Jfe Steel Corporation

Yusuke Dohi

Kiyoshi Fukada

Hiroyuki Sumi

Izumi Shimoyama

Takashi Matsui

Tetsuya Yamamoto

Takashi Anyashiki

Hidekazu Fujimoto

Mikiya Nagayama

Daisuke Igawa

Kazutoshi Hanada

Masahiro Shinohara

Michio Honma

Narumi Nanri

Yoshiko Maeta

Issui Akishika

A method of producing a coal blend by blending plural brands of coal to produce a coal blend includes letting a surface tension of coal when inert material is assumed to be 100 vol % be γ, and letting a surface tension of coal when reactive material is assumed to be 100 vol % be γ, determining γof coal; among brands of coal 1, 2, . . . i, . . . , and n to be blended in a coal blend, specifying coal i in which γis outside of γ; measuring TI of coal i; and determining a blending ratio of coal i such that w calculated by formula (1) is 20.4 mass % or less=Σ()  (1).

Method of producing coal blend and method of producing coke

A method of estimating a surface tension of coal inert material includes determining in advance a first relational expression representing a relationship between a surface tension of coal inert material and a physical property value representing a coal rank; and measuring the physical property value representing the coal rank of a coal for which the surface tension of coal inert material is to be estimated, and calculating the surface tension of the coal inert material by using the measured physical property value representing the coal rank and the first relational expression.

Method of estimating surface tension of coal inert material, method of estimating surface tension of coal, and method of producing coke

Methods for evaluating whether there is a probability that coal will reduce the strength of coke using an apparatus including a stirrer. A degree of entanglement (a−b)/a represented by the heights a and b, or the height a only, is used as an evaluation index for coal, where a height of the semicoke on an inner wall of the container is represented by b, and a height of the semicoke on the stirrer is represented by a. Semicoke formed from heated coal is formed in the container using the degree of entanglement as an evaluation index.

Method for evaluating coal, method for preparing coal blend, and method for producing coke

A method of estimating a surface tension of coal includes subjecting a surface tension, a physical property value representing a coal rank, and a total inert content of each of different brands of coal to multiple regression analysis to determine in advance a regression equation including the surface tension of coal as an objective variable and the physical property value and the total inert content as explanatory variables; and measuring the physical property value and the total inert content of a coal of which the surface tension is to be estimated, and calculating the surface tension of the coal with the measured physical property value and the measured total inert content, and the regression equation.

Method of estimating surface tension of coal and method of producing coke

A method of producing a coal mixture includes blending a plurality of coals, wherein formula (1) and formula (2) are satisfied: α≤1.2×10(mol/g-coal)  (2)wherein αis a hydrogen ion release capacity per unit mass (mol/g-coal) of the coal mixture, αis the hydrogen ion release capacity per unit mass (mol/g-coal) of a coal i, xis a blending ratio of the coal i blended in the coal mixture, and N is a total number of brands of coal contained in the coal mixture.

Method of producing coal mixture and method of producing coke

In order to evaluate the compatibility of coals used in coke production and to produce cokes with desired strength by blending coals in consideration of the compatibility, the invention provides a technique which evaluates the adhesion strength obtained when two kinds of coals are carbonized based. on properties of the coals. Surface tensions of two kinds of semicokes obtained by heat treating two kinds of coals are measured. Based on the difference between the two measured values of surface tension, the quality of the adhesiveness between the two kinds of coals is evaluated.

Coal-to-coal adhesiveness evaluation method

A method for accurately measuring the thermoplasticity of a coal whose thermoplasticity has been difficult to evaluate and determining whether the coal that is to be measured does not significantly reduce the coke strength when used for a coal blend is disclosed. Also disclosed is a method for evaluating a coal used as a raw material for coke and includes using a physical property value relating to a thermoplasticity of a coal as an index for evaluating the coal, wherein a primary or secondary amine including an aromatic ring have been added to the coal, thereby enhancing the thermoplasticity of the coal.

