JP2018048355A - Crushing facility of coke breeze, crushing method of coke breeze - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crushing facility of coke breeze and a crushing method of coke breeze capable of adjusting a particle size of coke breeze even when the particle size distribution of the supplied coke breeze changes.SOLUTION: A crushing facility 100 of coke breeze includes a primary sieve 11 for sieving coke and supplying the undersize coke to a sinter machine (not represented) and a primary crusher 13 for crushing the oversize coke of the primary sieve 11. The crushing facility 100 of coke breeze further includes a secondary sieve 15 for sieving the coke crushed by the primary crusher 13 and supplying the undersize coke to the sinter machine and a secondary crusher 17 for crushing the oversize coke of the secondary sieve 15 and supply it to the sinter machine.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a powder coke crushing facility and a powder coke crushing method.

  Conventionally, powder coke for sintering is used by pulverizing the sieving (particle size of about 15 mm or less) of blast furnace coke to a particle size of about 3 mm or less.

  Under the present circumstances, in order to suppress the dispersion | variation in a particle size, the equipment which adjusts a particle size by putting a powder coke over a sieve and crushing on a sieve is known (patent document 1).

JP 60-238167 A

The technique of Patent Document 1 is useful as a structure for adjusting the powder coke particle size.
On the other hand, since the powder coke to be supplied does not necessarily have a constant particle size distribution, a structure capable of sufficiently following such a change in distribution is more preferable.

  This invention is made | formed in view of the said subject, and is providing the powder coke crushing equipment and the powder coke crushing method which can adjust the particle size of a powder coke even when the particle size distribution of the powder coke supplied changes. .

In order to solve the above-described problems, the present invention has the following configuration.
(1) sieving the coke, and supplying a primary sieve that supplies the coke under the sieve to the sintering machine;
A primary crusher for crushing coke on the sieve of the primary sieve;
Sieving the coke crushed by the primary crusher, a secondary sieve that supplies the coke under the sieve to the sintering machine, and
A secondary crusher that crushes the coke on the sieve of the secondary sieve and supplies it to the sintering machine;
A powder coke crushing facility characterized by comprising:
(2) The powder coke crushing facility according to (1), wherein the primary crusher is a double roll crusher.
(3) The powder coke crushing facility according to (1) or (2), wherein the secondary crusher is a rod mill.
(4) The coke on the sieve of the secondary sieve is temporarily stored, and has an intermediate hopper that supplies the stored coke to the secondary crusher. (1) to (3) The powder coke crushing equipment as described in any one.
(5) first step of sieving the coke with a primary sieve and supplying the coke under the sieve to the sintering machine;
A second step of crushing the coke on the sieve of the primary sieve with a primary crusher;
Sieving the coke crushed by the primary crusher with a secondary sieve, and supplying the coke under the sieve to the sintering machine; and
A fourth step of crushing the coke on the sieve of the secondary sieve with a secondary crusher and supplying it to the sintering machine;
A method for crushing powder coke, comprising:
(6) The method for crushing powder coke according to (5), wherein the second step is a step of crushing coke on the sieve of the primary sieve with a double roll crusher.
(7) The powder coke crushing method according to (5) or (6), wherein the fourth step is a step of crushing coke on the sieve of the secondary sieve with a rod mill.
(8) The third step includes
Coke crushed by the primary crusher is sieved with the secondary sieve, and the coke under the sieve is supplied to the sintering machine,
Coke crushing according to any one of (5) to (7), characterized in that it is a step of temporarily storing coke on a sieve and supplying the stored coke to the secondary crusher. Method.
(9) The ratio of the powder having a particle diameter of more than 0.5 mm and less than 3 mm in the coke supplied to and mixed with the sintering machine in the first step, the third step, and the fourth step. The method for crushing powder coke according to any one of (5) to (8), characterized in that is 45% or more.

