ISO 4689-3:2015

Iron ores — Determination of sulfur content — Part 3: Combustion/infrared method

ISO 4689-3:2015 specifies a combustion/infrared method, using a high-frequency induction furnace, for the determination of the sulfur content of iron ores. This method is applicable to sulfur contents between 0,002 % (mass fraction) and 0,25 % (mass fraction) in natural iron ores, iron ore concentrates and agglomerates, including sinter products. The method is not applicable to iron ores containing more than 1,0 % (mass fraction) of combined water. The apparatus, of which the metal filter is equipped with a heating device, can be applied to iron ores containing less than 3,0 % (mass fraction) of combined water.

Minerais de fer — Dosage du soufre — Partie 3: Méthode par combustion et infrarouge

Železove rude - Določevanje žvepla - 3. del: Metoda s sežiganjem/infrardeča metoda

Ta del standarda ISO 4689 določa metodo s sežiganjem/infrardečo metodo v visokofrekvenčni indukcijski peči za določevanje vsebnosti žvepla v železovih rudah.
Ta metoda se uporablja za vsebnosti žvepla od 0,002 % (masni delež) do 0,25 % (masni delež) v naravnih železovih rudah, koncentratih železove rude in aglomeratih, vključno s sintranimi izdelki. Ta metoda se ne uporablja za železove rude z vsebnostjo vode več kot 1,0 % (masni delež). Naprave, pri katerih je kovinski filter opremljen z napravo za segrevanje, je mogoče uporabiti za železove rude z vsebnostjo vode manj kot 3,0 % (masni delež).

General Information

• Status: Withdrawn
• Publication Date: 19-Jul-2015
• Withdrawal Date: 19-Jul-2015
• ICS: 73.060.10 - Iron ores
• Technical Committee: ISO/TC 102/SC 2 - Chemical analysis
• Drafting Committee: ISO/TC 102/SC 2 - Chemical analysis
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 02-Mar-2017
• Ref Project: SIST ISO 4689-3:2016 - Iron ores - Determination of sulfur content - Part 3: Combustion/infrared method

Relations

• Revised: ISO 4689-3:2017 - Iron ores — Determination of sulfur content — Part 3: Combustion/infrared method
• Effective Date: 13-Aug-2016
• Revises: ISO 4689-3:2004 - Iron ores — Determination of sulfur content — Part 3: Combustion/infrared method
• Effective Date: 18-Oct-2014

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4689-3
Second edition
2015-08-01
Iron ores — Determination of sulfur
content —
Part 3:
Combustion/infrared method
Minerais de fer — Dosage du soufre —
Partie 3: Méthode par combustion et infrarouge
Reference number
ISO 4689-3:2015(E)
©
ISO 2015

---------------------- Page: 1 ----------------------
ISO 4689-3:2015(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 4689-3:2015(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Principle . 1
4 Reagents . 1
5 Apparatus . 2
6 Sampling and samples . 5
6.1 Laboratory sample . 5
6.2 Preparation of predried test samples . 5
7 Procedure. 5
7.1 Number of determinations . 5
7.2 Test portion . 5
7.3 Blank test and check test . 5
7.4 Determination . 6
7.5 Preparation of calibration graph . 6
8 Expression of results . 7
8.1 Calculation of sulfur content . 7
8.2 General treatment of results . 7
8.2.1 Repeatability and permissible tolerance . 7
8.2.2 Determination of analytical result . 7
8.2.3 Between-laboratories precision . 8
8.2.4 Check for trueness . 8
8.2.5 Calculation of final result . 9
9 Test report . 9
Annex A (normative) Flowsheet of the procedure for the acceptance of analytical values for
test samples .10
Annex B (informative) Derivation of repeatability and permissible tolerance equations .11
Annex C (informative) Precision data obtained by international analytical trial .12
Bibliography .13
© ISO 2015 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 4689-3:2015(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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.
The committee responsible for this document is ISO/TC 102, Iron ore and direct reduced iron,
Subcommittee, Subcommittee SC 2, Chemical analysis.
This second edition cancels and replaces the first edition (ISO 4689-3:2004), of which 4.6 and 8.2.4
have been technically revised.
ISO 4689 consists of the following parts, under the general title Iron ores — Determination of sulfur
content:
— Part 1: Barium sulfate gravimetric method
— Part 2: Combustion/titration method
— Part 3: Combustion/infrared method
iv © ISO 2015 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 4689-3:2015(E)

