ISO 11258:1999

Iron ores — Determination of reducibility and metallization of feedstock for direct reduction by gas reforming processes

Minerais de fer — Détermination de la réductibilité et de la métallisation des charges utilisées dans les procédés de reforming par réduction directe

Železove rude – Ugotavljanje stisljivosti in metalizacije vhodne surovine za direktno redukcijo s procesi transformacije plinov

General Information

• Status: Withdrawn
• Publication Date: 11-Aug-1999
• Withdrawal Date: 11-Aug-1999
• 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: 9599 - Withdrawal of International Standard
• Completion Date: 30-Oct-2007
• Ref Project: SIST ISO 11258:2001 - Iron ores -- Determination of reducibility and metallization of feedstock for direct reduction by gas reforming processes

Relations

• Revised: ISO 11258:2007 - Iron ores for shaft direct-reduction feedstocks — Determination of the reducibility index, final degree of reduction and degree of metallization
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 11258
First edition
1999-08-01
Iron ores — Determination of reducibility
and metallization of feedstock for direct
reduction by gas reforming processes
Minerais de fer — Détermination de la réductibilité et de la métallisation des
charges utilisées dans les procédés de reforming par réduction directe
A
Reference number
ISO 11258:1999(E)

---------------------- Page: 1 ----------------------
ISO 11258:1999(E)
Contents Page
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Principle.2
5 Apparatus .2
6 Test conditions .5
7 Sampling and sample preparation .5
8 Procedure .6
9 Expression of results .7
10 Verification .9
Annex A (informative) Derivation of equation for reducibility .11
Annex B (informative) Derivation of equation for degree of metallization from R .12
90
(normative)
Annex C Flowsheet for the procedure for the acceptance of the test results .14
©  ISO 1999
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [e-mail]
Printed in Switzerland
ii

---------------------- Page: 2 ----------------------
© ISO
ISO 11258:1999(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
International Standard ISO 11258 was prepared by Technical Committee ISO/TC 102, Iron ores and direct reduced
iron, Subcommittee SC 5, Physical testing of direct reduction feedstock and DRI.
Annex C forms an integral part of this International Standard. Annexes A and B are for information only.
iii

---------------------- Page: 3 ----------------------
© ISO
ISO 11258:1999(E)
Introduction
Direct reduction processes are intended to partially or almost completely reduce iron ores by thermal processes in
order to form high grade feedstocks for iron- and steelmaking. Several kinds of direct reduction process are in
operation worldwide and others are still under development. The behaviour of the iron ores, as feedstock, may vary
from process to process. This International Standard was prepared in order to specifically address direct reduction
by gas reforming processes.
The obtained reducibility index is a relative measure of the reducibility behaviour, and the degree of metallization is
a relative measure of the metallization behaviour of the iron ore.
The results of this test should be considered in conjunction with the results of other tests used to evaluate the
quality of iron ores as feedstock for direct reduction processes.
iv

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD  © ISO ISO 11258:1999(E)
Iron ores — Determination of reducibility and metallization of
feedstock for direct reduction by gas reforming processes
WARNING — This International Standard may involve hazardous materials, operations and equipment. This
International Standard does not purport to address all of the safety problems associated with its use. It is
the responsibility of the user of this International Standard to establish appropriate safety and health
practices and determine the applicability of regulatory limitations prior to its use.
1 Scope
This International Standard describes a test method for evaluating the reducibility and metallization behaviour of iron
ore pellets and lumps under conditions which resemble the ones prevailing in direct reduction by gas reforming
processes.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 2597-1:1994, Iron ores — Determination of total iron content — Part 1: Titrimetric methods after tin (II) chloride
reduction.
1)
ISO 3310-1:— , Test sieves —Requirements and tests — Part 1: Metal wire cloth sieves.
ISO 5416:1997, Direct reduced iron — Determination of metallic iron content — Bromine-methanol titrimetric
method.
ISO 9035:1989, Iron ores — Determination of acid-soluble iron (II) content — Titrimetric method.
ISO 9507:1990, Iron ores — Determination of total iron content — Titanium (III) chloride reduction methods.
ISO 9508:1990, Iron ores — Determination of total iron content — Silver reduction titrimetric method.
ISO 10836:1994, Iron ores — Method of sampling and sample preparation for physical testing.
ISO 11323:1996, Iron ores — Vocabulary.

