Method for producing coke for blast furnaces

Abstract

The present invention provides a method for producing blast furnace coke that can suppress a decrease in coke strength even when non-coking coal is incorporated. [Solution] A method for producing blast furnace coke by charging blended coal into a coke oven and carbonizing it, wherein the blended coal comprises molded coal obtained by molding a mixture of a first blended coal, which includes long-penetration distance coal and non-coking coal, and further includes one or more types of raw coal selected from other raw coals, to which a binder has been added, and a second blended coal, which includes one or more types of raw coal separately selected from other raw coals, wherein the blending ratio of long-penetration distance coal in the first blended coal is greater than 0% by mass and 50% by mass or less, and the blending ratio of non-coking coal in the first blended coal is 1% by mass or more and 30% by mass or less.

Description

[[Technical Field]]

[0001] The present invention relates to a method for producing coke for blast furnaces. [[Background Art]]

[0002] Coke is a massive product mainly composed of carbon obtained by carbonizing coal. Blast furnace coke used in blast furnaces functions as a heat source and a reducing agent, and also functions as a support material that ensures air permeability and liquid permeability in the blast furnace. Therefore, in order to stably operate a blast furnace, mechanical strength is required for blast furnace coke.

[0003] For the production of blast furnace coke, blended coal obtained by blending a plurality of types of coal at a predetermined ratio is used. By carbonizing the blended coal as it is, or after molding part or all of the blended coal, at a temperature of 1000°C or higher, massive blast furnace coke in which coal particles are bonded to each other is obtained. High-strength blast furnace coke can be obtained by using coal having a property of being easily softened and melted, called caking coal, as a part of the blended coal.

[0004] Among caking coals, when a caking coal called long permeation distance coal having particularly high permeability when softened and melted is used, the softened and melted long permeation distance coal permeates between surrounding coal particles. As a result, there is a problem that coarse pores are generated in the portion occupied by the particles of the long permeation distance coal, and the strength of the obtained coke decreases.

[0005] As a means for solving the above problem, for example, Patent Document 1 discloses blended coal containing long permeation distance coal at 900kg / m 3 A method of charging into a coke oven and performing carbonization so as to achieve the above bulk density is disclosed. According to this method, even if the blended coal contains long permeation distance coal, since the gap between coal particles is small, the permeation of the softened and melted long permeation distance coal is suppressed. As a result, the generation of coarse pores is suppressed, and a decrease in coke strength can be inhibited.

[0006] Methods for predicting coke strength based on the properties of coal are known. For example, Patent Document 2 discloses a method for predicting coke strength based on property parameters calculated from the measured values ​​of multiple types of coal included in a blend, by individually measuring the penetration distance and maximum fluidity (MF) of each type of coal. The smaller the weighted average deviation penetration distance, which is one of the property parameters, according to the blending ratio of the coal, the more suppressed the decrease in coke strength is. According to this method, the blending ratio of the coal can be adjusted so that the predicted coke strength falls within a predetermined control range.

[0007] Among the different types of coal, there are those called non-coking coals, which are less prone to softening and melting and have low coking properties. One known method for effectively utilizing non-coking coals as a coke raw material is to mold coal (briquettes) by blending them with non-coking coals, and then to carbonize the resulting blended coal, which is mixed with pulverized coal, in a coke oven. For example, Patent Document 3 discloses a method for producing coke using this method, in which the blending ratio of non-coking coals is suitably adjusted using the maximum fluidity (CATMF) measured with a predetermined amine compound added to the non-coking coals, and then the blended coal with the adjusted blending ratio is carbonized to produce coke. According to this method, the target strength can be achieved for coke produced using blended coals that include non-coking coals. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2015-86301 [Patent Document 2] Japanese Patent Publication No. 2013-181048 [Patent Document 3] Japanese Patent Publication No. 2024-149761 [Overview of the project] [Problems that the invention aims to solve]

[0009] When attempting to produce coke using a blended coal, which is made by molding coal containing long-penetration distance coal into molded coal and then further blending it with other raw coals different from the molded coal, the bulk density of the molded coal containing long-penetration distance coal is high, but the bulk density of the other raw coals that are not molded is low. Therefore, when the blended coal is carbonized, the molded coal expands, and the overall bulk density of the blended coal decreases. Consequently, when using molded coal containing long-penetration distance coal, there was a problem in that, unlike in the case disclosed in Patent Document 1, it was not possible to suppress the penetration of long-penetration distance coal by increasing the bulk density.

