JP7216338B2 - coke production method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing coke by dry distillation of blended coal containing coal briquette.

As a raw material for coke oven charging, instead of making briquette coal by adding a binder to dried coal or preheated coal, compacted dried coal or preheated coal to a predetermined size is coated with an organic polymer thin film. Charcoal is known (see, for example, Patent Document 1).

By eliminating the binder, it is possible to reduce problems in coke oven operation such as tar leakage from the oven lid.

JP-A-62-41286

In the method of coating coal briquette using an organic polymer material such as a phenolic resin liquid in Patent Document 1, there is concern that the strength of briquette coal is not sufficient because no binder is added.

For this reason, there is a risk that cracks will be generated in the briquettes due to impact (dropping impact) during transportation, and fine powder generated from the briquettes will increase. Therefore, when carbonized in a coke oven, the thickness of carbon deposits may increase. Here, if the strength of the briquettes can be increased, the formation of cracks in the briquettes can be suppressed, and an increase in the thickness of carbon deposits can be suppressed. Further, if the strength of the briquette can be increased, the amount of fine powder generated from the briquette can be suppressed, so that the amount of the organic polymeric material used can be reduced.

Therefore, the object of the present invention is to provide a method for increasing the strength of coal briquette without substantially adding a binder when producing coke using briquette coal coated with an organic polymer material. .

In order to solve the above problems, the coke production method of the present invention includes: (1) adding a first added coal containing ultrafine coal and/or a second added coal containing coarse coal to dry coal or preheated coal; By adding and mixing, mixed coal that satisfies predetermined conditions is manufactured, and coke is manufactured by using coal briquettes obtained by coating the mixed coal with an organic polymer material as part of the blended coal, and the predetermined conditions are: The total content of ultrafine coal is 1.5% by mass or more and 5.0% by mass or less and/or coarse coal with respect to dry coal or preheated coal excluding ultrafine coal and/or coarse coal is 3.0% by mass or more and 10.0% by mass or less as an external number.

(2) The content of ultrafine coal contained in the dried coal or preheated coal is measured in advance, and the first additive coal is added based on the difference between the measured value and the total content of the ultrafine coal. The method for producing coke according to (1) above, wherein the amount is determined.

(3) The method for producing coke according to (1) or (2) above, wherein the ultrafine coal has a particle size of 0.01 mm or less.

(4) The content of coarse-grained coal contained in the dried coal or preheated coal is measured in advance, and the second additive coal is added based on the difference between the measured value and the total content of the coarse-grained coal. The method for producing coke according to (1) above, wherein the amount is determined.

(5) The method for producing coke according to (1) or (4) above, wherein the coarse-grained coal has a particle size of 6 mm or more.

(6) The first added coal contains 70% by mass or more of ultrafine coal with a particle size of 0.01 mm or less, and the second added coal contains 70% by mass of coarse coal with a particle size of 6 mm or more. The method for producing coke according to any one of the above (1) to (5), comprising the above.

(7) Solid pitch is added and mixed with the first additive coal and/or the second additive coal, and the amount of the solid pitch added is dry coal excluding the ultrafine coal and/or coarse coal Alternatively, the method for producing coke according to any one of the above (1) to (6), wherein the coke is 2% by mass or less with respect to the preheated coal.

According to the present invention, by increasing the strength of the briquette, it is possible to suppress an increase in the thickness of carbon deposits and to reduce the amount of the organic polymer material used.

FIG. 1(a) is a diagram schematically showing a particle group such as dry coal, and FIG. 1(b) is a diagram schematically showing a state in which ultrafine coal is added to the particle group such as dry coal. Yes (first embodiment). 1 is a block diagram for explaining a coke manufacturing process (first embodiment); FIG. FIG. 4 is a block diagram for explaining a coke production process (second embodiment). FIG. 10 is a block diagram for explaining a coke production process (third embodiment).

(First embodiment)
The inventors of the present invention have found that when dry coal or preheated coal (hereinafter referred to as "dried coal, etc." unless otherwise specified) is made into briquettes, the addition of ultra-fine coal improves the briquette properties, resulting in briquettes. It was found that the apparent density and drop strength index of FIG. 1(a) is a diagram schematically showing a group of particles such as dry coal. FIG. 1(b) is a diagram schematically showing a state in which ultrafine coal is added to a group of particles such as dry coal. In this specification, coal particles with a particle size of 0.01 mm or less are defined as ultrafine coal.