Evaluating method for coal and producing method for coke

A method for manufacturing coke having a high strength and excellent extrusion capability. The method includes a preparing step of blending two or more coal brands to prepare a coal blend, a stirring and mixing step of stirring and mixing the coal blend to disintegrate at least a part of pseudo-particles that have been formed by agglomeration of coal particles in the coal blend, and a carbonizing step of charging the stirred and mixed coal blend into a coke oven to carbonize the stirred and mixed coal blend. Additionally, a mixing apparatus is used in the stirring and mixing step that has a capability of controlling a degree of mixing of the coal blend to be 0.85 or more at 60 seconds after start of a mixing operation. The degree of mixing is calculated by the following equation (1):degree of mixing=(&#x3c3;)/(&#x3c3;)&#x2003;&#x2003;(1).

Method for manufacturing coke, coke, and method for evaluating homogeneity of coal blend

A coal mixture is provided that maintains a high level of coke strength after carbonization, even where coal having an excessively large permeation distance is used in a large amount. The coal mixture includes large-permeation-distance coal and permeation-distance-decreasing coal. The permeation-distance-decreasing coal has a mean maximum vitrinite reflectance Ro of 1.25% or more and a total inert amount TI of 30 vol. % or less. The blending ratio of the permeation-distance-decreasing coal in the coal mixture is in a range derived by multiplying the blending ratio of the large-permeation-distance coal by 0.25 or more and 3.0 or less.

Coal mixture, method for manufacturing coal mixture, and method for manufacturing coke

Provided are, by using an index with which the influence on the strength of coke can be evaluated, a method for evaluating a weathering degree of coal and a coking property of weathered coal within the ranges in which the weathering degree and coking property cannot be determined by using conventional methods, and a method for controlling the weathering degree of coal with which it is possible to add weathered coal to a coal blend to be used for producing coke without decreasing the strength of coke by using the index. The weathering degree of coal is evaluated by using the surface tension of semicoke which is prepared by performing a heat treatment on weathered coal as an index. The weathering degree of each brand of coal is controlled so that the interfacial tension &#x3b3;of a semicoke blend which is prepared by blending the plural brands of semicoke in accordance with the proportions is 0.03 mN/m or lower.

Method for evaluating weathering degree of coal, method for evaluating coking property of weathered coal, method for controlling weathering degree of coal, and method for producing coke

In order to evaluate the compatibility of coals used in coke production and to produce cokes with desired strength by blending coals in consideration of the compatibility, the invention provides a technique which evaluates the adhesion strength obtained when two kinds of coals are carbonized based on properties of the coals. Surface tensions of two kinds of semicokes obtained by heat treating two kinds of coals are measured. Based on the difference between the two measured values of surface tension, the quality of the adhesiveness between the two kinds of coals is evaluated.

There is provided a method for blending coals for coke production, in which the strength of coke produced from a coal blend serving as a raw material is estimated using a physical property that has not been taken into consideration in the past as an index, so that the method is capable of suppressing an increase in the raw material cost of the coal blend and increasing the strength of coal. Two or more coal brands are blended together to provide a coal blend for coke production. When the two or more coal brands are blended together, the coal brands and the blending ratio of the coal brands are determined using the surface tension of each of the coal brands subjected to heat treatment, the surface tension serving as a control index.

Method for blending coals, and method for producing coke

Method for preparing coal for coke making includes controlling particles size of coal or caking additive before arriving at the plant so particles content having diameter of 6 mm or more in the coal or caking additive reaches 30% by mass or less when the coal or caking additive has permeation distance of 15 mm or more. In another method, the relationship between a critical permeation distance and Gieseler maximum fluidity is obtained using permeation distances and Gieseler maximum fluidity values of one or more brands of coal or caking additive, particles size of coal or caking additive is controlled before arriving at the plant so particles content having diameter of 6 mm or more in coal or caking additive reaches 30% by mass or less when permeation distance of coal or caking additive is larger or equal to a critical permeation distance calculated from the Gieseler maximum fluidity.

Method for preparing coal for coke making

A coke manufacturing method includes preparing blended coal by blending coal of at least two types, stirring and mixing the blended coal so as to disintegrate at least a part of pseudo-particles in the blended coal that have been formed by agglomeration of coal particles, and charging the blended coal after stirring and mixing into a coke oven and carbonizing the blended coal so as to manufacture coke.

Coke manufacturing method

Coke is manufactured by blending two or more kinds of coal to form a coal blend and by carbonizing the coal blend. Interfacial tension among coal kinds is used as a control index for determining the blending ratio of each coal when forming the coal blend. It is possible to increase the strength of coke without increasing the material cost of a coal blend.

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Fukuyama, Japan

Yusuke Dohi