[0010] When attempting to produce coke by further blending non-caking coal with a coal blend containing long-penetration coal, the non-caking coal has a small penetration distance, and it also has the effect of reducing the pressure of the gas generated within the coal particles during carbonization, which is the driving force for the penetration of long-penetration coal. Therefore, blending non-caking coal is effective in reducing the weighted average deviation penetration distance described in Patent Document 2. However, because non-caking coal has a low maximum fluidity (MF), the process of non-caking coal melting and bonding with the surrounding coal during softening and melting does not proceed, resulting in defects in the coke. Therefore, there has been a problem that the strength of coke is reduced by blending non-caking coal.

[0011] The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a method for producing blast furnace coke that can suppress a decrease in coke strength even when non-coking coal is blended with it. [Means for solving the problem]

[0012] The gist of the present invention, as completed by the inventors to achieve the above objectives, is as follows.

[0013] [1] A method for producing blast furnace coke, comprising charging a blend of coals into a coke oven and carbonizing it, The aforementioned blended coal is Molded coal obtained by molding a compound obtained by adding a binder to a first blended coal which includes long-penetration distance coal and non-micro-coking coal, and further includes one or more types of raw coal selected from other raw coals, a second blended coal comprising one or more types of coking coal separately selected from said other coking coals, and a blending ratio of the long permeation distance coal in the first blended coal is more than 0% by mass and 50% by mass or less, a blending ratio of the semi-weakly caking coal in the first blended coal is 1% by mass or more and 30% by mass or less. A method for producing coke for a blast furnace.

[0014] [2] As the long permeation distance coal, a long permeation distance coal having a deviation permeation distance of 5.0 mm or more is used, The method for producing coke for a blast furnace according to [1] above.

[0015] [3] As the semi-weakly caking coal, a semi-weakly caking coal having a maximum fluidity expressed in common logarithm (logMF) of 1.50 (log[ddpm]) or less is used, The method for producing coke for a blast furnace according to [1] or [2] above. Effects of the Invention

[0016] According to the method for producing coke for a blast furnace of the present invention, by blending the long permeation distance coal and the semi-weakly caking coal into the first blended coal which is formed coal, permeation of the long permeation distance coal is suppressed, and a decrease in coke strength can be suppressed. Furthermore, since the first blended coal, which is formed coal, has a high bulk density, the distance between the semi-weakly caking coal and surrounding coal particles is small, so the process of melting and bonding with surrounding coal during softening and melting proceeds. Therefore, the present invention also has the effect of suppressing a decrease in coke strength associated with the blending of semi-weakly caking coal. Brief Description of the Drawings

[0017] [Figure 1] It is a schematic diagram showing a softened and melted state of the coke for a blast furnace according to the present invention. [Figure 2] It is a graph showing the relationship between the blending ratio of the long permeation distance coal in the first blended coal and the drum strength index of the coke for a blast furnace. Mode for Carrying Out the Invention

[0018] Hereinafter, modes for carrying out the present invention will be described in detail.

[0019] In one embodiment, the present invention provides a method for producing blast furnace coke, in which blended coal is charged into a coke oven and carbonized, wherein the blended coal comprises formed coal obtained by adding a binder to first blended coal, molding the resulting kneaded product, and second blended coal comprising one or more other types of coking coal separately selected from other coking coals; said first blended coal comprises long penetration distance coal and semi-weakly caking coal, and further comprises one or more types of coking coal selected from other coking coals; the blending ratio of the long penetration distance coal in the first blended coal is more than 0% by mass and 50% by mass or less, and the blending ratio of the semi-weakly caking coal in the first blended coal is 1% by mass or more and 30% by mass or less.

[0020] <Long Penetration Distance Coal> In the present embodiment, the first blended coal comprises long penetration distance coal. As mentioned above, the long penetration distance coal refers to caking coal having particularly high permeability when softened and melted among caking coals. The permeability of coking coal can be quantified by measuring the distance that a softened and melted sample penetrates into a packed bed of glass beads arranged adjacently, that is, the penetration distance. The method for measuring the penetration distance follows the procedure below. First, a coking coal sample adjusted to a particle diameter of 2 mm or less is filled into a container to a thickness of 10 mm at a packing density of 0.8 g / cm 3 Next, glass beads with a diameter of 2 mm are placed on the sample, and a load of 50 kPa is applied from above the glass bead layer. When the sample is heated from room temperature to 550°C at a heating rate of 3°C / min, the distance that the softened and melted sample penetrates into the glass beads is measured, and this distance is defined as the penetration distance.

