ASTM D6559-22

Standard Test Method for Determination of Thermogravimetric (TGA) Air Reactivity of Baked Carbon Anodes and Cathode Blocks

SIGNIFICANCE AND USE
5.1 The air reactivity rates are used to quantify the tendency of a carbon artifact to react with air. Carbon consumed by this unwanted side reaction is unavailable for the primary reactions of reducing alumina to the primary metal. Air reactivity dusting rate is used by some companies to quantify the tendency of the coke aggregate or binder coke of a carbon artifact to selectively react with these gases. Preferential attack of the binder coke or coke aggregate of a carbon artifact by these gases causes some carbon to fall off or dust, making the carbon unavailable for the primary reaction of reducing alumina and, more importantly, reducing the efficiency of the aluminum reduction cell.  
5.2 Comparison of air reactivity and dusting rates is useful in selecting raw materials for the manufacture of commercial anodes for specific smelting technologies in the aluminum reduction industry.  
5.3 Air reactivity rates are used for evaluating effectiveness and beneficiation processes or for research purposes.
SCOPE
1.1 This test method covers the thermogravimetric (TGA) determination of air reactivity and dusting of shaped carbon anodes and cathode blocks used in the aluminum reduction industry. The apparatus selection covers a significant variety of types with various thermal conditions, sample size capability, materials of construction, and procedures for determining the mass loss and subsequent rate of reaction. This test method standardizes the variables of sample shape, reaction temperature, gas velocity over the exposed surfaces, and reaction time such that results obtained on different apparatuses are correlatable.  
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-Apr-2022
• ICS: 77.020 - Production of metals
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.05 - Properties of Fuels, Petroleum Coke and Carbon Material

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.
Designation: D6559 − 22
Standard Test Method for
Determination of Thermogravimetric (TGA) Air Reactivity of
1
Baked Carbon Anodes and Cathode Blocks
This standard is issued under the fixed designation D6559; 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* Carbon Cathode Blocks Used in Aluminum Production
E691 Practice for Conducting an Interlaboratory Study to
1.1 This test method covers the thermogravimetric (TGA)
Determine the Precision of a Test Method
determination of air reactivity and dusting of shaped carbon
anodes and cathode blocks used in the aluminum reduction
3. Terminology
industry.The apparatus selection covers a significant variety of
3.1 Definitions of Terms Specific to This Standard:
types with various thermal conditions, sample size capability,
3.1.1 dusting, n—the quantity of carbon that falls off the
materials of construction, and procedures for determining the
carbonartifactwhileinthereactionchamberandiscollectedin
mass loss and subsequent rate of reaction. This test method
a container at the bottom of the reaction chamber plus the
standardizes the variables of sample shape, reaction
quantity of carbon that is collected from the carbon artifact
temperature, gas velocity over the exposed surfaces, and
after cooling (optional).
reactiontimesuchthatresultsobtainedondifferentapparatuses
are correlatable. 3.1.2 final air reactivity, n—the mass loss of the carbon
artifactduringthefinal30 minofexposuretoairinthereaction
1.2 The values stated in SI units are to be regarded as
chamber divided by the initial geometric (right cylindrical)
standard. No other units of measurement are included in this
exposed surface area of the sample, expressed as milligrams
standard.
per centimetre squared per hour.
1.3 This standard does not purport to address all of the
3.1.3 initial air reactivity, n—the mass loss of the carbon
safety concerns, if any, associated with its use. It is the
artifact during the first 30 min of exposure to air in the reaction
responsibility of the user of this standard to establish appro-
chamber divided by the initial geometric (right cylindrical)
priate safety, health, and environmental practices and deter-
exposed surface area of the sample, expressed as milligrams
mine the applicability of regulatory limitations prior to use.
per centimetre squared per hour.
1.4 This international standard was developed in accor-
3.1.4 total air reactivity, n—thetotalmasslossofthecarbon
dance with internationally recognized principles on standard-
artifact(includingdusting)duringthetotaltimethatthesample
ization established in the Decision on Principles for the
is exposed to air (60 min to 210 min) in the reaction chamber
Development of International Standards, Guides and Recom-
divided by the initial geometric (right cylindrical) exposed
mendations issued by the World Trade Organization Technical
surface area of the sample, expressed as milligrams per
Barriers to Trade (TBT) Committee.
centimetre squared per hour.
2. Referenced Documents
4. Summary of Test Method
2
2.1 ASTM Standards:
4.1 Initial, final, and total air reactivity and dusting are
D6353 Guide for Sampling Plan and Core Sampling for
determined by passing air at flow rates, giving a standard
Prebaked Anodes Used in Aluminum Production
velocity of reactant gas around cylindrically shaped carbon
D6354 Guide for Sampling Plan and Core Sampling of
artifacts under nearly isothermal conditions for a specified
length of time. The reactivity is determined by continuously
1
This test method is under the jurisdiction of ASTM Committee D02 on monitoring the sample mass loss. The dusting term is deter-
Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of
mined by collecting and determining the mass of carbon
SubcommitteeD02.05onPropertiesofFuels,PetroleumCokeandCarbonMaterial.
particles that fall off the sample during reaction or collected
CurrenteditionapprovedMay1,2022.PublishedJuly2022.Originallyapproved
ɛ1
from the sample after the heat treatment.
in 2000. Last previous edition approved in 2016 as D6559 – 00a (2016) . DOI:
10.1520/D6559-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 5. Significance and Use
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
5.1 The air reactivity rates are used to quantify the tendency
Standards volume information, refer to the standard’s Document Summary page o
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D6559 − 00a (Reapproved 2016) D6559 − 22
Standard Test Method for
Determination of Thermogravimetric (TGA) Air Reactivity of
1
Baked Carbon Anodes and Cathode Blocks
This standard is issued under the fixed designation D6559; 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
ε NOTE—SI units formatting was corrected editorially in May 2016.
1. Scope Scope*
1.1 This test method covers the thermogravimetric (TGA) determination of air reactivity and dusting of shaped carbon anodes and
cathode blocks used in the aluminum reduction industry. The apparatus selection covers a significant variety of types with various
thermal conditions, sample size capability, materials of construction, and procedures for determining the mass loss and subsequent
rate of reaction. This test method standardizes the variables of sample dimensions,shape, reaction temperature, gas velocity over
the exposed surfaces, and reaction time such that results obtained on different apparatuses are correlatable.
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
2.1 ASTM Standards:
D6353 Guide for Sampling Plan and Core Sampling for Prebaked Anodes Used in Aluminum Production
D6354 Guide for Sampling Plan and Core Sampling of Carbon Cathode Blocks Used in Aluminum Production
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 dusting, n—the quantity of carbon that falls off the carbon artifact while in the reaction chamber and is collected in thea
container at the bottom of the reaction chamber.chamber plus the quantity of carbon that is collected from the carbon artifact after
cooling (optional).
1
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of Subcommittee
D02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.
Current edition approved April 1, 2016May 1, 2022. Published May 2016July 2022. Originally approved in 2000. Last previous edition approved in 20102016 as
ɛ1
D6559 – 00a (2010).(2016) . DOI: 10.1520/D6559-00AR16E01.10.1520/D6559-22.
2
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 ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D6559 − 22
3.1.2 final air reactivity, n—the mass loss of the carbon artifact during the final 30 min of exposure to air in the reaction chamber
divided by the initial geometric (right cylindrical) exposed surface area of the sample, expressed as milligrams per centimetre
squared per hour.
3.1.3 initial air reactivity, n—the mass loss of the carbon artifact during the first 30 min of exposure to air in the reaction chamber
divided by the initial geometric (right cylindrical) exposed surface area of the sample, expressed as milligrams per centimetre
squared per hour.
3.1.4 total air reactivity, n—the total mass loss of the carbon artifact (including dusting) during the total time that the sample is
exposed to air (180 min) (60 min to 210 min) in the reaction chamber divided by the initial geometric (right cylindrical) exposed
surface area of the sample, expressed as milligrams per cen
...