JP2017088869A - Carbonaceous material for coke production, production method thereof and production method of coke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbonaceous material for coke production that can produce coke having sufficient strength and particle size while suppressing fissure.SOLUTION: In a carbonaceous material for producing coke added to coal when producing coke by dry distillation of coal, the coal has a minimum of a coke contraction coefficient at a temperature higher than a re-solidifying temperature of the coal in the relationship between a heating temperature during dry distillation of the coal and the coke contraction coefficient, and the carbonaceous material has a maximum of a carbonaceous material contraction coefficient at a temperature higher than a re-solidifying temperature of the coal in the relationship between a heating temperature during dry distillation of a raw material coal of the carbonaceous material and the carbonaceous material coke contraction coefficient, the temperature showing the maximum is within ±30°C of the temperature showing the minimum of the coal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a carbon material for coke production for producing coke by adding 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 pulverizing and blending various types of coal, charging the coke into a coke oven, and performing dry distillation in the oven. Although coke with sufficient strength can be produced by using high-quality coal as coke-producing coal, the high-quality coal is in a resource-depleted state. On the other hand, inferior quality coal has abundant reserves, and it is desired to produce coke having sufficient strength using inferior quality coal.

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

  There are a primary peak (maximum) due to primary shrinkage and a secondary peak (maximum) due to secondary shrinkage in the change in coke shrinkage coefficient with respect to heating temperature (shrinkage coefficient curve) during the coal carbonization process. The primary peak is a peak due to shrinkage that occurs when coal softens and melts in the temperature range of about 400 to 500 ° C. and then solidifies, and the secondary peak is the shrinkage that occurs when dehydrogenation occurs at about 700 ° C. It is a peak by.

  The primary shrinkage varies depending on the type of coal. Inferior coal with a high volatile content has a large primary shrinkage. Therefore, in the method of producing coke by blending several kinds of coal, when blending inferior coal with high volatile content, the difference in contraction between the coals becomes large and micro cracks are likely to occur. On the other hand, the secondary shrinkage rate is almost constant regardless of the type of coal, but it develops micro cracks.

  In order to suppress such cracks, expand the coke particle size, and obtain coke with sufficient strength, while adding a carbonaceous material such as coke powder whose shrinkage rate above the re-solidification temperature of coal is smaller than coal, In order to reinforce the adhesive strength between the carbonaceous material and the coal particles, a technique of adding a bitumen such as a pitch together is known (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 6-264069 JP-A-56-136880 Japanese Patent Laid-Open No. 56-136881 JP-A-56-136882 Japanese Patent Application Laid-Open No. 07-003309 International Publication No. 2010/087468

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

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

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

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

  Thus, with respect to the relationship between the heating temperature at the time of dry distillation of coal and the coke shrinkage coefficient, the carbon material has a relationship between the heating temperature at the time of specific raw material coal dry distillation and the carbon material shrinkage coefficient. It has been found that when a mixture of coal and carbonaceous material is dry-distilled, the coke shrinkage coefficient changes little and can be kept low throughout the temperature range of 500 to 1000 ° C., and as a result, the occurrence of cracks can be suppressed. It was.

The present invention has been made based on the above findings, and the gist thereof is as follows.
(1) In the carbon material for coke production added to the coal when carbonizing the coal to produce coke,
The coal has a minimum of the coke 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 coke shrinkage coefficient during the coal dry distillation,
The carbon material has a maximum carbon material shrinkage coefficient at a temperature equal to or higher than the re-solidification temperature of the coal in the relationship between the heating temperature and the carbon material shrinkage coefficient at the time of carbonization of the raw material coal. A carbon material for coke production, wherein the temperature is within ± 30 ° C. of the temperature at which the minimum of the coal is exhibited.