  ADVANTAGE OF THE INVENTION According to this invention, even when the particle size distribution of the supplied powder coke changes, the powder coke crushing equipment and the powder coke crushing method which can adjust the particle size of powder coke can be provided.

The figure which shows the example of the particle size of the powder coke supplied to a powder coke crushing installation. The figure which shows the relationship between a powder coke particle size and the highest ultimate temperature in a layer in a preliminary test. The figure which shows the relationship between the powder coke particle size and the temperature of 900 degreeC or more x time in a preliminary test. The figure which shows the relationship between a powder coke particle size and a yield in a preliminary test. Schematic of the powder coke crushing equipment concerning this embodiment. Schematic of the powder coke crushing equipment of a comparative example. The figure which shows the particle size distribution of the powder coke after the crushing of an Example and a comparative example. The figure which shows the yield at the time of performing a sintering test with an actual machine using the powder coke after crushing with the powder coke crushing equipment of an Example and a comparative example. The figure which shows the particle size distribution of the powder coke after a crushing for every crusher. For each crusher, the relationship between the amount of decrease in the ratio of powder coke with a particle size of 3 mm or more after crushing compared to that before crushing and the amount of increase in the ratio of powder coke with a particle size of 0.5 mm or less before crushing FIG.

  Hereinafter, the configuration of the preferred embodiment of the present invention will be described in detail with reference to the drawings.

<Basic concept of the present invention>
First, the basic concept of the present invention will be described.
Coke supplied to the blast furnace is mixed with the central coke (grain size of 40 mm or more) charged to the center of the blast furnace by classification, lump coke (diameter of 40 mm or more) charged in the radial direction from the center of the blast furnace, ore Small coke (particle size 15-40 mm). In addition, particles having a particle size of less than 15 mm or less are used after being crushed by the powder coke crushing equipment of the present invention and then sintered by a sintering machine. The particle size is an example.

On the other hand, depending on the operating conditions of the blast furnace, the particle size of the charged central coke, lump coke, and small lump coke may be increased. In this case, the particle size of the powder coke supplied to the sintering process increases, and the powder coke The particle size of the powder coke to be crushed by the crushing equipment also increases.
For example, FIG. 1 is an example showing the cumulative distribution of the maximum particle size, the minimum particle size, and the average particle size when the particle size of the powder coke to be crushed by the powder coke crushing equipment is measured for 2 years. It is. Among these, the “smallest particle size” powder coke contains almost no powder having a particle size of 5 mm or more, but the “average particle size” powder coke has a 10% proportion of powder having a particle size exceeding 15 mm. As described above, the powder coke having the “maximum particle size” has a ratio of powder having a particle size exceeding 15 mm of 75% or more. Therefore, for example, when the object to be crushed is changed from one that shows a cumulative distribution equivalent to the average particle size to one that shows a cumulative distribution equivalent to the maximum particle size, It is not easy for the powder coke crushing equipment to follow.

Further, coke used for operation of the blast furnace includes yard via coke conveyed to the blast furnace via the yard and direct coke conveyed to the blast furnace using a belt conveyor or the like from the coke manufacturing process.
Among these, coke via yard is stored in an open-air storage location (yard), so rainwater penetrates into the interior of the coke when it rains, and the average moisture value of the coke increases.
In such a raw material with a large amount of water, fine coke is adhered to the raw material particles due to water, and therefore fine coke may not be removed even if the particle size is adjusted with a sieve or the like. Therefore, when the proportion of coke via yard increases, the sieve efficiency decreases, and the amount of coke to be crushed by the powder coke crushing equipment increases.
On the other hand, in the conventional sieving equipment, it may be difficult to follow the change in the particle size distribution due to the increase in the particle size of coke and the increase in the amount of water as described above.
Therefore, the present invention has changed the conventional configuration in order to follow such a change in particle size distribution.

