YB/T 077-2017 English PDF (YBT077-2017)

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YB/T 077-2017: Method for determining optical texture of coke
YB/T 077-2017
YB
FERROUS METALLURGY INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 75.160.10
H 32
Replacing YB/T 077-1995
Method for determining optical texture of coke
ISSUED ON: APRIL 12, 2017
IMPLEMENTED ON: OCTOBER 01, 2017
Issued by: Ministry of Industry and Information Technology of the People's
Republic of China
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Principle ... 6
5 Instruments and materials ... 6
6 Sampling and preparation of specimens ... 7
7 Determination procedures ... 7
8 Result calculation ... 9
9 Test report ... 9
Annex A (informative) Report format and content of measurement results for optical
texture of coke ... 10
Method for determining optical texture of coke
1 Scope
This Standard specifies the measurement principles, instruments, sampling and
preparation of specimens, measurement procedures and result calculations for each
optical texture of the coke pore wall.
This Standard applies to metallurgical coke. It can be used as a reference for other types
of coke.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 1997, Coke -- Sampling and preparation of samples
GB/T 8899, Determination of maceral group composition and minerals in coal
GB/T 16773, Method of preparing coal samples for the coal petrographic analysis
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 optical texture of coke
When the total magnification is 400 times to 600 times under the oil immersion
objective lens with a polarized reflection microscope, the observed coke pore wall
texture (expressed as a map).
3.2 isotropic texture
The texture with the same optical properties in all directions formed by the softening
and melting of the active components when the coal is dry. The structure is dense. The
surface is flat. The edges of pores are smooth. After inserting the test board, the
interference color is first-grade red. The color does not change (represented as a map)
when the stage is rotated.
3.3 anisotropic texture
When the coal is dried and melted, the active components are softened and melted to
form a texture with different shapes, different sizes of isochromatic regions, and
different optical properties in each direction. After inserting the test board, it will appear
in different colors such as red, yellow and green. The colors alternately change when
the stage is rotated. Generally, anisotropic textures with similar size and shape under
the microscope are divided into the same type.
3.4 fine mosaic texture
The texture with an equichromatic zone size < 1.0 μm under the microscope. When the
stage is rotated, red and yellow are alternately displayed (represented by a spectrum).
3.5 medium mosaic texture
The texture with equichromatic zone size ≥1.0 μm ~ 5.0 μm under the microscope.
When the stage is rotated, red, yellow and green are alternately displayed (represented
by a spectrum).
3.6 coarse mosaic texture
The texture with equichromatic zone size ≥5.0 μm ~ 10.0 μm under the microscope.
When the stage is rotated, red, yellow and green are alternately displayed (expressed by
a spectrum).
3.7 uncompletely fibrous texture
The texture that seems to flow in one direction, with equichromatic zone size under the
microscope: width < 10.0 μm, length ≥10.0 μm ~ 30.0 μm. When the stage is rotated,
red, yellow and green are alternately displayed (represented by a spectrum).
3.8 completely fibrous texture
The texture that is mostly arranged in fascicles in parallel, with equichromatic zone size
under the microscope: width < 10.0 μm, length ≥30.0 μm. When the stage is rotated, red,
yellow and green are alternately displayed (represented by a spectrum).
3.9 leaflet texture
The texture with equichromatic zone size under the microscope: length and width about
≥10.0 μm. When the stage is rotated, red, yellow and green are alternately displayed
(represented by a spectrum).
3.10 fusinite and frag mental texture
When the coal is dry, the texture that is formed by not softening molten
microcomponents (inertites). Some preserve the original form of the silk structure in
coal. Some have no definite forms. Generally, the particle interface is clear. There are
many edges and corners and protrusions. After inserting the test board, it turns first-
6 Sampling and preparation of specimens
6.1 Coke samples are taken in accordance with GB/T 1997.
6.2 Coke samples are prepared according to the provisions of GB/T 1997. Prepare
representative < 3mm coke samples, not less than 2 kg. Mix and shrink to 1 kg. Crush
all to less than 1 mm. Crush to 1 mm specimens and mix well. Divide to 40 g ~ 50 g.
The particle size must be all less than 1.0 mm (square hole sieve). Discard the fine
particles smaller than 0.071 mm. They shall not be crushed too much. It is required that
fine particles smaller than 0.071 mm shall not exceed 15% of the total amount. If the
mass of the particle size less than 0.071 mm is more than 15% of the total weight, re-
prepare the sample until it meets the requirements. Take 4 g ~ 5 g of 0.071 mm ~ 1.0
mm class sample for sheet making.
6.3 The preparation method of powder coke and block coke shall refer to the provisions
of GB/T 16773. The polishing material can be aluminum oxide, silicon oxide or
chromium oxide solution. The diameter of the powder focal plate shall not be less than
22 mm. The volume occupied by the cement shall be less than 1/3. After polishing, the
surface shall be smooth and clean, without obvious pitting, scratches and dirt. The
interface of the optical texture shall be clear and well-defined.
7 Determination procedures
7.1 Adjust the microscope
7.1.1 Place the specimen on a slide with cement. Flatten it. Then place it on the stage
for quasi-focus. Correct the objective lens center.
7.1.2 Adjust the light source, aperture diaphragm and field diaphragm, so that the
brightness of the field of view is moderate, the light is uniform, and the image is clear.
7.1.3 Adjust the polarizer and analyzer to make them orthogonal. Insert the gypsum
inspection board (1 λ), so that the visual field presents the first-grade red interference
color.
7.2 Determination of powder focal light film
7.2.1 Determine the moving step size of the stage. Ensure that more than 500 effective
measuring points evenly cover the entire film. The dot pitch is preferably 0.3 mm ~ 0.5
mm. The line spacing is preferably 0.4 mm ~ 0.8 mm, which shall not be less than the
dot pitch.
7.2.2 Starting from one end of the specimen, identify what kind of optical texture the
substance under the intersection of the crosshairs (see Table 1 for the classification
diagram) belongs to. Count into the corresponding count key. Then move one step in a