ASTM E247-21

Standard Test Method for Determination of Silica in Manganese Ores, Iron Ores, and Related Materials by Gravimetry

SIGNIFICANCE AND USE
5.1 This test method is intended to be used for compliance with compositional specifications for silica content. 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 silica in iron ores, iron ore concentrates and agglomerates, and manganese ore in the range from 0.5 % to 15 %.  
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-Sep-2021
• ICS: 73.060.10 - Iron ores
• ICS: 73.060.20 - Manganese ores
• Technical Committee: E01 - Analytical Chemistry for Metals, Ores, and Related Materials
• Drafting Committee: E01.02 - Ores, Concentrates, and Related Metallurgical Materials

Relations

• Refers: ASTM E135-20 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Jan-2020
• Refers: ASTM E135-19 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2019
• 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 E882-10(2016) - Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
• Effective Date: 01-Dec-2016
• Refers: ASTM E882-10(2016)e1 - Standard Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
• Effective Date: 01-Dec-2016
• 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 E135-16 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2016
• Refers: ASTM E135-15a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Jul-2015
• Refers: ASTM E135-15 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-May-2015
• Refers: ASTM E135-14b - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-Aug-2014
• Refers: ASTM E135-14a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Apr-2014
• Refers: ASTM E135-14 - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 15-Feb-2014
• Refers: ASTM E135-13a - Standard Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
• Effective Date: 01-Dec-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011

Overview

ASTM E247-21 is the internationally recognized standard test method for the determination of silica in manganese ores, iron ores, iron ore concentrates, agglomerates, and related materials using gravimetric analysis. Developed by ASTM International, this standard provides detailed procedures for accurately measuring silica content within the range of 0.5% to 15%. Laboratories implementing ASTM E247-21 ensure the quality, compliance, and consistency of materials used in various metallurgical processes by accurately determining silica levels.

Key Topics

• Scope:

  • Applicable to iron ores, manganese ores, concentrates, and agglomerates.
  • Determines silica content from 0.5% to 15%.
  • Specifies the use of SI units exclusively.

• Test Method Summary:

  • Involves fusion of the sample with sodium peroxide in a zirconium crucible.
  • Silica is separated via precipitation and quantification through gravimetric analysis.
  • The analytical sequence includes controlled heating, leaching, filtration, ignition, and volatilization, resulting in precise silica measurement.

• Quality Control:

  • Emphasizes the necessity for skilled laboratory analysts and a properly equipped laboratory environment.
  • Requires appropriate quality assurance protocols, such as those outlined in ASTM Guide E882.
  • Calls for safe waste disposal, as well as adherence to relevant safety, health, and environmental regulations.

• Precision and Bias:

  • Results have been validated using certified reference materials, ensuring accuracy and reliability.
  • Interlaboratory studies inform the precision but note that specific repeatability and reproducibility projections are not included due to the scope of data.

• Interferences:

  • The method is proven effective for most iron and manganese ores with low fluorine content (<0.25%), with minimal interference from common constituents.

Applications

Implementing the ASTM E247-21 standard is vital for several industrial and laboratory contexts:

• Quality Control in Mining and Metallurgy:
  Compliance with precise silica specifications is critical for the production and processing of iron and manganese ores. Excess silica can reduce metal yield, affect blast furnace operation, and impact product quality.

• Material Certification and Specification Verification:
  Used by producers, traders, and regulatory bodies to ensure that ore shipments meet contractual silica requirements.

• Laboratory Analysis:
  Analytical laboratories depend on this method for accurate and repeatable measurement of silica, supporting research, development, and compliance documentation.

• Environmental and Safety Compliance:
  The methodology encourages best practices for laboratory safety, proper waste disposal, and adherence to environmental regulations.

