the particle size of intermediate raw material stone MO2 when the amount of large-diameter stones in the raw material stone M is large as shown in FIG. 10 and when it is small as shown in FIG. . According to this figure, it is understood that when the amount of large-diameter stones is large, the grain size of the intermediate raw material stone MO2 becomes fine, and when the amount of large-diameter stones is small, the grain size of the intermediate raw material stone MO2 becomes coarse. Note that the upper and lower broken lines A and B in FIG. 13 indicate that the range surrounded by these lines is the desired particle size range of the product layer G to be obtained.

(Problems to be Solved by the Invention) By the way, according to the above-mentioned conventional crushing method, when the amount of large-diameter stones in the raw material stone M is large and when it is small, the amount of intermediate raw material stone crushed by the cone crusher 41 is A relatively large variation in particle size is observed, and the particle size may deviate greatly from the above-mentioned desired particle size range, which is unfavorable in terms of the quality of the product layer G.

Therefore, conventionally, in order to obtain a product layer G having a desired particle size within the JIS standard, the intermediate raw material stone Mo2 crushed by the cone crusher 41 is further sorted by particle size and blended. However, for sorting and blending as described above, sieving requires machines and connection equipment for each device, a hopper and stockyard for intermediate product stone, and cutting equipment and transportation equipment for blending. Therefore, the equipment configuration becomes extremely complicated.

(Purpose of the Invention) This invention was made in view of the above-mentioned circumstances, and when attempting to obtain product stone by crushing raw material stone such as blast furnace slag, the particle size distribution of conventional intermediate product stone is JIS for roadbed materials
By not only meeting the standard range, but also as close as possible to the median value, and making the product stone equivalent to the conventional intermediate product stone, we can improve the equipment for converting the conventional intermediate product stone into the product stone. The purpose is to simplify the equipment and reduce power loss during manufacturing.

(Structure of the Invention) The present invention for achieving the above object is characterized by a method of crushing raw stones with different particle sizes to obtain product stones having a particle size distribution falling within a certain range. The raw material stone is sorted into small diameter raw material stone and large diameter raw material stone, and then the small diameter R raw material stone is made into product stone without going through the crushing process, while the large diameter raw material stone is made into product stone through the crushing process, In this crushing step, the large-diameter raw material stone is crushed by being crushed between the two facing crushing surfaces, and when the load applied to the crushing surfaces during this crushing is small, the gap between the two crushing surfaces is narrowed, When the load applied to the fracture surfaces is large, the gap between the fracture surfaces is widened.

(Example) Examples of the present invention will be described below with reference to FIGS. 1 to 7.

In FIG. 1, first, the raw material stone M is sieved through a sieve (not shown) and is sorted by a machine into small-diameter raw material stone and a first large-diameter raw material stone M+ using a particle size of 25+sm as the boundary. In this case, the first product stone G
1 is a small-sized stone, which is made into a part of the final product stone G without going through a crushing process.

On the other hand, the first large diameter raw material stone Ml is a large diameter stone. For this reason, this is coarsely crushed by a coarse crusher C, and the coarsely crushed material is sieved again (not shown) into second product stone G2 and second large-diameter raw material stone M2 with a grain size of 25 layer 1 as a boundary. Sort by. The second product stone G2 is a small-sized stone, and is used as a part of the product stone G as it is. Further, the second large-diameter raw material stone M2 is crushed by a cone crusher I, which is a crusher, and a sieve (not shown) is passed through a machine to obtain a third product stone G3 having a particle size of 25+sm. This third product stone Ca is used as a product stone G together with the first product stone G1 and the second product stone G2 described above.

In the above case, for example, the amount of the first product stone G1 is 10 to 40% (weight%, the same hereinafter) of the product stone G, the second product stone G2 is 13 to 15%, and the third product stone G3 is 45% of the product stone G. ~77%.

Next, the cone crusher 1 and related devices will be explained in detail.

In Figures 2 and 3, 2 is a conveyor;
supplies this second large diameter raw material stone M2 to the cone crusher 1.