(2) A method for producing a carbonaceous material for coke production that is added to the coal when carbonized to produce coke,
For the coal, measure the relationship between the heating temperature and the coke shrinkage coefficient during the coal dry distillation, find the temperature that indicates the minimum of the coke shrinkage coefficient among the temperatures above the resolidification temperature of the coal,
Carbonizing the raw material coal for producing the carbonaceous material at a temperature lower than the temperature indicating the minimum of the coal, the carbonaceous material in the relationship between the heating temperature and the carbonaceous material shrinkage coefficient during the raw material coal dry distillation The carbon material has a maximum shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal, and the temperature indicating the maximum is within ± 30 ° C. of the temperature indicating the minimum of the coal. A method for producing carbonaceous materials for coke production.
(3) As described in (2) above, the raw material coal is one that satisfies at least one condition of 35 to 50% in dry base volatile matter VM and a caking index CI of 20 or more. Of carbon material for the production of coke.
(4) The method for producing a carbon material for coke production according to (2) or (3) above, 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 in which carbonaceous material for coke production is added to coal and subjected to dry distillation,
As the coal, in the relationship between the heating temperature and the coke shrinkage coefficient during the coal dry distillation, the one having the minimum coke shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal,
As the carbon material, the relationship between the heating temperature and the carbon material shrinkage coefficient during the raw coal dry distillation of the carbon material has a maximum carbon material shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal, and shows the maximum value. A method for producing coke, characterized in that the temperature is within ± 30 ° C. of the minimum temperature of the coal.

  In the present invention and the specification, coal for producing coke is simply referred to as “coal”, and coal for producing carbonaceous material is referred to as “raw coal”.

  According to the present invention, the carbonaceous material for coke production has a relationship between the heating temperature at the time of dry distillation of the coal and the coke shrinkage coefficient, and the relationship between the heating temperature at the time of carbonization of the specific raw material and the carbonaceous material shrinkage coefficient. As a result, cracks are suppressed and coke having sufficient strength and particle 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 at the time of dry distillation of coal A and B, and a shrinkage coefficient. Relationship between heating temperature and shrinkage coefficient during dry distillation of coal A, No. It is a figure which shows the relationship between the heating temperature at the time of the raw material coal dry distillation of 1-4 carbonaceous materials, and a shrinkage | contraction coefficient.

  The carbon material for coke production of the present invention (hereinafter referred to as “the carbon material of the present invention”) is added to coal when producing coke, and the relationship between the heating temperature and the carbon material shrinkage coefficient during raw coal dry distillation. In this case, the carbon material shrinkage coefficient has a maximum at a temperature equal to or higher than the resolidification temperature of the coal, and the temperature indicating the maximum is the minimum of the coke shrinkage coefficient in the relationship between the heating temperature of the coal during carbonization and the coke shrinkage coefficient. The temperature is within ± 30 ° C of the indicated temperature.

  Hereinafter, the background of the study that led to the carbonaceous material of the present invention will be described. Unless otherwise specified, “%” of the blending ratio of coal and carbonaceous material and volatile content indicates “mass%”.

  The inventors of the present invention conducted the following investigation on carbon materials that can suppress cracking and produce coke having sufficient strength and particle size in the production of coke. First, carbon materials obtained by preliminary carbonization at various temperatures are prepared, added to one type of coal, and a plurality of mixtures are obtained. These are carbonized, and the relationship between differences in carbon materials and cracks. investigated. As a result, cracks were suppressed in specific carbon materials.

  Therefore, the relationship between the heating temperature and the shrinkage coefficient during dry distillation was measured for coal, carbon material X in which cracks were suppressed, and carbon material Y in which cracks occurred. In FIG. 1, the relationship between the heating temperature at the time of dry distillation and a shrinkage coefficient is shown. In FIG. 1, the solid line is the coal, the dotted line X is the carbon material X in which cracking is suppressed, and the dotted line Y is the relationship between the heating temperature and the shrinkage coefficient during carbonization of the carbonaceous material Y in which the crack is generated.