Related Standards

For comprehensive laboratory practices and consistency with related analyses, consider the following ASTM standards:

• ASTM D1193: Specification for Reagent Water
• ASTM E29: Practice for Using Significant Digits in Test Data
• ASTM E50: Practices for Apparatus, Reagents, and Safety in Chemical Analysis
• ASTM E135: Terminology Relating to Analytical Chemistry
• ASTM E691: Practice for Conducting Interlaboratory Studies
• ASTM E877: Practice for Sampling and Sample Preparation of Iron Ores
• ASTM E882: Guide for Accountability and Quality Control in the Chemical Analysis Laboratory

By following ASTM E247-21, laboratories, manufacturers, and regulatory agencies ensure reliable silica analysis in manganese and iron ores, supporting quality, safety, and compliance within the mineral processing and metallurgical 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.
Designation: E247 − 21
Standard Test Method for
Determination of Silica in Manganese Ores, Iron Ores, and
Related Materials by Gravimetry
This standard is issued under the fixed designation E247; 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 E877 Practice for Sampling and Sample Preparation of Iron
Ores and Related Materials for Determination of Chemi-
1.1 This test method covers the determination of silica in
cal Composition and Physical Properties
iron ores, iron ore concentrates and agglomerates, and manga-
E882 Guide for Accountability and Quality Control in the
nese ore in the range from 0.5 % to 15 %.
Chemical Analysis Laboratory
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
3. Terminology
standard.
3.1 Definitions—For definitions of terms used in this test
1.3 This standard does not purport to address all of the
method, refer to Terminology E135.
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4.1 The sample is fused with sodium peroxide in a zirco-
mine the applicability of regulatory limitations prior to use.
nium crucible. The melt is leached with water and dissolved in
1.4 This international standard was developed in accor-
HCl. Silica is separated by double dehydration with HClO .
dance with internationally recognized principles on standard-
The two precipitates are combined, ignited, and weighed. The
ization established in the Decision on Principles for the
silica is volatilized by treatment with HF and H SO and the
2 4
Development of International Standards, Guides and Recom-
residue weighed.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 5. Significance and Use
5.1 This test method is intended to be used for compliance
2. Referenced Documents
with compositional specifications for silica content. It is
2.1 ASTM Standards:
assumed that all who use these procedures will be trained
D1193 Specification for Reagent Water
analysts capable of performing common laboratory procedures
E29 Practice for Using Significant Digits in Test Data to
skillfully and safely. It is expected that work will be performed
Determine Conformance with Specifications
in a properly equipped laboratory and that proper waste
E50 Practices for Apparatus, Reagents, and Safety Consid-
disposal procedures will be followed. Appropriate quality
erations for Chemical Analysis of Metals, Ores, and
control practices must be followed such as those described in
Related Materials
Guide E882.
E135 Terminology Relating to Analytical Chemistry for
6. Interferences
Metals, Ores, and Related Materials
E691 Practice for Conducting an Interlaboratory Study to
6.1 This test method is written for iron and manganese ores
Determine the Precision of a Test Method
containing less than 0.25 % of fluorine. None of the elements
normallyfoundinironoresorinmanganeseoresinterferewith
this test method.
This test method is under the jurisdiction of ASTM Committee E01 on
Analytical Chemistry for Metals, Ores, and Related Materials and is the direct
7. Apparatus
responsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-
lurgical Materials.
7.1 Zirconium Crucible (50-mL capacity).
Current edition approved Oct. 1, 2021. Published October 2021. Originally
ε1
7.2 Platinum Filter Cone.
approved in 1964. Last previous edition approved in 2015 as E247 – 01(2015) .
DOI: 10.1520/E0247-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 8. Reagents and Materials
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
8.1 Purity of Reagents—Reagent grade chemicals shall be
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. used in all tests. Unless otherwise indicated, it is intended that
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E247 − 21
all reagents conform to the specifications of the Committee on 10 mL to 15 mL of water into the crucible. When the reaction
Analytical Reagents of the American Chemical Society where ceases, empty the crucible contents and crucible rinsings into
such specification are available. Other grades may be used, the beaker. Add 25 mL HCl by means of the crucible. Finally,
provided it is first ascertained that the reagent is of sufficient rinse and police crucible with water and add rinsings to the
high purity to permit its use without lessening the accuracy of
beaker. Heat to a boil to obtain a complete and clear solution.
the determination. Cool for 1 min to 2 min. Add 25 mL of HClO . Cover with a
watchglass and heat to dense white fumes in the HClO fume
8.2 Purity of Water—Unless otherwise indicated, refer-
hood.Fumefor15 minto20 min.Coolfor1 minto2 min.Add
ences to water shall be understood to mean reagent water
50 mL of water containing 2 mL HCl and heat the contents to
conforming to Type I or Type II of Specification D1193. Type
dissolve soluble salts. Filter through a fine-textured paper with
III orType IVmay be used if they effect no measurable change
the aid of paper pulp and a platinum filter cone using suction.
in the blank or sample.
Wash filter five times with hot HCl (1 + 49) and then ten times
8.3 Hydrochloric Acid (1 + 49)—Mix 1 volume of concen-
with hot water, to remove all perchlorates (see Note 2).
trated HCl (sp gr 1.19) with 49 volumes of water.
Reserve the filtrate. Transfer filter paper and residue to a
8.4 Sodium Peroxide Powder—Na O .
platinum crucible.
2 2
8.5 Sulfuric Acid (1 + 1)—Carefully pour one volume of
NOTE 2—The residue must be washed free of perchlorates to prevent
concentrated H SO , sp gr 1.84, into one volume of water.
possible loss of residue by deflagration during the ignition.
2 4
11.3 Add 10 mL of HClO to the reserved filtrate. Cover
9. Hazards
...