[0021] In the present embodiment, from the viewpoint of maintaining the strength of coke, the blending ratio of the long penetration distance coal in the first blended coal is 50% by mass or less, preferably 40% by mass or less. On the other hand, the lower limit of the blending ratio of the long penetration distance coal contained in the first blended coal is not particularly limited, as long as it is more than 0% by mass.

[0022] In a preferred embodiment, long-penetration-distance coal is used, which has a deviation penetration distance of 5.0 mm or more. In this specification, "deviation penetration distance" refers to the value calculated by the following formula (1) from the penetration distance (mm) measured for a sample of long-penetration-distance coal by the method described above and the maximum fluidity (MF, unit: ddpm) measured for the same sample by the method specified in Japanese Industrial Standard JIS M 8801. Deviation penetration distance = Penetration distance - (a × logMF) ... (1)

[0023] Here, "logMF" is the maximum fluidity expressed on a common logarithmic scale, with units of log[ddpm]. "a" is the slope of the regression line passing through the origin when logMF measured for multiple types of coking coal is plotted on the x-axis and infiltration distance on the y-axis, with units of mm / log[ddpm]. The set of measurements used to calculate a is limited to those in the range of logMF values ​​greater than 1.00log[ddpm] and less than 2.50log[ddpm]. When the value of a is within this range, the infiltration distance shows a generally positive correlation with logMF. The deviation infiltration distance corresponds to the positive deviation of the infiltration distance from the regression line described above. If the value calculated by equation (1) is negative, the deviation infiltration distance is considered to be zero.

[0024] On the other hand, there is no particular upper limit to the deviation penetration distance of long-penetration coal, but from the viewpoint of preventing a decrease in coke strength due to the formation of coarse air pores, it is preferable that the deviation penetration distance of long-penetration coal be 20 mm or less, and more preferably 15 mm or less.

[0025] <Non-slightly caking coal> In this embodiment, the first blended coal includes non-coking coal. As mentioned above, non-coking coal is a type of coal that is difficult to soften and melt and has low coking properties. Non-coking coal includes both coking coal, which has very little coking ability, and non-coking coal, which has a maximum fluidity (MF) value of zero.

[0026] In this embodiment, from the viewpoint of suppressing the penetration of long-penetration distance coal, the proportion of non-coking coal in the first blended coal is 1% by mass or more, preferably 5% by mass or more, and more preferably 10% by mass or more. On the other hand, from the viewpoint of preventing the non-coking coal from becoming a defect in the coke and reducing the strength of the coke because the process of melting and bonding with the surrounding coal during softening and melting does not proceed, the proportion of non-coking coal in the first blended coal is 30% by mass or less, preferably 20% by mass or less, and more preferably 15% by mass or less.

[0027] In a preferred embodiment, non-coking coal is used, which has a maximum fluidity (logMF) expressed on a common logarithmic scale of 1.50log[ddpm] or less. Coking coal with a maximum fluidity (logMF) expressed on a common logarithmic scale of 1.50log[ddpm] or less is less prone to softening and melting compared to coking coal and has lower coking properties. Therefore, when it is blended with long-penetration distance coal to form molded coal, it can suppress the penetration of softened and melted long-penetration distance coal, thereby suppressing the decrease in coke strength.

[0028] Furthermore, non-coking coals with a maximum flow rate (logMF) expressed on a common logarithm of 1.50 log [ddpm] or less have low coking properties, making it difficult to accurately evaluate the maximum flow rate using the method specified in Japanese Industrial Standard JIS M 8801. In this case, as described in Patent Document 3, it is preferable to evaluate the coking properties using the maximum flow rate (logCATMF) measured after adding a predetermined amine compound to the non-coking coal to increase its fluidity. The maximum flow rate (logCATMF) expressed on a common logarithm for non-coking coal measured in this way is preferably 4.00 log [ddpm] or less, and more preferably 3.00 log [ddpm] or less, from the viewpoint of suppressing the penetration distance of long-penetration distance coal. On the other hand, from the viewpoint of suppressing the decrease in coke strength, it is preferably 0.50 log [ddpm] or more, and more preferably 1.00 log [ddpm] or more.

