JP6720827B2 - Carbon material for producing coke, method for producing the same, and method for producing coke - Google Patents

Description

TECHNICAL FIELD The present invention relates to a carbon material for coke production for producing coke by adding it to coal to be carbonized.

Coke used for blast furnace operation is required to have required strength and particle size in order to ensure air permeability in the blast furnace. Such coke is produced by crushing and blending various types of coal, charging the coke into a coke oven, and dry-distilling in the oven. By using good quality coal as the coal for producing coke, coke having sufficient strength can be produced, but good quality coal is in a resource depleted state. On the other hand, inferior coal has a large reserve, and it is desired to produce coke having sufficient strength by using inferior coal.

The strength of the coke is related to the crack of the coke, and it is necessary to suppress the crack of the coke in order to obtain the coke having a sufficient strength. Such coke cracks are said to occur due to the shrinkage of coal during the coal carbonization process.

The change in the coke shrinkage coefficient with respect to the heating temperature (shrinkage coefficient curve) in the carbonization process of coal includes a primary peak (maximum) due to primary shrinkage and a secondary peak (maximum) due to secondary shrinkage. The first peak is a peak caused by shrinkage that occurs when coal softens and melts in a temperature range of about 400 to 500° C. and then solidifies, and the second peak shrinks when dehydrogenating at about 700° C. Is the peak.

The primary shrinkage depends on the type of coal, and inferior coal with a high volatile content has a large primary shrinkage. Therefore, in a method of producing coke by mixing several types of coal, when poor quality coal having a high volatile content is mixed, the difference in shrinkage between coals becomes large, and microcracks are likely to occur. On the other hand, although the secondary shrinkage is almost constant regardless of the type of coal, it causes microcracks to grow.

Such cracks are suppressed, the coke grain size is expanded, and in order to obtain coke having sufficient strength, while adding a carbonaceous material such as a coke powder having a shrinkage rate smaller than that of coal at a resolidification temperature of coal, A technique is known in which bituminous substances such as pitch are added together to reinforce the adhesive strength between the carbonaceous material and the coal particles (see, for example, Patent Document 1).

JP-A-6-264069 JP-A-56-136880 JP-A-56-136881 JP-A-56-136882 JP, 07-003309, A International Publication No. 2010/087468

In the technique of adding a carbonaceous material having a shrinkage rate smaller than that of coal, cracks may not be sufficiently suppressed depending on the type of coal to be carbonized, and coke having a sufficient grain size and strength may not be obtained.
In view of such circumstances, an object of the present invention is to provide a carbon material for producing coke, which can suppress cracks and produce coke having sufficient strength and grain size.

In order to solve the above problems, the present inventors first investigated carbonaceous materials added to coal. As the carbonaceous material, char that has been preliminarily carbonized at 450 to 600° C. in order to use inferior coal as a raw material for coke production is widely known (see, for example, Patent Documents 2 to 6).

The present inventors prepared carbonaceous materials obtained by preliminary carbonization at various temperatures, added carbonaceous materials to coal, and carbonized them to investigate the relationship between the difference in carbonaceous materials and cracks. As a result, they found that cracks were suppressed in the combination of specific coal and carbonaceous material.

Therefore, in the combination coal and carbonaceous material in which cracks are suppressed, the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient and the relationship between the heating temperature during carbonization of the raw material coal and the carbonaceous material contraction coefficient are described. As a result of measurement, a peak (maximum) of the shrinkage coefficient of the carbonaceous material was present at a minimum between the first peak (maximum) and the second peak (maximum) of the coke shrinkage coefficient of coal.

