ASTM C816-15(2020)e1

Standard Test Method for Sulfur Content in Graphite by Combustion-Iodometric Titration Method

SIGNIFICANCE AND USE
5.1 Sulfur, even in very low concentrations, is of concern in a nuclear reactor because of potential corrosion of metallic components. This test method has the sensitivity to analyze very low sulfur contents in graphite using very small samples.  
5.2 This test method can be used to characterize graphite for design purposes.
SCOPE
1.1 This test method covers the determination of sulfur in graphite in the concentration range from 1 μg/g to 1000 μg/g (ppm).  
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, 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: 30-Nov-2020
• ICS: 71.060.10 - Chemical elements
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.F0 - Manufactured Carbon and Graphite Products

Relations

• Refers: ASTM E50-17 - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 01-Sep-2017
• Refers: ASTM E50-11(2016) - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 01-Aug-2016
• Refers: ASTM E50-11 - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 15-Oct-2011
• Refers: ASTM E50-00(2005) - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 01-May-2005
• Refers: ASTM D3177-02 - Standard Test Methods for Total Sulfur in the Analysis Sample of Coal and Coke
• Effective Date: 10-Sep-2002
• Refers: ASTM E50-00 - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 10-Nov-2000
• Refers: ASTM D3177-89(2002) - Standard Test Methods for Total Sulfur in the Analysis Sample of Coal and Coke
• Effective Date: 29-Sep-1989

Overview

ASTM C816-15(2020)e1 provides a standardized test method for the determination of sulfur content in graphite using the combustion-iodometric titration method. Published by ASTM International, this standard specifies procedures to accurately measure sulfur in graphite within the range of 1 μg/g to 1000 μg/g (ppm). The method is especially significant in sectors such as nuclear energy, where even trace amounts of sulfur can lead to corrosion of metallic components. This test utilizes a sensitive analytical process capable of detecting low sulfur levels using small sample sizes, making it suitable for quality control, research, and manufacturing applications where precision is paramount.

Key Topics

• Sulfur Analysis in Graphite: Focus on the quantitative assessment of sulfur present in graphite materials using validated analytical chemistry techniques.
• Combustion-Iodometric Titration: The method involves combusting graphite in pure oxygen at high temperatures, converting sulfur into sulfur dioxide, which is subsequently measured through iodometric titration.
• Sensitivity and Range: Suitable for detecting sulfur concentrations from as low as 1 μg/g (1 ppm) up to 1000 μg/g (1000 ppm).
• Quality Control: Enables manufacturers and researchers to characterize and certify graphite materials, particularly for critical applications.
• Procedural Guidance: Outlines steps for furnace operation, sample handling, reagent preparation, titration procedures, and calculation of sulfur content.

Applications

The ASTM C816 standard is widely utilized in several sectors where the integrity of graphite materials is critical:

• Nuclear Industry:
  • Sulfur in graphite can accelerate corrosion in nuclear reactors, posing safety and material lifespan concerns. This test method is crucial for screening graphite used in moderators, reflectors, and other structural components.
• Design and Specification of Graphite Components:
  • Supports design engineers and material scientists by providing reliable data on sulfur impurity levels for product development, certification, and compliance with industry standards.
• Research and Development:
  • Used in laboratories to analyze and compare sulfur content in graphite samples for R&D projects, supporting the development of advanced graphite materials with tailored properties.
• Quality Assurance in Manufacturing:
  • Essential in routine quality control protocols for graphite production to verify that the sulfur concentration falls within specified limits.

Related Standards

The ASTM C816-15(2020)e1 test method references and is supported by several related standards, which may be relevant for organizations implementing sulfur analysis procedures:

• ASTM D3177: Test Methods for Total Sulfur in the Analysis Sample of Coal and Coke (withdrawn), formerly a key reference for sulfur standard preparation.
• ASTM E50: Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials, which outlines required protocols for laboratory practices.
• International Standardization Principles: This standard is developed following principles set out by the World Trade Organization Technical Barriers to Trade (TBT) Committee, ensuring global relevance and harmonization.

Practical Value

ASTM C816-15(2020)e1 is an essential standard for ensuring the safe and effective use of graphite in sensitive applications, most notably in nuclear energy. Its rigorous methodology for detecting low-level sulfur contamination helps prevent material failure due to corrosion, supports compliance with regulatory requirements, and assures product performance. By following this standard, laboratories and manufacturers gain confidence in the quality and safety of their graphite materials, fostering trust in critical infrastructure and energy systems.

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.
´1
Designation: C816 − 15 (Reapproved 2020)
Standard Test Method for
Sulfur Content in Graphite by Combustion-Iodometric
Titration Method
This standard is issued under the fixed designation C816; 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—Editorially corrected 10.1 in December 2020.
1. Scope 3. Terminology
3.1 Definitions:
1.1 This test method covers the determination of sulfur in
3.1.1 combustion, n—chemical reaction by which graphite
graphite in the concentration range from 1 µg⁄g to 1000 µg⁄g
is combined in a controlled manner with pure oxygen in a high
(ppm).
temperature furnace for analytical purposes.
1.2 The values stated in SI units are to be regarded as
3.1.2 sulfur content, n—percentage content by weight of
standard. No other units of measurement are included in this
elemental sulfur present in graphite.
standard.
3.1.3 titration, n—quantitative chemical analysis method
1.3 This standard does not purport to address all of the
used to determine the unknown concentration of a specified
safety concerns, if any, associated with its use. It is the
element by reacting a solution prepared from the sample to be
responsibility of the user of this standard to establish appro-
analyzed with a known concentration and volume of specific
priate safety, health, and environmental practices and deter-
reagent.
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
4. Summary of Test Method
dance with internationally recognized principles on standard-
4.1 The sample is combusted with pure oxygen in a high-
ization established in the Decision on Principles for the
temperature furnace and a major portion of the sulfur is
Development of International Standards, Guides and Recom-
converted to sulfur dioxide. The sulfur dioxide is passed
mendations issued by the World Trade Organization Technical
through a potassium iodide-starch solution where it is titrated
Barriers to Trade (TBT) Committee.
with potassium iodate solution. The potassium iodate solution
is standardized against samples of known sulfur content.
2. Referenced Documents
2.1 ASTM Standards:
5. Significance and Use
D3177 Test Methods forTotal Sulfur in theAnalysis Sample
5.1 Sulfur, even in very low concentrations, is of concern in
of Coal and Coke (Withdrawn 2012)
a nuclear reactor because of potential corrosion of metallic
E50 Practices for Apparatus, Reagents, and Safety Consid-
components. This test method has the sensitivity to analyze
erations for Chemical Analysis of Metals, Ores, and
very low sulfur contents in graphite using very small samples.
Related Materials
5.2 This test method can be used to characterize graphite for
design purposes.
This test method is under the jurisdiction of ASTM Committee D02 on
6. Interferences
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.F0 on Manufactured Carbon and Graphite Products.
6.1 Any substance that releases volatile material, which
Current edition approved Dec. 1, 2020. Published December 2020. Originally
tends to enhance or to bleach the starch-iodine complex, will
approved in 1977. Last previous edition approved in 2015 as C816 – 15. DOI:
interfere. Halogens and oxides of nitrogen interfere through
10.1520/C0816-15R20E01.
darkening the color of the starch-iodine complex. Ultraviolet
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
light will also darken the solution. A tube packed with either
Standards volume information, refer to the standard’s Document Summary page on
silver wool or antimony filings placed in the line between the
the ASTM website.
furnace and titration assembly will remove halogens from the
The last approved version of this historical standard is referenced on
www.astm.org. gas stream.
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´1
C816 − 15 (2020)
6.2 If the solution in the titration vessel becomes colorless 9.8 Remove the stopper from the mouth of the combustion
during the titration, some SO will be lost and a low res
...