JP5737002B2 - Method for producing blended coal for coke oven charging - Google Patents

Method for producing blended coal for coke oven charging Download PDF

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JP5737002B2
JP5737002B2 JP2011140516A JP2011140516A JP5737002B2 JP 5737002 B2 JP5737002 B2 JP 5737002B2 JP 2011140516 A JP2011140516 A JP 2011140516A JP 2011140516 A JP2011140516 A JP 2011140516A JP 5737002 B2 JP5737002 B2 JP 5737002B2
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窪田　征弘
征弘 窪田
野村　誠治
誠治 野村
孝 有馬
孝 有馬
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Nippon Steel Corp
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本発明は、コークス炉に装入される配合炭の製造方法に関し、特に配合炭の粉砕方法に関する。   The present invention relates to a method for producing blended coal charged in a coke oven, and more particularly to a method for pulverizing blended coal.

高炉用コークスに代表される各種コークスは、多数の銘柄の石炭（原料炭）を粉砕して配合した後、コークス炉に装入される。装入された配合炭は、炉内で乾留されることによりコークスとなる。コークス製造の際に特に重要とされる品質管理項目として、コークス強度が知られている。コークス強度は、石炭の配合条件が同じであっても、粉砕後の石炭の粒度に左右される。   Various cokes such as blast furnace coke are pulverized and blended with many brands of coal (coking coal) and then charged into the coke oven. The charged coal mixture is coke by being carbonized in the furnace. Coke strength is known as a quality control item that is particularly important in the production of coke. The coke strength depends on the grain size of the pulverized coal even if the coal blending conditions are the same.

そこで、本発明者等は、コークス強度を高める方法として、最大長さで１．５ｍｍ以上の粗大イナート組織の含有量が境界値（５〜７体積％）以上である高イナート含有炭を強粉砕する粉砕工程を含む高炉用コークスの製造方法を開示している（特許文献１）。   Therefore, the inventors of the present invention, as a method for increasing the coke strength, strongly pulverize high inert coal having a maximum length of 1.5 mm or more of coarse inert structure content of a boundary value (5 to 7% by volume) or more. The manufacturing method of the blast furnace coke including the crushing process to perform is disclosed (patent document 1).

特開２００８−２９７３８５号公報JP 2008-297385 A

しかしながら、上記特許文献１に示す粉砕方法に対して、さらに、コークス強度を確実に向上できる粉砕方法が望まれてきた。そこで、本願発明は、コークス強度を向上させるためのコークス炉装入用配合炭の製造方法を提供することを目的とする。     However, in addition to the pulverization method disclosed in Patent Document 1, a pulverization method that can reliably improve coke strength has been desired. Then, an object of this invention is to provide the manufacturing method of the coal blend for coke oven charging for improving coke intensity | strength.

本発明者等は、コークス用原料炭として使用する石炭を高イナート含有炭と低イナート低石炭化度炭とに分類し、これらをそれぞれ粉砕した粉砕炭を含む配合炭を製造するコークス炉装入用配合炭の製造方法において、高イナート含有炭および低イナート低石炭化度炭それぞれの粉砕粒度とコークス強度との関係を調べたところ、高イナート含有炭および低イナート低石炭化度炭のそれぞれの粉砕粒度がある範囲に達した時にコークス強度が極大となることを発見した。   The present inventors categorized coal used as coking raw material coal into high-inert coal and low-inert low-coalized coal, and manufactured a coal blend containing pulverized coal obtained by pulverizing these respectively. In the blended coal manufacturing method, the relationship between the pulverized particle size and coke strength of each of the high inert content coal and the low inert low coal content coal was investigated, and each of the high inert content coal and the low inert low coal content coal was examined. It has been found that the coke strength becomes maximum when the pulverized particle size reaches a certain range.

本発明者等は、コークス用原料炭として使用する石炭を高イナート含有炭と低イナート含有炭に分類し、さらに低イナート含有炭は高石炭化度炭と、低石炭化度炭に分類し、これらをそれぞれ粉砕した粉砕炭を含む配合炭を製造するコークス炉装入用配合炭の製造方法において、低石炭化度炭の粉砕粒度とコークス強度との関係を調べたところ、さらに、低イナート高石炭化度炭の粉砕粒度がある範囲に達した時にコークス強度が極大となることを発見した。
本明細書では、粗大イナート組織の含有量が５〜７体積％の境界値を用いて、該含有量よりも高い銘柄の石炭を高イナート含有炭と定義し、粗大イナート組織の含有量が境界値以下の銘柄の石炭を低イナート含有炭と定義する。この境界値の設定については、後述する。
さらに、低イナート含有炭のうちビトリニット平均反射率Ｒｏ（％）が０．９％よりも高い銘柄の石炭を高石炭化度炭と定義し、ビトリニット平均反射率Ｒｏ（％）が０．９％以下の銘柄の石炭を低石炭化度炭と定義する。なお、粗大イナート組織の含有量は、粒径３ｍｍ以下の累積％が７０〜８０質量％となるように粒度調整した原料炭中に含まれる、１．５ｍｍ以上の最大長さを有するイナート組織の含有量（ｖｏｌ．％）と定義する。この定義の詳細については、特開2008-297385号公報に記載されているため、詳細な説明を省略する。 The present inventors classify coal used as coking raw material coal into high inert coal and low inert coal, and further classify low inert coal into high coal and low coal. In the method for producing a blended coal for charging a coke oven that produces a blended coal containing pulverized coal obtained by pulverizing each of these, the relationship between the pulverized particle size of low-coalized coal and coke strength was investigated. It was found that the strength of coke is maximized when the pulverized particle size of coalified coal reaches a certain range.
In the present specification, using a boundary value having a coarse inert structure content of 5 to 7% by volume, coal of a brand higher than the content is defined as a high inert coal, and the coarse inert structure content is the boundary. Coal with a grade below the value is defined as low inert coal. The setting of this boundary value will be described later.
Further, among low-inert coal, a coal having a vitrinite average reflectance Ro (%) higher than 0.9% is defined as a high-coalized coal, and a vitrinite average reflectance Ro (%) is 0.9%. The following brands of coal are defined as low-rank coal. In addition, the content of the coarse inert structure is that of the inert structure having a maximum length of 1.5 mm or more, which is included in the raw coal whose particle size is adjusted so that the cumulative% of the particle diameter of 3 mm or less is 70 to 80% by mass. It is defined as the content (vol.%). The details of this definition are described in Japanese Patent Application Laid-Open No. 2008-297385, and thus detailed description thereof is omitted.

低石炭化度炭は、強粉砕することにより、その内部に生成されるクラックのサイズが小さくなり、コークス強度が上昇する。図２は、コークス中の低石炭化度炭由来の部分の拡大写真であり、矢印で示す部分がクラックである。しかしながら、低石炭化度炭の粉砕粒度がある境界値を超えて小さくすると、再固化温度が低い低石炭化度炭が分散することにより、高石炭化度炭の膨張性を阻害する阻害効果が高くなり、結果的にコークス強度の上昇が妨げられるということがわかった。そして、本発明者等は、この境界値が低石炭化度炭の全膨張率及び低石炭化度炭を含む配合炭全体の全膨張率によって変動することを発見した。本明細書では、配合炭全体の全膨張率を、配合炭に使用した各石炭の全膨張率を配合比率で加重平均することにより算出した値と定義する。   When the low-carbonized coal is strongly pulverized, the size of cracks generated in the inside is reduced, and the coke strength is increased. FIG. 2 is an enlarged photograph of a portion derived from low-rank coal in coke, and a portion indicated by an arrow is a crack. However, if the pulverized particle size of the low-carbonized coal is reduced beyond a certain boundary value, the low-carbonized coal having a low resolidification temperature is dispersed, thereby inhibiting the expansion of the high-carbonized coal. As a result, it was found that the increase in coke strength was hindered. And the present inventors discovered that this boundary value was fluctuate | varied with the total expansion coefficient of the whole coal blend including the low expansion coal and the low expansion coal. In this specification, the total expansion coefficient of the entire blended coal is defined as a value calculated by weighted averaging the total expansion ratio of each coal used in the blended coal with a blend ratio.

さらに、本発明者等は、高イナート含有炭を強粉砕し、かつ、低石炭化度炭を適切に強粉砕することによるコークス強度向上効果が飛躍的に向上することを発見した。
より具体的には、本発明に係るコークス炉装入用配合炭の製造方法は、（１）コークス用原料炭として使用する複数銘柄の石炭を粒径３ｍｍ以下の累積％が７０〜８０質量％となるように粒度調整した原料炭中に含まれる、１．５ｍｍ以上の最大長さを有する粗大イナート組織の含有量が５〜７体積％の境界値を用いて、この含有量が境界値よりも高い高イナート含有炭と、粗大イナート組織の含有量が境界値以下であって、ビトリニット平均反射率が０．９％以下である低イナート低石炭化度炭に分類し、それぞれ粉砕して配合した配合炭を製造するコークス炉装入用配合炭の製造方法であって、前記高イナート含有炭を粒径３ｍｍ以下の累積％が９０質量％以上となるように強粉砕する第１の工程と、前記配合炭全体の全膨張率が４０％未満の場合、全膨張率が２０％以上の前記低イナート低石炭化度炭は、粒径３ｍｍ以下の累積％が８２〜８８質量％となるように粉砕し、全膨張率が２０％未満の前記低イナート低石炭化度炭は、粒径３ｍｍ以下の累積％が７２〜７８質量％となるように粉砕し、前記配合炭全体の全膨張率が４０％以上の場合、全膨張率が２０％以上の前記低イナート低石炭化度炭は、粒径３ｍｍ以下の累積％が９０質量％以上となるように粉砕し、全膨張率が２０％未満の前記低イナート低石炭化度炭は、粒径３ｍｍ以下の累積％が８２質量％以上となるように粉砕する第２の工程、を含むことを特徴とする。
Furthermore, the present inventors have found that the effect of improving the coke strength by strongly pulverizing high inert-containing coal and appropriately pulverizing low-carbonized coal is dramatically improved.
More specifically, the method for producing a blended coal for charging a coke oven according to the present invention is as follows: (1) Cumulative% of a plurality of brands used as coking coal is 70 to 80% by mass with a particle size of 3 mm or less. The content of the coarse inert structure having a maximum length of 1.5 mm or more contained in the raw coal whose particle size was adjusted to be 5% to 7% by volume is used, and this content is more than the boundary value. Are classified into low-inert low-coalizing coals with high high-inert content coal and low-inert low-coalization coal with a coarse inert structure content below the boundary value and a vitrinite average reflectance of 0.9% or less. A method for producing a blended coal for charging a coke oven for producing a blended coal, wherein the high inert-containing coal is strongly pulverized such that a cumulative percentage of a particle size of 3 mm or less is 90% by mass or more; The overall expansion rate of the blended coal is 40% When full, the low-inert low-coalized coal with a total expansion rate of 20% or more is pulverized so that the cumulative percentage with a particle size of 3 mm or less is 82 to 88% by mass, and the total expansion rate is less than 20%. The low-inert low-coalized coal is pulverized so that the cumulative percentage with a particle size of 3 mm or less is 72 to 78 mass%, and when the total expansion coefficient of the entire blended coal is 40% or more, the total expansion coefficient is 20 % Of the low inert low-coalized coal with a particle size of 3 mm or less is pulverized so that the cumulative percentage with a particle size of 3 mm or less is 90% by mass or more. And a second step of pulverizing so that the cumulative percentage with a particle size of 3 mm or less is 82 mass% or more.

本発明に係るコークス炉装入用配合炭の製造方法は、（２）前記粗大イナート組織の含有量が前記の境界値以下である低イナート含有炭について、さらにビトリニット平均反射率が０．９％よりも高い低イナート高石炭化度炭に分類し、それぞれ粉砕して配合した配合炭を製造するコークス炉装入用配合炭の製造方法であって、さらに、前記低イナート高石炭化度炭を粒径３ｍｍ以下の累積％が８２質量％以上８８質量％以下となるように粉砕する第３の工程、を含むことを特徴とする。   The method for producing a blended coal for charging a coke oven according to the present invention is as follows: (2) For a low inert coal having a coarse inert structure content equal to or less than the boundary value, the vitrinite average reflectance is 0.9%. A method for producing a blended coal for charging a coke oven, which is classified into higher low-inert and high-coalized coal, and pulverized and blended respectively, and further comprising the low-inert and high-coalized coal And a third step of pulverizing so that the cumulative percentage of the particle size of 3 mm or less is 82 mass% or more and 88 mass% or less.

本発明によれば、石炭の強粉砕によるコークス強度向上効果が極めて高いコークス炉装入用配合炭の製造方法を提供することができる。   ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the coke oven charging coal blend with the extremely high effect of the coke strength improvement by the strong pulverization of coal can be provided.