In this way, with respect to the relationship between the heating temperature and the coke shrinkage coefficient during the carbonization of coal, the carbonaceous material has a relationship between the heating temperature during the carbonization of a specific raw material coal and the carbonaceous material shrinkage coefficient. It has been found that, when a mixture of coal and carbonaceous materials is subjected to carbonization, the coke shrinkage coefficient changes little and can be kept at a low level through a temperature range of 500 to 1000° C., and as a result, the occurrence of cracks can be suppressed. It was

The present invention was made based on the above findings, and the gist thereof is as follows.
(1) In the carbonaceous material for coke production, which is added to the coal when carbonizing carbon to produce coke,
The coal has a minimum coke shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal in the relationship between the heating temperature during the coal carbonization and the coke shrinkage coefficient,
The carbonaceous material has a maximum of the carbonaceous material shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal in the relationship between the heating temperature and the carbonaceous material shrinkage coefficient during carbonization of the raw material coal of the carbonaceous material, and shows the maximum. A carbonaceous material for producing coke, characterized in that the temperature is within ±30° C. of the temperature showing the minimum of the coal.

(2) A method for producing a carbonaceous material for coke production, which is added to the coal when carbonizing carbon to produce coke,
Regarding the coal, the relationship between the heating temperature and the coke shrinkage coefficient during the coal carbonization was measured, and the temperature showing the minimum of the coke shrinkage coefficient was found among the temperatures above the resolidification temperature of the coal.
At a temperature lower than the temperature showing the minimum of the coal, the raw material coal for producing the carbonaceous material is carbonized, and the carbonaceous material has a relationship between the heating temperature and the carbonaceous material shrinkage coefficient during the carbonization of the raw material coal. And having a maximum of the carbonaceous material shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal, and the temperature showing the maximum is within ±30° C. of the temperature showing the minimum of the coal. A method for producing carbonaceous material for coke production.
(3) The above-mentioned (2), characterized in that, as the raw material coal, a coal having a dry base volatile matter VM of 35 to 50% and a cohesion index CI of at least one of 20 or more is used. Method for producing carbonaceous material for coke production.
(4) The method for producing a carbon material for coke production according to the above (2) or (3), wherein a granular material or a granulated material having an average particle size of 3 mm or more is used as the raw material coal.

(5) A method for producing coke, comprising adding carbon material for producing coke to coal and carbonizing
As the coal, in the relationship between the heating temperature during the coal carbonization and the coke shrinkage coefficient, one having a minimum coke shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal,
As the carbonaceous material, in the relationship between the heating temperature and the carbonaceous material shrinkage coefficient during carbonization of the raw material coal of the carbonaceous material, the carbonaceous material shrinkage coefficient has a maximum at a temperature equal to or higher than the resolidification temperature of the coal, and exhibits the maximum. A method for producing coke, characterized in that the temperature is within ±30° C. of the temperature at which the minimum of the coal is shown.

In addition, in this invention and a specification, the coal for coke manufacture is only described as "coal", and the coal for carbon material manufacture is described as "raw material coal."

According to the present invention, the carbonaceous material for coke production has a relationship between the heating temperature during carbonization of coal and the coefficient of coke shrinkage, and the relationship between the heating temperature during carbonization of a specific raw material and the coefficient of carbonaceous material shrinkage. Therefore, cracks are suppressed, and coke having sufficient strength and grain size can be produced.

It is a figure which shows the relationship between the heating temperature at the time of dry distillation, and a shrinkage coefficient. It is a figure which shows the relationship between the heating temperature and the shrinkage coefficient at the time of carbonization of coals A and B. The relationship between the heating temperature and the shrinkage coefficient during the carbonization of coal A, No. It is a figure which shows the relationship between the heating temperature at the time of raw material coal carbonization of a carbonaceous material of 1-4, and a shrinkage coefficient.

The carbonaceous material for producing coke of the present invention (hereinafter referred to as "carbonaceous material of the present invention") is added to coal during the production of coke, and the relationship between the heating temperature during carbonization of the raw material coal and the carbonaceous material shrinkage coefficient. In, in the temperature of the coal re-solidification temperature or higher, has a maximum of the carbonaceous material shrinkage coefficient, the temperature showing the maximum, in the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient, the minimum of the coke shrinkage coefficient. It is within ±30°C of the indicated temperature.