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: E247 − 01 (Reapproved 2015) E247 − 21
Standard Test Method for
Determination of Silica in Manganese Ores, Iron Ores, and
Related Materials by Gravimetry
This standard is issued under the fixed designation E247; 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—Editorially corrected 1.1 and Table 1 in November 2015.
1. Scope
1.1 This test method covers the determination of silica in iron ores, iron ore concentrates and agglomerates, and manganese ore
in the range from 0.5 % to 15 %.
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:
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
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E877 Practice for Sampling and Sample Preparation of Iron Ores and Related Materials for Determination of Chemical
Composition and Physical Properties
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.
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, 2015Oct. 1, 2021. Published December 2015October 2021. Originally approved in 1964. Last previous edition approved in 20102015
ε1
as E247 – 01 (2010).(2015) . DOI: 10.1520/E0247-01R15E01.10.1520/E0247-21.
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
E247 − 21
4. Summary of Test Method
4.1 The sample is fused with sodium peroxide in a zirconium crucible. The melt is leached with water and dissolved in HCl. Silica
is separated by double dehydration with HClO . The two precipitates are combined, ignited, and weighed. The silica is volatilized
by treatment with HF and H SO and the residue weighed.
2 4
5. Significance and Use
5.1 This test method is intended to be used for compliance with compositional specifications for silica content. 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 This test method is written for iron and manganese ores containing less than 0.25 % of fluorine. None of the elements normally
found in iron ores or in manganese ores interfere with this test method.
7. Apparatus
7.1 Zirconium Crucible (50-mL capacity).
7.2 Platinum Filter Cone.
8. Reagents and Materials
8.1 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 Reagents of the American Chemical Society where such
specification are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficient high purity
to permit its use without lessening the accuracy of the determination.
8.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by
Type II conforming to Type I or Type II of Specification D1193. Type III or Type IV may be used if they effect no measurable
change in the blank or sample.
8.3 Hydrochloric Acid (sp gr 1.19)—Concentrated HCl.
8.3 Hydrochloric Acid (1 + 49)—Mix 1 volume of concentrated HCl (sp gr 1.19) with 49 volumes of water.
8.5 Hydrofluoric Acid (48 %)—Concentrated HF.
8.6 Perchloric Acid (70 %)—HClO .
8.4 Sodium Peroxide Powder—Na O .
2 2
8.5 Sulfuric Acid (1 + 1)—Carefully pour one volume of concentrated H SO , sp gr 1.84, into one volume of water.
2 4
9. Hazards
9.1 For precautions to be observed in this test method, refer to Practices E50.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC, www.chemistry.org. For suggestions on the testing of
reagents not listed by the American Chemical Society, see the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD, http://www.usp.org.
E247 − 21
10. Sampling and Sample Preparation
10.1 Sampling—The gross sample shall be collected and prepared in accordance with Practice E877.
10.2 Sample Preparation—The laboratory sample shall be pulverized to pass a No. 100 (150-μm) sieve.
NOTE 1—To facilitate decomposition, some ores, such as specular hematite, require grinding to pass a No. 200 (75-μm) sieve.
10.3 Sample Weight—Weigh approximately (wit
...