  Regarding the relationship between the heating temperature during coal carbonization and the coke shrinkage coefficient, the primary peak P1 (maximum) due to the primary shrinkage that occurs when softening and melting in the temperature range of about 400 to 500 ° C. and then solidifying is about 700 A secondary peak (maximum) due to secondary contraction that occurred when dehydrogenating at 0 ° C. was confirmed. In the case of the carbon material X in which cracks are suppressed and the carbon material Y in which cracks are generated, the peak is at a temperature equal to or higher than the resolidification temperature of the coal, specifically, about 570 ° C for the carbon material X and about 700 ° C for the carbon material Y. confirmed.

  From this, in the carbonaceous material X in which cracks are suppressed, the position corresponding to the minimum sandwiched between the primary peak P1 and the secondary peak P2 in the relationship between the heating temperature during the carbonization of coal and the coke shrinkage coefficient, There was a peak of the carbonaceous material shrinkage coefficient. On the other hand, in the carbon material Y in which the crack occurred, 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 that shows the maximum of the shrinkage coefficient of coal is made equal to the temperature that shows the minimum of the coke shrinkage coefficient of coal, the change in the coke shrinkage coefficient of the mixture of coal and coal is reduced, and cracking of coke is suppressed. However, if the temperature at which the maximum shrinkage coefficient of coal is made equal to the temperature at which the maximum coke shrinkage coefficient of coal is obtained, the change in the coke shrinkage coefficient of the mixture of coal and coal will increase, causing distortion in the coke. It was considered that cracks occurred in the coke.

  Therefore, as a result of examining in detail the relationship between the difference between the temperature that shows the maximum shrinkage coefficient of various carbon materials and the temperature that shows the minimum coke shrinkage coefficient of coal, and the presence or absence of cracks, It was found that cracking of coke can be suppressed by setting the temperature showing the maximum to be within ± 30 ° C. of the temperature showing the minimum of the coke shrinkage coefficient of coal.

  The present invention has reached the inventions described in the above (1) to (5) through the examination process as described above, and the necessary and preferred requirements will be further described in order for such the present invention. .

The carbonaceous material of the present invention is added to coal when producing coke, and in the relationship between the heating temperature and carbonaceous material shrinkage coefficient during raw coal dry distillation, the carbonaceous material shrinkage coefficient is higher than the coal resolidification temperature. The temperature showing the maximum is ± 30 ° C. of the temperature showing the minimum of the coke shrinkage coefficient of coal.
First, the coal to which the carbonaceous material of the present invention is added will be described.

(coal)
The coal to which the carbonaceous material of the present invention is added is particularly limited as long as it has a minimum of the 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 coal dry distillation and the coke shrinkage coefficient. It is not what is done. This minimum is due to the primary peak (maximum) due to primary shrinkage that occurs when the coal solidifies after softening and melting of coal, and the dehydrogenation at about 700 ° C. It is observed during the secondary peak (maximum) due to secondary contraction that occurs when heat shrinks, and is observed at least in the temperature range of the resolidification temperature to 1000 ° C.

  Since the method for obtaining the relationship between the heating temperature during coal dry distillation and the coke shrinkage coefficient 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., for example, at a heating rate of 3 ° C./min. The sample length during temperature rise 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, a change in the coke shrinkage ratio R per unit temperature change is defined as a coke shrinkage coefficient (− / ° C.), and a relationship between the temperature and the coke shrinkage coefficient is obtained.
R = (L _R −L _T ) / L _R