Hereinafter, the background of the study leading to the carbonaceous material of the present invention will be described. In addition, unless otherwise specified, the blending ratio of coal and carbonaceous material, and “%” of volatile matter indicate “mass %”.

In the production of coke, the present inventors conducted the following investigation on a carbonaceous material capable of suppressing cracking and producing coke having sufficient strength and grain size. First, prepare carbonaceous materials obtained by preliminary carbonization at various temperatures, add them to one kind of coal, respectively, obtain a plurality of mixtures, and carbonize them to determine the relationship between carbonaceous materials and cracks. investigated. As a result, the crack was suppressed in the specific carbonaceous material.

Therefore, the relationship between the heating temperature and the shrinkage coefficient during carbonization was measured for coal, carbon material X with cracks suppressed, and carbon material Y with cracks. FIG. 1 shows the relationship between the heating temperature during dry distillation and the shrinkage coefficient. In FIG. 1, the solid line represents the coal, the dotted line X represents the carbon material X with cracks suppressed, and the dotted line Y represents the relationship between the heating temperature and the shrinkage coefficient during carbonization of the carbon material Y with cracks.

Regarding the relationship between the heating temperature and the coke shrinkage coefficient during the carbonization of coal, the primary peak P1 (maximum) due to the primary shrinkage that occurs when the coal softens and melts in the temperature range of about 400 to 500° C. and then solidifies, and about 700 A secondary peak (maximum) due to secondary contraction that occurred during dehydrogenation at ℃ was confirmed. In the carbonaceous material X in which cracks are suppressed and the carbonaceous material Y in which cracks are generated, the temperature is equal to or higher than the resolidification temperature of coal, specifically, the carbonaceous material X has a peak at about 570°C and the carbonaceous material Y has a peak at about 700°C. confirmed.

From this, in the carbonaceous material X in which cracks were suppressed, at the position corresponding to the minimum between the primary peak P1 and the secondary peak P2 in the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient, There was a peak of carbon material shrinkage coefficient. On the other hand, in the carbon material Y in which cracks were generated, the peak of the carbon material shrinkage coefficient was present so as to overlap with the maximum of the coke shrinkage coefficient of coal (secondary peak P2).

Then, if the temperature showing the maximum shrinkage coefficient of the carbonaceous material is made equal to the temperature showing the minimum shrinkage coefficient of the coke of the coal, the change in the coke shrinkage coefficient of the mixture of the carbonaceous material and the coal is reduced, and the cracking of the coke is suppressed. However, if the temperature showing the maximum shrinkage coefficient of the carbonaceous material is made equal to the temperature showing the maximum shrinkage coefficient of the coke of the coal, the change in the coke shrinkage coefficient of the mixture of the carbonaceous material and the coal becomes large, and the strain in the coke becomes large. It was thought that cracks would form in the coke.

Therefore, as a result of detailed study on the relationship between the temperature showing the maximum of the shrinkage coefficient of various carbon materials and the temperature showing the minimum of the coke shrinkage coefficient of coal, and the presence or absence of cracks, It was found that coke cracking can be suppressed by setting the temperature at which the maximum is within ±30° C. of the temperature at which the coke shrinkage coefficient of coal is minimum.

The present invention has reached the inventions described in (1) to (5) above through the above-described examination process, and the necessary requirements and preferable requirements of the present invention will be sequentially described. ..

The carbonaceous material of the present invention is to be added to coal during the production of coke, and in the relationship between the heating temperature and the carbonaceous material contraction coefficient at the time of raw material coal carbonization, the carbonaceous material contraction coefficient is at a temperature above the resolidification temperature of coal. Of the coke shrinkage coefficient of the coal is ±30°C.
First, the coal to which the carbonaceous material of the present invention is added will be described.

(coal)
Coal to which the carbonaceous material of the present invention is added is particularly limited as long as it has a minimum coke shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of coal in the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient. Not what is done. In the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient, this local minimum is due to the primary peak (maximum) due to primary shrinkage that occurs when coal solidifies after softening and melting, and dehydrogenation at about 700°C. It is observed during the secondary peak (maximum) due to the secondary shrinkage that occurs during thermal shrinkage, and is observed at least in the temperature range from the resolidification temperature to 1000°C.