コークスの製造工程を示した工程図である。It is process drawing which showed the manufacturing process of coke. コークス中の低石炭化度炭由来の部分の拡大図（拡大写真）であるIt is an enlarged view (magnified photo) of the part derived from low-rank coal in coke

図１を参照しながらコークスの製造方法について説明する。図１は、コークスの製造工程を示した工程図である。石炭ヤード１Ａ〜１Ｅのそれぞれには、単一もしくは複数の銘柄の石炭が貯留されている。各石炭ヤード１Ａ〜１Ｅの各石炭は各配合層２Ａ〜２Ｅに搬送される。各配合層２Ａ〜２Ｅの石炭はそれぞれ各粉砕機３Ａ〜３Ｅにおいて粉砕される。
ここで、各粉砕機３Ａ〜３Ｅにおいて粉砕される石炭が高イナート含有炭である場合には、「粒径３ｍｍ以下の累積％が９０質量％以上」となるように強粉砕する。他方、各粉砕機３Ａ〜３Ｅにおいて粉砕される石炭が低イナート含有炭で、かつ低石炭化度炭である場合には、低石炭化度炭の単味全膨張率と、配合炭全体の全膨張率との関係から適切な粉砕粒度を割り出し（詳細については後述する）、当該粉砕粒度に基づき粉砕する。さらに、各粉砕機３Ａ〜３Ｅにおいて粉砕される石炭が低イナート含有炭で、かつ高石炭化度炭も配合する場合には、「粒径３ｍｍ以下の累積％が８２質量％以上８８質量％以下」となるように粉砕する。 A method for producing coke will be described with reference to FIG. FIG. 1 is a process diagram showing a coke production process. In each of the coal yards 1A to 1E, single or plural brands of coal are stored. Each coal of each coal yard 1A-1E is conveyed to each compounding layer 2A-2E. The coal of each compounding layer 2A-2E is grind | pulverized in each grinder 3A-3E, respectively.
Here, when the coal pulverized in each of the pulverizers 3A to 3E is high-inert coal, strong pulverization is performed so that "cumulative percentage of particle size of 3 mm or less is 90 mass% or more". On the other hand, when the coal pulverized in each of the pulverizers 3A to 3E is low-inert coal and low-carbon coal, the total expansion rate of the low-carbon coal and the total blended coal An appropriate pulverized particle size is determined from the relationship with the expansion coefficient (details will be described later), and pulverized based on the pulverized particle size. Furthermore, when the coal pulverized in each of the pulverizers 3A to 3E is a low-inert coal and a high-coalized coal, the cumulative percentage with a particle size of 3 mm or less is 82% by mass or more and 88% by mass or less. ”

粉砕された石炭は配合されて乾燥分級機４に搬送される。配合炭にはコークス炉において発塵しやすい微粉が含まれている。このため、乾燥分級機４では、配合炭を乾燥させながら粗粒と微粉とに分級する。粗粒はそのままコークス炉６に装入される。微粉は塊成機５に搬送され、粘結材とともに混練などされることにより、フレーク状又はブリケット状に塊成化され、コークス炉６に装入される。   The pulverized coal is blended and conveyed to the drying classifier 4. The blended coal contains fine powder that tends to generate dust in a coke oven. For this reason, the drying classifier 4 classifies the blended coal into coarse particles and fine powder while drying. The coarse particles are charged into the coke oven 6 as they are. The fine powder is conveyed to the agglomeration machine 5 and kneaded together with the caking additive, so that it is agglomerated into flakes or briquettes and charged into the coke oven 6.

次に、石炭の銘柄に応じた粉砕粒度について実施例を示して詳細に説明する。互いに石炭の銘柄及び/又は配合比率が異なる配合炭（１）―１、配合炭（１）―２、配合炭（１）―３、配合炭（２）―１、配合炭（２）―２、配合炭（２）―３、配合炭（３）―１、配合炭（３）−２、配合炭（４）―１及び配合炭（４）―２について粉砕粒度とコークス強度との関係を調べた。   Next, the pulverization particle size corresponding to the brand of coal will be described in detail with reference to examples. Blended coal (1) -1, blended coal (1) -2, blended coal (1) -3, blended coal (2) -1, blended coal (2) -2 with different coal brands and / or blending ratios , The relationship between the pulverized particle size and the coke strength for blended coal (2) -3, blended coal (3) -1, blended coal (3) -2, blended coal (4) -1 and blended coal (4) -2 Examined.

表１は、配合炭（１）―１、配合炭（１）―２、配合炭（１）―３にそれぞれ含まれる石炭Ａ、石炭Ｂ、石炭Ｃ、石炭Ｄ、石炭Ｅ及び石炭Ｆの配合比率と、これらの石炭Ａ〜Ｆの石炭性状を示している。Ｉ（％）は粗大イナート含有量を示し、Ｒｏ（％）はビトリニット平均反射率を示し、ＴＤ（％）は全膨張率を示している。なお、石炭中の粗大イナート組織の含有量が６体積％を境界値として、粗大イナート含有量Ｉ（％）が６体積％よりも高い石炭を高イナート含有炭とし、粗大イナート含有量Ｉ（％）が６体積％以下の石炭を低イナート含有炭と分類した場合について、以下に詳述する。   Table 1 shows the blends of Coal A, Coal B, Coal C, Coal D, Coal E, and Coal F included in Coal Coal (1) -1, Coal Coal (1) -2, Coal Coal (1) -3, respectively. The ratio and the coal properties of these coals A to F are shown. I (%) indicates the coarse inert content, Ro (%) indicates the vitrinite average reflectance, and TD (%) indicates the total expansion coefficient. In addition, the content of the coarse inert structure in the coal is 6% by volume as a boundary value, coal having a coarse inert content I (%) higher than 6% by volume is defined as the high inert content coal, and the coarse inert content I (% ) Will be described in detail below when the coal of 6 vol% or less is classified as low-inert coal.

Ａ炭は、粗大イナート含有量Ｉ（％）が７.３%であり、ビトリニット平均反射率Ｒｏ（％）が１．４２％であり、全膨張率ＴＤ（％）が９８％であり、粗大イナート含有量Ｉ（％）が６％よりも高いため、高イナート含有炭である（以下、高イナート含有炭Ａと称する場合がある）。Ｂ炭は、粗大イナート含有量Ｉ（％）が８.７％であり、ビトリニット平均反射率Ｒｏ（％）が１．４０％であり、全膨張率ＴＤ（％）が１９％であり、粗大イナート含有量Ｉ（％）が６％よりも高いため、高イナート含有炭である（以下、高イナート含有炭Ｂと称する場合がある）。Ｃ炭は、粗大イナート含有量Ｉ（％）が７．６％であり、ビトリニット平均反射率Ｒｏ（％）が１．２２％であり、全膨張率ＴＤ（％）が８９％であり、粗大イナート含有量Ｉ（％）が６％よりも高いため、高イナート含有炭である（以下、高イナート含有炭Ｃと称する場合がある）。   Coal A has a coarse inert content I (%) of 7.3%, a vitrinite average reflectance Ro (%) of 1.42%, a total expansion coefficient TD (%) of 98%, and is coarse Since the inert content I (%) is higher than 6%, it is a high-inert coal (hereinafter, sometimes referred to as a high-inert coal A). B charcoal has a coarse inert content I (%) of 8.7%, a vitrinite average reflectance Ro (%) of 1.40%, a total expansion coefficient TD (%) of 19%, and is coarse Since the inert content I (%) is higher than 6%, it is a high-inert coal (hereinafter, sometimes referred to as a high-inert coal B). Coal C has a coarse inert content I (%) of 7.6%, a vitrinite average reflectance Ro (%) of 1.22%, a total expansion coefficient TD (%) of 89%, and coarse Since the inert content I (%) is higher than 6%, it is a high-inert coal (hereinafter sometimes referred to as a high-inert coal C).

Ｄ炭は、粗大イナート含有量Ｉ（％）が４.１％であり、ビトリニット平均反射率Ｒｏ（％）が１．２８％であり、全膨張率ＴＤ（％）が１５０％であり、粗大イナート含有量Ｉ（％）が６．０％以下でありビトリニット平均反射率Ｒｏ（％）が０．９％よりも高いため、低イナート高石炭化度炭である（以下、高石炭化度炭Ｄと称する場合がある）。   D charcoal has a coarse inert content I (%) of 4.1%, a vitrinite average reflectance Ro (%) of 1.28%, a total expansion coefficient TD (%) of 150%, and is coarse Since the inert content I (%) is 6.0% or less and the vitrinite average reflectance Ro (%) is higher than 0.9%, it is a low inert high-coalizing coal (hereinafter referred to as high-coalizing coal). May be referred to as D).

Ｅ炭は、粗大イナート含有量Ｉ（％）が３.５％であり、ビトリニット平均反射率Ｒｏ（％）が０．７２％であり、全膨張率ＴＤ（％）が４３％であり、ビトリニット平均反射率Ｒｏ（％）が０．９％以下であるため、低イナート低石炭化度炭である（以下、低石炭化度炭Ｅと称する場合がある）。Ｆ炭は、粗大イナート含有量Ｉ（％）が４.３％であり、ビトリニット平均反射率Ｒｏ（％）が０．６９％であり、全膨張率ＴＤ（％）が３０％であり、粗大イナート含有量Ｉ（％）が６．０％以下でありビトリニット平均反射率Ｒｏ（％）が０．９％以下であるため、低イナート低石炭化度炭である（以下、低石炭化度炭Ｆと称する場合がある）。   E charcoal has a coarse inert content I (%) of 3.5%, a vitrinite average reflectance Ro (%) of 0.72%, a total expansion coefficient TD (%) of 43%, and vitrinite Since the average reflectance Ro (%) is 0.9% or less, it is a low-inert low-coalized coal (hereinafter sometimes referred to as low-carbonized coal E). F charcoal has a coarse inert content I (%) of 4.3%, a vitrinite average reflectance Ro (%) of 0.69%, a total expansion coefficient TD (%) of 30%, and is coarse Since the inert content I (%) is 6.0% or less and the vitrinite average reflectance Ro (%) is 0.9% or less, it is a low inert low-coalizing coal (hereinafter referred to as low-coalizing coal). May be referred to as F).

配合炭（１）―１は、高イナート含有炭Ａを２０質量％含み、高イナート含有炭Ｂを２０質量％含み、高石炭化度炭Ｄを２０質量％含み、低石炭化度炭Ｅを２５質量％含み、低石炭化度炭Ｆを１５質量％含む。配合炭（１）―１は、ビトリニット平均反射率Ｒｏ（％）が１．１０％であった。配合炭（１）―１のビトリニット平均反射率Ｒｏ（％）は、石炭Ａ〜Ｆの各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（１）―１の全膨張率ＴＤ（％）は６９％であった。配合炭（１）―１の全膨張率ＴＤ（％）は、石炭Ａ〜Ｆの各全膨張率ＴＤ（％）を配合比率で加重平均することにより算出した。   Blended coal (1) -1 contains 20% by mass of high inert-containing coal A, 20% by mass of high inert-containing coal B, 20% by mass of high coal content coal D, and low coal content coal E 25% by mass, and 15% by mass of low-carbonized coal F. The blended charcoal (1) -1 had a vitrinite average reflectance Ro (%) of 1.10%. Vitrinite average reflectance Ro (%) of blended coal (1) -1 was calculated by weighted averaging the vitrinite average reflectance Ro (%) of coals A to F by blending ratio. The total expansion coefficient TD (%) of the blended coal (1) -1 was 69%. The total expansion coefficient TD (%) of the blended coal (1) -1 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals A to F with the blend ratio.

配合炭（１）―２は、高イナート含有炭Ａを１０質量％含み、高イナート含有炭Ｂを２５質量％含み、高イナート含有炭Ｃを１５質量％含み、低石炭化度炭Ｅを２５質量％含み、低石炭化度炭Ｆを２５質量％含む。配合炭（１）―２は、ビトリニット平均反射率Ｒｏ（％）が１．０３％であった。配合炭（１）―２のビトリニット平均反射率Ｒｏ（％）は、石炭Ａ〜Ｆの各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（１）―２の全膨張率ＴＤ（％）は４６％であった。配合炭（１）―２の全膨張率ＴＤ（％）は、石炭Ａ〜Ｆの各全膨張率ＴＤ（％）を配合比率で加重平均することにより算出した。   The blended coal (1) -2 contains 10% by mass of the high inert content coal A, 25% by mass of the high inert content coal B, 15% by mass of the high inert content coal C, and 25% of the low-coalizing coal E Contains 25% by mass of low-carbonized coal F. The blended charcoal (1) -2 had a vitrinite average reflectance Ro (%) of 1.03%. The vitrinite average reflectance Ro (%) of the blended coal (1) -2 was calculated by weighted averaging the vitrinite average reflectance Ro (%) of the coals A to F by the blending ratio. The total expansion coefficient TD (%) of the blended coal (1) -2 was 46%. The total expansion coefficient TD (%) of the blended coal (1) -2 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals A to F with the blend ratio.

