ASTM D3174-12(2018)e1

Standard Test Method for Ash in the Analysis Sample of Coal and Coke from Coal

SIGNIFICANCE AND USE
5.1 Ash, as determined by this test method, is the residue remaining after burning the coal and coke. Ash obtained differs in composition from the inorganic constituents present in the original coal. Incineration causes an expulsion of all water, the loss of carbon dioxide from carbonates, the conversion of iron pyrites into ferric oxide, and other chemical reactions. Ash, as determined by this test method, will differ in amount from ash produced in furnace operations and other firing systems because incineration conditions influence the chemistry and amount of the ash. References for correcting ash results determined by this test method to a mineral-matter-free basis are listed in Classification D388, Section 9.
SCOPE
1.1 This test method covers the determination of the inorganic residue as ash in the analysis sample of coal or coke as prepared in accordance with Practice D2013 or Practice D346. The results obtained can be applied as the ash in the proximate analysis, Practice D3172, and in the ultimate analysis, Practice D3176. For the determination of the constituents in ash, reference is made to Test Methods D3682, D4326, and D6349. Test Methods D6357 should be used to prepare ash to be used for trace element analysis. See Terminology D121 for definition of ash.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered 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, health, and environmental 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.

General Information

• Status: Published
• Publication Date: 14-Oct-2018
• ICS: 75.160.10 - Solid fuels
• Technical Committee: D05 - Coal and Coke
• Drafting Committee: D05.21 - Methods of Analysis

Relations

• Refers: ASTM D3176-24 - Standard Practice for Ultimate Analysis of Coal and Coke
• Effective Date: 01-Apr-2024
• Refers: ASTM D121-15(2024) - Standard Terminology of Coal and Coke
• Effective Date: 01-Mar-2024
• Refers: ASTM D3180-15(2023) - Standard Practice for Calculating Coal and Coke Analyses from As-Determined to Different Bases
• Effective Date: 01-Dec-2023
• Refers: ASTM D3176-15(2023) - Standard Practice for Ultimate Analysis of Coal and Coke
• Effective Date: 01-Dec-2023
• Refers: ASTM D388-19 - Standard Classification of Coals by Rank
• Effective Date: 01-Jun-2019
• Refers: ASTM D388-18a - Standard Classification of Coals by Rank
• Effective Date: 01-Nov-2018
• Refers: ASTM D388-18 - Standard Classification of Coals by Rank
• Effective Date: 01-Feb-2018
• Refers: ASTM D388-17a - Standard Classification of Coals by Rank
• Effective Date: 01-Nov-2017
• Refers: ASTM D388-17 - Standard Classification of Coals by Rank
• Effective Date: 01-Jul-2017
• Refers: ASTM D5016-16 - Standard Test Method for Total Sulfur in Coal and Coke Combustion Residues Using a High-Temperature Tube Furnace Combustion Method with Infrared Absorption
• Effective Date: 01-Sep-2016
• Refers: ASTM D121-15 - Standard Terminology of Coal and Coke
• Effective Date: 01-Sep-2015
• Refers: ASTM D388-15 - Standard Classification of Coals by Rank
• Effective Date: 15-May-2015
• Refers: ASTM D3176-15 - Standard Practice for Ultimate Analysis of Coal and Coke
• Effective Date: 01-Jan-2015
• Refers: ASTM D3180-15 - Standard Practice for Calculating Coal and Coke Analyses from As-Determined to Different Bases
• Effective Date: 01-Jan-2015
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013

Overview

ASTM D3174-12(2018)e1 is the Standard Test Method for Ash in the Analysis Sample of Coal and Coke from Coal, developed by ASTM International. This test method specifies procedures for determining the inorganic residue, or ash, remaining after burning an analysis sample of coal or coke. The method is widely used in laboratory settings for both proximate and ultimate analyses of coal and coke, supporting fuel classification, quality control, and regulatory compliance in the coal and coke industries. The ash content measured by this method is crucial for understanding the performance and environmental impact of coal and coke in various applications.

Key Topics

• Ash Determination: This test method involves incinerating a precisely prepared analysis sample of coal or coke and weighing the inorganic residue, known as ash, after combustion. The resulting ash content is expressed as a percentage of the initial sample.
• Significance of Ash: The ash obtained differs chemically and quantitatively from the original inorganic components in the raw coal due to loss of water, carbon dioxide, and conversion of certain minerals during incineration. The results may vary from ash produced in real furnace operations.
• Sample Preparation: Samples must be pulverized to pass through a 250 µm (No. 60) sieve for analysis. The procedure requires accurate weighing and ashing under controlled furnace conditions.
• Controlled Conditions: The process uses specified temperatures (typically 500 °C, then 750 °C for coal, up to 950 °C for coke) and regulated airflow to ensure repeatable and reliable results.
• Precision and Reliability: The standard defines repeatability and reproducibility limits for ash content determinations, ensuring high accuracy across laboratories.
• Safety and Compliance: Users are responsible for adhering to all safety, health, and environmental regulations during testing.