Since the method for obtaining the relationship between the heating temperature and the coke shrinkage coefficient during coal carbonization is described in detail in JP-A-2005-232349, the method for obtaining this relationship will be briefly described below.

A thin tube is filled with a coal sample, a piston is inserted on the coal sample in the thin tube, and the temperature is raised to 1000° C. at a temperature rising rate of 3° C./min, for example. The sample length during temperature increase is measured based on the position of the piston, and the relationship between the sample length and the temperature is obtained. The length L _R of the sample at resolidification temperature, when a sample length at a temperature T and a L _T, coke shrinkage at temperature T R (-) is defined by the following equation. Then, the change in the coke shrinkage rate R per unit temperature change is taken as the coke shrinkage coefficient (−/° C.), and the relationship between the temperature and the coke shrinkage coefficient is obtained.
_{R = (L R -L T)} / L R

Further, the coal to which the carbonaceous material of the present invention is added may be plain coal composed of one brand or blended coal composed of multiple brands. However, if the blending ratio of the non-caking coal is less than 50%, the effect of suppressing the cracking of coke and improving the strength due to the blending of the carbon material is small. Therefore, the blending coal should contain 50% or more of the non-caking coal. Is preferred. Moreover, the volatile matter and particle size of coal are not particularly limited, and those having a dry base volatile matter VM of 17 to 40% and a particle size of 3 mm or less of 60% to 95% are exemplified.

(Carbon material)
The carbonaceous material of the present invention has a maximum of the carbonaceous material shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the target coal in the relationship between the heating temperature during the raw material coal carbonization and the carbonaceous material shrinkage coefficient, and the temperature showing the maximum. Is within ±30° C. of the temperature showing the minimum coke shrinkage coefficient of the coal. By the way, the method for obtaining the relationship between the heating temperature and the carbon material shrinkage coefficient during carbonization of the raw material coal is the same as the method for obtaining the relationship between the temperature and the coke shrinkage coefficient.
As shown in Examples described later, by setting the temperature showing the maximum of the shrinkage coefficient of the carbonaceous material within ±30°C of the temperature showing the minimum of the coke shrinkage coefficient of the target coal, Throughout the temperature range, there is little change in the coke shrinkage coefficient, it can be kept at a low level, and the occurrence of cracks can be suppressed.

The temperature indicating the minimum coke shrinkage coefficient of the target coal may be read from the drawing of the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient, or may be obtained by differentiating the equation of the approximate curve of the relationship.

The maximum value of the shrinkage coefficient of the carbon material is not particularly limited, and may be larger or smaller than the minimum value of the coke shrinkage coefficient of coal. Further, the shape of the peak having the maximum value of the carbon material shrinkage coefficient is not particularly limited, and may be a sharp shape or a broad shape.

In order for the carbonaceous material to exhibit the maximum shrinkage coefficient at a temperature above the resolidification temperature of such coal, it is important to leave the volatile content in the carbonaceous material, but the amount is particularly limited. Instead, it may be set appropriately within a range in which cracking of coke can be suppressed.
The cohesive strength index CI of the carbonaceous material is preferably 20 or more. When the cohesion index CI is less than 20, it is difficult to adhere to surrounding particles, and thus the strength of coke produced by carbonization with coal may be reduced.

Here, the volatile matter VM is measured by the method specified in JIS M8812. In addition, the cohesion index CI is a coal utilization technical terminology dictionary (edited by Japan Fuel Association) p. 255, 1 g of inferior coal of 0.25 mm or less is mixed with 9 g of powder coke of 0.25 to 0.30 mm, and the mixture is dry-distilled in a magnetic crucible at 950° C. for 7 minutes, and then sieved with a screen of 0.30 mm or more. It is a value expressed as a percentage of the mass remaining after sieving.