Introduction
This part of ISO 4689 is a new procedure. ISO 4689-2 was originally published as ISO 4690:1986.
Under a policy of rationalization of the numbering system used in ISO/TC 102, it has been decided to
re-designate ISO 4690:1986 as ISO 4689-2. It was further decided to introduce a combustion/infrared
method, numbered ISO 4689-3, i.e. this part of ISO 4689.
When next revised, ISO 4689:1986 will be re-designated as ISO 4689-1.
© ISO 2015 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 4689-3:2015(E)
Iron ores — Determination of sulfur content —
Part 3:
Combustion/infrared method
WARNING — This part of ISO 4689 may involve hazardous materials, operations, and equipment.
This part of ISO 4689 does not purport to address all of the safety problems associated with its
use. It is the responsibility of the user of this part of ISO 4689 to establish appropriate health
and safety practices and determine the applicability of regulatory limitations prior to use.
1 Scope
This part of ISO 4689 specifies a combustion/infrared method, using a high-frequency induction
furnace, for the determination of the sulfur content of iron ores.
This method is applicable to sulfur contents between 0,002 % (mass fraction) and 0,25 % (mass
fraction) in natural iron ores, iron ore concentrates and agglomerates, including sinter products. The
method is not applicable to iron ores containing more than 1,0 % (mass fraction) of combined water.
The apparatus, of which the metal filter is equipped with a heating device, can be applied to iron ores
containing less than 3,0 % (mass fraction) of combined water.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3082, Iron ores — Sampling and sample preparation procedures
ISO 7764, Iron ores — Preparation of predried test samples for chemical analysis
ISO Guide 35, Reference materials — General and statistical principles for certification
3 Principle
The sample is mixed with a flux containing iron, tin, and tungsten and heated in a high-frequency
induction furnace, using oxygen as a supporting fuel and carrier gas.
The evolved sulfur dioxide is carried by oxygen into the cell of an infrared detector, where the
absorption scale is read.
4 Reagents
During analysis, use only reagents of recognized analytical grade, and only distilled water or water of
equivalent purity.
4.1 Metallic iron, particle size 0,2 mm to 1,2 mm containing less than sulfur.
© ISO 2015 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 4689-3:2015(E)

4.2 Magnesium perchlorate, Mg(ClO ) , anhydrous, free flowing, particle size 0,5 mm to 2 mm.
4 2
4.3 Iron(III) oxide, containing less than 0,003 % sulfur.
4.4 Metallic tin, particle size 0,2 mm to 1,2 mm containing less than 0,001 % sulfur.
4.5 Metallic tungsten, particle size 0,2 mm to 1,2 mm containing less than 0,001 % sulfur.
4.6 Sodium hydroxide coated silica, particle size 0,5 mm to 2 mm.
4.7 Sodium hydroxide, particle size 0,5 mm to 2 mm.
4.8 Standard sulfur solution, prepared as follows.
Dry 8 g of potassium sulfate (purity >99,99 % [mass fraction]) to constant mass at 105 °C to 110 °C and
cool in a desiccator. Weigh the dried masses of potassium sulfate specified in Table 1 and dissolve each
portion in water. Cool, transfer each portion to separate 100 ml volumetric flasks and dilute to volume
with water.
Table 1 — Sulfur standard solution (calibration series)
Solution No. Mass of potassium sulfate Concentration of sulfur
g mg/ml
1 0,543 5 1,00
2 1,087 0 2,00
3 1,902 2 3,50
4 2,717 4 5,00
5 Apparatus
Ordinary laboratory apparatus, including one-mark pipettes and one-mark volumetric flasks complying
with the specifications of ISO 648 and ISO 1042 respectively, as well as the following.
5.1 Oxygen supply.
5.2 Absorption tower, containing sodium hydroxide coated silica (4.6) or sodium hydroxide (4.7).
5.3 Drying tower, containing magnesium perchlorate (4.2).
5.4 High-frequency induction furnace, having a heating induction coil (height 30 mm to 55 mm, 4 to
5 rolls), capable of heating to a temperature of 1 200 °C.
An example of a combustion furnace, with combustion gas-refining section, is given in Figure 1.
5.5 Combustion tube, quartz.
5.6 Refractory combustion crucible.
2 © ISO 2015 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 4689-3:2015(E)