配合炭（１）―３は、高イナート含有炭Ａを１０質量％含み、高イナート含有炭Ｂを２０質量％含み、高石炭化度炭Ｄを３０質量％含み、低石炭化度炭Ｅを２５質量％含み、低石炭化度炭Ｆを１５質量％含む。配合炭（１）―３は、ビトリニット平均反射率Ｒｏ（％）が１．０９％であった。配合炭（１）―３のビトリニット平均反射率Ｒｏ（％）は、石炭Ａ〜Ｆの各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（１）―３の全膨張率ＴＤ（％）は７４％であった。配合炭（１）―３の全膨張率ＴＤ（％）は、石炭Ａ〜Ｆの各全膨張率ＴＤ（％）を配合比率で加重平均することにより算出した。   The blended coal (1) -3 contains 10% by mass of the high inert content coal A, 20% by mass of the high inert content coal B, 30% by mass of the high coal content coal D, and low coal content coal E. 25% by mass, and 15% by mass of low-carbonized coal F. The blended charcoal (1) -3 had a vitrinite average reflectance Ro (%) of 1.09%. The vitrinite average reflectance Ro (%) of the blended coal (1) -3 was calculated by weighted averaging the vitrinite average reflectance Ro (%) of the coals A to F by the blending ratio. The total expansion coefficient TD (%) of the blended coal (1) -3 was 74%. The total expansion coefficient TD (%) of the blended coal (1) -3 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals A to F with the blend ratio.

表２は、配合炭（２）―１、配合炭（２）−２、配合炭（２）―３に含まれる石炭Ａ〜Ｈの配合比率と、これらの石炭Ａ〜Ｈの石炭性状を示している。   Table 2 shows the blending ratio of coals A to H contained in blended coal (2) -1, blended coal (2) -2, blended coal (2) -3, and the coal properties of these coals A to H. ing.

Ｇ炭は、粗大イナート含有量Ｉ（％）が４.８％であり、ビトリニット平均反射率Ｒｏ（％）が０．６６％であり、全膨張率ＴＤ（％）が１５％であり、粗大イナート含有量Ｉ（％）が６．０％以下でありビトリニット平均反射率Ｒｏ（％）が０．９％以下であるため、低イナート低石炭化度炭である（以下、低石炭化度炭Ｇと称する場合がある）。Ｈ炭は、粗大イナート含有量Ｉ（％）が４.６％であり、ビトリニット平均反射率Ｒｏ（％）が０．６６％であり、全膨張率ＴＤ（％）が３％であり、粗大イナート含有量Ｉ（％）が６．０％以下でありビトリニット平均反射率Ｒｏ（％）が０．９％以下であるため、低イナート低石炭化度炭である（以下、低石炭化度炭Ｈと称する場合がある）。   G charcoal has a coarse inert content I (%) of 4.8%, a vitrinite average reflectance Ro (%) of 0.66%, a total expansion coefficient TD (%) of 15%, and is coarse Since the inert content I (%) is 6.0% or less and the vitrinite average reflectance Ro (%) is 0.9% or less, it is a low inert low-coalizing coal (hereinafter referred to as low-coalizing coal). May be referred to as G). H charcoal has a coarse inert content I (%) of 4.6%, a vitrinite average reflectance Ro (%) of 0.66%, a total expansion coefficient TD (%) of 3%, and coarse. Since the inert content I (%) is 6.0% or less and the vitrinite average reflectance Ro (%) is 0.9% or less, it is a low inert low-coalizing coal (hereinafter referred to as low-coalizing coal). May be referred to as H).

配合炭（２）―１は、高イナート含有炭Ａを１０質量％含み、高イナート含有炭Ｂを３５質量％含み、高石炭化度炭Ｄを２０質量％含み、低石炭化度炭Ｇを２５質量％含み、低石炭化度炭Ｈを１０質量％含む。配合炭（２）―１のビトリニット平均反射率Ｒｏ（％）は１．１２％であった。配合炭（２）―１のビトリニット平均反射率Ｒｏ（％）は、石炭Ａ〜Ｈ炭の各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（２）―１の全膨張率ＴＤ（％）は５１％であった。配合炭（２）―１の全膨張率ＴＤ（％）は、石炭Ａ〜Ｈ炭の各全膨張率ＴＤ（％）を配合比率で加重平均することにより算出した。   The blended coal (2) -1 contains 10% by mass of the high inert content coal A, 35% by mass of the high inert content coal B, 20% by mass of the high coal degree coal D, and low coal degree coal G. 25% by mass and 10% by mass of low-carbonized coal H. The blended charcoal (2) -1 had an average vitrinite reflectance Ro (%) of 1.12%. The vitrinite average reflectance Ro (%) of the blended coal (2) -1 was calculated by weighted averaging the vitrinite average reflectance Ro (%) of the coals A to H with the blending ratio. The total expansion coefficient TD (%) of the blended coal (2) -1 was 51%. The total expansion coefficient TD (%) of the blended coal (2) -1 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals A to H with the blending ratio.

配合炭（２）―２は、高イナート含有炭Ａを３０質量％含み、高イナート含有炭Ｃを４０質量％含み、低石炭化度炭Ｇを５質量％含み、低石炭化度炭Ｈを２５質量％含む。配合炭（２）―２のビトリニット平均反射率Ｒｏ（％）は１．１１％であった。配合炭（２）―２のビトリニット平均反射率Ｒｏ（％）は、石炭Ａ〜Ｈの各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（２）―２の全膨張率ＴＤ（％）は６７％であった。配合炭（２）―２の全膨張率ＴＤ（％）は、石炭Ａ〜Ｈの各全膨張率ＴＤ（％）を配合比率で加重平均することにより算出した。   The blended coal (2) -2 contains 30% by mass of the high inert content coal A, 40% by mass of the high inert content coal C, 5% by mass of the low coal content coal G, and the low coal content coal H. Contains 25% by mass. The blended charcoal (2) -2 had a vitrinite average reflectance Ro (%) of 1.11%. The vitrinite average reflectance Ro (%) of the blended coal (2) -2 was calculated by weighted averaging the vitrinite average reflectance Ro (%) of the coals A to H by the blending ratio. The total expansion coefficient TD (%) of the blended coal (2) -2 was 67%. The total expansion coefficient TD (%) of the blended coal (2) -2 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals A to H with the blend ratio.

表３は、配合炭（３）―１、配合炭（３）−２に含まれる石炭Ａ〜Ｈの配合比率と、これらの石炭Ａ〜Ｈの石炭性状を示している。   Table 3 shows the blending ratio of coals A to H contained in blended coal (3) -1 and blended coal (3) -2, and the coal properties of these coals A to H.

配合炭（３）―１は、高イナート含有炭Ａを１０質量％含み、高イナート含有炭Ｂを３０質量％含み、高石炭化度炭Ｄを１０質量％含み、低石炭化度炭Ｇを２５質量％含み、低石炭化度炭Ｈを２５質量％含む。配合炭（３）―１のビトリニット平均反射率Ｒｏ（％）は１．０２％であった。配合炭（３）―１のビトリニット平均反射率Ｒｏ（％）は、石炭Ａ〜Ｈ炭の各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（３）―１の全膨張率ＴＤ（％）は３５％であった。配合炭（３）―１の全膨張率ＴＤ（％）は、石炭Ａ〜Ｈの各全膨張率ＴＤ（％）を配合比率で加重平均することにより算出した。   The blended coal (3) -1 contains 10% by mass of the high inert content coal A, 30% by mass of the high inert content coal B, 10% by mass of the high coal degree coal D, and the low coal degree coal G. 25% by mass and 25% by mass of low-carbonized coal H. The blended charcoal (3) -1 had a vitrinite average reflectance Ro (%) of 1.02%. The vitrinite average reflectance Ro (%) of the blended coal (3) -1 was calculated by weighted averaging the vitrinite average reflectance Ro (%) of the coals A to H with the blending ratio. The total expansion coefficient TD (%) of the blended coal (3) -1 was 35%. The total expansion coefficient TD (%) of the blended coal (3) -1 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals A to H by the blend ratio.

配合炭（３）―２は、高イナート含有炭Ｂを３５質量％含み、高イナート含有炭Ｃを１５質量％含み、低石炭化度炭Ｇを２５質量％含み、低石炭化度炭Ｈを２５質量％含む。配合炭（３）―２のビトリニット平均反射率Ｒｏ（％）は１．００％であった。配合炭（３）―２のビトリニット平均反射率Ｒｏ（％）は、石炭Ｂ〜Ｈの各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（３）―２の全膨張率ＴＤ（％）は２５％であった。配合炭（３）―２の全膨張率ＴＤ（％）は、石炭Ｂ〜Ｈの各全膨張率ＴＤ（％）を配合条件で加重平均することにより算出した。   Blended coal (3) -2 contains 35% by mass of high inert coal B, 15% by mass of high inert coal C, 25% by mass of low coal G, and low coal H Contains 25% by mass. The blended charcoal (3) -2 had a vitrinite average reflectance Ro (%) of 1.00%. The vitrinite average reflectance Ro (%) of the blended coal (3) -2 was calculated by weighted averaging the vitrinite average reflectance Ro (%) of the coals B to H by the blending ratio. The total expansion coefficient TD (%) of the blended coal (3) -2 was 25%. The total expansion coefficient TD (%) of the blended coal (3) -2 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals B to H under blending conditions.

表４は、配合炭（４）―１、配合炭（４）―２に含まれる石炭Ｂ〜Ｇの配合比率と、これらの石炭Ｂ〜Ｇの石炭性状を示している。   Table 4 shows the blending ratio of coals BG contained in the blended coal (4) -1 and blended coal (4) -2, and the coal properties of these coals BG.

配合炭（４）―１は、高イナート含有炭Ｂを４５質量％含み、高石炭化度炭Ｄを５質量％含み、低石炭化度炭Ｅを２５質量％含み、低石炭化度炭Ｇを２５質量％含む。配合炭（４）―１のビトリニット平均反射率Ｒｏ（％）は１．０４％であった。配合炭（４）―１のビトリニット平均反射率Ｒｏ（％）は、石炭Ｂ〜Ｇの各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（４）―１の全膨張率ＴＤ（％）は３０％であった。配合炭（４）―１の全膨張率ＴＤ（％）は、石炭Ｂ〜Ｇの各全膨張率ＴＤ（％）を配合比率で加重平均することにより算出した。   Blended coal (4) -1 contains 45% by mass of high inert-containing coal B, 5% by mass of high coal content coal D, 25% by mass of low coal content coal E, and low coal content coal G 25 mass%. The blended charcoal (4) -1 had a vitrinite average reflectance Ro (%) of 1.04%. Vitrinite average reflectance Ro (%) of blended coal (4) -1 was calculated by weighted average of vitrinite average reflectance Ro (%) of coals B to G by blending ratio. The total expansion coefficient TD (%) of the blended coal (4) -1 was 30%. The total expansion coefficient TD (%) of the blended coal (4) -1 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals B to G with the blend ratio.

配合炭（４）―２は、高イナート含有炭Ｂを３０質量％含み、高イナート含有炭Ｃを２０質量％含み、低石炭化度炭Ｆを２５質量％含み、低石炭化度炭Ｇを２５質量％含む。配合炭（４）―２のビトリニット平均反射率Ｒｏ（％）は１．００％であった。配合炭（４）―２のビトリニット平均反射率Ｒｏ（％）は、石炭Ｂ〜Ｇの各ビトリニット平均反射率Ｒｏ（％）を配合比率で加重平均することにより算出した。配合炭（４）―２の全膨張率ＴＤ（％）は３５％であった。配合炭（４）―２の全膨張率ＴＤ（％）は、石炭Ｂ〜Ｇの各全膨張率ＴＤ（％）を配合比率で加重平均することにより算出した。   Blended coal (4) -2 contains 30% by mass of high inert-containing coal B, 20% by mass of high inert-containing coal C, 25% by mass of low-carbonized coal F, Contains 25% by mass. The blended charcoal (4) -2 had a vitrinite average reflectance Ro (%) of 1.00%. The vitrinite average reflectance Ro (%) of the blended coal (4) -2 was calculated by weighted averaging the vitrinite average reflectance Ro (%) of the coals BG with the blending ratio. The total expansion coefficient TD (%) of the blended coal (4) -2 was 35%. The total expansion coefficient TD (%) of the blended coal (4) -2 was calculated by weighted averaging the total expansion coefficients TD (%) of the coals B to G with the blend ratio.

