ISO 4695:2021

Iron ores for blast furnace feedstocks — Determination of the reducibility by the rate of reduction index

This document specifies a method to provide a relative measure for evaluating the extent to and ease with which oxygen can be removed from iron ores, when reduced under conditions resembling those prevailing in the reduction zone of a blast furnace. This document is applicable to lump ores, sinters and hot-bonded pellets.

Minerais de fer pour charges de hauts fourneaux — Détermination de la réductibilité à partir de la vitesse de réduction

General Information

• Status: Published
• Publication Date: 10-Oct-2021
• ICS: 73.060.10 - Iron ores
• Technical Committee: ISO/TC 102/SC 3 - Physical testing
• Drafting Committee: ISO/TC 102/SC 3 - Physical testing
• Current Stage: 6060 - International Standard published
• Start Date: 11-Oct-2021
• Due Date: 30-Sep-2022
• Completion Date: 11-Oct-2021

Relations

• Revises: ISO 4695:2015 - Iron ores for blast furnace feedstocks — Determination of the reducibility by the rate of reduction index
• Effective Date: 17-Jul-2021

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4695
Fifth edition
2021-10
Iron ores for blast furnace
feedstocks — Determination of the
reducibility by the rate of reduction
index
Minerais de fer pour charges de hauts fourneaux — Détermination de
la réductibilité à partir de la vitesse de réduction
Reference number
ISO 4695:2021(E)
© ISO 2021

---------------------- Page: 1 ----------------------
ISO 4695:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2021 – All rights reserved

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ISO 4695:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Sampling, sample preparation and preparation of test portions . 2
5.1 Sampling and sample preparation . 2
5.2 Preparation of test portions . 2
6 Apparatus . 2
7 Test conditions .5
7.1 General . 5
7.2 Reducing gas . 5
7.2.1 Composition . 5
7.2.2 Purity . 5
7.2.3 Flow rate . 5
7.3 Heating and cooling gas . 5
7.4 Temperature of the test portion . 6
8 Procedure .6
8.1 Number of determinations for the test . 6
8.2 Chemical analysis . 6
8.3 Reduction . 6
9 Expression of results . 7
9.1 Calculation of the reducibility index . 7
9.2 Repeatability and acceptance of test results . 8
10 Test report . 8
11 Verification . 8
Annex A (normative) Flowsheet of the procedure for the acceptance of test results .10
Annex B (informative) Derivation of equation for reducibility .11
iii
© ISO 2021 – All rights reserved

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ISO 4695:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron,
Subcommittee SC 3, Physical testing.
This fifth edition cancels and replaces the fourth edition (ISO 4695:2015), of which it constitutes a
minor revision to correct Formula B.3 in Annex B.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
  © ISO 2021 – All rights reserved

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ISO 4695:2021(E)
Introduction
This document concerns one of a number of physical test methods that have been developed to
measure various physical parameters and to evaluate the behaviour of iron ores, including reducibility,
disintegration, crushing strength, apparent density, etc. This method was developed to provide a
uniform procedure, validated by collaborative testing, to facilitate comparisons of tests made in
different laboratories.
The results of this test have to be considered in conjunction with other tests used to evaluate the quality
of iron ores as feedstocks for blast furnace processes.
This document can be used to provide test results as part of a production quality control system, as a
basis of a contract or as part of a research project.
v
© ISO 2021 – All rights reserved

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 4695:2021(E)
Iron ores for blast furnace feedstocks — Determination of
the reducibility by the rate of reduction index
CAUTION — This document can involve hazardous operations and equipment. This document
does not purport to address all of the safety issues associated with its use. It is the responsibility
of the user of this document to establish appropriate safety and health practices and determine
the applicability of regulatory limitations prior to its use.
1 Scope
This document specifies a method to provide a relative measure for evaluating the extent to and ease
with which oxygen can be removed from iron ores, when reduced under conditions resembling those
prevailing in the reduction zone of a blast furnace.
This document is applicable to lump ores, sinters and hot-bonded pellets.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 2597-1, Iron ores — Determination of total iron content — Part 1: Titrimetric method after tin(II)
chloride reduction
ISO 2597-2, Iron ores — Determination of total iron content — Part 2: Titrimetric methods after
titanium(III) chloride reduction
ISO 3082, Iron ores — Sampling and sample preparation procedures
ISO 9035, Iron ores — Determination of acid-soluble iron(II) content — Titrimetric method
ISO 11323, Iron ore and direct reduced iron — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11323 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
The test portion is isothermally reduced in a fixed bed, at 950 °C, using a reducing gas consisting of CO
and N , and the mass loss of the test portion is recorded continuously or at specified time intervals until
2
its degree of reduction reaches 65 %. The rate of reduction is calculated at the oxygen/iron ratio of 0,9.
1
© ISO 2021 – All rights reserved