With reference to these figures, when ultra-fine coal is not added to dried coal, etc., the voids formed between particles of dried coal, etc., are large, so cracks and the like occur during molding, resulting in poor moldability. exacerbate On the other hand, when ultra-fine coal is added to dry coal or the like, the ultra-fine coal enters voids formed between particles of dry coal or the like, and the porosity decreases. Therefore, it is considered that the ultrafine coal particles that have entered the voids function as a so-called binder, improving the moldability.

Therefore, when comparing briquettes of the same size, briquettes to which ultrafine coal is added can have higher apparent density and drop strength index than briquettes to which ultrafine coal is not added. When the drop strength index is high, the briquette is less likely to break when it receives a drop impact during transportation, so an increase in the amount of fine powder generated can be suppressed, and an increase in the thickness of carbon deposits in the coke oven can be suppressed. . In addition, since the amount of the organic polymer material used to cover the briquette can be reduced, the cost can be reduced.

In addition, by improving the formability, compared to conventional briquettes (briquettes produced by the method described in Patent Document 1), the apparent density and drop strength index of briquettes are almost maintained. Can be increased in size. The reason for this is not clear, but because coal briquettes are obtained by compacting and agglomerating pulverized coal, as the size of the coal briquettes increases, the central part of the coal briquettes has a smaller compaction ratio than the outer part. Since the apparent density of the central part of the coal briquette is increased, cracks are less likely to occur in the central part where the compaction ratio is small, and it is thought that the drop strength index is almost maintained.
Thus, coke strength can be improved by increasing the size of coal briquettes. The reason is as follows.
(1) The organic polymeric material itself does not greatly affect coke strength, but if the organic polymeric material is present on the surface of the coal, there is a risk that the adhesion between the coal particles will be impaired. That is, since the organic polymer material present on the surface of the coal is thermally decomposed and disappeared before the coal softens and melts, minute gaps are formed between adjacent coal particles, and the distance between the coal particles is large. Become. Therefore, by reducing the amount of the organic polymer material, the gap formed when the organic polymer material disappears can be made smaller, so the coke strength is improved. That is, when compared with the same mass, the larger the size of the coal briquette, the smaller the surface area, and the amount of the organic polymer material used is reduced, so that the coke strength can be improved as a result.
(2) In addition, since large coal briquettes can also be increased, as a result, the particle size distribution of the blended coal 17 charged into the coke oven 18 can be broadened, and the bulk density of the coal in the coke oven can be increased. Thereby, coke strength can be improved.

A method for producing coke, which is an embodiment of the present invention, will be described with reference to the block diagram of FIG. The drying device 2 dries the raw material coal 1 and adjusts the humidity so that the water content is 5% by mass or more, for example. The raw material coal 1 is pulverized coal, and the brand is not particularly limited.

By drying the raw material coal 1, the productivity of the coke oven can be improved. However, when the water content is less than 5% by mass, the amount of dust generated from the raw material coal 1 increases rapidly, which may lead to the generation of carryover coal. Therefore, the preferable humidity control limit (lower limit) of the raw material coal 1 is 5% by mass.

A portion 3 of the conditioned coal is sent to a preheating or drying device 5 and the remainder 4 of the conditioned coal is sent to a second mixer 16 . A part of the moisture-conditioned coal 3 is heated in the preheating or drying device 5 to produce dried coal 6 having a moisture content of 5% by mass or less.

Here, the dried coal 6 often contains about 0.3 to 1.0% by mass of ultrafine coal with a particle size of 0.01 mm or less. The content of ultrafine coal contained in the dried coal 6 can be examined by a laser diffraction method or the like. Therefore, before the dried coal 6 is sent to the first mixer 7, the content of ultra-fine coal contained in the dried coal 6 is checked in advance by a laser diffraction method or the like. The addition amount of the added coal 9a (corresponding to the first added coal) can be determined from the difference from the target total content of ultrafine coal of 01 mm or less. Details on this point will be described later. Note that the dried coal 6 may contain a small amount of coarse-grained coal having a particle size of 6 mm or more.

The dried coal 6 is sent to the first mixer 7 and mixed with the added coal 9a supplied from the ultrafine coal hopper 8a. The first mixer 7 may be of any type as long as it is a mixer that can be used industrially. Gemixer or the like can be used. As shown in the schematic diagram of FIG. 1(b), the ultrafine coal mixed with the dried coal 6 enters the voids formed between the particles of the dried coal 6, so the porosity of the mixed coal 10 is can be lowered.