Key
1 metal filter
2 heating device
3 quartz combustion tube
4 dust trap
5 high-frequency induction coil
6 crucible
7 holder
a
Oxygen.
b
Combustion gas.
Figure 1 — Example of combustion furnace with combustion gas-refining section
© ISO 2015 – All rights reserved 3

--------
...

SLOVENSKI STANDARD
SIST ISO 4689-3:2016
01-maj-2016
1DGRPHãþD
SIST ISO 4689-3:2005
äHOH]RYHUXGH'RORþHYDQMHåYHSODGHO0HWRGDVVHåLJDQMHPLQIUDUGHþD
PHWRGD
Iron ores - Determination of sulfur content - Part 3: Combustion/infrared method
Minerais de fer - Dosage du soufre - Partie 3: Méthode par combustion et infrarouge
Ta slovenski standard je istoveten z: ISO 4689-3:2015
ICS:
73.060.10 Železove rude Iron ores
SIST ISO 4689-3:2016 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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

SIST ISO 4689-3:2016

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

SIST ISO 4689-3:2016
INTERNATIONAL ISO
STANDARD 4689-3
Second edition
2015-08-01
Iron ores — Determination of sulfur
content —
Part 3:
Combustion/infrared method
Minerais de fer — Dosage du soufre —
Partie 3: Méthode par combustion et infrarouge
Reference number
ISO 4689-3:2015(E)
©
ISO 2015

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

SIST ISO 4689-3:2016
ISO 4689-3:2015(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

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

SIST ISO 4689-3:2016
ISO 4689-3:2015(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Principle . 1
4 Reagents . 1
5 Apparatus . 2
6 Sampling and samples . 5
6.1 Laboratory sample . 5
6.2 Preparation of predried test samples . 5
7 Procedure. 5
7.1 Number of determinations . 5
7.2 Test portion . 5
7.3 Blank test and check test . 5
7.4 Determination . 6
7.5 Preparation of calibration graph . 6
8 Expression of results . 7
8.1 Calculation of sulfur content . 7
8.2 General treatment of results . 7
8.2.1 Repeatability and permissible tolerance . 7
8.2.2 Determination of analytical result . 7
8.2.3 Between-laboratories precision . 8
8.2.4 Check for trueness . 8
8.2.5 Calculation of final result . 9
9 Test report . 9
Annex A (normative) Flowsheet of the procedure for the acceptance of analytical values for
test samples .10
Annex B (informative) Derivation of repeatability and permissible tolerance equations .11
Annex C (informative) Precision data obtained by international analytical trial .12
Bibliography .13
© ISO 2015 – All rights reserved iii

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

SIST ISO 4689-3:2016
ISO 4689-3:2015(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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.
The committee responsible for this document is ISO/TC 102, Iron ore and direct reduced iron,
Subcommittee, Subcommittee SC 2, Chemical analysis.
This second edition cancels and replaces the first edition (ISO 4689-3:2004), of which 4.6 and 8.2.4
have been technically revised.
ISO 4689 consists of the following parts, under the general title Iron ores — Determination of sulfur
content:
— Part 1: Barium sulfate gravimetric method
— Part 2: Combustion/titration method
— Part 3: Combustion/infrared method
iv © ISO 2015 – All rights reserved

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

SIST ISO 4689-3:2016
ISO 4689-3:2015(E)

Introduction
This part of ISO 4689 is a new procedure. ISO 4689-2 was originally published as ISO 4690:1986.
Under a policy of rationalization of the numbering system used in ISO/TC 102, it has been decided to
re-designate ISO 4690:1986 as ISO 4689-2. It was further decided to introduce a combustion/infrared
method, numbered ISO 4689-3, i.e. this part of ISO 4689.
When next revised, ISO 4689:1986 will be re-designated as ISO 4689-1.
© ISO 2015 – All rights reserved v