1)
To be published. (Revision of ISO 3310-1:1990)
1

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© ISO
ISO 11258:1999(E)
3 Terms and definitions
For the purposes of this International Standard the terms and definitions given in ISO 11323 and the following apply.
3.1
degree of reduction
extent to which oxygen has been removed from iron oxides, expressed as the ratio of oxygen removed to oxygen
originally combined with iron, relative to the iron (III)-state
4 Principle
Heating of the test portion in an inert atmosphere.
Isothermal reduction of the test portion at a specified size range in a fixed bed, at a temperature of 800 °C, using a
reducing gas consisting of H , CO, CO and N .
2 2 2
Continuous weighing or intermittent weighing of the test portion at specified time intervals for 90 min reduction in
total.
Cooling of the test portion in an inert atmosphere.
Calculation of the degree of reduction, after reduction for 90 min, relative to the iron (III)-state and the reducibility
index at the oxygen:iron ratio of 0,9.
Calculation of the degree of metallization from the chemical analysis of the reduced test portion or from the final
degree of reduction (R ).
90
5 Apparatus
The apparatus shall consist of the following (Figure 1 and Figure 2 show an example of the arrangement).
5.1  Gas supply system, capable of supplying the gases and regulating the gas flow rates, freely suspended and
connected to the tube in such a way that weighing is not affected.
5.2  Reduction tube, made of non-scaling, heat-resisting metal to withstand temperatures greater than 800 °C and
having an internal diameter of 75 mm ± 1 mm. A perforated plate is mounted inside the reduction tube to support the
test portion.
 capable of weighing the reduction tube, including the test portion, to an accuracy of 1 g.
5.3 Weighing device,
5.4  Electrically heated furnace, having a heating capacity and controls sufficient to maintain the entire test
portion and the gas entering the bed at 800 °C 6 5 °C.
5.5  Test sieves conforming to ISO 3310-1 and having square openings of the following nominal aperture size:
16 mm; 12,5 mm and 10 mm.
2

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© ISO
ISO 11258:1999(E)
Key
1 Plotter for recording temperature
2 Gas outlet
3 Beam
4 Mixing vessel
5 Gas inlet
6 Thermocouple
7 Test portion
8 Layer of porcelain balls
9 Double wall retort with perforated plate as sample holder
10 Electrically heated furnace
11 Gas flow meters
12 Gas cylinders with manometers and reduction valve
Figure 1 — Arrangement of a test unit
3

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© ISO
ISO 11258:1999(E)
Dimensions in millimetres
NOTE — The dimensions specified in clause 5 are shown for information only.
Key
1:
Hole diameter: 2,5 mm
Pitch between holes: 4,0 mm
Number of holes: 241
2
Total hole area: 11,8 cm
Thickness of plate: 4 mm
Figure 2 — Example of reduction tube
4

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© ISO
ISO 11258:1999(E)
6 Test conditions
6.1 General
Volumes and flow rate of gases used in this International Standard are as measured at a temperature of 0 °C and at
an atmospheric pressure of 101,325 kPa (1,013 25 bar).
6.2 Composition of reducing gas
The reducing gas shall consist of:
 H 45 % 6 1,0 % (V/V)
2
 CO 30 % 6 1,0 % (V/V)
 CO 15 % 6 1,0 % (V/V)
2
 N 10 % 6 1,0 % (V/V)
2
6.3 Purity of reducing gas
Impurities in the reducing gas shall not exceed
 O 0,1 % (V/V)
2
 H O 0,2 % (V/V)
2
6.4 Flow rate of reducing gas
Flow rate of the reducing gas shall, during the test period, be maintained at 50 l/min 6 0,5 l/min.
6.5 Purity of heating and cooling gas
Impurities in nitrogen shall not exceed 0,1 % (V/V).
6.6 Temperature of test
The test portion shall be reduced at 800 °C 6 5 °C.
The reducing gas shall be preheated while entering the reduction tube to maintain the temperature within the
reduction tube and hence the entire test portion at 800 °C 6 5 °C, during the entire reduction period.
7 Sampling and sample preparation
2)
The sampling and the preparation of test samples and test portions shall be in accordance with ISO 10836 .
The test sample shall be oven dried at 105 °C 6 5 °C and cooled to room temperature before the preparation of the
test portions.
At least five test portions each of approximately 500 g mass shall be prepared.
Collect each test portion by taking ore particles at random. The target mass of the test portion is 500 g 6 the mass
of one particle.