表５は、配合炭（１）−１において、低石炭化度炭Ｅの粉砕粒度を、粒径３ｍｍ以下の累積％を７５質量％、８２質量％、９０質量％、９５質量％、１００質量％の間で変化させたときの各配合炭（１）―１のコークス強度ＤＩ１５０ １５（-）を示している。なお、表５の試験では、高イナート含有炭ＡおよびＢの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、高石炭化度炭Ｄの粉砕粒度を「粒径３ｍｍ以下の累積％が８５質量％」に、低石炭化度炭Ｆの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 5 shows the pulverized particle size of the low-coalized coal E in the blended coal (1) -1, 75% by mass, 82% by mass, 90% by mass, 95% by mass, and 100% by mass. The coke strength DI 150 15 (-) of each blended coal (1) -1 when changed between% is shown. In the test of Table 5, the pulverized particle size of the high-inert coals A and B is “95% by mass when the particle size is 3 mm or less is 95% by mass”, and the pulverized particle size of the high coal degree coal D is “the particle size is 3 mm or less. The crushed particle size of the low-coalized coal F was unified to "cumulative% with a particle size of 3 mm or less is 75 mass%".

表６は、配合炭（１）−２において、低石炭化度炭Ｆの粉砕粒度を、粒径３ｍｍ以下の累積％を７５質量％、８２質量％、９０質量％、９５質量％、１００質量％の間で変化させたときの各配合炭（１）―２のコークス強度ＤＩ１５０ １５（-）を示している。なお、表６の試験では、高イナート含有炭Ａ乃至Ｃの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、低石炭化度炭Ｅの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 6 shows the pulverized particle size of the low-coalizing coal F in the blended coal (1) -2, and the cumulative percentage with a particle size of 3 mm or less is 75% by mass, 82% by mass, 90% by mass, 95% by mass, 100% by mass. The coke strength DI 150 15 (-) of each blended coal (1) -2 when changed between% is shown. In the tests of Table 6, the pulverized particle size of the high inert coals A to C is “95% by mass of the cumulative particle size of 3 mm or less is 95% by mass”, and the pulverized particle size of the low coal degree coal E is “the particle size of 3 mm or less. The cumulative percentage was unified to 75% by mass.

表７は、配合炭（１）―３において、低石炭化度炭Ｅの粉砕粒度を、粒径３ｍｍ以下の累積％を７５質量％、８２質量％、９０質量％、９５質量％、１００質量％の間で変化させたときの各配合炭（１）―３のコークス強度ＤＩ１５０ １５（-）を示している。なお、表７の試験では、高イナート含有炭Ａ及びＢの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、高石炭化度炭Ｄの粉砕粒度を「粒径３ｍｍ以下の累積％が８８質量％」に、低石炭化度炭Ｆの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 7 shows the blended coal (1) -3, in which the pulverized particle size of the low-coalizing coal E is 75% by mass, 82% by mass, 90% by mass, 95% by mass, and 100% by mass. The coke strength DI 150 15 (-) of each blended coal (1) -3 when changed between% is shown. In the test of Table 7, the pulverized particle size of the high inert coals A and B is “95% by mass of the cumulative particle size of 3 mm or less is 95% by mass”, and the pulverized particle size of the high coal degree coal D is “the particle size of 3 mm or less. The crushed particle size of the low-coalized coal F was unified to "cumulative% with a particle size of 3 mm or less is 75 mass%".

表８は、これらの表５〜７の結果をグラフにしたものであり、横軸が低石炭化度炭の粉砕粒度を示し、縦軸が配合炭のコークスのコークス強度ＤＩ１５０ １５（-）を示している。 Table 8 is a graph of the results of Tables 5 to 7, in which the horizontal axis indicates the pulverized particle size of the low-coalized coal, and the vertical axis indicates the coke strength DI 150 15 (−) of the blended coal. Is shown.

これらの表５〜表８から、配合炭（１）−１、（１）―２、（１）―３の場合には、粒径３ｍｍ以下の累積％が７５〜９０質量％の粉砕粒度において粉砕粒度が増す程、コークス強度ＤＩ１５０ １５（−）が増加することがわかった。また、粒径３ｍｍ以下の累積％が９０質量％より大きい場合には、コークス強度ＤＩ１５０ １５（−）は僅かしか向上しないことがわかった。したがって、配合炭（１）−１、（１）―２、（１）−３の場合には、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が９０質量％以上」に設定することにより、コークス強度を向上させることができるということがわかった。 From these Tables 5 to 8, in the case of blended coals (1) -1, (1) -2, (1) -3, the cumulative percentage with a particle size of 3 mm or less is 75 to 90% by mass. It was found that the coke strength DI 150 15 (−) increased as the pulverized particle size increased. Further, it was found that the coke strength DI 150 15 (−) is only slightly improved when the cumulative percentage with a particle size of 3 mm or less is larger than 90 mass%. Therefore, in the case of blended coals (1) -1, (1) -2, and (1) -3, the pulverized particle size of the low-coalizing coal is set to "cumulative percentage of particle size of 3 mm or less is 90 mass% or more" It was found that the coke strength can be improved by setting.

表９は、配合炭（２）―１において、低石炭化度炭Ｇの粉砕粒度を、粒径３ｍｍ以下の累積％が７２質量％、８２質量％、８８質量％、９５質量％、１００質量％の間で変化させたときの各配合炭（２）―１のコークス強度ＤＩ１５０ １５（-）を示している。なお、表９の試験では、高イナート含有炭Ａの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、高イナート含有炭Ｂの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、高石炭化度炭Ｄの粉砕粒度を「粒径３ｍｍ以下の累積％が８５質量％」に、低石炭化度炭Ｈの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 9 shows that the blended coal (2) -1 has a pulverized particle size of the low-coalized coal G, and the cumulative percentage with a particle size of 3 mm or less is 72% by mass, 82% by mass, 88% by mass, 95% by mass, 100% by mass. The coke strength DI 150 15 (-) of each blended coal (2) -1 when it is changed between%. In the tests shown in Table 9, the pulverized particle size of the high-inert coal A is “95% by mass when the particle size is 3 mm or less is 95% by mass”, and the pulverized particle size of the high-inert coal B is “the cumulative% when the particle size is 3 mm or less. 95% by mass, the pulverized particle size of the high-coalized coal D is “85% by mass with a cumulative particle size of 3 mm or less”, and the pulverized particle size of the low-coalized coal H is “the cumulative% with a particle size of 3 mm or less”. To 75% by mass.

表１０は、配合炭（２）−２において、低石炭化度炭Ｈの粉砕粒度を、粒径３ｍｍ以下の累積％が７２質量％、８２質量％、８８質量％、９５質量％、１００質量％の間で変化させたときの各配合炭（２）―２のコークス強度ＤＩ１５０ １５（-）を示している。なお、表１０の試験では、高イナート含有炭Ａ乃至Ｃの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、低石炭化度炭Ｇの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 10 shows the pulverized particle size of the low-coalized coal H in the blended coal (2) -2, in which the cumulative percentage with a particle size of 3 mm or less is 72 mass%, 82 mass%, 88 mass%, 95 mass%, 100 mass%. The coke strength DI 150 15 (−) of each blended coal (2) -2 when changed between% is shown. In the test of Table 10, the pulverized particle size of the high-inert coals A to C is “95% by mass when the particle size is 3 mm or less is 95% by mass”, and the pulverized particle size of the low-coalized coal G is “the particle size is 3 mm or less. The cumulative percentage was unified to 75% by mass.

表１１は、配合炭（２）―３において、低石炭化度炭Ｈの粉砕粒度を、粒径３ｍｍ以下の累積％が７２質量％、８２質量％、８８質量％、９５質量％、１００質量％の間で変化させたときの各配合炭（２）―３のコークス強度ＤＩ１５０ １５（-）を示している。なお、表１１の試験では、高イナート含有炭Ｂの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、高石炭化度炭Ｄの粉砕粒度を「粒径３ｍｍ以下の累積％が８８質量％」に、低石炭化度炭Ｇの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 11 shows that in the blended coal (2) -3, the pulverized particle size of the low-coalized coal H is 72% by mass, 82% by mass, 88% by mass, 95% by mass, and 100% by mass with a particle size of 3 mm or less. The coke strength DI 150 15 (−) of each blended coal (2) -3 when changed between% is shown. In the test of Table 11, the pulverized particle size of the high inert coal B is “95% by mass when the particle size is 3 mm or less is 95% by mass”, and the pulverized particle size of the high coal degree coal D is “cumulative% when the particle size is 3 mm or less. Is 88 mass% ", and the pulverized particle size of the low-coalized coal G is unified to" cumulative percentage of particle size of 3 mm or less is 75 mass% ".

表１２は、これら表９乃至表１１の結果をグラフにしたものであり、横軸が低石炭化度炭の粉砕粒度を示し、縦軸が配合炭のコークス強度ＤＩ１５０ １５（-）を示している。 Table 12 is a graph of the results of Tables 9 to 11, with the horizontal axis indicating the pulverized particle size of the low-coalized coal and the vertical axis indicating the coke strength DI 150 15 (-) of the blended coal. ing.

これらの表９〜１２から、配合炭（２）−１、（２）―２、（２）―３の場合には、粒径３ｍｍ以下の累積％が７２〜８２質量％の粉砕粒度において粉砕粒度が細かくなる程、コークス強度ＤＩ１５０ １５（−）が増加することがわかった。また、粒径３ｍｍ以下の累積％が８２質量％よりも大きくなると、コークス強度ＤＩ１５０ １５（−）は殆ど変わらなくなることがわかった。したがって、配合炭（２）−１、（２）―２、（２）―３の場合には、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が８２質量％以上」に設定することにより、コークス強度を向上させることができるということがわかった。 From these Tables 9-12, in the case of blended coals (2) -1, (2) -2, (2) -3, the cumulative percentage with a particle size of 3 mm or less is pulverized at a pulverized particle size of 72-82 mass%. It was found that the coke strength DI 150 15 (−) increases as the particle size becomes finer. It was also found that the coke strength DI 150 15 (−) hardly changed when the cumulative percentage with a particle size of 3 mm or less was larger than 82 mass%. Therefore, in the case of blended coals (2) -1, (2) -2, and (2) -3, the pulverized particle size of the low-coalizing coal is set to “cumulative percentage of particle size of 3 mm or less is 82% by mass or more”. It was found that the coke strength can be improved by setting.

表１３は、配合炭（３）―１において、低石炭化度炭Ｇの粉砕粒度を、粒径３ｍｍ以下の累積％が６５質量％、７２質量％、７８質量％、８５質量％、９５質量％の間で変化させたときの各配合炭（３）−１のコークス強度ＤＩ１５０ １５（-）を示している。なお、表１３の試験では、高イナート含有炭ＡおよびＢの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、高炭化度炭Ｄの粉砕粒度を「粒径３ｍｍ以下の累積％が８５質量％」に、低石炭化度炭Ｈの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 13 shows that in the blended coal (3) -1, the pulverized particle size of the low-coalizing coal G is 65% by mass, 72% by mass, 78% by mass, 85% by mass, and 95% by mass. The coke strength DI 150 15 (−) of each blended coal (3) -1 when changed between% is shown. In the test of Table 13, the pulverized particle size of the high inert coals A and B is “95% by mass when the particle size is 3 mm or less is 95% by mass”, and the pulverized particle size of the high carbonized coal D is “the accumulated particle size is 3 mm or less. % Is 85% by mass ”, and the pulverized particle size of the low-carbonized coal H is unified as“ cumulative% having a particle size of 3 mm or less is 75% by mass ”.

表１４は、配合炭（３）−２において、低石炭化度炭Ｈの粉砕粒度を粒径３ｍｍ以下の累積％が６５質量％、７２質量％、７８質量％、８５質量％、９５質量％の間で変化させたときの各配合炭（３）―２のコークス強度ＤＩ１５０ １５（-）を示している。なお、表１４の試験では、高イナート含有炭Ｂ及びＣの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、低石炭化度炭Ｇの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 14 shows that, in the blended coal (3) -2, the pulverized particle size of the low-coalized coal H is 65% by mass, 72% by mass, 78% by mass, 85% by mass, and 95% by mass with a cumulative particle size of 3 mm or less. The coke strength DI 150 15 (−) of each blended coal (3) -2 when changed between the two is shown. In the test of Table 14, the pulverized particle size of the high inert coals B and C is “95% by mass when the particle size is 3 mm or less is 95% by mass”, and the pulverized particle size of the low-coalized coal G is “the particle size is 3 mm or less. The cumulative percentage was unified to 75% by mass.

表１５は、これら表１３、表１４の結果をグラフにしたものであり、横軸が低石炭化度炭の粉砕粒度、縦軸が配合炭のコークス強度ＤＩ１５０ １５（-）を示している。 Table 15 is a graph of the results of Tables 13 and 14, where the horizontal axis indicates the pulverized particle size of the low-coalized coal and the vertical axis indicates the coke strength DI 150 15 (-) of the blended coal. .