The cone crusher 1 will be explained in more detail.

Reference numeral 4 denotes an upper body, which is supported on a base 5 and has a crushing chamber 6 inside. The conveyor 2 supplies the second large-diameter raw material stone M2 into the crushing chamber 6 from above. A concave ring 7 in the shape of a truncated conical cylinder whose axis is vertically oriented is attached to the inner wall of the base 5 at its upper and lower midpoints. Also,
Inside the concave ring 7 is a cone head mantle 8.
This cone head mantle 8 is supported by a main shaft 9 provided on the axis of the concave ring 7. In this case, the cone head mantle 8 and the main shaft 9 are eccentric with respect to the axial center, and the main shaft 9 is supported by a hydraulic cylinder 13 fixed to the body arm 4a and is rotatable about the axial center.

An eccentric bearing (not shown) is operatively connected to an electric motor 12 via a gear set 11 made up of bevel gears. That is,
The driven side 11a of the gear set 11 is attached to the eccentric bearing (not shown) with a key or the like, and is slidable in the axial direction with respect to the main shaft 9, thereby indirectly rotating the main shaft 9. On the other hand, the drive side 11b of this gear set 11 is driven by an electric motor 12. The electric motor 12 is driven to rotate the eccentric bearing, and accordingly, the main shaft 9 and the cone head mantle 8 are eccentrically rotated around the axis of the concave ring 7.

A hydraulic cylinder 13 is provided at the lower end of the main shaft 9, and the cone head mantle 8 is raised and lowered in the axial direction by the expansion and contraction of the hydraulic cylinder 13. That is, this hydraulic cylinder 13 includes a cylinder tube 14 supported on the upper body 4 side, and a piston 15 that is slidably fitted into the cylinder tube 14 and connected to the main shaft 9 via a step bearing (not shown). The discharge side of a hydraulic pump 18 is connected to a pressure oil chamber 16 surrounded by the inner surface of the cylinder tube 14 and the piston 15. 19 is a hydraulic oil tank for the hydraulic cylinder 13.

On the other hand, each opposing surface of the concave ring 7 and the cone head mantle 8 is a fracture surface, and a fracture gap 20 is formed between the two fracture surfaces. Then, the second large-diameter raw material stone M2 supplied from above is passed through this crushing gap 20, and the second large-diameter raw material stone M2 is compressed by the relative rotation of the concave ring 7 and the cone head mantle 8 at this time. Crush. The stone that has passed through this crushing gap 20 becomes the third product stone G3.

Then, when the hydraulic pump 18 is rotated normally, the hydraulic oil in the oil tank 19 is sent into the pressure oil chamber 16 (arrow C in the figure).
As the piston 15 rises due to this, the cone head mantle 8 rises. Then, the gap dimensions of the crushing gap 20 are narrowed. Conversely, when the hydraulic pump 18 is reversed, the hydraulic oil in the pressure oil chamber 16 flows back into the oil tank 19 (
The cone head mantle 8 is lowered by the lowering of the piston 15 as indicated by the arrow D in the figure. Then, the above-mentioned crushing gap 2
The gap size of 0 is expanded.

In the above configuration, a pressure detection means 22 is provided for detecting the crushing pressure, which is the hydraulic oil pressure in the pressure oil chamber 16. Further, a differential transformer 23 is provided which detects the gap dimensions of the crushing gap 20 by raising and lowering the main shaft 9. A control circuit 24 is provided which drives the hydraulic pump 1B using output signals detected by the pressure detection means 22 and the differential transformer 23, thereby operating the hydraulic cylinder 13.

By the way, when the raw material layer M contains many large-diameter stones, that is, when the raw material layer M is coarse as a whole, the amount of the second large-diameter raw material stone M2 increases, causing the crushing inside the chamber 6 and the crushing gap 20.
When the second large-diameter raw material stone M2 is bitten into the cone head mantle 8, the load on the cone head mantle 8 increases, and the crushing pressure increases.