2)
ISO 10836:1994 does not
...

SLOVENSKI STANDARD
SIST ISO 11258:2001
01-junij-2001
Železove rude – Ugotavljanje stisljivosti in metalizacije vhodne surovine za
direktno redukcijo s procesi transformacije plinov
Iron ores -- Determination of reducibility and metallization of feedstock for direct
reduction by gas reforming processes
Minerais de fer -- Détermination de la réductibilité et de la métallisation des charges
utilisées dans les procédés de reforming par réduction directe
Ta slovenski standard je istoveten z: ISO 11258:1999
ICS:
73.060.10 Železove rude Iron ores
SIST ISO 11258:2001 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ISO 11258:2001

---------------------- Page: 2 ----------------------

SIST ISO 11258:2001
INTERNATIONAL ISO
STANDARD 11258
First edition
1999-08-01
Iron ores — Determination of reducibility
and metallization of feedstock for direct
reduction by gas reforming processes
Minerais de fer — Détermination de la réductibilité et de la métallisation des
charges utilisées dans les procédés de reforming par réduction directe
A
Reference number
ISO 11258:1999(E)

---------------------- Page: 3 ----------------------

SIST ISO 11258:2001
ISO 11258:1999(E)
Contents Page
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Principle.2
5 Apparatus .2
6 Test conditions .5
7 Sampling and sample preparation .5
8 Procedure .6
9 Expression of results .7
10 Verification .9
Annex A (informative) Derivation of equation for reducibility .11
Annex B (informative) Derivation of equation for degree of metallization from R .12
90
(normative)
Annex C Flowsheet for the procedure for the acceptance of the test results .14
©  ISO 1999
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [e-mail]
Printed in Switzerland
ii

---------------------- Page: 4 ----------------------

SIST ISO 11258:2001
© ISO
ISO 11258:1999(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
International Standard ISO 11258 was prepared by Technical Committee ISO/TC 102, Iron ores and direct reduced
iron, Subcommittee SC 5, Physical testing of direct reduction feedstock and DRI.
Annex C forms an integral part of this International Standard. Annexes A and B are for information only.
iii

---------------------- Page: 5 ----------------------

SIST ISO 11258:2001
© ISO
ISO 11258:1999(E)
Introduction
Direct reduction processes are intended to partially or almost completely reduce iron ores by thermal processes in
order to form high grade feedstocks for iron- and steelmaking. Several kinds of direct reduction process are in
operation worldwide and others are still under development. The behaviour of the iron ores, as feedstock, may vary
from process to process. This International Standard was prepared in order to specifically address direct reduction
by gas reforming processes.
The obtained reducibility index is a relative measure of the reducibility behaviour, and the degree of metallization is
a relative measure of the metallization behaviour of the iron ore.
The results of this test should be considered in conjunction with the results of other tests used to evaluate the
quality of iron ores as feedstock for direct reduction processes.
iv

---------------------- Page: 6 ----------------------

SIST ISO 11258:2001
INTERNATIONAL STANDARD  © ISO ISO 11258:1999(E)
Iron ores — Determination of reducibility and metallization of
feedstock for direct reduction by gas reforming processes
WARNING — This International Standard may involve hazardous materials, operations and equipment. This
International Standard does not purport to address all of the safety problems associated with its use. It is
the responsibility of the user of this International Standard to establish appropriate safety and health
practices and determine the applicability of regulatory limitations prior to its use.
1 Scope
This International Standard describes a test method for evaluating the reducibility and metallization behaviour of iron
ore pellets and lumps under conditions which resemble the ones prevailing in direct reduction by gas reforming
processes.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 2597-1:1994, Iron ores — Determination of total iron content — Part 1: Titrimetric methods after tin (II) chloride
reduction.
1)
ISO 3310-1:— , Test sieves —Requirements and tests — Part 1: Metal wire cloth sieves.
ISO 5416:1997, Direct reduced iron — Determination of metallic iron content — Bromine-methanol titrimetric
method.
ISO 9035:1989, Iron ores — Determination of acid-soluble iron (II) content — Titrimetric method.
ISO 9507:1990, Iron ores — Determination of total iron content — Titanium (III) chloride reduction methods.
ISO 9508:1990, Iron ores — Determination of total iron content — Silver reduction titrimetric method.
ISO 10836:1994, Iron ores — Method of sampling and sample preparation for physical testing.
ISO 11323:1996, Iron ores — Vocabulary.

