ASTM D2638-21

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Designation: D2638 − 10 (Reapproved 2015) D2638 − 21
Standard Test Method for
Real Density of Calcined Petroleum Coke by Helium
Pycnometer
This standard is issued under the fixed designation D2638; 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.
ε NOTE—Editorial changes were made throughout in December 2015.
1. Scope Scope*
1.1 This test method covers the determination of the real density (RD) of calcined petroleum coke. Real density, by definition is
obtained when the particle size of the specimen is smaller than 75 μm (U.S. No. 200 Sieve).
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D346D4930 Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisTest Method for Dust Control
Material on Calcined Petroleum Coke
D2013D6969 Practice for Preparing Coal Preparation of Calcined Petroleum Coke Samples for Analysis
D2234/D2234MD6970 Practice for Collection of a Gross Sample of CoalCalcined Petroleum Coke Samples for Analysis
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4292 Test Method for Determination of Vibrated Bulk Density of Calcined Petroleum Coke
D4930 Test Method for Dust Control Material on Calcined Petroleum Coke
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions:
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.
Current edition approved Oct. 1, 2015Jan. 1, 2021. Published December 2015January 2021. Originally approved in 1991. Last previous edition approved in 20102015 as
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D2638 – 10.D2638 – 10 (2015) . DOI: 10.1520/D2638-10R15E01. 10.1520/D2638-21.
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*A Summary of Changes section appears at the end of this standard
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D2638 − 21
3.1.1 calcined petroleum coke, n—petroleum coke that has been thermally treated to drive off the volatile matter and to develop
crystalline structure.
3.1.2 petroleum coke, n—a solid, carbonaceous residue produced by thermal decomposition of heavy petroleum fractions or
cracked stocks, or both.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 bulk density, n—the mass of the particles divided by the volume they occupy which includes the space between the particles.
Refer to Test Method D4292 for bulk density procedures.
3.2.1 dedusting material, n—See Test Method D4930.
3.2.2 real density, n—(RD) (also be referred to as true specific gravity). The mass divided by the volume occupied by the material
excluding pores and voids. It is required, therefore, that voids in the coke be eliminated and that pores in the material be filled by
the fluid being displaced. This requirement is met for the purposes of this test method by reducing the coke particles to a size
smaller than 75 μm.
3.2.2.1 Discussion—
The density of particles larger than 75 μm up to the largest that can be put into the helium pycnometer can also be determined,
but must be designated as particle density (PD). The precision data obtained for RD may not be applicable to PD.
4. Summary of Test Method
4.1 A representative sample of calcined petroleum coke is dried and ground to pass a 75 μm (200-mesh) screen. The mass of the
sample is determined directly and the volume derived by the volume of helium displaced when the sample is introduced into a
helium pycnometer. The ratio of the mass of the sample to the volume is reported as the real density.
5. Significance and Use
5.1 The real density of calcined petroleum coke directly influences the physical and chemical properties of the manufactured
carbon and graphite artifacts for which it is used. Density, therefore, is a major quality specification of calcined petroleum coke
and is used as a control in coke calcination.
6. Interferences
6.1 Oil or other dedust material sprayed on calcined petroleum coke to control dust will interfere with the determination of real
density so the oil must be removed before reducing the sample to 75 μm. Refer to Test Method D4930 for dedust oil removal.
7. Apparatus
7.1 Analytical Balance, accurate to 60.1 mg.
7.2 Desiccator.
7.3 Drying Oven, preferably a vacuum oven, for temperature to 120 °C.
7.4 Helium Pycnometer:
7.5 Jaw Crusher and Roll Crusher—Other style crushers which allow control over particle size without contamination are
acceptable.
7.6 Rifflers, with hoppers and closures.
7.7 Wire Sieve, 75 μm (U.S. No. 200 mesh), meeting Specification E11.
D2638 − 21
8. Reagents and Materials
8.1 Helium, 99.9 %.
9. Sample Preparation
9.1 For recomme
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