[0029] <Other types of coking coal> In this embodiment, the first blended coal further comprises one or more types of coking coal selected from other coking coals. In this specification, "other coking coals" refers to coking coals that are neither long-penetration distance coals nor non-coking coals among the coking coals used for coke. The other coking coals are preferably coking coals having moderate coking properties. Specifically, for the other coking coals, it is preferable that the maximum fluidity (logMF) expressed on a common logarithm is greater than 1.50log[ddpm], and the deviation penetration distance calculated by formula (1) is less than 5.0 mm. The other coking coals included in the first blended coal may be one type or two or more types. Here, "type" of other coking coals refers to the so-called brand determined by the origin or deposit of the coking coal.

[0030] <First blend of charcoal> In this embodiment, the first blended coal includes long-penetration distance coal and non-caking coal, and one or more types of coking coal selected from other coking coals. The blending ratio of these coking coals in the first blended coal is not particularly limited. However, it is preferable that the blending ratio of coking coals excluding non-caking coal in the blended coal of the first blended coal be such that the weighted average value of the maximum fluidity (logMF) expressed on a common logarithm is 1.50 log[ddpm] or more and 3.50 log[ddpm] or less, and the weighted average value of the average maximum reflectance (Ro) of vitrinite is 0.85% or more and 1.50% or less. Furthermore, it is preferable that the particle size of the first blended coal before adding the binder be adjusted so that the proportion of particles with a particle size of 3.0 mm or less is 70% by mass or more.

[0031] Furthermore, from the viewpoint of suppressing the penetration of long-penetration distance coal, the value obtained by dividing the proportion of non-coking coal in the first blended coal by the proportion of long-penetration distance coal is preferably 0.10 or more, and more preferably 0.15 or more. On the other hand, from the viewpoint of preventing the non-coking coal from becoming defects in the coke and reducing the strength of the coke due to the process of it melting and bonding with the surrounding coal during softening and melting not progressing, the value obtained by dividing the proportion of non-coking coal in the first blended coal by the proportion of long-penetration distance coal is preferably 0.90 or less, and more preferably 0.85 or less.

[0032] <Binder> In this embodiment, molded coal is obtained by molding a mixture of a first blended coal and a binder. The binder has the function of binding together one or more types of raw coal selected from long-penetration distance coal, non-coking coal, and other raw coals contained in the first blended coal to form molded coal. In this embodiment, coal tar, TARP (heavy pitch obtained from coal tar), and SOP (tar-based soft pitch) can be used as the binder. Preferably, the total amount of binder added to the first blended coal is 5% by mass or more and 20% by mass or less.

[0033] <Bulked coal> In this embodiment, the blended coal includes molded coal obtained by molding a mixture of the first blended coal and a binder. As described above, the first blended coal includes long-penetration distance coal with a blending ratio of more than 0% by mass and 50% by mass or less, and non-coating coal with a blending ratio of 1% by mass or more and 30% by mass or less. In the first blended coal, the remainder other than the long-penetration distance coal and non-coating coal may be one or more types of raw coal selected from other raw coals.

[0034] To produce molded coal from the first blended coal, first, a binder is added to the first blended coal, which has been mixed in a predetermined ratio, and the mixture is kneaded while heating to produce a compound. When producing the compound, it is preferable to heat the raw coal and binder while blowing steam into them. Next, the resulting compound is put into a molding machine to produce molded coal. The specifications of the molding machine are not particularly limited, and for example, a molding machine suitable for molding raw coal, such as a double-roll type molding machine, can be used.

[0035] As mentioned above, long-penetration coal has high permeability when softened and melted. Therefore, when coke is produced by carbonizing the blended coal, the softened and melted long-penetration coal penetrates into the spaces between the surrounding coal particles. As a result, coarse pores are formed in the areas previously occupied by the long-penetration coal particles, reducing the strength of the resulting coke. In contrast, the blast furnace coke according to the present invention uses molded coal in which long-penetration coal and non-coking coal are blended and molded simultaneously, thereby suppressing the reduction in coke strength caused by the blending of long-penetration coal.

[0036] Although the exact reason why the decrease in coke strength is suppressed in the blast furnace coke according to the present invention is unknown, the inventors believe the following. Figure 1 is a schematic diagram showing the state in which the blast furnace coke according to the present invention has been softened and melted. As shown in Figure 1, when blast furnace coke containing molded coal is softened and melted by heating, generated gas 3 is produced by the evaporation of volatile components contained in the long-penetration distance coal 1. Because molded coal has a high bulk density and small gaps between coal particles, the penetration distance of the softened and melted long-penetration distance coal is suppressed compared to the case where it is not molded. However, if the molded coal consisted only of long-penetration distance coal 1, the generated gas 3 would be trapped inside the long-penetration distance coal 1 that has been bonded by softening and melting, and the pressure of the generated gas 3 would increase. As a result, the pressure difference between the generated gas 3 and the atmosphere surrounding the molded coal would push out the softened and melted long-penetration distance coal, increasing the penetration distance.