これらの表１３〜表１５から、配合炭（３）―１、（３）―２の場合には、粒径３ｍｍ以下の累積％が６５質量％〜７２質量％の粉砕粒度において粉砕粒度が増す程、コークス強度ＤＩ１５０ １５（−）が増加し、７２質量％〜７８質量％の粉砕粒度においてコークス強度ＤＩ１５０ １５（−）が略一定であることがわかった。また、粒径３ｍｍ以下の累積％が７８質量％よりも大きくなると、粉砕粒度が高くなる程、コークス強度ＤＩ１５０ １５（−）が低下することがわかった。したがって、配合炭（３）―１、（３）―２を用いる場合には、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が７２質量％〜７８質量％」に設定することにより、コークス強度を向上させることができるということがわかった。 From Table 13 to Table 15, in the case of blended coals (3) -1 and (3) -2, the pulverized particle size increases in the pulverized particle size in which the cumulative percentage of the particle size of 3 mm or less is 65 mass% to 72 mass%. As a result, the coke strength DI 150 15 (−) increased, and the coke strength DI 150 15 (−) was found to be substantially constant at a pulverized particle size of 72 mass% to 78 mass%. Further, it was found that when the cumulative percentage of the particle size of 3 mm or less is larger than 78% by mass, the coke strength DI 150 15 (−) decreases as the pulverized particle size increases. Therefore, when blended coals (3) -1 and (3) -2 are used, the pulverized particle size of the low-coalizing coal is set to "cumulative percentage of particle size of 3 mm or less is 72 mass% to 78 mass%". It was found that the coke strength can be improved.

表１６は、配合炭（４）―１において、低石炭化度炭Ｅの粉砕粒度を粒径３ｍｍ以下の累積％が７２質量％、８２質量％、８８質量％、９５質量％、１００質量％の間で変化させたときの、各配合炭（４）−１のコークス強度ＤＩ１５０ １５（-）を示している。なお、表１６の試験では、高イナート含有炭Ｂの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、高炭化度炭Ｄの粉砕粒度を「粒径３ｍｍ以下の累積％が８５質量％」に、低石炭化度炭Ｇの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 16 shows that in the blended coal (4) -1, the pulverized particle size of the low-coalizing coal E is 72% by mass, 82% by mass, 88% by mass, 95% by mass, 100% by mass with a cumulative particle size of 3 mm or less. when changing between, the coke strength DI 0.99 15 of each coal blend (4) -1 - shows (). In the test of Table 16, the pulverized particle size of the high inert coal B is “95% by mass when the particle size is 3 mm or less”, and the pulverized particle size of the high carbonized coal D is “the accumulated% when the particle size is 3 mm or less. The pulverized particle size of the low-coalized coal G was unified to “85% by mass” and “cumulative% having a particle size of 3 mm or less is 75% by mass”.

表１７は、配合炭（４）−２において、低石炭化度炭Ｆの粉砕粒度を粒径３ｍｍ以下の累積％が７２質量％、８２質量％、８８質量％、９５質量％、１００質量％の間で変化させたときの、各配合炭（４）−２のコークス強度ＤＩ１５０ １５（-）を示している。なお、表１７の試験では、高イナート含有炭Ｂ及びＣの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に、低石炭化度炭Ｇの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に統一した。 Table 17 shows that in the blended coal (4) -2, the pulverized particle size of the low-coalizing coal F is 72% by mass, 82% by mass, 88% by mass, 95% by mass, and 100% by mass with a cumulative particle size of 3 mm or less. The coke strength DI 150 15 (−) of each blended coal (4) -2 when changed between the two is shown. In the test of Table 17, the pulverized particle size of the high inert coals B and C is “95% by mass when the particle size is 3 mm or less”, and the pulverized particle size of the low-coalized coal G is “3 mm or less particle size”. The cumulative percentage was unified to 75% by mass.

表１８は、これら表１６、表１７の結果をグラフにしたものであり、横軸が低石炭化度炭の粉砕粒度、縦軸が配合炭のコークス強度ＤＩ１５０ １５（-）を示している。 Table 18 is a graph of the results of Tables 16 and 17, with the horizontal axis indicating the pulverized particle size of the low-coalized coal and the vertical axis indicating the coke strength DI 150 15 (-) of the blended coal. .

これらの表１６〜表１８から、配合炭（４）−１、（４）−２の場合には、粒径３ｍｍ以下の累積％が７２質量％〜８２質量％の粉砕粒度において粉砕粒度が増す程、コークス強度ＤＩ１５０ １５（−）が増加し、粉砕粒度が８２質量％〜８８質量％の粉砕粒度においてコークス強度ＤＩ１５０ １５（−）が略一定であることがわかった。また、粒径３ｍｍ以下の累積％が８８質量％よりも大きくなると、粉砕粒度が高くなる程、コークス強度ＤＩ１５０ １５（−）が低下することがわかった。したがって、配合炭（４）−１、（４）−２を用いる場合には、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が８２質量％〜８８質量％」に設定することにより、コークス強度を向上させることができるということがわかった。 From these Tables 16 to 18, in the case of blended coals (4) -1 and (4) -2, the pulverized particle size increases in the pulverized particle size in which the cumulative percentage of the particle size of 3 mm or less is 72 mass% to 82 mass%. It was found that the coke strength DI 150 15 (−) increased, and the coke strength DI 150 15 (−) was substantially constant at a pulverized particle size of 82% by mass to 88% by mass. Further, it was found that when the cumulative percentage with a particle diameter of 3 mm or less is larger than 88 mass%, the coke strength DI 150 15 (−) decreases as the pulverized grain size increases. Therefore, when blended coal (4) -1 and (4) -2 are used, the pulverized particle size of the low-coalizing coal is set to "cumulative percentage of particle size of 3 mm or less is 82 mass% to 88 mass%". It was found that the coke strength can be improved.

表１９は、各配合炭（１）―１〜（４）―２の全膨張率と低イナート低石炭化度炭の単味全膨張率との関係を図示したグラフであり、横軸が配合炭全体の全膨張率を示し、縦軸が強粉砕の対象となる低イナート低石炭化度炭の単味全膨張率を示す。なお、配合炭（１）―１では低石炭化度炭Ｅの単味膨張率を縦軸としており、配合炭（１）―２では低石炭化度炭Ｆの単味膨張率を縦軸としており、配合炭（２）―１では低石炭化度炭Ｇの単味膨張率を縦軸としており、配合炭（２）―２では低石炭化度炭Ｈの単味膨張率を縦軸としており、配合炭（３）―１では低石炭化度炭Ｇの単味膨張率を縦軸としており、配合炭（３）―２では低石炭化度炭Ｈの単味膨張率を縦軸としており、配合炭（４）―１では低石炭化度炭Ｅの単味膨張率を縦軸としており、配合炭（４）―２では低石炭化度炭Ｆの単味膨張率を縦軸としている。配合炭（１）―１〜（４）―２はそれぞれ複数の銘柄の低石炭化度炭を含むが、低イナート低石炭化度炭を粉砕することによる効果を簡易に確認するために、一つの低イナート低石炭化度炭のみに着目した。   Table 19 is a graph illustrating the relationship between the total expansion rate of each of the blended coals (1) -1 to (4) -2 and the simple total expansion rate of the low inert low-coalizing coal, and the horizontal axis represents the blending. The total expansion rate of the whole charcoal is shown, and the vertical axis shows the simple total expansion rate of the low inert low-coalizing coal that is subject to strong pulverization. In the case of blended coal (1) -1, the simple expansion rate of low coal degree coal E is plotted on the vertical axis, and in the case of blended coal (1) -2, the simple expansion rate of low coal degree coal F is plotted on the vertical axis. In the case of blended coal (2) -1, the simple expansion rate of the low-coalizing coal G is plotted on the vertical axis, and in the blended coal (2) -2, the simple expansion rate of the low-coalizing coal H is plotted on the vertical axis. In the case of blended coal (3) -1, the simple expansion rate of low-coalizing coal G is plotted on the vertical axis, and in the case of blended coal (3) -2, the simple expansion rate of low-coalizing coal H is plotted on the vertical axis. In the case of blended coal (4) -1, the simple expansion rate of the low-coalizing coal E is plotted on the vertical axis, and in the blended coal (4) -2, the simple expansion rate of the low-coalizing coal F is plotted on the vertical axis. Yes. Each of the blended coals (1) -1 to (4) -2 contains a plurality of low-grade coals, but in order to easily confirm the effect of pulverizing the low-inert low-coal coals, Only two low inert coals were noted.

表１９において、配合炭全体の全膨張率の境界値を４０％、低イナート低石炭化度炭の単味全膨張率の境界値を２０％として、四つの領域に領域分けした場合に、配合炭（１）―１、（１）―２、（１）―３は配合炭全体の全膨張率が４０％以上であって、かつ、低イナート低石炭化度炭の単味全膨張率が２０％以上である領域１に分類され、配合炭（２）−１、（２）―２、（２）―３は配合炭全体の全膨張率が４０％以上であって、かつ、低イナート低石炭化度炭の単味全膨張率が２０％未満である領域２に分類され、配合炭（３）−１、（３）―２は配合炭全体の全膨張率が４０％未満であって、かつ、低イナート低石炭化度炭の単味全膨張率が２０％未満である領域３に分類され、配合炭（４）−１、（４）―２は配合炭全体の全膨張率が４０％未満であって、かつ、低イナート低石炭化度炭の単味全膨張率が２０％以上である領域４に分類される。   In Table 19, when the boundary value of the total expansion rate of the entire blended coal is 40% and the boundary value of the simple total expansion rate of the low inert low-coalized coal is 20%, the blending is performed in four regions. Charcoal (1) -1, (1) -2, (1) -3 has a total expansion rate of 40% or more of the entire blended coal, and the simple total expansion rate of the low inert low-coalizing coal Classified as Region 1 that is 20% or more, the blended coals (2) -1, (2) -2, and (2) -3 have a total expansion rate of 40% or more and a low inert It is classified into the region 2 in which the total expansion rate of low-rank coal is less than 20%, and the total expansion rates of the blended coals (3) -1 and (3) -2 are less than 40%. In addition, the simple total expansion rate of the low inert low-coalizing coal is less than 20%, and is classified into region 3, and the blended coals (4) -1 and (4) -2 are the total expansion of the entire blended coal. A rate of less than 40%, and are classified into region 4 low inert low coalification degree coal PLAIN total expansion of 20% or more.

したがって、配合炭全体の全膨張率の境界値が４０％以上の場合、全膨張率が２０％以上の低イナート低石炭化度炭の粉砕粒度（領域１）を「粒径３ｍｍ以下の累積％が９０質量％以上」に設定し、全膨張率が２０％未満の低イナート低石炭化度炭（領域２）の粉砕粒度を「粒径３ｍｍ以下の累積％が８２質量％以上」に設定する。配合炭全体の全膨張率の境界値が４０％未満の場合、全膨張率が２０％未満の低イナート低石炭化度炭（領域３）の粉砕粒度を「粒径３ｍｍ以下の累積％が７２質量％〜７８質量％」に設定し、全膨張率が２０％以上の低イナート低石炭化度炭（領域４）の粉砕粒度を「３ｍｍ以下の累積％が８２質量％〜８８質量％」に設定することにより、コークス強度を高めることができるということが証明された。   Therefore, when the boundary value of the total expansion coefficient of the entire blended coal is 40% or more, the pulverized particle size (region 1) of the low inert low-carbonized coal having a total expansion coefficient of 20% or more is expressed as “cumulative% of particle diameter of 3 mm or less. Is set to “90% by mass or more”, and the pulverized particle size of the low inert low-coalized coal (region 2) having a total expansion rate of less than 20% is set to “cumulative% of particle size of 3 mm or less is 82% by mass or more”. . When the boundary value of the total expansion rate of the entire blended coal is less than 40%, the pulverized particle size of the low inert low-carbonized coal (region 3) having a total expansion rate of less than 20% is expressed as “cumulative% with a particle size of 3 mm or less is 72%. “Mass% to 78% by mass” and the pulverized particle size of low inert low-coalizing coal (region 4) having a total expansion rate of 20% or more is changed to “cumulative% of 3 mm or less is 82% to 88% by mass”. It was proved that the coke strength can be increased by setting.

このように、本実施形態によれば、配合炭および使用する低炭化度炭を領域１〜４の中で分類しておくとともに、分類された領域に応じた粉砕粒度を設定することにより、コークス強度を向上させることができる。   As described above, according to the present embodiment, the blended coal and the low-carbon coal to be used are classified in the regions 1 to 4, and the coke is set by setting the pulverization particle size according to the classified region. Strength can be improved.