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ISO 4695:2021(E)
5 Sampling, sample preparation and preparation of test portions
5.1 Sampling and sample preparation
Sampling of a lot and preparation of a test sample shall be in accordance with ISO 3082.
The size range for pellets, sinters and lump ores shall be −12,5 mm + 10,0 mm.
A test sample of at least 2,5 kg, on a dry basis, of the sized material shall be obtained.
Oven-dry the test sample to constant mass at 105 °C ± 5 °C and cool it to room temperature before
preparation of the test portions.
NOTE Constant mass is achieved when the difference in mass between two subsequent measurements
becomes less than 0,05 % of the initial mass of the test sample.
5.2 Preparation of test portions
Collect each test portion by taking ore particles at random.
NOTE Manual methods of division recommended in ISO 3082, such as riffling, can be applied to obtain the
test portions.
At least five test portio
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 4695
ISO/TC 102/SC 3
Iron ores for blast furnace
Secretariat: ABNT
feedstocks — Determination of the
Voting begins on:
2021­06­01 reducibility by the rate of reduction
index
Voting terminates on:
2021­08-24
Minerais de fer pour charges de hauts fourneaux — Détermination de
la réductibilité à partir de la vitesse de réduction
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 4695:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2021

---------------------- Page: 1 ----------------------
ISO/FDIS 4695:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH­1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 4695:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Sampling, sample preparation and preparation of test portions .2
5.1 Sampling and sample preparation . 2
5.2 Preparation of test portions . 2
6 Apparatus . 2
7 Test conditions . 5
7.1 General . 5
7.2 Reducing gas . 5
7.2.1 Composition . 5
7.2.2 Purity . 5
7.2.3 Flow rate . 5
7.3 Heating and cooling gas . 5
7.4 Temperature of the test portion . 6
8 Procedure. 6
8.1 Number of determinations for the test . 6
8.2 Chemical analysis . 6
8.3 Reduction . 6
9 Expression of results . 7
9.1 Calculation of the reducibility index . 7
9.2 Repeatability and acceptance of test results . 8
10 Test report . 8
11 Verification . 8
Annex A (normative) Flowsheet of the procedure for the acceptance of test results .10
Annex B (informative) Derivation of equation for reducibility .11
© ISO 2021 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/FDIS 4695:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non­governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 201, Iron ore and direct reduced iron,
Subcommittee SC 3, Physical testing.
This fifth edition cancels and replaces the fourth edition (ISO 4695:2015), of which it constitutes a
minor revision to correct Formula B.3 in Annex B.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 4695:2021(E)

Introduction
This document concerns one of a number of physical test methods that have been developed to
measure various physical parameters and to evaluate the behaviour of iron ores, including reducibility,
disintegration, crushing strength, apparent density, etc. This method was developed to provide a
uniform procedure, validated by collaborative testing, to facilitate comparisons of tests made in
different laboratories.
The results of this test have to be considered in conjunction with other tests used to evaluate the quality
of iron ores as feedstocks for blast furnace processes.
This document can be used to provide test results as part of a production quality control system, as a
basis of a contract or as part of a research project.
© ISO 2021 – All rights reserved v

---------------------- Page: 5 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 4695:2021(E)
Iron ores for blast furnace feedstocks — Determination of
the reducibility by the rate of reduction index
CAUTION — This document can involve hazardous operations and equipment. This document
does not purport to address all of the safety issues associated with its use. It is the responsibility
of the user of this document to establish appropriate safety and health practices and determine
the applicability of regulatory limitations prior to its use.
1 Scope
This document specifies a method to provide a relative measure for evaluating the extent to and ease
with which oxygen can be removed from iron ores, when reduced under conditions resembling those
prevailing in the reduction zone of a blast furnace.
This document is applicable to lump ores, sinters and hot­bonded pellets.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 2597­1, Iron ores — Determination of total iron content — Part 1: Titrimetric method after tin(II)
chloride reduction
ISO 2597­2, Iron ores — Determination of total iron content — Part 2: Titrimetric methods after
titanium(III) chloride reduction
ISO 3082, Iron ores — Sampling and sample preparation procedures
ISO 9035, Iron ores — Determination of acid-soluble iron(II) content — Titrimetric method
ISO 11323, Iron ore and direct reduced iron — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11323 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Principle
The test portion is isothermally reduced in a fixed bed, at 950 °C, using a reducing gas consisting of CO
and N , and the mass loss of the test portion is recorded continuously or at specified time intervals until
2
its degree of reduction reaches 65 %. The rate of reduction is calculated at the oxygen/iron ratio of 0,9.
© ISO 2021 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO/FDIS 4695:2021(E)

5 Sampling, sample preparation and preparation of test portions
5.1 Sampling and sample preparation
Sampling of a lot and preparation of a test sample shall be in accordance with ISO 3082.
The size range for pellets, sinters and lump ores shall be −12,5 mm + 10,0 mm.
A test sample of at least 2,5 kg, on a dry basis, of the sized material shall be obtained.
Oven-dry the test sample to constant mass at 105 °C ± 5 °C and cool it to room temperature before
preparation of the test portions.
NOTE Constant mass is achieved when the difference in mass between two subsequent measurements
b
...