Next, the desirable range of the particle size of the powder coke crushed by the powder coke crushing facility of the present invention will be described below.
First, in order to investigate the relationship between the particle size of powder coke and the sintering yield, a preliminary test was performed under the following conditions.
First, in the same type of coke breeze, those with a particle size of 0.5 mm or less, those with a particle size greater than 0.5 mm, those with less than 3 mm, those with 3 mm or more, and these at a ratio of 20%, 50%, 30% A mixture was prepared.
Next, a pan test using these coke breeze was performed to measure the highest in-layer temperature, a temperature of 900 ° C. or higher × time (° C./min), and a yield. The conditions of the pan test are that the pan size is 500 mm in diameter, the layer thickness is 50 mm, and the supplied coke amount is 20% in the outer frame of the raw material blending amount.
The results are shown in FIGS. First, those having a particle size of 3 mm or more have low flammability and were extinguished during the test. Also, those having a particle size of 0.5 mm or less had a low combustion temperature and a short combustion time, so that the iron ore could not be sufficiently melted and recombined, resulting in a low yield.
On the other hand, as shown in FIGS. 2 to 4, those having a particle size of more than 0.5 mm and less than 3 mm are excellent in the maximum reachable temperature in the layer, the temperature × 900 ° C. or more, and the yield, It has been found desirable to have a particle size greater than 0.5 mm and less than 3 mm.
Therefore, the present invention has a configuration in which the ratio of the particle size of the ground coke after crushing is more than 0.5 mm and less than 3 mm is as large as possible.

<Configuration of the present invention>
Next, the configuration of the powder coke crushing facility according to the present invention will be described with reference to FIG.

  As shown in FIG. 5, the powder coke crushing facility 100 includes a primary sieve 11 that sifts coke and supplies coke under the sieve to the sintering machine, and a primary crusher 13 that crushes the coke on the sieve of the primary sieve 11. Have

  Moreover, the powder coke crushing equipment 100 sifts the coke crushed by the primary crusher 13, and supplies the coke under the sieve to a sintering machine (not shown), and on the sieve of the secondary sieve 15. A secondary crusher 17 for crushing the coke and supplying the coke to the sintering machine.

  The powder coke crushing facility 100 has an intermediate hopper 19 that temporarily stores the coke on the secondary sieve 15 and supplies the stored coke to the secondary crusher 17.

  Next, each structure of the powder coke crushing equipment 100 will be described in detail.

  The primary sieve 11 is a part that sifts the supplied powder coke, and the sieve mesh is about 5 mm × 30 mm, for example.

  The primary crusher 13 is not particularly limited as long as it can crush the coke on the sieve of the primary sieve 11, but a double roll crusher is preferable. The reason is that the powder coke crushed by the double roll crusher is less likely to generate fine powder than those crushed by other crushers, and it is easy to make the particle size uniform.

  The secondary sieve 15 is a part for sieving the coke crushed by the primary crusher 13, and the sieve mesh is, for example, about 5 mm × 30 mm.

  Although it will not specifically limit if the secondary crusher 17 can crush the coke on the sieve of the secondary sieve 15, For example, a rod mill is mentioned.

  The intermediate hopper 19 determines the amount of coke to be supplied to the secondary crusher 17 when the coke on the sieve of the secondary sieve 15 temporarily increases due to the particle size of the supplied coke being increased. The buffer to adjust.

Thus, the powder coke crushing equipment 100 is an open circuit in which a sieve and a crusher are arranged in two stages.
Therefore, even when the particle size distribution of the supplied powder coke changes, the particle size of the powder coke supplied to the sintering machine can be made uniform following the change.

  For example, the coke supplied to the sintering machine and mixed can have a ratio of powder having a particle size of more than 0.5 mm and less than 3 mm of 45% or more.

  Next, the powder coke crushing method using the powder coke crushing equipment 100 will be briefly described.

