ASTM D2797/D2797M-11

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Designation:D2797/D2797M–09 Designation: D2797/D2797M – 11
Standard Practice for
Preparing Coal Samples for Microscopical Analysis by
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Reflected Light
This standard is issued under the fixed designation D2797/D2797M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 Thispracticecoverslaboratoryproceduresforthepreparationofgranularsamplesofbituminouscoalandanthracitesamples
for examinationwith a microscope using reflected lightillumination.Itdoesnotapplytothepreparationoforientedblocksofcoal.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
1.3 This standard does not purport to address the safety concerns associated with its use. It is the responsibility of the user of
this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior
to use.
2. Referenced Documents
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2.1 ASTM Standards:
D2013 Practice for Preparing Coal Samples for Analysis
D2234/D2234M Practice for Collection of a Gross Sample of Coal
D2798 Test Method for Microscopical Determination of the Vitrinite Reflectance of Coal
D2799 Test Method for Microscopical Determination of the Maceral Composition of Coal
D4596 Practice for Collection of Channel Samples of Coal in a Mine
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
3. Summary of Practice
3.1 Arepresentative sample is crushed to a specified particle size, air-dried, mixed with a binder, and formed into a briquet.The
briquet is then polished to a flat, scratch-free surface for examination by vertical illumination.
4. Significance and Use
4.1 Briquets of granular bituminous coals and anthracite prepared in accordance with the laboratory procedures of this practice
will have flat, scratch-free surfaces suitable for examination with a microscope using reflected light illumination. The polished
surfaces of briquettes prepared by this practice will contain particles representative of the original gross sample.
4.2 Samples prepared by this practice are used for microscopical determination of the reflectance of the organic components in
a polished specimen of coal (Test Method D2798) and for microscopical determination of the volume percent of physical
components of coal (Test Method D2799).
5. Apparatus
5.1 Grinder, Pulverizer, or Mill, for final crushing of the sample to pass a 850-µm (No. 20) sieve. Mortar and pestle or other
equipment suitable for reducing the particle size of a 250-g sample that already passes a 4.75-mm (No. 4) sieve until all of it passes
a 850-µm (No. 20) sieve (see 6.5).
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5.2 Coarse Riffle Sampler—a riffle with at least twelve divisions of not less than 12.7 mm [ ⁄2 in.] and not greater than 19.1 mm
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[ ⁄4 in.].
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This practice is under the jurisdiction of ASTM Committee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.28 on Petrographic Analysis
of Coal and Coke.
Current edition approved Sept. 1, 2009. Published September 2009. Originally approved in 1969. Last previous edition approved in 2007 as D2797–07. DOI:
10.1520/D2797_D2797M-09.
Current edition approved April 15, 2011. Published June 2011. Originally approved in 1969. Last previous edition approved in 2009 as D2797 – 09. DOI:
10.1520/D2797_D2797M-11.
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D2797/D2797M – 11
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5.3 Fine Riffle Sampler—a riffle with at least twelve divisions of not less than 3.2 mm [ ⁄8 in.] and not greater than 6.4 mm [ ⁄4
in.].
5.4 Sieves—a 4.75-mm (No. 4) and a 850-µm (No. 20) U.S. Standard Sieve (Specification E11).
5.5 Molds—containers to hold the coal binder mixture while the binder hardens.
5.5.1 The mold shall be capable of withstanding pressures up to 70 MPa [10 0
...