Therefore, if the cone crusher 1 continues to operate with the gap dimensions of the crushing gap 20 as they are now, the pressing force between the second large-diameter raw materials M2 in the crushing chamber 6 and in the crushing gap 20 will be large, and therefore, This second large-diameter raw material stone M2 is over-crushed as a whole and becomes too fine, and the third product stone G
3 is finer than the desired particle size.

In addition, on the contrary, there are fewer large-sized stones in the raw material layer M,
That is, when the raw material layer M is fine as a whole, the second
The amount of large-diameter raw material stone M2 is small, and when the second large-diameter raw material stone M2 is bitten into the crushing chamber 6 and into the crushing gap 20, the load on the cone head mantle 8 is small, and the crushing pressure is low.

Therefore, if the cone crusher 1 continues to operate with the gap dimensions of the crushing gap 20 as they are now, the pressing force between the second large-diameter raw materials M2 in the crushing chamber 6 and in the crushing gap 20 will be small, and therefore, Since this second large-diameter raw material stone M2 is not sufficiently crushed, the third product stone G3 has a grain size coarser than the desired grain size.

Therefore, the control circuit 24 activates the hydraulic pump 18 in the forward and reverse directions to operate the hydraulic cylinder 13, thereby raising and lowering the cone head mantle 8 as follows.

First, when the load on the cone head mantle 8 is large, that is, when the crushing pressure in the pressure oil chamber 16 is high, the pressing force between the second large-diameter raw material stones M2 is lowered, and the hydraulic pressure is adjusted to prevent excessive crushing. The piston 15 of the cylinder 13 is lowered to lower the cone head mantle 8 (arrow F in the figure), thereby widening the gap dimension of the crushing gap 20. Conversely, when the load on the cone head mantle 8 is small, that is, when the crushing pressure in the pressure oil chamber 16 is small, the pressing force between the second large-diameter raw material stones M2 is increased to ensure sufficient For crushing, the piston 15 of the hydraulic cylinder 13 is raised to raise the cone head mantle 8 (arrow E in the figure), thereby narrowing the gap dimension of the crushing gap 20. next,
The specific configuration of the control circuit 24 will be explained with reference to FIG.

This figure shows a flowchart of the control circuit 24, in which (P-1) to (P-20) indicate each step.

In the figure, first, at (P-1), the crushing pressure to be taken in the pressure oil chamber 16 is set to 20±2 Kg/c+a2. Next, the pressure detection means 22 having a pressure transmitter
The crushing pressure is detected and a detection signal is outputted through the comparator 26 (P-2, 3), which is displayed on the pressure gauge 27. If the daily crushing pressure in the pressure oil chamber based on the output signal at this time is greater than 22 Kg/cab2, C
P-4), and after a certain set time has elapsed (P-5), a lowering command for the cone head mantle 8, that is, a reverse rotation start command is output to the hydraulic pump 18 (P-6).

On the other hand, in (P-7), the value that should be taken for the gap dimension intersection is 9±
It is set to 1mm. Next, the differential transformer 23 detects the amount of movement of the main shaft 9 and outputs a signal via the comparator 28 (P-8, 9), which is displayed on the pressure gauge 27. Then, the crushing gap 2 according to the output signal at this time
If it is determined that the value of the gap dimension statement 0 is smaller than 9ffiI11 (CP-10), the reverse start command to the hydraulic pump 18 in (P-6) above is executed (P-11),
Hydraulic pump 18 is reversed (P-12), hydraulic cylinder 1
The piston 15 of No. 3 is lowered, and the cone head mantle 8 is lowered. This reversal of the hydraulic pump 18 is performed for a preset period of 0.8 seconds (P-13), and after that period the hydraulic pump 18 stops (P-14), interrupting the downward force of the cone head mantle 8. be done. After that, the above (P
-2) to (P-6) and (p-a) to (P-14
) is repeated to lower the cone head mantle 8, thereby determining the gap dimension.