First, the powder coke is sieved with the primary sieve 11, and the coke under the sieve is supplied to the sintering machine (first step).
Next, the coke on the sieve of the primary sieve 11 is crushed by the primary crusher 13 (second step).
Next, the coke crushed by the primary crusher 13 is sieved by the secondary sieve 15, and the coke under the sieve is supplied to the sintering machine (third step).
Next, the coke on the sieve of the secondary sieve 15 is crushed by the secondary crusher 17 and supplied to the sintering machine (fourth step).

  The coke supplied to and mixed with the sintering machine in the first step, the third step, and the fourth step has a ratio of powder having a particle size of more than 0.5 mm and less than 3 mm of 45% or more. Is preferred.

  The above is the description of the powder coke crushing method using the powder coke crushing facility 100.

  Hereinafter, based on an Example, this invention is demonstrated concretely. However, the present invention is not limited to the examples and the embodiments. It is natural for those skilled in the art to come up with various modifications and improvements within the scope of the present invention, and these are also included in the present invention.

[Example 1]
First, powder coke was crushed using the powder coke crushing equipment 100 shown in FIG. 5, and the particle size distribution of the powder coke after crushing was evaluated. The specific procedure is as follows.
First, as the coke to be supplied to the powder coke crushing facility 100, one having the following particle size distribution was prepared.
Particle size distribution:
Particle size 0.5 mm or less: 20%
Particle size greater than 0.5mm and less than 3mm: 50%
Particle size 3mm or more: 30%

Next, this coke was supplied to the powder coke crushing equipment 100. Conditions for each component are as follows.
Primary sieve 11: sieve mesh 5 mm × 30 mm
Primary crusher 13: Double roll crusher Secondary sieve 15: Mesh size 5mm x 30mm
Secondary crusher 17: Rod mill

[Comparative example]
Moreover, the powder coke crushing equipment 101 shown in FIG. 6 was prepared as a comparative example, and the same coke as the Example was supplied.
The powder coke crushing equipment 101 is configured to have only the primary sieve 11 and the secondary crusher 17 (rod mill) in the powder coke crushing equipment 100.
Specifically, the powder coke crushing facility 101 sifts coke and supplies a primary sieve 11 that supplies coke under the sieve to the sintering machine, and a secondary crusher 17 that crushes the coke on the sieve of the primary sieve 11 ( Only rod mill).
The conditions of the primary sieve 11 and the secondary crusher 17 of the powder coke crushing equipment 101 are the same as those of the powder coke crushing equipment 100.

FIG. 7 shows the particle size distribution of the ground coke after crushing in Examples and Comparative Examples.
The proportion of the particle size of the powder coke having a particle size of more than 0.5 mm and less than 3 mm was larger in the example than in the comparative example. Moreover, the ratio of the powder coke of the particle size of 0.5 mm or less of an excessive grinding | pulverization was less in the Example than the comparative example.

[Example 2]
Next, using the powder coke crushed using the crushing equipment of Example 1 and the comparative example, sintering is performed using an actual machine 600 m ² sinter, and the particle size of the powder coke having a particle size of more than 0.5 mm and less than 3 mm is obtained. The relationship between grain size ratio and corrected yield was compared.
The yield of the sintering machine is shown in FIG.
As shown in FIG. 8, the yield was higher in the case where the ratio of the particle size of the powder coke having a particle diameter of more than 0.5 mm and less than 3 mm was larger (Example) than in the case where the ratio was smaller (Comparative Example).
From the above results, by crushing the powder coke using the powder coke crushing equipment 100, it is possible to increase the proportion of the particle size of the powder coke having a particle size of more than 0.5 mm and less than 3 mm compared to the conventional method. It turns out that the yield of the result improves.

[Example 3]
Next, in order to investigate the influence on the particle size distribution of the crushed powder coke due to the difference in the pulverizer, pulverized coke with a particle size of 3 mm or more is crushed with a rod mill, impact crusher, hammer crusher and double roll crusher, respectively. The particle size distribution was evaluated.
The results are shown in FIG.
As shown in FIG. 9, the double roll crusher had a larger proportion of the particle size of the powdered coke having a particle size of more than 0.5 mm and less than 3 mm compared to other crushers.