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

(Charcoal)
The carbonaceous material of the present invention has a maximum carbonaceous material shrinkage coefficient at a temperature equal to or higher than the re-solidification temperature of the target coal in the relationship between the heating temperature and the carbonaceous material shrinkage coefficient during carbonization of the raw material coal, and a temperature indicating the maximum. Is within ± 30 ° C. of the temperature at which the coal exhibits a minimum coke shrinkage coefficient. Incidentally, the method for obtaining the relationship between the heating temperature and the carbon material shrinkage coefficient during the raw coal dry distillation is the same condition as the method for obtaining the relationship between the temperature and the coke shrinkage coefficient.
As shown in the examples described later, the temperature indicating the maximum of the shrinkage coefficient of the carbonaceous material is within ± 30 ° C of the temperature indicating the minimum of the coke shrinkage coefficient of the target coal, Through the temperature range, the change in the coke shrinkage coefficient is small and can be kept low, 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 dry distillation 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. Moreover, the shape of the peak having the maximum value of the carbonaceous material shrinkage coefficient is not particularly limited, and may be a sharp shape or a broad shape.

In order for a carbon material to exhibit a maximum shrinkage coefficient at a temperature higher than the re-solidification temperature of such coal, it is important to leave volatile matter in the carbon material, but the amount is particularly limited Instead, it may be set appropriately within a range in which cracking of coke can be suppressed.
Further, the cohesive strength index CI of the carbon material is preferably 20 or more. When the cohesive strength index CI is less than 20, it is difficult to adhere to surrounding particles, and the strength of coke produced by dry distillation with coal may be reduced.

  Here, the volatile content VM is measured by a method defined in JIS M8812. In addition, the cohesive strength index CI is a dictionary of coal utilization technical terms (edited by the Japan Fuel Association) p. 255, and 9 g of 0.25 to 0.30 mm powdered coke is mixed with 1 g of inferior charcoal of 0.25 mm or less, dried at 950 ° C. for 7 minutes with a magnetic crucible, and then screened with a sieve of 0.30 mm or more. It is a value expressed as a percentage of the mass after sieving and remaining on the sieve.

  Next, a method for producing a carbonaceous material for producing coke according to the present invention (hereinafter referred to as “the method for producing the carbonaceous material according to the present invention”) and a method for producing the coke according to the present invention (hereinafter referred to as “the method for producing the coke according to the present invention”). ) And the necessary and preferred requirements will be explained in turn.

  The method for producing a carbonaceous material according to the present invention is obtained by carbonizing raw material coal for producing a carbonaceous material at a temperature lower than the temperature at which the coke shrinkage coefficient of the coal is minimum, and the carbonaceous material is heated 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 coal. Properties of raw coal (volatile matter, average particle size, etc.) The carbonization conditions are adjusted so as to obtain a carbon material having a target carbon material shrinkage coefficient.

  First, prepare coal. As described above, the coal 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 the coal in the relationship between the heating temperature at the time of coal dry distillation and the coke shrinkage coefficient. There may be simple charcoal or blended charcoal.

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

Next, raw material coal for producing carbonaceous materials is prepared.
The raw material coal is not particularly limited as long as the temperature at which the shrinkage coefficient is maximized is within the above range when used as a carbon material, but the volatilization of the dry base is not limited. It is preferable to employ coal having a minute VM of 35 to 50%. The cohesive strength index CI of the raw coal is preferably 20 or more.

  The VM value of the raw material coal affects the shrinkage coefficient of the carbonaceous material. If the value is less than 35%, the volatile matter remaining in the carbonaceous material is reduced, so the absolute value of the shrinkage coefficient is small. In this case, since the effect of relaxing the stress by reducing the stress by combining those having different shrinkage coefficients becomes smaller, the effect of improving the coke particle size even if the shrinkage coefficient maximum temperature is within the above range. May not be effective. On the other hand, if it exceeds 50%, the absolute value of the shrinkage coefficient increases because the volatile matter remaining in the carbon material increases, and even if the maximum shrinkage coefficient temperature is within the above range, there is a possibility of cracking of coke. There is a case where the effect of improving the coke particle size cannot be exhibited effectively.

  As for CI of raw material coal, if the value is less than 20, the caking property of coal is insufficient, the adhesion of coal particles is inhibited, and the coke strength may be lowered.