On the other hand, in the above (P-4), if it is determined that the value of the crushing pressure in the pressure oil chamber 16 is smaller than 18 Kg/cm2, the cone head mantle 8 is raised after a certain set time has elapsed (P-15). A command, that is, a normal rotation start command is output to the hydraulic pump 18 (P-16).

On the other hand, if it is determined in the above (P-10) that the value of the gap dimension of the crushing gap 20 is the same as or larger than 91 mm, the normal rotation start command to the hydraulic pump 18 in the above (P-16) is executed. CP-17), the hydraulic pump 18 rotates normally P-18).

The piston 15 of the hydraulic cylinder 13 rises, and the cone head mantle 8 rises. The normal rotation of the hydraulic pump 18 is performed for a preset period of 1 or 2 seconds (P-19).
, 18 hydraulic pumps stopped after that period (P-2
0), the raising of the connhet mantle 8 is interrupted.

After that, see (p-2) to (P-4), (P-8) above.
From (P-10) and (P-15) to (P-20)
is repeated to raise the cone head mantle 8, thereby determining the gap dimension.

FIG. 4 shows the above-mentioned crushing characteristics in a table. According to this FIG. 4, firstly, when the amount of small diameter stones in the raw material stone M is small, the amount of large diameter stones in the second large diameter raw material stone M2 supplied to the cone crusher 1 is In other words, the amount of large-diameter stones supplied to the cone crusher 1 increases, and the crushing pressure increases. Here, if the cone crusher l is controlled as described above and the crushing gap 20 is widened, over-crushing is prevented and the crushing grain size tends to be coarse, so that the third product stone G3 with the desired grain size can be obtained. It happens. Then, if this third product stone G3 is mixed with the first product stone G1 and second product stone G2, the product stone G of the desired particle size
is obtained.

Second, when the amount of small diameter stones in the raw material stone M is large, the second large diameter raw material stone M supplied to the cone crusher 1
The amount of large-diameter stones in the cone crusher 1 decreases, that is, the amount of large-diameter stones supplied to the cone crusher 1 decreases, and the crushing pressure becomes low. Here, cone crusher 1 as described above
If the crushing gap 20 is narrowed by performing control over
will be obtained. Therefore, even in this case,
By mixing this third product stone G3 with the first product stone G1 and second product stone G2, a product stone G with a desired particle size can be obtained.

(Specific Examples) Next, more specific examples will be described with reference to FIGS. 5 to 7.

Two types of raw stone M have different mixing rates of small-sized stones, and the first
The second raw material stone M has a small mixed rate of small-sized stones, and the second raw stone M has a high mixed rate of small-sized stones. Table 1 below shows the weight balance in each process when each of these raw stones M is crushed with a coarse crusher aC or a cone crusher I to produce a product stone G. Note that the numbers in Table 1 correspond to the numbers on the drawings of raw stones and product stones in each process. In addition, the supply amount of each raw material stone M in this case is fixed, and is 120 T/H each.The explanation of the flowchart of the control circuit 24 and the actual number of supply amounts are based on the physical properties of the raw material stone M and the equipment. It varies depending on the ability, and this is an example based on one condition. Moreover, these setting values should of course be changed depending on the purpose, and the settings can be changed.

In addition, in the crushing process of each of the raw material stones M, the particle size distribution when the first product stone G and the second product stone G2 are mixed is as shown in Figure 5, which is shown in the upper part of the figure. , the particle size is coarser overall than the desired particle size range shown between the lower broken lines A and B.

On the other hand, the third product stone G3 has a particle size as shown in FIG. 6 even if the mixing ratio of small-sized stones changes like each raw material stone M, and this is fine overall.

Figure 7 shows the particle size of product stone G, which is the same as the
Product stone G1. It is a mixture of the second product stone G2 and the third product stone G3, and is located within the desired particle size range.

Although the above is based on the illustrated example, the coarse crusher C may be omitted and the entire amount of the first large-diameter raw material stone M1 may be supplied to the cone crusher 1.