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

SIST ISO 4689-3:2016

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

SIST ISO 4689-3:2016
INTERNATIONAL STANDARD ISO 4689-3:2015(E)
Iron ores — Determination of sulfur content —
Part 3:
Combustion/infrared method
WARNING — This part of ISO 4689 may involve hazardous materials, operations, and equipment.
This part of ISO 4689 does not purport to address all of the safety problems associated with its
use. It is the responsibility of the user of this part of ISO 4689 to establish appropriate health
and safety practices and determine the applicability of regulatory limitations prior to use.
1 Scope
This part of ISO 4689 specifies a combustion/infrared method, using a high-frequency induction
furnace, for the determination of the sulfur content of iron ores.
This method is applicable to sulfur contents between 0,002 % (mass fraction) and 0,25 % (mass
fraction) in natural iron ores, iron ore concentrates and agglomerates, including sinter products. The
method is not applicable to iron ores containing more than 1,0 % (mass fraction) of combined water.
The apparatus, of which the metal filter is equipped with a heating device, can be applied to iron ores
containing less than 3,0 % (mass fraction) of combined water.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3082, Iron ores — Sampling and sample preparation procedures
ISO 7764, Iron ores — Preparation of predried test samples for chemical analysis
ISO Guide 35, Reference materials — General and statistical principles for certification
3 Principle
The sample is mixed with a flux containing iron, tin, and tungsten and heated in a high-frequency
induction furnace, using oxygen as a supporting fuel and carrier gas.
The evolved sulfur dioxide is carried by oxygen into the cell of an infrared detector, where the
absorption scale is read.
4 Reagents
During analysis, use only reagents of recognized analytical grade, and only distilled water or water of
equivalent purity.
4.1 Metallic iron, particle size 0,2 mm to 1,2 mm containing less than sulfur.
© ISO 2015 – All rights reserved 1

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

SIST ISO 4689-3:2016
ISO 4689-3:2015(E)

4.2 Magnesium perchlorate, Mg(ClO ) , anhydrous, free flowing, particle size 0,5 mm to 2 mm.
4 2
4.3 Iron(III) oxide, containing less than 0,003 % sulfur.
4.4 Metallic tin, particle size 0,2 mm to 1,2 mm containing less than 0,001 % sulfur.
4.5 Metallic tungsten, particle size 0,2 mm to 1,2 mm containing less than 0,001 % sulfur.
4.6 Sodium hydroxide coated silica, particle size 0,5 mm to 2 mm.
4.7 Sodium hydroxide, particle size 0,5 mm to 2 mm.
4.8 Standard sulfur solution, prepared as follows.
Dry 8 g of potassium sulfate (purity >99,99 % [mass fraction]) to constant mass at 105 °C to 110 °C and
cool in a desiccator. Weigh the dried masses of potassium sulfate specified in Table 1 and dissolve each
portion in water. Cool, transfer each portion to separate 100 ml volumetric flasks and dilute to volume
with water.
Table 1 — Sulfur standard solution (calibration series)
Solution No. Mass of potassium sulfate Concentration of sulfur
g mg/ml
1 0,543 5 1,00
2 1,087 0 2,00
3 1,902 2 3,50
4 2,717 4 5,00
5 Apparatus
Ordinary laboratory apparatus, including one-mark pipettes and one-mark volumetric flasks complying
with the specifications of ISO 648 and ISO 1042 respectively, as well as the following.
5.1 Oxygen supply.
5.2 Absorption tower, containing sodium hydroxide coated silica (4.6) or sodium hydroxide (4.7).
5.3 Drying tower, containing magnesium perchlorate (4.2).
5.4 High-frequency induction furnace, having a heating induction coil (height 30 mm to 55 mm, 4 to
5 rolls), capable of heating to a temperature of 1 200 °C.
An example of a combustion furnace, with combustion gas-refining section, is given in Figure 1.
5.5 Combustion tube, quartz.
5.6 Refractor
...