Applications

• Coal and Coke Quality Control: Ash content is a primary quality parameter in coal and coke used for energy production, steelmaking, and chemical feedstocks.
• Fuel Characterization: Ash analysis supports classification of coal by rank and helps to predict combustion behavior, slagging, and fouling tendencies in boilers and furnaces.
• Proximate and Ultimate Analysis: Results feed into other standardized analyses, such as ASTM D3172 (proximate analysis) and ASTM D3176 (ultimate analysis), contributing to comprehensive fuel characterization.
• Compliance and Reporting: Power plants, mining operations, and testing laboratories use ash data for reporting to regulatory bodies and for ensuring that fuel meets contract specifications.
• Environmental Impact Assessment: Determining ash content helps estimate the volume and composition of combustion residues for waste management and environmental control.

Related Standards

Several ASTM standards are referenced for sample preparation, further analysis, and terminology related to coal and coke testing:

• ASTM D121: Terminology of Coal and Coke
• ASTM D2013 and ASTM D346: Practices for Preparing Coal and Coke Samples for Analysis
• ASTM D3172: Practice for Proximate Analysis of Coal and Coke
• ASTM D3173: Test Method for Moisture in Coal and Coke
• ASTM D3176: Practice for Ultimate Analysis of Coal and Coke
• ASTM D3180: Practice for Calculating Coal and Coke Analyses from As-Determined to Different Bases
• ASTM D388: Classification of Coals by Rank
• ASTM D3682, D4326, D6349, D6357: Methods for determination of major, minor, and trace elements in combustion residues

Conclusion

ASTM D3174-12(2018)e1 provides a reliable, standardized approach for measuring ash in coal and coke analysis samples, supporting quality assurance, fuel classification, and regulatory compliance. By following this method, laboratories can obtain consistent, accurate data critical for industrial, environmental, and commercial applications within the global coal and coke industries.

Standards Content (Sample)