(Effects of the Invention) According to the present invention, there is provided a method for obtaining a product stone having a particle size distribution within a certain range by crushing raw material stones with different grain sizes. After sorting into large raw materials, small-diameter raw stones are made into product stones without going through a crushing process, while large-diameter raw materials are made into product stones through a crushing process. Further crushing, that is, over crushing, is prevented. Therefore, part of the product stone is prevented from becoming too fine.

Further, according to the present invention, in the crushing step, the large-diameter raw material stone is crushed by being compressed between the two facing crushing surfaces, and when the load applied to the crushing surfaces at the time of crushing is small, the both crushing surfaces are crushed. While the gap between the surfaces is narrowed, when the load applied to the fracture surface is large, the gap between the fracture surfaces is widened, resulting in the following effects.

That is, for example, if a large-diameter raw material stone is coarse when crushing a large-diameter raw material stone, the load on the cone head mantle is large, that is, the pressing force between the large-diameter raw materials tends to be large, and the product stone grain size is There is a risk of it becoming too detailed. However, in this case, if the gap size of the crushing gap is widened, the pressing force between the large-diameter raw materials stones will be lowered, over-crushing will be prevented, and product stones with the desired particle size will be obtained.

On the other hand, if the large-diameter raw material stone is fine, the load on the cone head mantle is small, that is, the pressing force between the large-diameter raw material stones tends to be small, and the product stone grain size may become coarse. There is.

However, in this case, if the gap size of the crushing gap is narrowed, the pressing force between the large-diameter raw materials stones will be increased, and product stones with the desired particle size will be obtained. Therefore, since the gap size of the crushing gap is selected to match the particle size at the time of crushing, it is possible to make the product stone particle size uniform even when the particle size of the large-diameter raw stone is not constant.

Therefore, when a final product stone is produced by mixing the above-mentioned small-diameter raw material stone with a large-diameter raw material stone crushed in the crushing process, the particle size of the final product stone becomes more uniform, and quality improvement is achieved. be done.

Further, in the crushing process, small-diameter raw stones that can be used as product stones as they are are not crushed, so there is an advantage that power loss during crushing is reduced.

[Brief explanation of the drawing]

1 to 7 show embodiments of the present invention, where FIG. 1 is an overall flow diagram, FIG. 2 is an overall side sectional view of the cone crusher 7 shear, FIG. 3 is a flow chart of the control circuit, and FIG. 4 is a crushing characteristic diagram, Figures 5 to 7 are graphs showing particle size distribution in each crushing process, Figures 8 to 13 are conventional examples, Figure 8 is an overall flow diagram, and Figure 9 is a cone diagram. A partial side view of the crusher, Figures 1O and 11 are graphs showing the mixing rate of small-sized stones in the raw stone, Figure 12 is a crushing characteristic diagram, and Figure 13 is a graph showing the particle size distribution of the product stone. It is a diagram. 1. Cone crusher (iJlJl), 7. Concave ring (crushing surface), 8. Working cone head mantle (
fracture surface), 20φ, fracture gap, M, raw material stone, M1φ,
1st large diameter raw material stone (large diameter raw material stone), G... product stone, G1...
φ1st type product stone (small diameter raw material stone), MO, - Raw material stone in the conventional example, Got... Intermediate product stone in the conventional example. Patent applicant: Kobe Steel, Ltd. Figure 1 Figure 4 Figure 10 Figure 11 Figure 12 Figure 13

Claims (1)

[Claims] 1. A method of crushing raw stones with different particle sizes to obtain product stones with a particle size distribution within a certain range, in which the raw stones are first sorted into small-diameter raw stones and large-diameter raw stones, and then Small-diameter raw stones are made into product stones without going through a crushing process, while large-diameter raw stones are made into product stones through a crushing process.In this crushing process, large-diameter raw stones are crushed by squeezing them between two facing crushing surfaces. In addition, when the load applied to the fracture surface during this crushing is small, the gap between the two fracture surfaces is narrowed, while when the load applied to the fracture surface is large, the gap between the fracture surfaces is widened. A method for crushing raw stone, characterized by: