ASTM E342-23

Standard Test Method for Determination of Chromium Oxide in Chrome Ores by Permanganate Titrimetry

SIGNIFICANCE AND USE
5.1 This test method is intended to be used for compliance with compositional specifications for chromium oxide content in chromium-bearing ores. It is assumed that all who use these procedures will be trained analysts capable of performing common laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory and that proper waste disposal procedures will be followed. Appropriate quality control practices must be followed such as those described in Guide E882.
SCOPE
1.1 This test method covers the determination of chromium oxide (Cr2O3) in chrome ores in the compositional range from 25 % to 60 %.
Note 1: As used in this test method, “%” refers to a mass fraction (wt/wt %) (g/100g).  
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: 31-Mar-2023
• ICS: 73.060.30 - Chromium ores
• Technical Committee: E01 - Analytical Chemistry for Metals, Ores, and Related Materials
• Drafting Committee: E01.02 - Ores, Concentrates, and Related Metallurgical Materials

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: E342 − 23
Standard Test Method for
Determination of Chromium Oxide in Chrome Ores by
1
Permanganate Titrimetry
This standard is issued under the fixed designation E342; 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 E276 Test Method for Particle Size or Screen Analysis at
4.75 mm (No. 4) Sieve and Finer for Metal-Bearing Ores
1.1 This test method covers the determination of chromium
and Related Materials
oxide (Cr O ) in chrome ores in the compositional range from
2 3
E882 Guide for Accountability and Quality Control in the
25 % to 60 %.
Chemical Analysis Laboratory
NOTE 1—As used in this test method, “%” refers to a mass fraction
(wt/wt %) (g/100g).
3. Terminology
1.2 The values stated in SI units are to be regarded as
3.1 Definitions—For definitions of terms used in this test
standard. No other units of measurement are included in this
method, refer to Terminology E135.
standard.
1.3 This standard does not purport to address all of the
4. Summary of Test Method
safety concerns, if any, associated with its use. It is the
4.1 The sample is decomposed by fusion with sodium
responsibility of the user of this standard to establish appro-
peroxide. After leaching in water and boiling to decompose
priate safety, health, and environmental practices and deter-
peroxides, the solution is acidified with HNO and H SO .
3 2 4
mine the applicability of regulatory limitations prior to use.
Residual chromium is oxidized to chromate with silver nitrate,
1.4 This international standard was developed in accor-
potassium permanganate, and peroxydisulfate. The excess of
dance with internationally recognized principles on standard-
permanganate is destroyed by the addition of NaCl. After
ization established in the Decision on Principles for the
cooling, the chromate is reduced by the addition of a measured
Development of International Standards, Guides and Recom-
excess of a ferrous ammonium sulfate, and the excess is titrated
mendations issued by the World Trade Organization Technical
with a permanganate solution.
Barriers to Trade (TBT) Committee.
5. Significance and Use
2. Referenced Documents
2
5.1 This test method is intended to be used for compliance
2.1 ASTM Standards:
with compositional specifications for chromium oxide content
D1193 Specification for Reagent Water
in chromium-bearing ores. It is assumed that all who use these
E29 Practice for Using Significant Digits in Test Data to
procedures will be trained analysts capable of performing
Determine Conformance with Specifications
common laboratory procedures skillfully and safely. It is
E50 Practices for Apparatus, Reagents, and Safety Consid-
expected that work will be performed in a properly equipped
erations for Chemical Analysis of Metals, Ores, and
laboratory and that proper waste disposal procedures will be
Related Materials
followed. Appropriate quality control practices must be fol-
E135 Terminology Relating to Analytical Chemistry for
lowed such as those described in Guide E882.
Metals, Ores, and Related Materials
6. Interferences
1
This test method is under the jurisdiction of ASTM Committee E01 on
6.1 None of the elements normally found in chrome ores
Analytical Chemistry for Metals, Ores, and Related Materials and is the direct
interfere with this test method.
responsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-
lurgical Materials.
Current edition approved April 1, 2023. Published April 2023. Originally
7. Reagents and Materials
approved in 1967. Last previous edition approved in 2016 as E342 – 11 (2016).
DOI: 10.1520/E0342-23.
7.1 Purity of Reagents—Reagent grade chemicals shall be
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
used in all tests. Unless otherwise indicated, it is intended that
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
all reagents conform to the specifications of the Committee on
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Analytical Reagents of the American Chemical Society where
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E342 − 23
3
such specifications are available . Other grades may be used, 9. Sampling, Test Specimens, and Test Units
provided it is first ascertained that the reagent is of s
...

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.
Designation: E342 − 11 (Reapproved 2016) E342 − 23
Standard Test Method for
Determination of Chromium Oxide in Chrome Ores by
1
Permanganate Titrimetry
This standard is issued under the fixed designation E342; 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
1.1 This test method covers the determination of chromium oxide (Cr O ) in chrome ores in the compositional range from 25 %
2 3
to 60 %.
NOTE 1—As used in this test method, “%” refers to a mass fraction (wt/wt %) (g/100g).
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 and healthsafety, 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D1193 Specification for Reagent Water
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E50 Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
E276 Test Method for Particle Size or Screen Analysis at 4.75 mm (No. 4) Sieve and Finer for Metal-Bearing Ores and Related
Materials
E882 Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
3. Terminology
3.1 Definitions—For definitions of terms used in this test method, refer to Terminology E135.
1
This test method is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility of
Subcommittee E01.02 on Ores, Concentrates, and Related Metallurgical Materials.
Current edition approved Nov. 15, 2016April 1, 2023. Published December 2016April 2023. Originally approved in 1967. Last previous edition approved in 20112016
as E342 – 11.E342 – 11 (2016). DOI: 10.1520/E0342-11R16.10.1520/E0342-23.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E342 − 23
4. Summary of Test Method
4.1 The sample is decomposed by fusion with sodium peroxide. After leaching in water and boiling to decompose peroxides, the
solution is acidified with HNO and H SO . Residual chromium is oxidized to chromate with silver nitrate, potassium
3 2 4
permanganate, and peroxydisulfate. The excess of permanganate is destroyed by the addition of NaCl. After cooling, the chromate
is reduced by the addition of a measured excess of a ferrous ammonium sulfate, and the excess is titrated with a permanganate
solution.
5. Significance and Use
5.1 This test method is intended to be used for compliance with compositional specifications for chromium oxide content in
chromium-bearing ores. It is assumed that all who use these procedures will be trained analysts capable of performing common
laboratory procedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory and that
proper waste disposal procedures will be followed. Appropriate quality control practices must be followed such as those described
in Guide E882.
6. Interferences
6.1 None of the elements normally found in chrome ores interfere with this test method.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents conform to the specifications of the Committee on Analytical
...