ISO/FDIS 4695

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
• 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: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 01-Jun-2021
• Completion Date: 01-Jun-2021

RELATIONS

• Revised: 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)

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
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ISO/FDIS 4695:2021(E)
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© ISO 2021

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ii © ISO 2021 – All rights reserved
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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
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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
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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
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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

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
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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

...