The additive coal 9a preferably contains 70% by mass or more of ultrafine coal with a particle size of 0.01 mm or less. can be manufactured. Here, it is difficult in view of the performance of the crusher to crush all the coal to be crushed by the ultra-fine coal crusher to a particle size of 0.01 mm or less. Therefore, it is preferable that the added coal 9a is produced by adjusting the operating conditions (rotation speed, etc.) of the ultra-fine coal pulverizer so that the ultra-fine coal with a particle size of 0.01 mm or less is contained in an amount of 70% by mass or more. .

It has been experimentally confirmed that when the content of ultrafine coal in the additive coal 9a is less than 70% by mass, the particle size becomes coarse, and the expected effects of ultrafine coal become difficult to be sufficiently exhibited. As the ultrafine coal pulverizer, for example, pulverizers such as ball mills and roller presses can be used.

Here, the total of ultra-fine coal with a particle size of 0.01 mm or less for dry coal etc. 6 excluding ultra-fine coal with a particle size of 0.01 mm or less and / or coarse coal with a particle size of 6 mm or more The addition amount of the additive coal 9a supplied from the ultra-fine coal hopper 8a is adjusted so that the content is the target total content selected from the range of 1.5% by mass or more and 5.0% by mass or less as an external number. be done. That is, the added amount of the added coal 9a is adjusted so that the mixed coal 10 satisfies the above-described target total content.
Here, "dry coal 6 excluding ultrafine coal having a particle size of 0.01 mm or less and/or coarse coal having a particle size of 6 mm or more" refers to ultrafine coal among ultrafine coal and coarse coal When only dry coal, etc. 6 is included in dry coal, etc. 6, it means dry coal, etc. 6 excluding ultra-fine coal, and only coarse-grained coal among ultra-fine coal and coarse-grained coal is included in dry coal, etc. 6. 6 means dried coal, etc. excluding coarse-grained coal, and if both ultra-fine coal and coarse-grained coal are included in dried coal, etc. 6, ultra-fine coal and coarse-grained coal means dry coal etc. 6 excluding, and when dry coal etc. 6 contains neither ultrafine coal nor coarse coal, it means dry coal etc. 6 (in other embodiments and modifications is also the same). Since the dried coal etc. 6 contains ultra-fine coal, and the added coal 9a stored in the ultra-fine coal hopper 8a also contains coal particles with a particle size of more than 0.01 mm, these points are taken into consideration. Meanwhile, the addition amount of the additive coal 9a is adjusted so that the total content of the ultrafine coal contained in the mixed coal 10 satisfies the target total content.

If the total content of the ultrafine coal is less than 1.5% by mass, the binder effect of the ultrafine coal cannot be obtained, and the moldability is not improved. For this reason, the apparent density and drop strength index of the coal briquette 14 cannot be increased, resulting in an increase in the thickness of carbon deposits.

If the total content of ultrafine coal exceeds 5.0% by mass, the ultrafine coal becomes excessive and moldability deteriorates. Moreover, the ultra-fine coal that did not contribute to the molding is not molded and dust is generated.

In addition, when the dry coal 6 does not contain ultra-fine coal (including cases where the amount is negligible), the ultra-fine coal in the mixed coal 10 satisfies the target total content with only the added coal 9a. The amount to be added can be adjusted accordingly.

The mixed coal 10 produced in the first mixer 7 is sent to the compression molding machine 11 . The compression molding machine 11 may be of any type as long as it is an industrially usable molding machine. For example, it may be a briquette machine, a roll compactor, a double roll molding machine, or an extruder. The size of the coal briquette 14 is preferably 50 cm ³ or more, more preferably 60 cm ³ or more.

Here, the size of the coal briquette produced by the method described in Patent Document 1 is 43.0 g per 50 g and the apparent density is 1.03 to 1.14 (g/cm ³ ). It is 9 to 48.5 cm ³ , and this size has been normal in the past. ^On the other hand, in the present embodiment, by adding ultrafine coal particles, the formability is improved. The index does not drop significantly.

The organic polymer material 13 stored in the organic polymer material tank 12 is sprayed onto the surface of the compression molding machine 11 that comes into contact with the mixed coal 10 . Therefore, when molding coal briquette 14 in compression molding machine 11 , the surface of mixed coal 10 can be covered with organic polymer material 13 . As the organic polymer material, polyethylene, polyvinyl chloride, nylon, phenolic resin, paraffins, etc. can be used.

Here, in the present embodiment, since the drop strength index of the briquettes can be increased, the formation of cracks in the briquettes due to the impact (dropping impact) during transportation is suppressed, and the generation of fine powder is suppressed, so coke It is possible to suppress an increase in the carbon deposit thickness when carbonized in a furnace.
In addition, by suppressing the formation of cracks in the coal briquette, the amount of the organic polymer material 13 sprayed can be reduced. Furthermore, since the size of the coal briquette 14 can be made larger than the conventional size, the amount of spraying of the organic polymer material 13 can be reduced. This can reduce costs.
In addition, by reducing the amount of the organic polymer material 13, the gaps between the coal particles formed by the disappearance of the organic polymer material 13 during the dry distillation can be reduced, so the coke strength can be improved.

The charcoal briquette 14 obtained in the compression molding machine 11 is hardened by being heated by the hardening treatment device 15 . The hardening treatment device 15 may be, for example, a device that heats the coal briquette 14 placed on the net conveyor with hot air.

The coal briquette 14 hardened by the hardening treatment device 15 is mixed with the remainder 4 of the moisture-conditioned coal in the second mixer 16 to form blended coal 17 , which is carbonized in the coke oven 18 .

(Second embodiment)
The present inventors have found that when dry coal or the like is made into briquettes, adding coarse-grained coal together with ultra-fine coal can further improve the apparent density and drop strength index of briquettes. In this specification, coal with a particle size of 6 mm or more is defined as coarse coal. Although the upper limit of the grain size of coarse coal is not particularly limited, it is preferably 15 mm. Coarse coal should just have the property of the general raw material coal used for coke manufacture. Specifically, VM (volatile matter), which is a volatile matter, is 20 to 35% by mass, and the total expansion rate, which is an indicator of caking property (JIS M 8801 Total expansion measured by the expansion test method rate) is 20% or more.

By adding coarse-grained coal to dry coal or the like, the particle size distribution becomes broader, so that the apparent density and drop strength index of the coal briquette can be improved. By increasing the drop strength index, the briquette is less likely to crack when subjected to a drop impact during transportation, and an increase in the amount of fine powder generated can be suppressed. In addition, since the addition amount of the organic polymer material covering the briquettes can be reduced while preventing an increase in the carbon adhesion thickness in the coke oven, costs can be reduced.

A method for producing coke according to the present embodiment will be described with reference to the block diagram of FIG. However, detailed description of the steps common to the first embodiment is omitted. The added coal 9b (corresponding to the second added coal) containing coarse-grained coal can be obtained by setting the pulverized coal particle size to 3 mm or less and 70 to 90% by mass, and sieving the pulverized coal. For example, when the raw material coal 1 is obtained, the crushed particle size is set to 70 to 90% by mass of 3 mm or less, and sieving is performed to obtain the added coal 9b containing coarse coal. It is desirable that the added coal 9b contains 70% by mass or more of coarse coal having a particle size of 6 mm or more.

The added coal 9b is stored in the coarse-grain coal storage hopper 8b and supplied to the first mixer 7 . The added coal 9b supplied to the first mixer 7 is mixed with the dry coal etc. 6 and the added coal 9a. That is, in the first mixer 7, the dry coal or the like 6, ultrafine coal and coarse coal are mixed.

Here, the total content of ultra-fine coal is 1.0% in terms of dry coal, etc. 6 excluding ultra-fine coal with a particle size of 0.01 mm or less and/or coarse coal with a particle size of 6 mm or more. Addition of additive coals 9a and 9b so that the content of coarse coal is 5% by mass or more and 5.0% by mass or less, and the content of coarse coal is 3.0% by mass or more and 10.0% or less by mass. Amount is determined. The dry coal or the like 6 before being sent to the first mixer 7 usually contains 0.5 to 3% by mass of coarse coal. Therefore, the content of coarse-grained coal contained in the dried coal, etc. 6 is checked in advance before the dried coal, etc. 6 is sent to the first mixer 7, and the difference between this content and the target total content of coarse-grained coal is determined. It is desirable to determine the addition amount of the additive coal 9b from the difference. The content of coarse-grained coal contained in the dried coal 6 can be examined by a laser diffraction method or the like.

Here, if the content of coarse-grained coal is less than 3.0% by mass as an external number, the effect of broadening the particle size distribution cannot be enjoyed, so the apparent density and drop strength index of the coal briquette cannot be improved. If the content of coarse-grained coal exceeds 10.0% by mass as an external number, the particle size distribution will be such that there is too much coarse-grained coal, and the packing density will decrease. Can not.

However, when the dry coal 6 does not contain coarse-grained coal (including cases where the amount is negligible), the coarse-grained coal in the mixed coal 10 satisfies the target total content with only the added coal 9b. The amount to be added can be adjusted accordingly.

The processes after the first mixer 7 are the same as those in the first embodiment, so description thereof will be omitted.

(Modification of Second Embodiment)
In the second embodiment, ultrafine coal and coarse coal are added as additive coal, but the present invention is not limited to this, and only coarse coal may be added. Even if only coarse coal is added, the effect of broadening the particle size distribution can be obtained, so that the apparent density and drop strength index of the coal briquette can be increased. The amount of coarse-grained coal to be added is the same as in the second embodiment, so a detailed description is omitted.

(Third Embodiment)
A small amount of solid pitch may be added together with ultrafine coal if the impact (dropping impact) during transportation is large when making briquettes from dry coal or the like. As a result, the briquette drop strength index increases, so even if the impact (dropping impact) during transportation is large, the formation of cracks in the briquette is suppressed and the generation of fine powder is suppressed. It is possible to suppress the increase in the carbon adhesion thickness at the time. In addition, by suppressing the formation of cracks in the coal briquette, the amount of organic polymer material used can be reduced.
As the solid pitch, solid pitch that is in a solid state at room temperature, such as hard pitch (coal-based pitch) and petroleum heavy residue (for example, ASP), can be used.
The solid pitch has plasticity and has the effect of penetrating into minute gaps caused by unevenness of the contact surface of the coal particles in the mixing process by the first mixer 7 and the molding process by the compression molding machine 11. It is believed that the strength index can be increased. In order to enhance this filling effect, the solid pitch is preferably ground. The particle size of the solid pitch is preferably 1 mm or less.

A method for producing coke according to the present embodiment will be described with reference to the block diagram of FIG. However, detailed description of the steps common to the first embodiment is omitted. Solid pitch is stored in a solid pitch storage hopper 8 c and supplied to the first mixer 7 . The solid pitch 9c supplied to the first mixer 7 is mixed with the dry coal etc. 6 and the added coal 9a.

Here, the total content of ultra-fine coal is 1.00 mm with respect to dry coal 6 excluding ultra-fine coal with a particle size of 0.01 mm or less and/or coarse coal with a particle size of 6 mm or more. It is 5 mass % or more and 5.0 mass % or less. In addition, the amount of solid pitch 9c added is 2% by mass or less (external number) is preferred. If the amount of the solid pitch 9c added exceeds 2% by mass, the solid pitch may ooze out and adhere to the briquettes, or the strength of the briquettes may decrease.

The method of treating the mixed coal 10 obtained by the first mixer 7 is the same as in the first embodiment, so the explanation is omitted.

(Modified example of the third embodiment)
In the third embodiment, ultrafine coal and solid pitch are added to dry coal or the like 6, but the present invention is not limited to this, and the coarse coal of the second embodiment is added together with ultrafine coal and solid pitch. may Alternatively, coarse coal and solid pitch may be added to dry coal 6 without adding ultrafine coal. The effects of adding ultrafine coal, coarse coal, and solid pitch will be omitted because they are redundant.