但し、低イナート低石炭化度炭を上記のように粉砕することによるコークス強度の向上効果は、粗大なイナートをより多く含む高イナート含有炭、つまり、粗大イナートの含有量が６％よりも高い高イナート含有炭（以下、単に高イナート含有炭という）を強粉砕することにより、発現するものである。以下に実施例を示して、より具体的に説明する。表２０は、表５に対応するものであり、高イナート含有炭Ａ、Ｂを「粒径３ｍｍ以下の累積％が９０質量％」なる粉砕粒度でそれぞれ粉砕している点で表５と異なる。表２１は、表５に対応するものであり、イナート含有炭Ａ、Ｂを「粒径３ｍｍ以下の累積％が８０質量％」なる粉砕粒度でそれぞれ粉砕している点で表５と異なる。表２２は、表５、表２０、表２１の結果をグラフにしたものである。   However, the effect of improving the coke strength by pulverizing low-inert low-coalized coal as described above is high-inert-containing coal containing more coarse inert, that is, the content of coarse inert is higher than 6%. It is expressed by pulverizing high inert coal (hereinafter simply referred to as high inert coal). Examples will be described below in more detail. Table 20 corresponds to Table 5 and differs from Table 5 in that the high inert carbons A and B are pulverized with a pulverized particle size of “90% by mass of cumulative percentage of particle size of 3 mm or less”. Table 21 corresponds to Table 5 and differs from Table 5 in that the inert coals A and B are pulverized with a pulverized particle size of “cumulative percentage of particle size of 3 mm or less is 80 mass%”. Table 22 is a graph of the results of Table 5, Table 20, and Table 21.

高イナート含有Ａ、Ｂの粉砕粒度を「粒径３ｍｍ以下の累積％が８０質量％」に設定した場合、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」から「粒径３ｍｍ以下の累積％が１００質量％」に上昇させても、コークス強度ＤＩ１５０ １５（-）は僅か０．３しか上昇しなかった。これに対して、高イナート含有炭Ａ、Ｂの粉砕粒度を「粒径３ｍｍ以下の累積％が９０質量％」に設定した場合、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」から「粒径３ｍｍ以下の累積％が１００質量％」に上昇させることにより、コークス強度ＤＩ１５０ １５（-）が１．３も上昇した。また、高イナート含有炭Ａ、Ｂの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に設定した場合、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」から「粒径３ｍｍ以下の累積％が１００質量％」に上昇させることにより、コークス強度ＤＩ１５０ １５（-）が１．２も上昇した。これらの結果から、高イナート含有炭の粉砕粒度を「粒径３ｍｍ以下の累積％が９０質量％以上」に設定することにより、コークス強度が飛躍的に高まることが証明された。 When the pulverization particle size of the high inert content A and B is set to “80% by mass when the cumulative particle size is 3 mm or less”, the pulverization particle size of the low-coalized coal is “75% by mass when the particle size is 3 mm or less”. The coke strength DI 150 15 (−) increased only by 0.3 even when “cumulative percentage with a particle size of 3 mm or less was increased to 100 mass%”. On the other hand, when the pulverized particle size of the high inert-containing coals A and B is set to “90% by mass, the cumulative percentage of the particle size of 3 mm or less is 90% by mass”, the pulverized particle size of the low-carbonized coal is “the cumulative particle size of 3 mm or less. % ”Increased from“ 75% by mass ”to“ 100% by mass with a particle size of 3 mm or less ”, the coke strength DI 150 15 (−) increased by 1.3. In addition, when the pulverized particle size of the high-inert coals A and B is set to “95% by mass of the cumulative particle size of 3 mm or less is 95% by mass”, the pulverized particle size of the low-carbonized coal is “75% of the particle size of 3 mm or less is 75%. By increasing from “mass%” to “accumulated percentage of particle size of 3 mm or less is 100 mass%”, the coke strength DI 150 15 (−) increased by 1.2. From these results, it was proved that the coke strength is remarkably increased by setting the pulverized particle size of the high-inert-containing charcoal to “the cumulative percentage of the particle size of 3 mm or less is 90% by mass or more”.

表２３は、表６に対応するものであり、高イナート含有Ａ乃至Ｃを「粒径３ｍｍ以下の累積％が９０質量％」なる条件でそれぞれ粉砕している点で表６と異なる。表２４は、表６に対応するものであり、高イナート含有炭Ａ乃至Ｃを「粒径３ｍｍ以下の累積％が８０質量％」なる条件でそれぞれ粉砕している点で表６と異なる。表２５は、表６、表２３、表２４の結果をグラフにしたものである。   Table 23 corresponds to Table 6 and differs from Table 6 in that the high inert content A to C is pulverized under the condition that “cumulative percentage of particle size of 3 mm or less is 90 mass%”. Table 24 corresponds to Table 6 and differs from Table 6 in that the high inert coals A to C are pulverized under the condition that “cumulative percentage of particle size of 3 mm or less is 80 mass%”. Table 25 is a graph of the results of Table 6, Table 23, and Table 24.

高イナート含有炭Ａ乃至Ｃの粉砕粒度を「粒径３ｍｍ以下の累積％が８０質量％」に設定した場合、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」から「粒径３ｍｍ以下の累積％が１００質量％」に上昇させても、コークス強度ＤＩ１５０ １５（-）は僅か０．３しか上昇しなかった。これに対して、高イナート含有Ａ乃至Ｃの粉砕粒度を「粒径３ｍｍ以下の累積％が９０質量％」に設定した場合、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」から「粒径３ｍｍ以下の累積％が１００質量％」に上昇させることにより、コークス強度ＤＩ１５０ １５（-）が１．５も上昇した。また、高イナート含有Ａ乃至Ｃの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に設定した場合、低石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」から「粒径３ｍｍ以下の累積％が１００質量％」に上昇させることにより、コークス強度ＤＩ１５０ １５（-）が１．４も上昇した。これらの結果から、高イナート含有炭の粉砕粒度を「粒径３ｍｍ以下の累積％が９０質量％以上」に設定することにより、コークス強度が飛躍的に高まることが証明された。 When the pulverized particle size of the high inert-containing coals A to C is set to “80% by mass when the cumulative particle size of 3 mm or less is 80% by mass”, the pulverized particle size of the low-coalized coal is “75% by mass when the particle size is 3 mm or less. The coke strength DI 150 15 (−) increased only by 0.3, even when the cumulative percentage with a particle size of 3 mm or less was increased to “100 mass%”. On the other hand, when the pulverized particle size of the high inert content A to C is set to “90% by mass of cumulative particle size 3 mm or less is 90% by mass”, the pulverized particle size of low-carbonized coal is “cumulative% of particle size 3 mm or less. The coke strength DI 150 15 (−) was increased by 1.5 by increasing “75% by mass” from “cumulative% of particle size of 3 mm or less to 100% by mass”. Further, when the pulverized particle size of the high inert content A to C is set to “95% by mass of the cumulative particle size of 3 mm or less is 95% by mass”, the pulverized particle size of the low-carbonized coal is 75% by mass of the particle size of 3 mm or less. By increasing the “%” to “the cumulative percentage of the particle size of 3 mm or less is 100 mass%”, the coke strength DI 150 15 (−) is increased by 1.4. From these results, it was proved that the coke strength is remarkably increased by setting the pulverized particle size of the high-inert-containing charcoal to “the cumulative percentage of the particle size of 3 mm or less is 90% by mass or more”.

このように、高イナート含有炭の粉砕粒度を「粒径３ｍｍ以下の累積％が９０質量％以上」に設定し、かつ、低イナート低石炭化度炭を全膨張率に応じて適切に強粉砕することにより、コークス強度効果が飛躍的に高まる理由は下記の通りと考えられる。
同一サイズのイナートと低石炭化度炭では、一般的にイナートの方が、コークス強度低下影響が大きい。そのため、配合炭中にサイズの大きなイナートが多く存在する条件では、イナート周囲のクラックがコークス強度を決定する主要な欠陥となるため、低石炭化度炭を強粉砕してもコークス強度向上効果は小さい。一方で、配合炭中にサイズの大きなイナートがほとんど存在しない条件では、イナート周囲のクラックが主要な欠陥とならないため、低石炭化度炭を強粉砕することによってコークス強度が飛躍的に向上するものと考えられる。
また、粗大イナートの含有量が５〜７体積％の境界値以下で、ビトリニット平均反射率が０．９％以上の低イナート高石炭化度炭をさらに配合する場合、所定の粉砕粒度の範囲に粉砕することが、より好ましい。表２６は、表７に対応するものであり、高石炭化度炭Ｄを「粒径３ｍｍ以下の累積％が９５質量％」なる条件でそれぞれ粉砕している点で表７と異なる。表２７は、表７に対応するものであり、高石炭化度炭Ｄを「粒径３ｍｍ以下の累積％が８２質量％」なる条件でそれぞれ粉砕している点で表７と異なる。表２８は、表７に対応するものであり、高石炭化度炭Ｄを「粒径３ｍｍ以下の累積％が７５質量％」なる条件でそれぞれ粉砕している点で表７と異なる。表２９は、表６、表２６、表２７、表２８の結果をグラフにしたものである。 As described above, the pulverization particle size of the high-inert coal is set to “cumulative percentage of particle size of 3 mm or less is 90% by mass or more”, and low-inert low-coalizing coal is appropriately strongly pulverized according to the total expansion rate. By doing so, the reason why the coke strength effect is remarkably increased is considered as follows.
Inerts with the same size and low-grade coals generally have a greater effect on coke strength reduction. Therefore, under conditions where there are many large-sized inerts in the blended coal, cracks around the inert are a major defect that determines the coke strength. small. On the other hand, under conditions where there is almost no large-sized inert in the blended coal, cracks around the inert do not become a major defect, so the strength of coke is dramatically improved by pulverizing low-carbon coal. it is conceivable that.
In addition, when a low inert high-coalized coal having a coarse inert content of 5 to 7% by volume or less and a vitrinite average reflectance of 0.9% or more is further blended, a predetermined pulverized particle size range is obtained. It is more preferable to grind. Table 26 corresponds to Table 7 and is different from Table 7 in that the high-coalized coal D is pulverized under the condition that “cumulative percentage with a particle size of 3 mm or less is 95 mass%”. Table 27 corresponds to Table 7 and is different from Table 7 in that the high-coalized coal D is pulverized under the condition that “cumulative% with a particle size of 3 mm or less is 82% by mass”. Table 28 corresponds to Table 7, and differs from Table 7 in that the high-coalized coal D is pulverized under the condition that “cumulative percentage of particle size of 3 mm or less is 75 mass%”. Table 29 is a graph of the results of Table 6, Table 26, Table 27, and Table 28.

表２９に示すように、高石炭化度炭Ｄの粉砕粒度が「粒径３ｍｍ以下の累積％が８２質量％」および「粒径３ｍｍ以下の累積％が８８質量％」の時は、「粒径３ｍｍ以下の累積％が７５質量％」および「粒径３ｍｍ以下の累積％が９５質量％」の時に比べて、コークス強度ＤＩ１５０ １５が高い。これらの結果から、高石炭化度炭Ｄの粉砕粒度が「粒径３ｍｍ以下の累積％が８２質量％〜８８質量％」に設定することにより、コークス強度ＤＩ１５０ １５（-）が極大となるため、好ましいことが分かった。 As shown in Table 29, when the pulverized particle size of the high-coalized coal D is “82% by mass when the particle size is 3 mm or less” and “88% by mass when the particle size is 3 mm or less is 88% by mass”, The coke strength DI 150 15 is higher than when the cumulative percentage with a diameter of 3 mm or less is 75 mass% and the cumulative percentage with a particle diameter of 3 mm or less is 95 mass%. From these results, the coke strength DI 150 15 (−) is maximized by setting the pulverized particle size of the high coal degree coal D to “cumulative% having a particle size of 3 mm or less is 82 mass% to 88 mass%”. Therefore, it turned out that it is preferable.

表３０は、表１１に対応するものであり、高石炭化度炭Ｄを「粒径３ｍｍ以下の累積％が９５質量％」なる条件で粉砕している点で表１１と異なる。表３１は、表１１に対応するものであり、高石炭化度炭Ｄを「粒径３ｍｍ以下の累積％が８２質量％」なる条件で粉砕している点で表１１と異なる。表３２は、表１１に対応するものであり、高石炭化度炭Ｄを「粒径３ｍｍ以下の累積％が７５質量％」なる条件で粉砕している点で表１１と異なる。表３３は、表１１、表３０、表３１、表３２の結果をグラフにしたものである。   Table 30 corresponds to Table 11 and is different from Table 11 in that the high-coalized coal D is pulverized under the condition that “cumulative percentage with a particle size of 3 mm or less is 95 mass%”. Table 31 corresponds to Table 11 and is different from Table 11 in that the high degree coalized coal D is pulverized under the condition that “cumulative% with a particle size of 3 mm or less is 82% by mass”. Table 32 corresponds to Table 11 and is different from Table 11 in that the high-coalized coal D is pulverized under the condition that “cumulative percentage with a particle size of 3 mm or less is 75 mass%”. Table 33 is a graph of the results of Table 11, Table 30, Table 31, and Table 32.

