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

Patent metadata

Field	Value
Publication number	US-10240092-B2
Application number	US-201515129983-A
Country	US
Kind code	B2
Filing date	Mar 23, 2015
Priority date	Mar 28, 2014
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

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.

First claim

The invention claimed is:

1. A coal mixture comprising:
large-permeation-distance coal; and
permeation-distance-decreasing coal,
wherein:
a mass fraction of the permeation-distance-decreasing coal in the coal mixture is in a range derived by multiplying a mass fraction of the large-permeation-distance coal by 0.25 or more and 3.0 or less,
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 permeation-distance-decreasing coal makes a permeation distance of a 1:1 coal mixture of the permeation-distance-decreasing coal and the large-permeation-distance coal smaller than or equal to a value calculated by multiplying a weighted average value by a constant 0.67, the weighted average value being calculated from permeation distances of the large-permeation-distance coal and the permeation-distance-decreasing coal at a mass ratio of 1:1 thereof,
the large-permeation-distance coal has a permeation distance (mm) that is determined by the following steps:
placing a material having through-holes penetrating from an upper surface to a lower surface of the material on the top of a coal sample packed in a container;
heating the coal sample to permeate into the through-holes; and
determining a distance over which the coal permeates into the through-holes as the permeation distance (mm), and

the permeation distance (mm) of the large-permeation-distance coal is more than a value of criteria permeation distance derived by using the following equation [I]:
criteria permeation distance=1.3× a ×log MF   [I]

where MF is the Gieseler maximum fluidity (ddpm) of coal, and a is a constant defined as a coefficient of the common logarithm log MF of Gieseler maximum fluidity MF multiplied by a value in the range of 0.7 or more and 1.0 or less, when a regression line that passes through the origin is drawn based on data sets of the determined value of permeation distance (mm) and log MF of at least one of coal brands having a log MF of less than 2.5.

2. The coal mixture according to claim 1 , wherein the constant a is a constant defined as a coefficient of the common logarithm log MF of Gieseler maximum fluidity MF multiplied by a value in the range of 0.7 or more and 1.0 or less, when a regression line that passes through the origin is drawn based on data sets of the determined value of permeation distance (mm) and log MF of at least one of coal brands having a log MF of more than 1.75 and less than 2.50.

3. The coal mixture according to claim 1 , wherein a content of the large-permeation-distance coal in the coal mixture is 30 mass % or less.

4. A method for manufacturing the coal mixture according to claim 1 , the method comprising the steps of:
preparing the large-permeation-distance coal and the permeation-distance-decreasing coal; and
mixing the large-permeation-distance coal and the permeation-distance-decreasing coal so that a content of the permeation-distance-decreasing coal in the coal mixture is in a range derived by multiplying a content of the large-permeation-distance coal in the coal mixture by 0.25 or more and 3.0 or less.

5. A method for manufacturing coke, the method comprising coking the coal mixture according to claim 1 as a raw material for the coke by:
preparing a coal blend from the coal mixture or a mixture of the coal mixture and other coal;
charging the coal blend into a coke oven; and
performing carbonization on the charged coal blend to form coke.

6. A coal mixture comprising:
large-permeation-distance coal; and
permeation-distance-decreasing coal,
wherein:
a mass fraction of the permeation-distance-decreasing coal in the coal mixture is in a range derived by multiplying a mass fraction of the large-permeation-distance coal by 0.25 or more and 3.0 or less,
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 permeation-distance-decreasing coal makes a permeation distance of a 1:1 coal mixture of the permeation-distance-decreasing coal and the large-permeation-distance coal smaller than or equal to a value calculated by multiplying a weighted average value by a constant 0.67, the weighted average value being calculated from permeation distances of the large-permeation-distance coal and the permeation-distance-decreasing coal at a mass ratio of 1:1 thereof,
the large-permeation-distance coal has a permeation distance (mm) that is determined by the following steps:
placing a material having through-holes penetrating from an upper surface to a lower surface of the material on the top of a coal sample packed in a container;
heating the coal sample to permeate into the through-holes; and
determining a distance over which the coal permeates into the through-holes as the permeation distance (mm), and

the permeation distance (mm) of the large-permeation-distance coal is more than a value of criteria permeation distance derived by using the following equation [II]:
criteria permeation distance= a ′×log MF+b   [II],

where MF is the Gieseler maximum fluidity (ddpm) of the coal,
a′ is a constant defined as a coefficient of the common logarithm log MF of a Gieseler maximum fluidity MF multiplied by a value in the range of 0.7 or more and 1.0 or less, when a regression line that passes through the origin is drawn based on data sets of the determined value of permeation distance (mm) and log MF of at least one of coal brands having a log MF of less than 2.5, and
b is a constant defined as a value equal to or more than the average value of the standard deviation of permeation distance and equal to or less than a value derived by multiplying the average value by 5, when determination is performed plural times for the same sample of one or more kinds of coal selected from among the coal brands which are used for deriving the regression line.

7. The coal mixture according to claim 6 , wherein the constant a′ is a constant defined as a coefficient of the common logarithm log MF of Gieseler maximum fluidity MF multiplied by a value in the range of 0.7 or more and 1.0 or less, when a regression line is drawn based on data sets of the determined value of permeation distance (mm) and log MF of at least one of coal brands having a log MF of more than 1.75 and less than 2.50.

8. The coal mixture according to claim 6 , wherein the content of the large-permeation-distance coal in the coal mixture is 30 mass % or less.

9. A method for manufacturing the coal mixture according to claim 6 , the method comprising the steps of:
preparing the large-permeation-distance coal and the permeation-distance-decreasing coal; and
mixing the large-permeation-distance coal and the permeation-distance-decreasing coal so that a content of the permeation-distance-decreasing coal in the coal mixture is in a range derived by multiplying a content of the large-permeation-distance coal in the coal mixture by 0.25 or more and 3.0 or less.

10. A method for manufacturing coke, the method comprising coking the coal mixture according to claim 6 as a raw material for the coke by:
preparing a coal blend from the coal mixture or a mixture of the coal mixture and other coal;
charging the coal blend into a coke oven; and
performing carbonization on the charged coal blend to form coke.

11. A coal mixture comprising:
large-permeation-distance coal; and
permeation-distance-decreasing coal,
wherein:
a mass fraction of the permeation-distance-decreasing coal in the coal mixture is in a range derived by multiplying a mass fraction of the large-permeation-distance coal by 0.25 or more and 3.0 or less

Assignees

• Jfe Steel Corp

Inventors

• Dohi Yusuke
• Fukada Kiyoshi
• Matsui Takashi
• Nagayama Mikiya
• Nanri Narumi

Classifications

• G01N33/222

  Solid fuels, e.g. coal · CPC title

• C10B57/04 Primary

  using charges of special composition · CPC title

• C10L5/02

  {Solid fuels such as} briquettes consisting mainly of carbonaceous materials of mineral {or non-mineral} origin (peat briquettes C10F) · CPC title

• G01N11/04

  through a restricted passage, e.g. tube, aperture · CPC title

• C21B5/007

  Conditions of the cokes or characterised by the cokes used · CPC title