  Moreover, it is preferable that raw material coal shall be 3 mm or more in average particle size. The raw material coal with a small particle size has a fast heat transfer and a large specific surface area, so that the volatile matter is easily released during carbonization, and the amount of volatile matter required for the carbonaceous material is less likely to remain. It is considered that the temperature range in which the carbonaceous material having the maximum shrinkage rate can be adjusted is narrowed. Furthermore, even if raw material coal with a large particle size is carbonized at a temperature higher than the intended carbonization temperature, volatile matter can remain. For this reason, it is preferable that raw material coal shall be a granular material with an average particle size of 3 mm or more, More preferably, it is a granular material with an average particle size of 10 mm or more.

  In addition, even if it is a granule of less than 3 mm, the desorption rate of the volatile matter can be suppressed by granulating it into a granulated product having an average particle size of 3 mm or more. It becomes easy to leave a part, and the particle size improvement effect can be improved. However, compared with a granular material having an average particle size of 3 mm or more, the volatile matter is easily released from the interface between the fine particles and the granular material, and therefore, when compared with the same average particle size, the effect of improving the particle size is larger for the coarse particles. .

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

  Moreover, it is preferable to use a granulated product obtained by kneading raw material coal with a binder such as pitch and granulating it. Thereby, since raw material coal is coat | covered with binders, such as a pitch, and the detachment | desorption rate of a volatile matter can be suppressed, the amount of volatile matter required for a carbonaceous material can remain. Furthermore, even if the raw material coal coated with the binder is carbonized at a temperature higher than the intended carbonization temperature, volatile components can remain.

  The binder added to the raw material coal when making 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 based on the external number relative to the raw material coal.

  Next, the raw material coal is carbonized so that the temperature showing the maximum of the shrinkage coefficient of the carbon material is within ± 30 ° C. of the temperature showing the minimum of the coke shrinkage coefficient of the coal. For example, by carbonizing (dry-distilling) the raw material coal at a temperature lower than the temperature indicating the minimum of coal (temperature difference ΔT = 20 to 80 ° C.), the temperature indicating the maximum shrinkage coefficient of the carbonaceous material is obtained. It was experimentally found that the temperature indicating the minimum shrinkage coefficient can be within ± 30 ° C. It is preferable to confirm and set this point in advance through experiments or the like as appropriate in accordance with the properties of the target coal for producing carbonaceous materials. Moreover, in carbonization of raw material coal, a heating furnace is not specifically limited, Raw material coal can be carbonized using a kiln or a shaft furnace as described in Patent Documents 2 to 6.

  When carbonizing the raw material coal in this way, the components that volatilize at the carbonization temperature escape from the carbonaceous material, but the carbonaceous material has a very low shrinkage coefficient at a temperature 20 to 80 ° C. lower than the temperature at which the coal coke shrinkage coefficient is minimal. It is preferable to use raw coal that has a value (ideally almost zero). On the other hand, components that volatilize at or above the carbonization temperature remain in the carbonaceous material, and when the temperature is higher than the carbonization temperature, volatile components are lost and the shrinkage coefficient increases. Thus, it is important to use raw material coal that can make 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 coal.

Next, the manufacturing method of the coke of this invention is demonstrated.
In the method for producing coke of the present invention, the carbon material of the present invention is added to the above-mentioned coal, charged into a coke oven, and subjected to dry distillation to produce coke.

  Coal is pulverized to a predetermined particle size and carbonaceous material is added. Coal pulverization is exemplified by pulverizing a ratio of 3 mm or less to a particle size of 60% to 95%. In addition, coal is blended coal containing 50% or more of non-slightly caking coal as required.

  The compounding ratio of the carbonaceous material with respect to coal is not particularly limited, and is, for example, 1 to 10%. If it is less than 1%, cracking of coke may not be suppressed. If it exceeds 10%, the coke strength may decrease.