表３３に示すように、高石炭化度炭Ｄの粉砕粒度が「粒径３ｍｍ以下の累積％が８２質量％」および「粒径３ｍｍ以下の累積％が８８質量％」の時は、「粒径３ｍｍ以下の累積％が７５質量％」および「粒径３ｍｍ以下の累積％が９５質量％」の時に比べて、コークス強度ＤＩ１５０ １５が高い。これらの結果から、高石炭化度炭Ｄの粉砕粒度が「粒径３ｍｍ以下の累積％が８２質量％〜８８質量％」のとき、コークス強度ＤＩ１５０ １５（-）が極大となるため、好ましいことが分かった。
このように、高石炭化度炭Ｄの粉砕粒度が「粒径３ｍｍ以下の累積％が８２％以上８８質量％以下」で極大となる理由は下記の通りと考えられる。
低イナート高石炭化度炭の粉砕粒度が粗すぎる場合、配合炭中に膨張率の高い粗大粒子が多く存在する。この粗大粒子周囲に膨張率が低い石炭が存在すると、高石炭化度炭の粗大粒子は自由膨張すると同時に粗大粒子内に発生した気泡が破裂し、複数の気泡同士が連結した大きな連結気孔が生成する。この大きな連結気孔はコークス強度低下の原因となる。そこで、高膨張率の粗大粒子を粉砕して減少させると、高膨張率炭粒子の個数の増加に起因して、高膨張率炭周囲に膨張性の高い粒子の存在する確率が上昇し、高膨張率炭粒子の自由膨張が抑制される作用により、大きな連結気孔の生成を抑制でき、コ−クス強度が上昇すると考えられる。
一方、低イナート高石炭化度炭の粉砕粒度が細かすぎると、石炭の膨張率自体が大幅に低下するため、石炭粒子同士の接着性が悪化し、コークス強度が低下すると考えられる。
これらの結果から、高石炭化度炭の粉砕粒度を「粒径３ｍｍ以下の累積％が８２％以上８８質量％以下」に設定することにより、コークス強度が飛躍的に高まるため、好ましい。 As shown in Table 33, when the pulverized particle size of the high-degree coalized coal D is “82% by mass when the particle size is 3 mm or less” and “88% by mass when the particle size is 3 mm or less”, The coke strength DI 150 15 is higher than when the cumulative percentage with a diameter of 3 mm or less is 75 mass% and the cumulative percentage with a particle diameter of 3 mm or less is 95 mass%. From these results, since the coke strength DI 150 15 (−) is maximized when the pulverized particle size of the high-coalized coal D is “82% by mass to 88% by mass with a particle size of 3 mm or less”, it is preferable. I understood that.
Thus, it is considered that the reason why the pulverized particle size of the high-coalized coal D becomes maximum when “the cumulative percentage of the particle size of 3 mm or less is 82% or more and 88% by mass or less” is as follows.
When the pulverized particle size of the low inert and high coalified coal is too coarse, there are many coarse particles having a high expansion coefficient in the blended coal. When coal with a low expansion coefficient is present around the coarse particles, the coarse particles of the high-coalized coal will expand freely, and at the same time, the bubbles generated in the coarse particles will burst, producing large connected pores connecting multiple bubbles. To do. These large connected pores cause a reduction in coke strength. Therefore, if the coarse particles with high expansion coefficient are pulverized and reduced, the probability of existence of highly expandable particles around the high expansion charcoal increases due to the increase in the number of high expansion charcoal particles. It is thought that the effect of suppressing the free expansion of the expansion coefficient carbon particles can suppress the formation of large connected pores and increase the coke strength.
On the other hand, if the pulverized particle size of the low inert high-coalized coal is too fine, the expansion rate of the coal itself is significantly reduced, so that the adhesiveness between the coal particles is deteriorated and the coke strength is reduced.
From these results, it is preferable to set the pulverized particle size of the high-coalized coal to “the cumulative percentage of the particle size of 3 mm or less is 82% or more and 88% by mass or less” because the coke strength is dramatically increased.

ちなみに、前述の高イナート含有炭の粉砕粒度を「粒径３ｍｍ以下の累積％が９０質量％以上」に設定し、かつ、低イナート低石炭化度炭の粉砕粒度を全膨張率に応じて適切に設定することにより、コークス強度効果が飛躍的に高まる相乗効果を、より詳細に説明する。
表３４は、石炭Ｉ、石炭Ｊ、石炭Ｋの石炭性状を示している。石炭Ｉは、粗大イナートの含有率が６％よりも高いため、高イナート含有炭である（以下、高イナート含有炭Ｉと称する場合がある）。石炭Ｊ、Ｋは粗大イナートの含有率が６％未満であり、ビトリニット平均反射率Ｒｏ（％）が０．９％よりも低いため、低イナート低石炭化度炭（以下、低石炭化度炭Ｊ、Ｋと称する場合がある）である。石炭Ｊは全膨張率が２０％以上、石炭Ｋは全膨張率が２０％未満に分類される。これらの高イナート含有炭Ｉ、低石炭化度炭Ｊ、Ｋを表３５に示す比率（質量％）で配合した配合炭を用いて、粉砕粒度とコークス強度ＤＩ１５０ １５（-）との関係を調べた。配合炭の全膨張率は６５％である。 By the way, the pulverization particle size of the above-mentioned high inert coal is set to “cumulative percentage of particle size of 3 mm or less is 90% by mass or more”, and the pulverization particle size of low inert coal is appropriate according to the total expansion rate. The synergistic effect in which the coke strength effect is remarkably increased by setting to will be described in more detail.
Table 34 shows the coal properties of Coal I, Coal J, and Coal K. Coal I is a high-inert coal because the content of coarse inert is higher than 6% (hereinafter sometimes referred to as high-inert coal I). Coal J and K have a coarse inert content of less than 6%, and vitrinite average reflectance Ro (%) is lower than 0.9%. Therefore, low inert low coal content coal (hereinafter referred to as low coal content coal) J, K may be referred to). Coal J has a total expansion rate of 20% or more, and coal K has a total expansion rate of less than 20%. Using the coal blended with these high-inert coal I and low-carbonized coals J and K in the ratio (mass%) shown in Table 35, the relationship between the pulverized particle size and coke strength DI 150 15 (-) Examined. The total expansion rate of the blended coal is 65%.

粉砕粒度を表３６に示すような水準１〜水準４の間で変化させた。
水準１の配合炭では、高イナート含有炭Ｉ、低石炭化度炭Ｊ，Ｋの粉砕粒度を全て「粒径３ｍｍ以下の累積％が８０質量％」に設定した後、コークス化してコークス強度ＤＩ１５０ １５（-）を測定した。
水準２の配合炭では、高イナート含有炭Ｉの粉砕粒度を「粒径３ｍｍ以下の累積％が８０質量％」に設定し、全膨張率が２０％以上の低石炭化度炭Ｊの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に設定し、全膨張率が２０％未満の低石炭化度炭Ｋの粉砕粒度を「粒径３ｍｍ以下の累積％が８５質量％」に設定した後、コークス化してコークス強度ＤＩ１５０ １５（-）を測定した。つまり、水準２では、イナートを多く含む高石炭化度炭Ｉを強粉砕せずに、低石炭化度炭Ｊ、Ｋのみを強粉砕している。
水準３の配合炭では、高イナート含有炭Ｉの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に設定し、低石炭化度炭Ｊの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に設定し、低石炭化度炭Ｋの粉砕粒度を「粒径３ｍｍ以下の累積％が７５質量％」に設定した後、コークス化してコークス強度ＤＩ１５０ １５（-）を測定した。つまり、水準３では、イナートを多く含む高イナート含有炭Ｉを強粉砕して、低石炭化度炭Ｊ、Ｋを強粉砕しなかった。
水準４の配合炭では、高イナート含有炭Ｉの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に設定し、全膨張率が２０％以上の低石炭化度炭Ｊの粉砕粒度を「粒径３ｍｍ以下の累積％が９５質量％」に設定し、全膨張率が２０％未満の低石炭化度炭Ｋの粉砕粒度を「粒径３ｍｍ以下の累積％が８５質量％」に設定した後、コークス化してコークス強度ＤＩ１５０ １５（-）を測定した。
なお、いずれの水準も嵩密度を一定にするために配合炭の水分を２質量％まで乾燥させ、0.5mmで分級した後、0.5mm以下の微粉炭をフレークおよびブリケットに塊成化し、0.5mm以上の粗粒炭と混合した後、コークス炉に装入し、コークス化した。 The pulverized particle size was changed between level 1 and level 4 as shown in Table 36.
In the case of Level 1 blended coal, all the pulverized particle sizes of high inert coal I and low coals J and K are set to “cumulative percentage of particle size of 3 mm or less is 80% by mass” and then coke to obtain coke strength DI. 150 15 (−) was measured.
For level 2 blended coal, the pulverized particle size of high-inert coal I is set to "80% by mass with a cumulative particle size of 3 mm or less is 80% by mass", and the pulverized particle size of low-carbonized coal J with a total expansion rate of 20% or more. Is set to “95% by mass of the cumulative particle size of 3 mm or less” and the pulverized particle size of the low-carbonized coal K having a total expansion rate of less than 20% is set to “85% by mass of the cumulative particle size of 3 mm or less” After setting, coke was formed and coke strength DI 150 15 (−) was measured. That is, at level 2, only the low-coalized coals J and K are strongly pulverized without strongly pulverizing the high-coalized coal I containing a large amount of inert.
In the case of level 3 blended coal, the pulverized particle size of high-inert coal I is set to “95% by mass when the particle size is 3 mm or less is 95% by mass”, and the pulverized particle size of low-coalized coal J is “cumulative particle size of 3 mm or less. % Is set to 75% by mass, and the pulverized particle size of the low-coalizing coal K is set to “cumulative% of particle size of 3 mm or less is 75% by mass”, and then coked to obtain coke strength DI 150 15 (−). It was measured. That is, at level 3, the high-inert coal I containing a large amount of inert was pulverized and the low-coalizing coals J and K were not pulverized.
For level 4 blended coal, the pulverized particle size of high-inert coal I is set to “95% by mass with a cumulative particle size of 3 mm or less is 95% by mass”, and the pulverized particle size of low-coalized coal J with a total expansion rate of 20% or more. Is set to “95% by mass of the cumulative particle size of 3 mm or less” and the pulverized particle size of the low-carbonized coal K having a total expansion rate of less than 20% is set to “85% by mass of the cumulative particle size of 3 mm or less” After setting, coke was formed and coke strength DI 150 15 (−) was measured.
In addition, in order to make the bulk density constant in any level, after drying the blended coal to 2% by mass and classifying it with 0.5 mm, pulverized coal of 0.5 mm or less is agglomerated into flakes and briquettes. After mixing with the above coarse coal, it was charged into a coke oven and coked.

水準１〜水準４に基づき製造されたコークスのコークス強度ＤＩ１５０ １５（-）と、水準１をベースとしたときのコークス強度ＤＩ１５０ １５（-）の変化量ΔＤＩ１５０ １５（-）とを表３７に示す。 The coke strength DI 150 15 (−) of the coke manufactured based on the level 1 to the level 4 and the change amount ΔDI 150 15 (−) of the coke strength DI 150 15 (−) based on the level 1 are shown. 37.

これらの結果を、表３８のグラフに示す。表３８のグラフは、横軸が配合炭全体の粉砕粒度を示し、縦軸が配合炭全体のコークス強度ＤＩ１５０ １５（-）を示す。 These results are shown in the graph of Table 38. In the graph of Table 38, the horizontal axis represents the pulverized particle size of the entire blended coal, and the vertical axis represents the coke strength DI 150 15 (−) of the entire blended coal.

水準２は変化量ΔＤＩ１５０ １５（-）が０．３であり、水準３は変化量ΔＤＩ１５０ １５（-）が１．０であり、これらを加算すると変化量ΔＤＩ１５０ １５（-）は１．３である。しかしながら、水準４は、変化量ΔＤＩ１５０ １５（-）が１．９もあった。つまり、高イナート含有炭を「粒径３ｍｍ以下の累積％が９０質量％以上」なる条件で強粉砕するとともに、低石炭化度炭を表１７の四象限グラフにしたがって強粉砕することの相乗効果により、コークス強度が飛躍的に向上することが証明された。 Level 2 has a change amount ΔDI 150 15 (−) of 0.3, and level 3 has a change amount ΔDI 150 15 (−) of 1.0. When these are added, the change amount ΔDI 150 15 (−) is 1. .3. However, at level 4, the change ΔDI 150 15 (−) was 1.9. In other words, the high-inert coal is strongly pulverized under the condition that “cumulative percentage of particle size of 3 mm or less is 90% by mass or more” and synergistic effect of strongly pulverizing low-carbon coal according to the four-quadrant graph of Table 17. As a result, it was proved that the strength of coke was drastically improved.