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.
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Designation: D3174 − 12 (Reapproved 2018)
Standard Test Method for
Ash in the Analysis Sample of Coal and Coke from Coal
This standard is issued under the fixed designation D3174; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—An editorial correction was made to 8.1 in September 2020.
1. Scope Samples for Laboratory Analysis
D388 Classification of Coals by Rank
1.1 This test method covers the determination of the inor-
D1757 Test Method for Sulfate Sulfur inAsh from Coal and
ganic residue as ash in the analysis sample of coal or coke as
Coke (Withdrawn 2009)
prepared in accordance with Practice D2013 or Practice D346.
D2013 Practice for Preparing Coal Samples for Analysis
The results obtained can be applied as the ash in the proximate
D2795 Test Methods for Analysis of Coal and Coke Ash
analysis, Practice D3172, and in the ultimate analysis, Practice
(Withdrawn 2001)
D3176. For the determination of the constituents in ash,
D3172 Practice for Proximate Analysis of Coal and Coke
reference is made to Test Methods D3682, D4326, and D6349.
D3173 Test Method for Moisture in the Analysis Sample of
Test Methods D6357 should be used to prepare ash to be used
Coal and Coke
for trace element analysis. See Terminology D121 for defini-
D3176 Practice for Ultimate Analysis of Coal and Coke
tion of ash.
D3180 Practice for Calculating Coal and Coke Analyses
1.2 The values stated in SI units are to be regarded as
from As-Determined to Different Bases
standard. The values given in parentheses after SI units are
D3682 Test Method for Major and Minor Elements in
provided for information only and are not considered standard.
Combustion Residues from Coal Utilization Processes
1.3 This standard does not purport to address all of the
D4326 Test Method for Major and Minor Elements in Coal
safety concerns, if any, associated with its use. It is the
and Coke Ash By X-Ray Fluorescence
responsibility of the user of this standard to establish appro-
D5016 Test Method for Total Sulfur in Coal and Coke
priate safety, health, and environmental practices and deter-
Combustion Residues Using a High-Temperature Tube
mine the applicability of regulatory limitations prior to use.
Furnace Combustion Method with Infrared Absorption
1.4 This international standard was developed in accor-
D6349 Test Method for Determination of Major and Minor
dance with internationally recognized principles on standard-
Elements in Coal, Coke, and Solid Residues from Com-
ization established in the Decision on Principles for the
bustion of Coal and Coke by Inductively Coupled
Development of International Standards, Guides and Recom-
Plasma—Atomic Emission Spectrometry
mendations issued by the World Trade Organization Technical
D6357 TestMethodsforDeterminationofTraceElementsin
Barriers to Trade (TBT) Committee.
Coal, Coke, and Combustion Residues from Coal Utiliza-
tion Processes by Inductively Coupled Plasma Atomic
2. Referenced Documents
Emission Spectrometry, Inductively Coupled Plasma
2.1 ASTM Standards:
Mass Spectrometry, and Graphite Furnace Atomic Ab-
D121 Terminology of Coal and Coke
sorption Spectro
D346 Practice for Collection and Preparation of Coke
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
This test method is under the jurisdiction of ASTM Committee D05 on Coal
3. Terminology
and Coke and is the direct responsibility of Subcommittee D05.21 on Methods of
Analysis.
3.1 For definitions of terms used in this test method, refer to
Current edition approved Oct. 15, 2018. Published April 2019. Originally
Terminology D121.
approved in 1973. Last previous edition approved in 2012 as D3174–12. DOI:
10.1520/D3174-12R18E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
D3174 − 12 (2018)
(Suggested method for inducing regulated air flow through ashing furnace.)
FIG. 1 Air Aspirator
4. Summary of Test Method ture regulated at 500 °C, 750 °C, and 950 °C.The furnace shall
be equipped with a temperature indicator and means of
4.1 Ash is determined by weighing the residue remaining
controlling the temperature within prescribed limits. Means
after burning the coal or coke under rigidly controlled condi-
shall be provided for maintaining air flow at a rate of two to
tions of sample weight, temperature, time, atmosphere, and
four changes per minute (see Fig. 1 and Fig. 2). Combustion
equipment specifications.
gases shall be vented from laboratory. Inlet and outlet ports
shall be located and arranged to distribute the air uniformly
5. Significance and Use
throughoutthefurnaceareawithoutthepossibilityofsweeping
5.1 Ash, as determined by this test method, is the residue
solid particles from the capsules. The temperature over the
remaining after burning the coal and coke.Ash obtained differs
entire working area of the furnace floor shall be maintained
in composition from the inorganic constituents present in the
within the specified temperature limits.
original coal. Incineration causes an expulsion of all water, the
loss of carbon dioxide from carbonates, the conversion of iron 6.2 Porcelain Capsules, about 22 mm ( ⁄8 in.) in depth, and
44 mm (1 ⁄4 in.) in diameter, or similar shallow dishes or
pyrites into ferric oxide, and other chemical reactions. Ash, as
platinum crucibles.
determined by this test method, will differ in amount from ash
produced in furnace operations and other firing systems be-
6.3 Balance, sensitive to 0.1 mg.
cause incineration conditions influence the chemistry and
6.4 Crucible Cover, aluminum, porcelain, or similar covers.
amount of the ash. References for correcting ash results
determined by this test method to a mineral-matter-free basis
7. Temperature Calibration
are listed in Classification D388, Section 9.
7.1 Place a preignited capsule with1gof sand at the center
6. Apparatus
of the working area of the furnace, and by the use of a
6.1 Electric Muffle Furnace for Coal or Coke—For deter- potentiometer and thermocouple or other suitable temperature
mination of ash of coal and coke, the furnace shall have an measuring device, measure the temperature of the sand in the
adequate air circulation and be capable of having its tempera- crucible. The crucible and sand should be at temperature
´1
D3174 − 12 (2018)
Calibration Flowmeter with Tubing—Ambient Air—For calibration use only, adjust forced air valve to deliver two to four furnace volume changes per minute (at standard
temperature-pressure conditions.)
NOTE 1—Flowmeters are usually calibrated for one atmosphere at 70 °F (760 mm Hg at 21.1 °C).
(Suggested layout for calibration.)
FIG. 2 Air Aspirator
equilibrium with the furnace. There should be two to four air 8.3 For coals continue heating the sample until the tempera-
changes per minute moving throughout the furnace (the air ture rises from 500 °C 6 10 °C to 750 °C 6 15 °C at the end
flow may be measured by using a wet-test meter or equivalent of 1 h. For cokes continue heating the sample until the
calibrated at standard conditions for air connected to the temperature rises from 500 °C 6 10 °C to 950 °C 6 20 °C at
ceramic-pipe exhaust).Adjust the furnace temperature until the theendof1 h.Continuetoheatatthefinaltemperature(750 °C
potentiometerreads750 °C 610 °Candthenadjustorreadthe or 950 °C) for an additional 2 h. Remove the capsule from the
temperature on the indicating pyrometer. Use this reading as muffle furnace, place the cover on the capsule, cool under
the proper setting for controlling the furnace. conditions to minimize moisture pickup, and weigh.
8.4 The two-stage ashing procedure allows pyritic sulfur to
8. Procedure
be oxidized and expelled before most metal carbonates are
8.1 The sample shall be the material pulverized to pass decomposed. An ample supply of air in the muffle furnace,
No. 60 (250 µm) sieve in accordance with Practice D2013 or
“two to four volume changes per minute,” must be assured at
Practice D346. all times to ensure complete oxidation of the pyritic sulfur and
to remove the SO formed.
8.2 Transfer approximately 1 g (weighed to the nearest
0.1 mg) of the thoroughly mixed sample to a weighed capsule 8.5 Whilethe4 hincinerationintervaldescribedissufficient
and cover quickly. An alternative way is to use the dried coal with most coals to reach a condition of complete burn off,
from the moisture determination in Test Method D3173. After certain cokes and nonreactive coals may require additional
removing the covers, place the capsule containing the sample time. If unburned carbon particles are observed, or if duplicate
in a cold furnace and heat gradually at such a rate that the results are suspect, the samples
...