And coal and a carbonaceous material are charged into the carbonization chamber of a coke oven. The charging bulk density is not particularly limited, and for example, 750 kg / m ³ is exemplified. When the charging bulk density is less than 750 kg / m ³ , in the case of a carbon material having a low caking strength index CI, the caking strength may be insufficient and the coke strength may be lowered.

  Next, examples of the present invention will be described. The conditions in the examples are one example of conditions used for confirming the feasibility and effects of the present invention, and the present invention is based on this one example of conditions. 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 producing coke, and coals C to F are raw material coals for producing carbonaceous materials. Table 1 shows the ash content, dry base volatile content VM, and fluidity. In addition, fluidity | liquidity was measured by the method prescribed | regulated to JISM8801.

  About coal A and B, the relationship between the heating temperature at the time of dry distillation and a coke shrinkage coefficient was measured. In FIG. 2, the relationship between the heating temperature at the time of dry distillation of coal A and B and a shrinkage coefficient is shown. From FIG. 2, the temperature indicating the minimum coke shrinkage coefficient of coals A and B was determined. The temperature showing the minimum coke shrinkage coefficient of coal A was 550 ° C., and the temperature showing the minimum coke shrinkage coefficient of coal B was 570 ° C.

  Next, as shown in Table 2, the particle sizes of coals C to F were adjusted to obtain raw material coal. In Table 2, the average particle sizes of 3 to 5 mm and 10 to 15 mm are expressed as +3 mm and +10 mm, respectively, and the ratio of the particle size of 3 mm or less under the sieve is 100% and is expressed as −3 mm and 100%. No. 6 and 12 were prepared by adding 10% by mass of a binder to coal C with a particle size of 3 mm or less under sieve being 100%, kneading and granulating, and coating with a binder having an average particle size of 3 mm or more. The raw material coal is described as +3 mm granulation.

  No. About 1-19 raw material coal, it carbonized at the carbonization temperature shown in Table 3, and it was set as the carbon material. And No. For Nos. 1 to 19, the relationship between the heating temperature during carbonization of raw material coal and the carbon material shrinkage coefficient was measured. The temperature which shows the maximum of the carbonaceous material shrinkage | contraction coefficient of 1-19 was calculated | required. In Table 3, no. The temperature (maximum temperature) which shows the maximum of the carbonaceous material shrinkage | contraction coefficient of 1-19, and No.1. The difference (temperature difference) of the temperature which shows the maximum of the coal material shrinkage | contraction coefficient of 1-19, and the temperature which shows the minimum of the coke shrinkage | contraction coefficient of coal A or B is shown.

And in coal shown in Table 3, No. Coke was produced by adding 5% each of 1-19 carbonaceous materials, and the average particle size and coke strength of the coke were measured. Table 3 shows the average particle size and coke strength DI ¹⁵⁰ ₁₅ of the coke. The coke strength was determined by actually measuring the coke percentage DI ¹⁵⁰ ₁₅ on a 15 mm sieve after the coke was rotated 150 times with a drum tester described in JIS K2151. Hereinafter, the coke strength DI ¹⁵⁰ ₁₅ will be abbreviated as the coke strength DI.

FIG. 3 shows the relationship between the heating temperature and the shrinkage coefficient during coal carbonization. The relationship between the heating temperature at the time of carbonization of raw material coal of 1-4 carbonaceous materials and a shrinkage coefficient is shown.
No. 2, 3, 5, 6, 8, 10-15, the temperature showing the maximum of the shrinkage coefficient of the carbonaceous material in the relationship between the heating temperature and the shrinkage coefficient during the raw coal dry distillation, the minimum of the coke shrinkage coefficient of coal A Since it is ± 30 ° C. (coal A: 520 to 580 ° C.) of the temperature shown, Compared with 1, 4, 7, and 9, the coke strength DI was increased. Further, coke having a large average particle size was obtained, and cracking of the coke was suppressed.