(Example)
EXAMPLES The present invention will be described more specifically with reference to examples.
As shown in the block diagrams of FIGS. 3 and 4, the raw coal 1 was first dried in a drying device 2 so that the water content was 5% by mass or more. The raw coal dried by the drying device 2 is called moisture-conditioned coal. A portion 3 of the moisture-conditioned coal was heated in a drying device 5 to obtain dried coal 6 having a moisture content of less than 5% by mass. Dry coal 6 was mixed with ultrafine coal and/or coarse coal and solid pitch in a first mixer 7 to obtain mixed coal 10 . The mixed charcoal 10 was molded by a compression molding machine 11, and its surface was coated with an organic polymer material. This is called coal briquette 14 . A mixture of the coal briquette 14 and the remainder 4 of the moisture-conditioned coal was called blended coal 17, and the blended coal 17 was charged into a coke oven.
Various samples shown in Table 1 were evaluated for effects on the apparent density of coal briquette, drop strength index, carbon deposit thickness in a coke oven, coke strength (DI ¹⁵⁰ ₁₅ ), and the like.
The carbon deposit thickness was obtained by suspending a brick sample in the coke oven top space immediately after charging coal, collecting the brick sample after coke extrusion, and actually measuring the thickness of carbon deposited on the brick surface.
In addition, the blending ratio (mass basis) of the remainder 4 of the moisture-conditioned coal and the dry coal 6 (excluding ultra-fine coal with a particle size of 0.01 mm or less and/or coarse coal with a particle size of 6 mm or more) is The ratio was 7:3. In this embodiment, dry coal excluding ultra-fine coal with a particle size of 0.01 mm or less and/or coarse coal with a particle size of 6 mm or more may be referred to as medium-grain dry coal for convenience.
The dry coal 6 before the addition of the ultrafine coal contained 0.5% by mass of ultrafine coal with a particle size of 0.01 mm or less. The dry coal 6 before addition of coarse coal contained 2.0% by mass of coarse coal having a particle size of 6 mm or more.
The drop strength index ( _SI25 ) is an index indicating the strength against drop impact described in JIS K 2151, and after dropping coal briquettes under the conditions specified in JIS K 2151, , and the yield on the sieve at this time is used as the drop strength index. A hard pitch was used for the solid pitch. Phenol resin was used as the organic polymer material.
The total content of ultrafine coal was expressed as an extra number relative to medium-grain dry coal. Similarly, the total content of coarse coal and the amount of solid pitch added were also expressed in terms of the medium dry coal.

In Reference Example, Comparative Example 1 and Comparative Example 2, ultrafine coal, coarse coal and solid pitch were not added. When no ultrafine coal was added, the apparent density and drop strength index decreased as the size of the coal briquettes increased. Therefore, the carbon adhesion thickness increased.
In Comparative Example 3, 6% by mass of ultrafine coal was added to make the total content of ultrafine coal 6.5% by mass. Since the total content of ultrafine coal was excessive, the briquette apparent density and the briquette drop strength index were lower than those of Inventive Examples 3 and 4. In addition, the thickness of the carbon deposit increased. In addition, the charged bulk density decreased and the coke strength decreased.

Incidentally, the charged bulk density is affected by the briquette size and briquette apparent density. That is, the larger the briquette size and the larger the briquette apparent density, the higher the charged bulk density. Also, the higher the bulk density of the charge, the higher the coke strength. Therefore, in Comparative Example 3, although the briquette size was the same as that of Invention Examples 3 and 4, the briquette apparent density was lowered, so the charged bulk density was lowered from 790 kg/m ³ to 750 kg/m ³ and the coke strength was reduced. decreased.

In Examples 1 to 4, ultrafine coal is added so that the total content of ultrafine coal is 1.5% by mass or 4.5% by mass. By comparing Invention Examples 1 and 2 (only ultrafine coal is added) with Comparative Example 1, the addition of ultrafine coal improves the apparent density and drop strength index of briquettes, and improves the organic polymer material. Although the amount used was the same, the carbon adhesion thickness was reduced and the coke strength was improved. Similar results were obtained from the comparison of Inventive Examples 3 and 4 (only ultrafine coal was added) and Comparative Example 2. In addition, as compared with Comparative Example 1, in Inventive Example 1, although the briquette size was the same, the charged bulk density increased from 750 kg/m ³ to 780 kg/m ³ due to the increased apparent density of the briquette. Further, when comparing Inventive Example 2 and Inventive Example 4, although the apparent densities of the briquettes were the same, the charging bulk density increased from 780 kg/m ³ to 790 kg/m ³ due to the increased briquette size.

In addition, compared to Invention Examples 1 and 2, Invention Examples 3 and 4 increased the size of the briquettes, but as in Comparative Examples 1 and 2, the apparent density and drop strength index of the briquettes did not decrease significantly. I didn't. In addition, the amount of organic polymer materials used was reduced by increasing the size of the coal briquette. As a result, it was possible to improve the coke strength while suppressing an excessive increase in the carbon deposit thickness.

In Invention Examples 5 and 6, the amount of the organic polymer material used was reduced compared to Invention Examples 3 and 4, respectively, so that the thickness of carbon adhesion increased, but the thickness of carbon adhesion was the same as in Comparative Example 2. Compared to , the amount of organic polymer materials used was reduced.