[0037] However, since the first blended coal according to the present invention contains non-coating coal 2 with low softening and melting properties, the process of long-penetration-distance coal 1 melting and bonding with the surrounding non-coating coal 2 does not proceed easily. As a result, a passage 4 for generated gas is formed at the interface between the non-coating coal 2 and the long-penetration-distance coal 1, reducing the pressure of the generated gas 3. This is thought to suppress the penetration of the softened and melted long-penetration-distance coal 1.

[0038] <Second blended charcoal> In this embodiment, the blended coal includes a second blended coal containing one or more types of coking coal separately selected from other coking coals. As mentioned above, "other coking coals" refers to coking coals that are neither long-penetration distance coals nor non-coking coals among the coking coals used for coke. The type of other coking coal separately selected in the second blended coal may be a different type of coking coal from the other coking coal selected in the first blended coal. However, in this embodiment, it is permissible for the type of other coking coal separately selected in the second blended coal to be the same as the type of other coking coal selected in the first blended coal. In this case, if the other coking coals contain two or more types of coking coals, the blending ratio of the two or more types of coking coals may be the same in the first blended coal and the second blended coal, or it may be a different blending ratio.

[0039] The proportion of other coking coals in the second blended coal is not particularly limited. However, it is preferable that the proportion of other coking coals in the second blend be such that the weighted average value of the maximum fluidity (logMF), expressed on a common logarithmic scale, is between 1.80log[ddpm] and 3.50log[ddpm], and the weighted average value of the average maximum reflectance (Ro) of vitrinite is between 0.90% and 1.40%. Furthermore, it is preferable that the particle size of the second blended coal before carbonization be adjusted so that the proportion of particles with a particle size of 3.0 mm or less is 70% by mass or more.

[0040] <Ratio of the second blended coal in the blended coal> In this embodiment, the proportion of the second blended coal in the blended coal is not particularly limited. However, from the viewpoint of suppressing a decrease in coke strength due to the excessive use of long-penetration distance coal, it is preferable that the proportion of the second blended coal in the blended coal is 60% by mass or more, and more preferably 70% by mass or more. On the other hand, there is no particular upper limit to the proportion of the second blended coal in the blended coal, but it is preferable that it is less than 100% by mass, and more preferably 90% by mass or less.

[0041] <Dry distillation of blended coal> In this embodiment, the blended coal, which includes molded coal obtained by molding the first blended coal and the second blended coal, is charged into a coke oven and carbonized. The carbonization of the blended coal can be carried out by conventional methods. [Examples]

[0042] The following describes embodiments of the present invention. However, the embodiments of the present invention are not limited to the following embodiments, and the embodiments of the present invention can be modified as appropriate without departing from the spirit of the invention.

[0043] To confirm the effects of the present invention, blast furnace coke was produced by carbonizing a blend of coal containing molded coal obtained by molding a first blend of coal and a second blend of coal, according to the procedure described below. First, as raw materials to be included in the first blend of coal, ten types of raw materials with appropriate coking properties, from A1 to A10, were prepared, including long-penetration distance coal, non-slightly caking coal, and other raw materials. Table 1 shows the maximum fluidity (logMF) expressed in common logarithms, penetration distance, deviation penetration distance calculated by equation (1), average maximum reflectance (Ro) of vitrinite, and total inert (TI) for these raw materials. Total inert refers to the mass percentage of the portion of the internal structure of the raw material coal that is difficult to soften and melt. For the non-slightly caking coal, the maximum fluidity (logCATMF), measured by the method described in Patent Document 3 and expressed in common logarithms, is also shown. The value of a in equation (1) used to calculate the deviation penetration distance was 3.25.

[0044] [Table 1]

[0045] Next, these raw coals were crushed to adjust the particle size so that 100% by mass contained particles with a particle size of 3.0 mm or less. Then, they were mixed according to the proportions shown in Table 2 to obtain the first blended coals for levels T1 to T7. In the proportions shown in Table 2, the proportions of raw coals excluding non-coking coals were all blended so that the weighted average value of the maximum fluidity (logMF), expressed on a common logarithmic scale, was 2.70 log [ddpm] and the weighted average value of the average maximum reflectance (Ro) of vitrinites was 0.95%. In addition, the values ​​obtained by dividing the proportion of non-coking coals in the first blended coal by the proportion of long-penetration distance coals are also shown in Table 2.