Next, a method for producing a carbon material for producing coke according to the present invention (hereinafter referred to as "method for producing carbon material according to the present invention") and a method for producing coke according to the present invention (hereinafter referred to as "method for producing coke according to the present invention") ), the necessary requirements and preferable requirements will be sequentially described.

The method for producing a carbonaceous material of the present invention is to carbonize a raw material coal for producing a carbonaceous material at a temperature lower than a temperature at which the coke shrinkage coefficient of the coal is minimal, and the carbonaceous material is a carbonaceous material at a temperature equal to or higher than the resolidification temperature of the coal. The shrinkage coefficient has a maximum, and is a method for producing so that the temperature showing the maximum is within ±30° C. of the temperature showing the minimum of the coal, and the properties of the raw material coal (volatile matter, average particle size, etc.) According to the above, the carbonization conditions are adjusted so that the carbon material has a target carbon material shrinkage coefficient.

First, prepare coal. Coal, as described above, in the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient, as long as it has a minimum coke shrinkage coefficient at a temperature above the resolidification temperature of the coal, it is particularly limited. Alternatively, plain coal or blended coal may be used.

Then, as described above, by the method described in JP-A-2005-232349, the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient was measured, and the coke shrinkage coefficient was measured at a temperature equal to or higher than the resolidification temperature of the coal. Find the temperature that shows the minimum. The temperature showing the minimum value can be obtained by reading from the drawing showing the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient.

Next, raw material coal for carbonaceous material production is prepared.
Raw coal is not particularly limited in other characteristics as long as the temperature at which the maximum shrinkage coefficient is in the above range when used as carbonaceous material is not particularly limited. It is preferable to use coal having a VM of 35 to 50%. Further, the cohesion index CI of the raw material coal is preferably 20 or more.

The value of VM of the raw material coal affects the shrinkage coefficient of the carbonaceous material, and if the value is less than 35%, the absolute value of the shrinkage coefficient becomes small because the volatile content remaining in the carbonaceous material decreases. In this case, the effect of improving coke grain size is obtained even if the maximum shrinkage coefficient temperature is in the above range, because the effect of relaxing the stress by reducing the shrinkage coefficient by combining those having different shrinkage coefficients is small. There may be cases where can not be effectively exhibited. On the other hand, if it exceeds 50%, the absolute value of the shrinkage coefficient becomes large due to the large amount of volatile components remaining in the carbonaceous material, and coke cracks may occur even if the maximum shrinkage coefficient temperature is within the above range. There is a case where the effect of improving the coke particle size cannot be effectively exhibited.

With respect to the CI of the raw material coal, if the value is less than 20, the caking property of the coal is insufficient, the adhesion of the coal particles is hindered, and the coke strength may be reduced.

In addition, the raw coal preferably has an average particle size of 3 mm or more. Raw coal with a small particle size has a fast heat transfer and a large specific surface area, so volatile components are likely to be released during carbonization, and as a result, it becomes difficult for the volatile component to remain in the carbonaceous material. It is considered that the temperature range in which the carbon material with the maximum shrinkage temperature can be adjusted is narrowed. Further, the raw material coal having a large particle size can leave the volatile components even when it is carbonized at a temperature higher than the expected carbonization temperature. For this reason, it is preferable that the raw material coal is a granular material having an average particle size of 3 mm or more, and more preferably a granular material having an average particle size of 10 mm or more.

Even if the fine particles are less than 3 mm, the desorption rate of volatile components can be suppressed by granulating the granulated product to have an average particle size of 3 mm or more, so that the amount of volatilization necessary for the carbonaceous material is reduced. It becomes easy to remain the amount, and the particle size improving effect can be improved. However, as compared with granules having an average particle size of 3 mm or more, volatile matter is more easily desorbed from the interface between fine particles and fine particles, so when compared with the same average particle size, the effect of improving particle size is larger for coarse particles. ..

Here, the average particle size can be determined from the cumulative distribution by sieving using a sieve defined in JIS Z 8801, measuring the mass of the sample remaining on each sieve, and calculating the cumulative distribution.

Further, it is preferable to use a granulated product obtained by kneading the raw material coal with a binder such as pitch and granulating. As a result, the raw coal is coated with a binder such as pitch and the desorption rate of volatile matter can be suppressed, so that a necessary amount of volatile matter can remain in the carbonaceous material. Further, the raw material coal coated with the binder can leave the volatile components even when the raw coal is carbonized at a temperature higher than the predetermined carbonization temperature.

The binder to be added to the raw coal in forming the granulated product is not particularly limited, and any of petroleum-based and coal-based binders (tar, pitch, etc.) can be used. The addition amount of the binder is also not particularly limited, and is exemplified by 5 to 15% by mass as an external number with respect to the raw coal.

Next, the raw material coal is carbonized so that the temperature at which the maximum shrinkage coefficient of the carbon material is maximum is within ±30°C of the temperature at which the minimum coke shrinkage coefficient of the coal is reached. For example, by coking (dry-distilling) the raw material coal at a temperature (temperature difference ΔT=20 to 80° C.) lower than the temperature at which the minimum of coal is obtained, the temperature at which the maximum shrinkage coefficient of the carbonaceous material is indicated is the coke of coal. It was experimentally found that the temperature can be set within ±30°C of the temperature at which the shrinkage coefficient is minimum. It is preferable that this point be appropriately confirmed and set in advance by experiments or the like in accordance with the properties of the target coal for coal production. Further, in the carbonization of the raw material coal, the heating furnace is not particularly limited, and the raw material coal can be carbonized by using a kiln or a shaft furnace as described in Patent Documents 2 to 6.

When the raw material coal is carbonized in this way, the components that volatilize at the carbonization temperature escape from the carbonaceous material, but the shrinkage coefficient of the carbonaceous material is extremely low at a temperature 20 to 80° C. lower than the temperature at which the coke shrinkage coefficient of coal is minimal. It is preferable to use a raw material coal that has a value (ideally, almost zero). On the other hand, the components that volatilize above the carbonization temperature remain in the carbonaceous material, and if the temperature is higher than the carbonization temperature, the volatile components escape and the shrinkage coefficient increases. Therefore, it is important to use the raw material coal that allows the temperature at which the shrinkage coefficient of the carbonaceous material is maximum to be within ±30° C. of the temperature at which the coke shrinkage coefficient of the coal is minimal.

Next, a method for producing coke according to the present invention will be described.
The method for producing coke of the present invention is to add the carbonaceous material of the present invention to the above-mentioned coal, charge the coke in a coke oven, and carry out dry distillation to produce coke.

Coal is crushed to a predetermined particle size and carbonaceous material is added. In the crushing of coal, crushing a ratio of 3 mm or less to a particle size of 60% to 95% is exemplified. In addition, the coal is blended coal in which 50% or more of non-caking coal is blended, if necessary.

The blending ratio of the carbonaceous material to the coal is not particularly limited, and is, for example, 1 to 10% in the internal number. If it is less than 1%, cracking of coke may not be suppressed. Further, if it exceeds 10%, the coke strength may decrease.

Then, coal and carbonaceous material are charged into the carbonization chamber of the coke oven. The charging bulk density is not particularly limited and is, for example, 750 kg/m ³ . When the charging bulk density is less than 750 kg/m ³ , carbonaceous materials having a low caking strength index CI may have insufficient caking properties and may have low coke strength.

Next, an example of the present invention will be described. The condition in the example is one condition example adopted for confirming the feasibility and effect of the present invention, and the present invention is based on this one condition example. It is not limited. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

First, coals A to F were prepared. Coals A and B are coals for coke production, and coals C to F are raw material coals for carbon material production. Table 1 shows the amount of ash, volatile matter VM on a dry basis, and fluidity. The fluidity was measured by the method specified in JIS M8801.

For coals A and B, the relationship between the heating temperature during carbonization and the coke shrinkage coefficient was measured. FIG. 2 shows the relationship between the heating temperature and the shrinkage coefficient during dry distillation of coals A and B. From FIG. 2, the temperature at which the minimum coke shrinkage coefficient of coals A and B was obtained was determined. The temperature at which the minimum coke shrinkage coefficient of coal A was 550°C, and the temperature at which the minimum coke shrinkage coefficient of coal B was 570°C.

Next, as shown in Table 2, the particle size of coals C to F was adjusted to obtain raw coal. In Table 2, the average particle sizes of 3 to 5 mm and 10 to 15 mm are described as +3 mm and +10 mm, respectively, and the ratio of the particle size under the sieve of 3 mm is 100% is described as -3 mm 100%. In addition, No. Nos. 6 and 12 were produced by adding 10% by mass of a binder to the coal C whose ratio under the sieve grain size is 3 mm or less to 100%, kneading and granulating, and coating with a binder having an average grain size of 3 mm or more. It is the raw material coal which was made, and is described as +3 mm granulation.

No. The raw material coals 1 to 19 were carbonized at carbonization temperatures shown in Table 3 to obtain carbonaceous materials. And No. For Nos. 1 to 19, the relationship between the heating temperature during carbonization of the raw material coal and the carbon material shrinkage coefficient was measured, and No. The temperature at which the carbon material shrinkage coefficient maximum of 1 to 19 was determined. In Table 3, No. The temperature (maximum temperature) showing the maximum of the carbon material shrinkage coefficient of 1 to 19, and No. The difference (temperature difference) between the temperature showing the maximum of the carbon material shrinkage coefficient of 1 to 19 and the temperature showing the minimum of the coke shrinkage coefficient of coal A or B is shown.

Then, the coal shown in Table 3 was added with No. Coke was manufactured by adding 5% of each of the carbonaceous materials 1 to 19 and the average particle size of the coke and the coke strength were measured. Table 3 shows the average particle size of coke and the coke strength DI ¹⁵⁰ ₁₅ . The coke strength was obtained by measuring the coke percentage DI ¹⁵⁰ ₁₅ on a 15 mm sieve after rotating the coke 150 times by a drum tester described in JIS K2151. Note that the coke strength DI ¹⁵⁰ ₁₅ will be simply referred to as coke strength DI hereinafter.

Fig. 3 shows the relationship between the heating temperature and the shrinkage coefficient of coal A during carbonization, No. The relationship between the heating temperature and the shrinkage coefficient at the time of carbonization of the raw material coal of the carbon materials 1 to 4 is shown.
No. In Nos. 2, 3, 5, 6, 8, and 10 to 15, in the relationship between the heating temperature and the shrinkage coefficient during carbonization of the raw material coal, the temperature showing the maximum shrinkage coefficient of the carbonaceous material shows the minimum of the coke shrinkage coefficient of coal A. Since the temperature is ±30° C. (coal A: 520 to 580° C.), No. The coke strength DI was larger than those of 1, 4, 7, and 9. In addition, coke having a large average particle size was obtained, and cracks in the coke were suppressed.

In particular, in the case of the +3 mm granular material, a desirable carbonaceous material could be produced in a wide temperature range of carbonization temperatures of 525°C (No. 3) and 475°C (No. 2).
In addition, the same temperature difference of 10 ℃ No. Comparing Nos. 8, 10, and 12, the average grain size is No. 8 (-3 mm 100%) <No. 12 (+3 mm granulation) <No. The order was 10 (+3 mm), and a preferable result was obtained with a granular material of +3 mm.

No. In Nos. 1 and 4, since the carbonization temperature was not appropriate, the volatile content was removed more than necessary or remained more than necessary, and the temperature at which the shrinkage coefficient of the carbonaceous material was maximum was the minimum coke shrinkage coefficient of coal A. Is outside the temperature range of ±30° C., and the coke strength DI is smaller than that of the invention examples. Further, as compared with the invention example, the coke had a smaller average particle size, and cracking of the coke was not suppressed.

In addition, No. In Nos. 7 and 9, since the raw material coal of the carbonaceous material has a small particle size, the volatile components are removed more than necessary, and the temperature at which the maximum coefficient of the carbonaceous material shrinkage is ± the temperature at which the minimum coke shrinkage coefficient of the coal A is ±. Outside of 30° C., No. The coke strength DI was smaller than that of Example 8 of the invention. Further, as compared with the invention example, the coke had a smaller average particle size, and cracking of the coke was not suppressed.

Next, No. In Nos. 17 and 18, in the relationship between the heating temperature and the shrinkage coefficient during carbonization of the raw material coal, the temperature at which the maximum shrinkage coefficient of the carbonaceous material is ±30° C. (the temperature at which the minimum coke shrinkage coefficient of coal B is shown) (Coal B: 540 to 600° C.), and No. Compared with Nos. 16 and 19, the coke strength DI was increased. In addition, coke having a large average particle size was obtained, and cracks in the coke were suppressed.

No. In Nos. 16 and 19, the carbonization temperature is not appropriate, so that the volatile content is removed more than necessary or remains more than necessary, and the temperature at which the maximum shrinkage coefficient of the carbonaceous material is shown is the minimum coke shrinkage coefficient of coal B. Is outside the temperature range of ±30° C., and the coke strength DI is smaller than that of the invention examples. Further, as compared with the invention example, the coke had a smaller average particle size, and cracking of the coke was not suppressed.

According to the present invention, the carbonaceous material for coke production has a relationship between the heating temperature during carbonization of coal and the coefficient of coke shrinkage, and the relationship between the heating temperature during carbonization of a specific raw material and the coefficient of carbonaceous material shrinkage. Therefore, cracks are suppressed, and coke having sufficient strength and grain size can be produced. Therefore, the present invention has high industrial applicability.

Claims (5)

In the carbonaceous material for coke production, which is added to the coal when carbonizing carbon to produce coke,
The coal has a minimum coke shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal in the relationship between the heating temperature during the coal carbonization and the coke shrinkage coefficient,
The carbonaceous material has a maximum of the carbonaceous material shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal in the relationship between the heating temperature and the carbonaceous material shrinkage coefficient during carbonization of the raw material coal of the carbonaceous material, and shows the maximum. A carbonaceous material for producing coke, characterized in that the temperature is within ±30° C. of the temperature showing the minimum of the coal. A method for producing carbonaceous material for coke production, which is added to the coal when carbonizing carbon to produce coke,
Regarding the coal, the relationship between the heating temperature and the coke shrinkage coefficient during the coal carbonization was measured, and the temperature showing the minimum of the coke shrinkage coefficient was found among the temperatures above the resolidification temperature of the coal.
At a temperature lower than the temperature showing the minimum of the coal, the raw material coal for producing the carbonaceous material is carbonized, and the carbonaceous material has a relationship between the heating temperature and the carbonaceous material shrinkage coefficient during the carbonization of the raw material coal. And having a maximum of the carbonaceous material shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal, and the temperature showing the maximum is within ±30° C. of the temperature showing the minimum of the coal. A method for producing carbonaceous material for coke production. The coke for producing coke according to claim 2, characterized in that the raw coal has a dry base volatile matter VM of 35 to 50% and a cohesion index CI of at least one of 20 or more. Carbonaceous material manufacturing method. The method for producing a carbon material for coke production according to claim 2 or 3, wherein a granular material or an agglomerated material having an average particle size of 3 mm or more is used as the raw material coal. A method for producing coke in which carbon material for coke production is added to coal and carbonized,
As the coal, in the relationship between the heating temperature during the coal carbonization and the coke shrinkage coefficient, one having a minimum coke shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal,
As the carbonaceous material, in the relationship between the heating temperature and the carbonaceous material shrinkage coefficient during carbonization of the raw material coal of the carbonaceous material, the carbonaceous material shrinkage coefficient has a maximum at a temperature equal to or higher than the resolidification temperature of the coal, and exhibits the maximum. A method for producing coke, characterized in that the temperature is within ±30° C. of the temperature at which the minimum of the coal is shown.

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