ASTM D5187-91(1997)

Standard Test Method for Determination of Crystallite Size (L_c) of Calcined Petroleum Coke by X-Ray Diffraction

SCOPE
1.1 This test method covers the determination of the mean crystallite thickness of a representative, pulverized sample of calcined petroleum coke by interpretation of a X-ray diffraction pattern produced through conventional X-ray scanning techniques.
1.2 Calcined petroleum coke contains crystallites of different thicknesses. This test method covers the determination of the average thickness of all crystallites in the sample by empirical interpretation of the X-ray diffraction pattern. The crystallite diameter ( La) is not determined by this test method.
1.3 The values stated in SI (metric) units are to be regarded as the standard. The inch-pound units given in parentheses are provided for information purposes only.
1.4 This standard does not purport to address all of the safety concerns, if any, 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.

General Information

• Status: Historical
• Publication Date: 14-Oct-1991
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.05 - Properties of Fuels, Petroleum Coke and Carbon Material

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5187 – 91 (Reapproved 1997)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Determination of Crystallite Size (L ) of Calcined Petroleum
c
1
Coke by X-Ray Diffraction
This standard is issued under the fixed designation D 5187; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope of graphite corresponding to a lattice spacing (d) of 3.35 Å.
3.1.4 Q—the glancing angle produced when a parallel beam
1.1 This test method covers the determination of the mean
of uniform X-rays impinges upon a crystalline lattice. This
crystallite thickness of a representative, pulverized sample of
angle is measured by the X-ray goniometer and is usually
calcined petroleum coke by interpretation of a X-ray diffraction
expressed in ° 2Q.
pattern produced through conventional X-ray scanning tech-
niques.
4. Summary of Test Method
1.2 Calcined petroleum coke contains crystallites of differ-
4.1 A packed sample pulverized to less than 75 μm is
ent thicknesses. This test method covers the determination of
subjected to a monochromatic X-ray beam and rotated to
the average thickness of all crystallites in the sample by
produce a diffraction pattern under specific conditions. The
empirical interpretation of the X-ray diffraction pattern. The
location and shape of the peak with hkl 5 (002) at d 5 3.35;
crystallite diameter (L ) is not determined by this test method.
a
˚
A is used to calculate the L by manual interpretation of the
c
1.3 The values stated in SI (metric) units are to be regarded
peak or by computer simulation.
as the standard. The inch-pound units given in parentheses are
provided for information purposes only.
5. Significance and Use
1.4 This standard does not purport to address all of the
5.1 The crystallinity of petroleum coke, as reflected by the
safety concerns, if any, associated with its use. It is the
L value, is a general measure of quality affecting suitability for
c
responsibility of the user of this standard to establish appro-
end use and is a function of the heat treatment.
priate safety and health practices and determine the applica-
5.2 The crystallite thickness is used to determine the extent
bility of regulatory limitations prior to use.
of such heat treatment, for example, during calcination. The
2. Referenced Documents value of the L determined is not affected by coke microporos-
c
ity or the presence of foreign, non-crystalline materials such as
2.1 ASTM Standards:
dedust oil.
D 346 Practice for Collection and Preparation of Coke
2
Samples for Laboratory Analysis
6. Apparatus
2
D 2013 Method for Preparing Coal Samples for Analysis
6.1 X-Ray Powder Diffractometer, equipped with an X-ray
D 2234 Test Methods for Collection of a Gross Sample of
2 source, a monochromator or filter for restricting the wave-
Coal
length range, a sample holder, a radiation detector, a signal
D 4057 Practice for Manual Sampling of Petroleum and
3 processor, and readout (chart or computer memory). The
Petroleum Products
diffractometer must be capable of rate scanning at 1° per
minute or incrementally step scanning at 0.2° per step.
3. Terminology
6.2 Sample Holders, as specified by the manufacturer of the
3.1 Definitions of Terms Specific to This Standard:
diffractometer that enables packing of a pulverized sample of
3.1.1 crystallites—stacks of graphitic carbon platelets lo-
sufficient thickness to expose a level, smooth surface to the
cated parallel to one another.
X-ray beam.
3.1.2 L —the mean or average thickness of crystallites in a
c
6.3 Briquetting Press, capable of generating pressures up to
sample. It is expressed as a linear dimension in angstrom units,
−1
10 000 psi (69 MPa).
˚
A (10 nm).
6.4 Compressible Aluminum Caps, used as a support for
3.1.3 hkl(002)—the Miller indices of the crystalline planes
producing a briquetted sample.
6.5 Silicon or Quartz Sample, available from National
1
This test method is under the jurisdiction of ASTM Committee D-2 on
Institute of Standards and Technology (NIST).
Petroleum Products and Lubricantsand is the direct responsibility of Subcommittee
D02.05.0Don Petroleum Coke Sampling and Procedures.
7. Reagents and Materials
Current edition approved Oct. 15, 1991. Published December 1991.
2
Annual Book of ASTM Standards, Vol 05.05.
7.1 Purity of Reagents—Reagent grade chemicals shall be
3
Annual Book of ASTM Standards, Vol 05.02.
1

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D 5187
used in all tests. It is intended that all
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