In addition, for each crusher, the amount of decrease in the ratio of the powder coke having a particle size of 3 mm or more after crushing to the amount before the crushing and the amount of increase in the ratio of the powder coke having a particle size of 0.5 mm or less in comparison with that before the crushing A graph of the relationship is shown in FIG.
The way of viewing FIG. 10 will be briefly described.
FIG. 10 shows how much the powder coke of fine powder (here, particle size 0.5 mm or less) increases when the powder coke having a large particle size (here particle size 3 mm or more) is reduced by crushing. For example, as it goes to the lower right of the graph, it means that the increase of fine powder due to crushing is suppressed, and as it goes to the upper left, it means that the increase of fine powder due to crushing is more remarkable.
Referring to FIG. 10, the powder coke pulverized using the double roll crusher had more values plotted on the lower right than the powder coke pulverized using other crushers. Therefore, it was found that when powder coke was pulverized using a double roll crusher, fine powder was less likely to be generated than when other crushers were used.

  From the above results, when a double roll crusher is used as a crusher, the proportion of the particle size of the powder coke with a particle size of more than 0.5 mm and less than 3 mm is larger than when other crushers are used, and fine powder is It turned out that it is hard to generate. Therefore, it turned out that it is more desirable to use a double roll crusher as a crusher.

  DESCRIPTION OF SYMBOLS 11 ... Primary sieve, 13 ... Primary crusher, 15 ... Secondary sieve, 17 ... Secondary crusher, 19 ... Intermediate hopper, 100 ... Powder coke crushing equipment, 101 ... Powder coke crushing equipment

Claims (9)

Sieving the coke and supplying the primary coke to the sintering machine;
A primary crusher for crushing coke on the sieve of the primary sieve;
Sieving the coke crushed by the primary crusher, a secondary sieve that supplies the coke under the sieve to the sintering machine, and
A secondary crusher that crushes the coke on the sieve of the secondary sieve and supplies it to the sintering machine;
A powder coke crushing facility characterized by comprising:   The ground coke crushing equipment according to claim 1, wherein the primary crusher is a double roll crusher.   The coke crushing equipment according to claim 1 or 2, wherein the secondary crusher is a rod mill.   4. The intermediate hopper according to claim 1, further comprising an intermediate hopper that temporarily stores coke on the sieve of the secondary sieve and supplies the stored coke to the secondary crusher. The powder coke crushing equipment as described in the item. A first step of sieving the coke with a primary sieve and feeding the coke under the sieve to the sintering machine;
A second step of crushing the coke on the sieve of the primary sieve with a primary crusher;
Sieving the coke crushed by the primary crusher with a secondary sieve, and supplying the coke under the sieve to the sintering machine; and
A fourth step of crushing the coke on the sieve of the secondary sieve with a secondary crusher and supplying it to the sintering machine;
A method for crushing powder coke, comprising:   The method of claim 5, wherein the second step is a step of crushing coke on the sieve of the primary sieve with a double roll crusher.   The method according to claim 5 or 6, wherein the fourth step is a step of crushing coke on the sieve of the secondary sieve with a rod mill. The third step includes
Coke crushed by the primary crusher is sieved with the secondary sieve, and the coke under the sieve is supplied to the sintering machine,
The coke on the sieve is temporarily stored, and the stored coke is supplied to the secondary crusher. The powder coke according to any one of claims 5 to 7, Crushing method.   The coke supplied to and mixed with the sintering machine in the first step, the third step, and the fourth step has a ratio of powder having a particle size of more than 0.5 mm and less than 3 mm of 45%. The method for crushing coke breeze according to any one of claims 5 to 8, wherein the method is as described above.

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