By comparing Inventive Example 7 and Comparative Example 2, increasing the total content of coarse coal to 6% by mass improved the apparent density and drop strength index of the coal briquette. In addition, it was found that by increasing the proportion of coarse-grained coal, it is possible to maintain the same carbon deposition thickness while reducing the amount of organic polymer used.

Invention Example 8 is an example in which the total content of coarse coal was increased to 3.5% by mass by increasing the amount of coarse coal compared to Invention Example 4, and the apparent density and drop strength index of the coal briquette increased. Further, in Invention Example 8, although the amount of the organic polymer material used was the same as in Invention Example 4, the thickness of carbon adhesion was reduced.

Inventive Example 9 is an example in which the amount of the organic polymer material used was reduced compared to Inventive Example 8, and although the apparent density and drop strength index of the briquette were the same, the thickness of the carbon deposit increased. By comparing Inventive Example 9 and Comparative Example 2, the apparent density and drop strength index of coal briquettes were improved by increasing the proportions of ultrafine coal and coarse coal. Also, it was found that by increasing the proportions of ultrafine coal and coarse coal, it is possible to maintain the same carbon deposition thickness while reducing the amount of organic polymer used. Inventive Example 10 is an example in which the amount of coarse-grained coal is increased more than that of Inventive Example 9 and the total content of coarse-grained coal is 9.5% by mass, but the same results as in Inventive Example 9 were obtained.

Inventive Example 11 is an example in which solid pitch is added to Inventive Example 4, and the drop strength index of coal briquettes is improved. Further, in Invention Example 11, although the amount of the organic polymer material used was the same as in Invention Example 4, the thickness of carbon adhesion was reduced.
In Invention Example 12, the amount of organic polymer material used was reduced compared to Invention Example 11, so the carbon adhesion thickness increased. quantity has been reduced.

1 Raw coal 2 Drying device 3 Part of moisture-conditioned coal 4 Remainder of moisture-conditioned coal 5 Drying or preheating device 6 Dry coal, etc. 7 First mixer 8a Ultra-fine coal hopper 8b Coarse coal hopper 8c Solid pitch hopper 9a 9b Addition Charcoal 9c Solid pitch 10 Mixed charcoal 11 Compression molding machine 12 Organic polymeric material tank 13 Organic polymeric material 14 Briquette charcoal 15 Curing treatment device 16 Second mixer 17 Blended charcoal 18 Coke oven

Claims (6)

By adding and mixing a first additive coal containing ultrafine coal and/or a second additive coal containing coarse coal to dry coal or preheated coal, mixed coal satisfying predetermined conditions is produced. Coke is manufactured by using briquette coal, which is a blended charcoal coated with an organic polymer material, as part of the blended charcoal,
The first added coal contains 70% by mass or more of ultrafine coal with a particle size of 0.01 mm or less, and the second added coal contains 70% by mass or more of coarse coal with a particle size of 6 mm or more. cage,
The predetermined condition is that the total content of ultrafine coal is 1.5% by mass or more and 5.0% by mass or less with respect to dry coal or preheated coal excluding ultrafine coal and/or coarse coal. and/or a method for producing coke, wherein the total content of coarse-grained coal is 3.0% by mass or more and 10.0% by mass or less. The content of ultrafine coal contained in the dried coal or preheated coal is measured in advance, and the addition amount of the first additive coal is determined based on the difference between this measured value and the total content of the ultrafine coal. The method for producing coke according to claim 1, characterized in that: 3. The method for producing coke according to claim 1, wherein the ultrafine coal contained in the dried coal or preheated coal has a particle size of 0.01 mm or less. The content of coarse-grained coal contained in the dried coal or preheated coal is measured in advance, and the addition amount of the second additive coal is determined based on the difference between this measured value and the total content of the coarse-grained coal. The method for producing coke according to claim 1, characterized in that: 5. The method for producing coke according to claim 1 or 4, wherein the coarse coal contained in the dried coal or preheated coal has a particle size of 6 mm or more. adding and mixing solid pitch with the first added coal and/or the second added coal;
6. Among claims 1 to 5 , wherein the amount of the solid pitch added is 2% by mass or less with respect to the dry coal or preheated coal excluding the ultrafine coal and/or coarse coal A method for producing coke according to any one of the above.

Images