Jfe Steel Corporation

Well Stone Co.

Jp Steel Plantech Co.

Hiroyuki Sumi

Tetsuya Yamamoto

Takeshi Sekiguchi

Koji Yano

Takeshi Sato

Kiyoshi Fukada

Hideaki Sato

Koichi Yasuda

Izumi Shimoyama

Yusuke Dohi

Takashi Anyashiki

Hidekazu Fujimoto

Yoichi Ishii

Etsuo Yoshida

Kenji Oi

Kazuyuki Ishii

Yasushi Kitani

Sayaka Ishii

Tokihiko Kataoka

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

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

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 method of manufacturing a laser welded steel pipe by forming a steel strip into a cylindrical open pipe and performing laser welding on edges that includes: emitting two laser beams along the edges from an upper surface side of the open pipe, the two laser beams being transmitted through different optical fibers with in-focus spot diameters exceeding 0.3 mm; emitting leading and trailing laser beams each inclined toward a direction in which welding proceeds at an incident angle with respect to a direction perpendicular to an upper surface of the open pipe; setting the incident angle of the leading laser beam to be larger than the incident angle of the trailing laser beam; and setting a gap between a center point of the leading laser beam and a center point of the trailing laser beam on a back surface of the open pipe to 1 mm or larger.

Method of manufacturing laser welded steel pipe

A method for evaluating thermal plasticity of coals and caking additives includes packing a coal or a caking additive into a vessel to prepare a sample; arranging a through-hole materialhaving through-holes from top to bottom surfaces, onto the sample; heating the sampleat a predetermined heating rate while maintaining a constant volume of or while applying a constant load onto the sampleand the through-hole material; measuring the permeation distance with which the molten sample has permeated into the through-holes; and evaluating thermal plasticity of the sample using the measured value. Alternatively, a method involves heating the sampleat a predetermined heating rate while maintaining the sampleand the through-hole materialin a constant volume; measuring the pressure of the sample that is transmitted via the through-hole material; and evaluating thermal plasticity of the sample using the measured value.

Method for evaluating thermal plasticity of coals and caking additives, and method for producing coke

A laser welding method includes emitting two laser beams along a weld line from an upper surface side of a workpiece, the two laser beams being transmitted through different optical fibers and having in-focus spot diameters of 0.3 mm or larger; emitting the laser beams such that a leading laser beam of the two laser beams and a trailing laser beam of the two laser beams are each inclined toward a direction in which welding proceeds at an incident angle with respect to a direction perpendicular to an upper surface of the workpiece, the leading laser beam being ahead of the trailing laser beam on the upper surface of the workpiece in the direction in which welding proceeds, the trailing laser beam being behind the leading laser beam; and setting the incident angle of the leading laser beam to be larger than the incident angle of the trailing laser beam.

Laser welding method

A method for estimating the thermal plasticity of coal and a caking additive by observing the thermal plasticity of coal and a caking additive under the condition that sufficiently simulates an environment surrounding thermal plastic coal and a caking additive in a coke oven and to provide a method for preparing coal of a brand having a specified quality by making clear the required quality of a coal brand which can be ideally used for manufacturing high-strength coke by using the estimation method. A method for preparing coal for coke making, the method including adjusting a permeation distance of one or more kinds of coal to a specified value or less when plural coal brands are blended as materials to be used for coke making is used.

Provided is a simple and easy method of producing an innoxious dry earthworm powder, while suppressing inactivation of the enzymes contained in earthworms. In the method, a homogenate obtained by grinding living earthworms is freeze-dried and the dried product is heat-treated at a temperature of 110&#xb0; C. or higher but lower than 130&#xb0; C. Preferably, the method according to the present invention comprises further a process for preparation of the living earthworms, which precedes the grinding step, comprising the steps of: standing the living earthworms under light for 10 to 50 hours; removing the dirt formed on the skin thereof, bringing the earthworms into contact with an organic acid for 30 seconds or less; diluting the acid with addition of water to adjust the pH of the aqueous acidic solution to a pH in the range of 2 to 5; standing the earthworm mixture under the pH condition for 3 to 180 minutes; and then washing the earthworms with water.

Method of producing a dry earthworm powder

Provided is a method of producing a dry earthworm powder without deterioration in useful pharmacological action, by removing dirt on the skin of earthworms while allowing the earthworms to excrete the digest remaining in the digestive tracts efficiently without weakening the earthworms, which comprises the steps of: standing living earthworms under light for 10 to 50 hours, removing the dirt formed on the skin thereof, adding an organic acid to the living earthworms, diluting the acid rapidly with addition of water, adjusting the pH of the aqueous acidic solution to 2 to 5, standing the earthworm mixture for 3 to 180 minutes under the pH condition, washing the earthworms with water, grinding the earthworms into a homogenate, freezing the homogenate at &#x2212;18&#xb0; C. to &#x2212;35&#xb0; C., keeping the frozen homogenate for 20 to 240 hours, and freeze-drying and degassing the frozen homogenate under vacuum simultaneously.

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Kawasaki, Japan

Hiroyuki Sumi