Jfe Steel Corporation

Nkk Corporation

Jp Steel Plantech Co.

Takashi Anyashiki

Tetsuya Yamamoto

Hidekazu Fujimoto

Hiroyuki Sumi

Kiyoshi Fukada

Izumi Shimoyama

Yusuke Dohi

Takeshi Sato

Keiji Yoshida

Toru Shiozawa

Kazumi Itou

Hiroyuki Kato

Kenji Yoshida

Hideaki Sato

Kenichi Sasaki

Masaaki Yamashita

Masaru Sagiyama

Yasuhiro Toyoda

Taihei Nouchi

Yasuyuki Kajita

Katsuyoshi Tanaka

Mamoru Ehara

Keiichi Kotani

Shouichi Oosuka

Toshiaki Amagasa

In a ferrocoke manufacturing method by shaping and carbonizing a mixture of coal and iron ore, a hardly softening coal having a button index (CSN) of not more than 2.0 is used as the coal. The coal can be a blend of hardly softening coal and easily softening coal, and the hardly softening coal can be a coal having a button index (CSN) of 1.0 and a volatile matter of not less than 17%, and the easily softening coal can be a coal satisfying that a value obtained by multiplying CSN of easily softening coal by a blending ratio of easily softening coal in all coals is a range of 0.3-5.2. The coal can also be a blend of hardly softening coal and easily softening coal, and the hardly softening coal can be a coal having a button index (CSN) of 1.5-2.0, and the easily softening coal can be a coal satisfying that a value obtained by multiplying CSN of easily softening coal by a blending ratio of easily softening coal in all coals is nit more than 5.0.

Ferrocoke manufacturing method

A method for producing ferrocoke in which it is possible to use a cheap and poor-quality coal having a high ash content while suppressing the decrease of the strength in ferrocoke or formed coke and a special coal mixing is not performed with respect to the fusion frequently causing problems in the carbonization with the shaft furnace. In a method for producing ferrocoke by molding and carbonizing a mixture of coal and iron ore, the coal is a single coal or a mixture of plural coals and a non-caking or slight caking coal having a load average value of ash content of not less than 10.7% and a load average value of mean maximum reflectance of not less than 0.81% is used.

Method for producing ferrocoke

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

Provided is a method for preparing a coal mixture used for the purpose of producing coke with desired strength by taking into account the compatibility between coals for cokemaking. In the case of preparing a coal mixture, used as at least one portion of a coal blend for cokemaking, containing two or more types of coals with different surface tensions, the blending ratio of each of the coals is adjusted using the surface tension of a semicoke mixture obtained from the coal mixture as an indicator.

Method for preparing coal mixture for cokemaking, coal mixture, and method for producing 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

Provided is a technique by which the compatibility between coals for cokemaking can be quantitatively determined to estimate the coke strength taking into account the compatibility and to select and blend coals based on the coke strength estimated taking into account the compatibility, thereby allowing the production of a coke with the desired strength. A method for blending coals for cokemaking includes predicting the strength of a coke to be produced from a blend of a plurality of coals based on a difference between the surface tensions of the plurality of coals after heat treatment and determining the types and proportions of the coals to be blended.

Method for blending coals for cokemaking and method for producing coke

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.

Method for manufacturing coke

A coke layer and an ore layer are formed in a blast furnace. The coke layer is formed of conventional coke and the ore layer is formed of carbon iron composite, conventional coke, and ore. The mixing percentage of the conventional coke in the ore layer with respect to the ore is 0.5 mass % or more. Slowing of the gasification reaction of carbon iron composite in the cohesive zone can be suppressed.

Method for operating blast furnace

Carbon iron composite is produced by feeding a formed product of a carbon-containing substance and an iron-containing substance into a carbonization furnace, carbonizing the formed product in a carbonization zone, blowing a coolant gas into the furnace through a coolant-gas-blowing tuyere disposed in a cooling zone to cool carbon iron composite, exhausting a furnace gas through an outlet in a top portion, and discharging the carbon iron composite through a lower portion of the cooling zone.

Method and apparatus for producing carbon iron composite

Coating composition for precoated steel sheet, precoated steel sheet,

This invention relates to a coating composition for precoated steel sheets which are required to have high hardness, high workability and high distinctness of image, and to a method for producing a precoated steel sheet having a coating film of the composition. The composition is prepared by adding a compound of any of the following (a) to (c) to a coating composition consisting essentially of a polyol and containing, as the curing agent, an isocyanate compound or an amino resin, and the coating film of the composition has both high-level workability and high-level hardness. (a) Polyester compounds comprising main repeating units of a general formula (1): ##STR1## wherein n is an integer; and R is an alkylene group having 10 or less carbon atoms, or a 1,4-cyclohexylene-dimethylene group, or a neopentylene group, or a polyoxyalkylene group. (b) Polyester compounds comprising main repeating units of a general formula (2): ##STR2## wherein n is an integer of 10 or less; and R is an alkylene group having 10 or less carbon atoms, or a 1,4-cyclohexylene-dimethylene group, or a neopentylene group. (c) Compounds having the structure of a general formula (3):

Coating composition and method for producing precoated steel sheets

This invention relates to a coating composition for precoated steel sheets which are required to have high hardness, high workability and high distinctness of image, and to a method for producing a precoated steel sheet having a coating film of the composition. The composition is prepared by adding a compound of any of the following (a) to (c) to a coating composition consisting essentially of a polyol and containing, as the curing agent, an isocyanate compound or an amino resin, and the coating film of the composition has both high-level workability and high-level hardness.

Growing community of inventors

Tokyo, Japan

Takashi Anyashiki