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

  No. Since the carbonization temperature is not appropriate for 1 and 4, the volatile matter escapes more than necessary, or the temperature at which it remains more than necessary and shows the maximum shrinkage coefficient of the carbonaceous material is the minimum of the coke shrinkage coefficient of coal A The coke strength DI was smaller than that of the inventive example. Moreover, it became coke with a small average particle diameter compared with the invention example, and the crack of coke was not suppressed.

  No. 7 and 9, since the raw material coal particle size of the carbon material is small, the volatile matter escapes more than necessary, and the temperature indicating the maximum of the carbon material shrinkage coefficient is ± of the temperature indicating the minimum of the coke shrinkage coefficient of coal A It is outside 30 ° C. Compared with the invention example of 8, the coke strength DI was decreased. Moreover, it became coke with a small average particle diameter compared with the invention example, and the crack of coke was not suppressed.

  Next, no. 17 and 18 are ± 30 ° C. (coal B: the temperature at which the maximum of the shrinkage coefficient of the carbonaceous material shows the minimum of the coke shrinkage coefficient of the coal B in the relationship between the heating temperature and the shrinkage coefficient during the dry distillation of the raw material coal. 540-600 ° C). Compared with 16 and 19, the coke strength DI was increased. Further, coke having a large average particle size was obtained, and cracking of the coke was suppressed.

  No. 16 and 19, since the carbonization temperature is not appropriate, the volatile matter escapes more than necessary or remains more than necessary, and the temperature at which the shrinkage coefficient of the carbonaceous material is maximized is the minimum of the coke shrinkage coefficient of coal B The coke strength DI was smaller than that of the inventive example. Moreover, it became coke with a small average particle diameter compared with the invention example, and the crack of coke was not suppressed.

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

Claims (5)

In the carbon material for coke production that is added to the coal when carbonizing carbon to produce coke,
The coal has a minimum of the coke 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 coke shrinkage coefficient during the coal dry distillation,
The carbon material has a maximum carbon material shrinkage coefficient at a temperature equal to or higher than the re-solidification temperature of the coal in the relationship between the heating temperature and the carbon material shrinkage coefficient at the time of carbonization of the raw material coal. A carbon material for coke production, wherein the temperature is within ± 30 ° C. of the temperature at which the minimum of the coal is exhibited. A method for producing a carbon material for coke production that is added to the coal when the coal is carbonized to produce coke,
For the coal, measure the relationship between the heating temperature and the coke shrinkage coefficient during the coal dry distillation, find the temperature that indicates the minimum of the coke shrinkage coefficient among the temperatures above the resolidification temperature of the coal,
Carbonizing the raw material coal for producing the carbonaceous material at a temperature lower than the temperature indicating the minimum of the coal, the carbonaceous material in the relationship between the heating temperature and the carbonaceous material shrinkage coefficient during the raw material coal dry distillation The carbon material has a maximum shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal, and the temperature indicating the maximum is within ± 30 ° C. of the temperature indicating the minimum of the coal. A method for producing carbonaceous materials for coke production.   3. The coke production according to claim 2, wherein the raw material coal uses at least one of a dry base volatile content VM of 35 to 50% and a cohesive strength index CI of 20 or more. A method for producing charcoal.   The method for producing a carbon material for coke production according to claim 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. A method for producing coke in which a carbon material for coke production is added to coal and subjected to dry distillation,
As the coal, in the relationship between the heating temperature and the coke shrinkage coefficient during the coal dry distillation, the one having the minimum coke shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal,
As the carbon material, the relationship between the heating temperature and the carbon material shrinkage coefficient during the raw coal dry distillation of the carbon material has a maximum carbon material shrinkage coefficient at a temperature equal to or higher than the resolidification temperature of the coal, and shows the maximum value. A method for producing coke, characterized in that the temperature is within ± 30 ° C. of the minimum temperature of the coal.

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