[0046] Next, to the total mass of each component of the first blended coal, 4.0% by mass of TARP, 0.5% by mass of tar-based soft pitch (SOP), and 6.0% by mass of coal tar were added as binders, and the mixture was kneaded for 1.5 minutes while heating with steam blown in. At this time, the temperature of the kneaded mixture was approximately 95°C, and the moisture content was between 12% by mass and 15% by mass. Subsequently, the resulting mixture was molded using a double-roll molding machine equipped with cups measuring 44 mm × 44 mm × 13 mm on one side, with a roll gap of 2 mm, to obtain Masec-type molded coals of levels T1 to T7. The density of all the resulting molded coals was 1130 kg / m³. 3 That was the case.

[0047] Next, as coking coal for the second blended coal, cohesive coking coals A1 to A10, which were the same coking coals used in the first blended coal, were prepared. These coking coals were blended in proportions such that the weighted average of the maximum fluidity (logMF) expressed on a common logarithmic scale was 2.54log[ddpm] and the weighted average of the average maximum reflectance (Ro) of the vitrinite was 1.00%. The resulting blended coal was crushed, and the particle size was adjusted so that the proportion of particles with a particle size of 3.0 mm or less was 100% by mass, thereby obtaining the second blended coal.

[0048] Next, 20 parts by mass of molded coal obtained from molding the first blended coal, ranging from levels T1 to T7, are mixed with 80 parts by mass of the second blended coal to create a blended coal with a bulk density of 825 kg / m³.3 The carbonization vessel was filled in this manner. A 10 kg weight was placed on top of the coal mixture in the carbonization vessel, and carbonization was performed in an electric furnace at a furnace temperature of 1050°C for 6 hours. After that, it was removed from the electric furnace, cooled under a nitrogen atmosphere, and then blast furnace coke was extracted from the carbonization vessel.

[0049] Next, for the blast furnace coke obtained at levels T1 to T7, the mass of blast furnace coke with a particle size of 15 mm or larger was measured after rotating the drum 150 times at a rotation speed of 15 rpm, using the rotation strength test specified in Japanese Industrial Standard JIS K 2151 (2004). The drum strength index DI(150 / 15) was calculated by multiplying the ratio of the mass of blast furnace coke subjected to the test to the total mass by 100. Table 2 shows the drum strength indices for the blast furnace coke. Figure 2 shows a graph illustrating the relationship between the blending ratio of long-penetration distance coal in the first blended coal and the drum strength index of the blast furnace coke.

[0050] [Table 2]

[0051] As shown in Table 2 and Figure 2, when comparing non-coking coal blending ratios at the same level, the drum strength index of blast furnace coke tended to decrease with increasing blending ratio of long-penetration distance coal in the first blend. On the other hand, when comparing non-coking coal blending ratios at different levels, the drum strength index was higher at levels T4 and T5, which contained 10% non-coking coal, compared to levels T1, T2, and T3, which contained no non-coking coal. At levels T6 and T7, which contained 20% non-coking coal, the drum strength index was equivalent to that of levels T2 and T3, which contained no non-coking coal. [Explanation of Symbols]

[0052] 1 Long permeation distance carbon 2 Non-slightly caking coal 3. Generated gas 4. Path of the generated gas

Claims

1. A method for producing blast furnace coke, comprising charging a blend of coals into a coke oven and performing carbonization, The aforementioned blended coal is Molded coal obtained by molding a compound obtained by adding a binder to a first blended coal which further contains long-penetration distance coal and non-micro-coking coal, and one or more types of raw coal selected from other raw coals, A second blended coal comprising one or more types of coking coal separately selected from the aforementioned other coking coals, The proportion of the long-penetration distance coal in the first blended coal is greater than 0% by mass and 50% by mass or less. A method for producing blast furnace coke, characterized in that the proportion of non-coking coal in the first blended coal is 1% by mass or more and 30% by mass or less.

2. As the long-penetration distance charcoal, a long-penetration distance charcoal with a deviation penetration distance of 5.0 mm or more is used. A method for producing blast furnace coke according to claim 1.

3. As the non-coking coal mentioned above, a non-coking coal is used in which the maximum fluidity (logMF) expressed on a common logarithm is 1.50 (log [ddpm]) or less. A method for producing blast furnace coke according to claim 1 or 2.

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