1)
To be published. (Revision of ISO 3310-1:1990)
1

---------------------- Page: 7 ----------------------

SIST ISO 11258:2001
© ISO
ISO 11258:1999(E)
3 Terms and definitions
For the purposes of this International Standard the terms and definitions given in ISO 11323 and the following apply.
3.1
degree of reduction
extent to which oxygen has been removed from iron oxides, expressed as the ratio of oxygen removed to oxygen
originally combined with iron, relative to the iron (III)-state
4 Principle
Heating of the test portion in an inert atmosphere.
Isothermal reduction of the test portion at a specified size range in a fixed bed, at a temperature of 800 °C, using a
reducing gas consisting of H , CO, CO and N .
2 2 2
Continuous weighing or intermittent weighing of the test portion at specified time intervals for 90 min reduction in
total.
Cooling of the test portion in an inert atmosphere.
Calculation of the degree of reduction, after reduction for 90 min, relative to the iron (III)-state and the reducibility
index at the oxygen:iron ratio of 0,9.
Calculation of the degree of metallization from the chemical analysis of the reduced test portion or from the final
degree of reduction (R ).
90
5 Apparatus
The apparatus shall consist of the following (Figure 1 and Figure 2 show an example of the arrangement).
5.1  Gas supply system, capable of supplying the gases and regulating the gas flow rates, freely suspended and
connected to the tube in such a way that weighing is not affected.
5.2  Reduction tube, made of non-scaling, heat-resisting metal to withstand temperatures greater than 800 °C and
having an internal diameter of 75 mm ± 1 mm. A perforated plate is mounted inside the reduction tube to support the
test portion.
 capable of weighing the reduction tube, including the test portion, to an accuracy of 1 g.
5.3 Weighing device,
5.4  Electrically heated furnace, having a heating capacity and controls sufficient to maintain the entire test
portion and the gas entering the bed at 800 °C 6 5 °C.
5.5  Test sieves conforming to ISO 3310-1 and having square openings of the following nominal aperture size:
16 mm; 12,5 mm and 10 mm.
2

---------------------- Page: 8 ----------------------

SIST ISO 11258:2001
© ISO
ISO 11258:1999(E)
Key
1 Plotter for recording temperature
2 Gas outlet
3 Beam
4 Mixing vessel
5 Gas inlet
6 Thermocouple
7 Test portion
8 Layer of porcelain balls
9 Double wall retort with perforated plate as sample holder
10 Electrically heated furnace
11 Gas flow meters
12 Gas cylinders with manometers and reduction valve
Figure 1 — Arrangement of a test unit
3

---------------------- Page: 9 ----------------------

SIST ISO 11258:2001
© ISO
ISO 11258:1999(E)
Dimensions in millimetres
NOTE — The dimensions specified in clause 5 are shown for information only.
Key
1:
Hole diameter: 2,5 mm
Pitch between holes: 4,0 mm
Number of holes: 241
2
Total hole area: 11,8 cm
Thickness of plate: 4 mm
Figure 2 — Example of reduction tube
4

---------------------- Page: 10 ----------------------

SIST ISO 11258:2001
© ISO
ISO 11258:1999(E)
6 Test conditions
6.1 General
Volumes and flow rate of gases used in this International Standard are as measured at a temperature of 0 °C and at
an atmospheric pressure of 101,325 kPa (1,013 25 bar).
6.2 Composition of reducing gas
The reducing gas shall consist of:
 H 45 % 6 1,0 % (V/V)
2
 CO 30 % 6 1,0 % (V/V)
 CO 15 % 6 1,0 % (V/V)
2
 N 10 % 6 1,0 % (V/V)
2
6.3 Purity of reducing gas
Impurities in the reducing gas shall not exceed
 O 0,1 % (V/V)
2
 H O 0,2 % (V/V)
2
6.4 Flow rate of reducing gas
Flow rate of the reducing gas shall, during the test period, be maintained at 50 l/min 6 0,5 l/min.
6.5 Purity of heating and cooling gas
Impurities in nitrogen shall not exceed 0,1 % (V/V).
6.6 Temperature of test
The test portion shall be reduced at 800 °C 6 5 °C.
The reducing gas shall be preheated while entering the reduction tube to maintain the temperature within the
reduction tube and hence the entire test portion at 800 °C 6 5 °C, during the entire reduction period.
7 Sampling and sample preparation
2)
The sampling and the preparation of test samples and test portio
...