以上、石炭中の粗大イナート組織の含有量が６体積％を境界値として、粗大イナート含有量Ｉ（％）が６％よりも高い石炭を高イナート含有炭とし、粗大イナート含有量Ｉ（％）が６％以下の石炭を低イナート含有炭と分類した場合について述べてきた。
ここで、本願発明では、粗大イナート組織の含有量が５〜７体積％の境界値を用いて、該含有量がよりも高い銘柄の石炭を高イナート含有炭と定義し、粗大イナート組織の含有量が境界値以下の銘柄の石炭を低イナート含有炭と定義している。以下に、この境界値の設定の考え方について述べる。 As described above, coal having a coarse inert structure content of 6% by volume as a boundary value, coal having a coarse inert content I (%) higher than 6% is regarded as a high inert content coal, and coarse inert content I (%) Has described the case where 6% or less of coal is classified as low inert coal.
Here, in the present invention, using a boundary value having a coarse inert structure content of 5 to 7% by volume, a coal having a higher content is defined as a high inert coal, and containing a coarse inert structure A coal whose quantity is less than the boundary value is defined as a low inert coal. The concept of setting this boundary value is described below.

コークス製造用に複数の銘柄の石炭を配合する際には、配合炭の粒度として、コークスを製造可能な粒度の範囲で設定される。従って、各銘柄の石炭の粉砕粒度や配合比率は、配合炭の粒度の設定値により制約される。   When blending a plurality of brands of coal for coke production, the particle size of the blended coal is set within a range of particle sizes that allow the production of coke. Therefore, the pulverization particle size and blending ratio of each brand of coal are limited by the set value of the coal blend particle size.

従って、粗大イナート含有量が相対的に高い銘柄の石炭の配合割合が多い場合に、粗大イナート含有量が相対的に高い銘柄の石炭をすべて強粉砕してしまうと、配合炭の粒度が細かくなり過ぎて、設定した粒度に調整できないケースがある。この様な場合は、粗大イナート含有量の境界値を５〜７体積％の範囲の中で、高めの値に設定することで、配合炭を所望の設定粒度とすることができる。   Therefore, if the blending ratio of brand coal with relatively high coarse inert content is large, and if all the brand coal with relatively high coarse inert content is pulverized, the grain size of the blended coal will become finer. In some cases, the granularity cannot be adjusted to the set granularity. In such a case, by setting the boundary value of the coarse inert content to a higher value within the range of 5 to 7% by volume, the blended coal can have a desired set particle size.

一方、粗大イナート含有量が相対的に高い銘柄の石炭の配合割合が少ない場合には、逆に、粗大イナート含有量の境界値を５〜７体積％の範囲の中で、低めの値に設定することで、配合炭を所望の設定粒度とすることができる。   On the other hand, if the blending ratio of brand coal with relatively high coarse inert content is small, conversely, the boundary value of coarse inert content is set to a lower value within the range of 5-7% by volume. By doing, blended charcoal can be made into a desired set particle size.

以下に表３９を用いて、配合炭の設定粒度が３ｍｍ以下８５質量％である場合を例に挙げて説明する。条件１では、石炭の銘柄としてＷ炭、Ｘ炭、Ｚ炭を配合する場合であり、Ｗ炭は粗大イナート含有量が７．３％のため、高イナート含有炭であり、Ｚ炭は粗大イナート含有量が３．５％のため、低イナート含有炭であることは明らかであるが、Ｘ炭は粗大イナート含有量が６．６％のため、５〜７％の境界領域にあるため、境界値を設定する必要がある。   Hereinafter, the case where the set particle size of the blended coal is 3 mm or less and 85% by mass will be described as an example using Table 39. Condition 1 is a case where W coal, X coal, and Z coal are blended as brands of coal. W coal is a high inert content coal because the coarse inert content is 7.3%, and Z coal is coarse inert. It is clear that it is a low inert coal because the content is 3.5%, but the X coal is in the boundary region of 5-7% because the coarse inert content is 6.6%, so the boundary It is necessary to set a value.

この条件１では、Ｗ炭の配合比率が５０％、Ｘ炭の配合比率が３０％であり、粗大イナート含有量が相対的に高い銘柄の石炭の配合割合が多いケースである。この場合には、Ｘ炭を高イナート含有炭と分類してしまうと、Ｘ炭を３ｍｍ以下９０質量％以上に粉砕することになるため、配合炭の設定値である３ｍｍ以下８５質量％に調整することができない。   In this condition 1, the blending ratio of W coal is 50%, the blending ratio of X coal is 30%, and the blending ratio of brand coal with relatively high coarse inert content is large. In this case, if the X charcoal is classified as a high inert content charcoal, the X charcoal is pulverized to 3 mm or less and 90 mass% or more. Can not do it.

そこで、粗大イナートの含有量の境界値を、６．６％と７．０％の間の数値（例えば、６．８％）に設定することで、Ｘ炭は低イナート炭に分類される。また、Ｘ炭はビトリニット平均反射率Ｒｏが０．８５％のため、低石炭化度炭に分類される。また、条件１の配合炭の全膨張率は、３６．３％と
計算される。従って、Ｘ炭は、表１９の領域３に分類されるため、粒径３ｍｍ以下を７２〜７８質量％で粉砕すれば良く、表３９に示す通り、Ｘ炭を粒径３ｍｍ以下を７５質量％で粉砕した。その結果、条件１の配合炭の粒度は、設定値である３ｍｍ以下８５質量％とすることができた。 Therefore, by setting the boundary value of the content of coarse inert to a value between 6.6% and 7.0% (for example, 6.8%), X coal is classified as low inert coal. Further, X-coal is classified as low-coalized coal because vitrinite average reflectance Ro is 0.85%. Moreover, the total expansion coefficient of the blended coal of condition 1 is calculated to be 36.3%. Therefore, since X char is classified into the region 3 of Table 19, the particle size of 3 mm or less may be pulverized at 72 to 78% by mass, and as shown in Table 39, the X coal has a particle size of 3 mm or less of 75% by mass. Crushed with. As a result, the particle size of the blended coal of Condition 1 could be set to 3 mm or less, which is a set value, and 85 mass%.

次に、条件２でも、配合炭の設定粒度が３ｍｍ以下８５質量％である場合を例に挙げて説明する。   Next, even in condition 2, the case where the set particle size of the blended coal is 3 mm or less and 85% by mass will be described as an example.

条件２では、石炭の銘柄としてＹ炭、Ｚ炭を配合する場合であり、Ｚ炭は粗大イナート含有量が３．５％のため、低イナート含有炭であることは明らかであるが、Ｙ炭は粗大イナート含有量が５．７％のため、５〜７％の境界領域にあるため、境界値を設定する必要がある。   Condition 2 is a case where Y charcoal and Z charcoal are blended as brands of coal, and since Z charcoal has a coarse inert content of 3.5%, it is clear that it is a low inert coal, Since the coarse inert content is 5.7% and is in the boundary region of 5 to 7%, it is necessary to set the boundary value.

この条件２では、Ｙ炭の配合比率が５０％、Ｚ炭の配合比率も５０％である。この場合は、Ｙ炭が低イナート含有炭と分類される。また、Ｙ炭のビトリニット平均反射率Ｒｏが１．３１のため、高石炭化度炭に分類される。このため、Ｙ炭を粒径３ｍｍ以下８２〜８８質量％で粉砕することになるため、配合炭の設定値である３ｍｍ以下８５質量％に調整することができない。   Under this condition 2, the blending ratio of Y charcoal is 50%, and the blending ratio of Z charcoal is also 50%. In this case, Y charcoal is classified as low inert coal. Moreover, since the vitrinite average reflectance Ro of Y charcoal is 1.31, it is classified as high coal degree coal. For this reason, since Y charcoal is pulverized with a particle size of 3 mm or less and 82 to 88 mass%, it cannot be adjusted to 3 mm or less and 85 mass%, which is a set value of the blended coal.

そこで、粗大イナートの含有量の境界値を、５．０％と５．７％の間の数値（例えば、５．５％）に設定することで、Ｙ炭は高イナート炭に分類される。
従って、Ｙ炭は、粒径３ｍｍ以下を９０質量％以上で粉砕すれば良いため、表３９に示す通り、Ｙ炭を粒径３ｍｍ以下９５質量％で粉砕した。その結果、条件２の配合炭の粒度は、設定値である３ｍｍ以下８５質量％とすることができた。 Therefore, by setting the boundary value of the content of coarse inert to a value between 5.0% and 5.7% (for example, 5.5%), Y coal is classified as high inert coal.
Therefore, Y charcoal may be pulverized with a particle size of 3 mm or less at 90% by mass or more. Therefore, as shown in Table 39, Y charcoal was pulverized with a particle size of 3 mm or less and 95% by mass. As a result, the particle size of the blended coal under Condition 2 could be set to a set value of 3 mm or less and 85% by mass.

以上の通り、粗大イナート組織の含有量が５〜７体積％の境界値については、配合炭の設定粒度に応じて、適切に設定することができる。


As described above, the boundary value with the coarse inert structure content of 5 to 7% by volume can be appropriately set according to the set particle size of the blended coal.


Claims (2)

コークス用原料炭として使用する複数銘柄の石炭を粒径３ｍｍ以下の累積％が７０〜８０質量％となるように粒度調整した原料炭中に含まれる、１．５ｍｍ以上の最大長さを有する粗大イナート組織の含有量が５〜７体積％の境界値を用いて、この含有量が境界値よりも高い高イナート含有炭と、粗大イナート組織の含有量が境界値以下であって、ビトリニット平均反射率が０．９％以下である低イナート低石炭化度炭に分類し、それぞれ粉砕して配合した配合炭を製造するコークス炉装入用配合炭の製造方法であって、
前記高イナート含有炭を粒径３ｍｍ以下の累積％が９０質量％以上となるように強粉砕する第１の工程と、
前記配合炭全体の全膨張率が４０％未満の場合、全膨張率が２０％以上の前記低イナート低石炭化度炭は、粒径３ｍｍ以下の累積％が８２〜８８質量％となるように粉砕し、全膨張率が２０％未満の前記低イナート低石炭化度炭は、粒径３ｍｍ以下の累積％が７２〜７８質量％となるように粉砕し、
前記配合炭全体の全膨張率が４０％以上の場合、全膨張率が２０％以上の前記低イナート低石炭化度炭は、粒径３ｍｍ以下の累積％が９０質量％以上となるように粉砕し、全膨張率が２０％未満の前記低イナート低石炭化度炭は、粒径３ｍｍ以下の累積％が８２質量％以上となるように粉砕する第２の工程、
を含むことを特徴とするコークス炉装入用配合炭の製造方法。 Coarse coal having a maximum length of 1.5 mm or more, which is included in coking coal whose particle size is adjusted such that the cumulative percentage of particle size of 3 mm or less is 70 to 80% by mass, as a coking coking coal. Using a boundary value with an inert structure content of 5 to 7% by volume, the high inert content charcoal whose content is higher than the boundary value, and the coarse inert structure content is less than or equal to the boundary value, and vitrinite average reflection A method for producing a coal blend for coke oven charging, which is classified into low inert low-coalized coal with a rate of 0.9% or less and pulverized and blended respectively,
A first step of strongly pulverizing the high inert content charcoal so that a cumulative percentage of a particle size of 3 mm or less is 90% by mass or more;
When the total expansion rate of the entire blended coal is less than 40%, the low inert low-carbonized coal having a total expansion rate of 20% or more has a cumulative percentage of particle size of 3 mm or less of 82 to 88% by mass. The low inert low-carbonized coal having a total expansion rate of less than 20% is pulverized and pulverized so that the cumulative percentage with a particle size of 3 mm or less is 72 to 78% by mass,
When the total expansion rate of the entire blended coal is 40% or more, the low inert low-carbonized coal having a total expansion rate of 20% or more is pulverized so that the cumulative percentage with a particle size of 3 mm or less is 90% by mass or more. The second inert low-coalized coal having a total expansion rate of less than 20% is pulverized so that the cumulative percentage with a particle size of 3 mm or less is 82% by mass or more,
The manufacturing method of the coal blend for coke oven charging characterized by including. 前記粗大イナート組織の含有量が前記境界値以下である低イナート含有炭について、さらにビトリニット平均反射率が０．９％よりも高い低イナート高石炭化度炭に分類し、それぞれ粉砕して配合した配合炭を製造するコークス炉装入用配合炭の製造方法であって、
さらに、前記低イナート高石炭化度炭を粒径３ｍｍ以下の累積％が８２質量％以上８８質量％以下となるように粉砕する第３の工程、
を含むことを特徴とする請求項１に記載のコークス炉装入用配合炭の製造方法。 The low inert coal with the coarse inert structure content equal to or less than the boundary value is further classified into low inert high coalification coal with a vitrinite average reflectance higher than 0.9%, and pulverized and blended. A method for producing a blended coal for coke oven charging to produce a blended coal,
Furthermore, a third step of pulverizing the low inert high-coalized coal so that the cumulative percentage with a particle size of 3 mm or less is 82% by mass or more and 88% by mass or less,
The manufacturing method of the coal blend for coke oven charging of Claim 1 characterized by the above-mentioned.
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