ISO 4689-2:2015

Iron ores — Determination of sulfur content — Part 2: Combustion/titration method

ISO 4689-2:2015 specifies a combustion/titration method 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 results are not affected by the presence of fluoride.

Minerais de fer — Dosage du soufre — Partie 2: Méthode par combustion et titration

Železove rude - Določevanje žvepla - 2. del: Metoda s sežiganjem/titracijo

Ta del standarda ISO 4689 določa metodo s sežiganjem/titracijo 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. Prisotnost fluorida ne vpliva na rezultate.

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• Status: Withdrawn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 4689-2:2016 - Iron ores - Determination of sulfur content - Part 2: Combustion/titration method

Relations

• Revised: ISO 4689-2:2017 - Iron ores — Determination of sulfur content — Part 2: Combustion/titration method
• Effective Date: 13-Aug-2016
• Revises: ISO 4689-2:2004 - Iron ores — Determination of sulfur content — Part 2: Combustion/titration method
• Effective Date: 18-Oct-2014

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4689-2
Second edition
2015-08-01
Iron ores — Determination of sulfur
content —
Part 2:
Combustion/titration method
Minerais de fer — Dosage du soufre —
Partie 2: Méthode par combustion et titration
Reference number
ISO 4689-2:2015(E)
©
ISO 2015

---------------------- Page: 1 ----------------------
ISO 4689-2:2015(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 4689-2:2015(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 . 4
6.1 Laboratory sample . 4
6.2 Preparation of predried test samples . 4
7 Procedure. 4
7.1 Number of determinations . 4
7.2 Test portion . 5
7.3 Blank test and check test . 5
7.4 Determination . 5
8 Expression of results . 6
8.1 Calculation of sulfur content . 6
8.2 General treatment of results . 6
8.2.1 Repeatability and permissible tolerance . 6
8.2.2 Determination of analytical result . 7
8.2.3 Between-laboratories precision . 7
8.2.4 Check for trueness . 7
8.2.5 Calculation of final result . 8
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 4689-2:2015(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 SC 2, Chemical analysis.
This second edition cancels and replaces the first edition (ISO 4689-2:2004), of which 4.4, 5.2, 8.2.4 and
Figure 1 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 4689-2:2015(E)

Introduction
This part of ISO 4689 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 this document as ISO 4689-2.
It was further decided to introduce a combustion/infrared method, numbered ISO 4689-3.
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 4689-2:2015(E)
Iron ores — Determination of sulfur content —
Part 2:
Combustion/titration 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/titration method 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
results are not affected by the presence of fluoride.
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 385-1, Laboratory glassware — Burettes — Part 1: General requirements
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 tungsten(VI) oxide and heated at 1 200 °C in a resistance furnace, using
nitrogen as a carrier gas.
The evolved sulfur dioxide is absorbed in dilute hydrochloric acid solution containing starch and
potassium iodide, and the solution is titrated continuously during evolution with a standard volumetric
solution of potassium iodate.
4 Reagents
During analysis, use only reagents of recognized analytical grade, and only distilled water or water of
equivalent purity.
4.1 Magnesium perchlorate, Mg(ClO ) , anhydrous, free flowing, particle size 0,5 mm to 2 mm.
4 2
© ISO 2015 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 4689-2:2015(E)

4.2 Tungsten(VI) oxide, (WO ).
3
4.3 Tin(II) chloride, SnCl ·2H O, particle size 0,5 mm to 2 mm.
2 2
4.4 Sodium hydroxide coated silica, particle size 0,5 mm to 2 mm.
4.5 Hydrochloric acid, ρ, 1,16 g/ml to 1,19 g/ml, diluted 1 + 66.
4.6 Potassium iodide, KI, 3 % (mass fraction) solution.
4.7 Starch, 2 % (mass fraction) solution.
Make a suspension of 2,0 g of starch in 10 ml of water, add to 50 ml of boiling water and stir. Cool, dilute
to 100 ml and mix.
Prepare this solution immediately prior to use.
4.8 Potassium iodate, KIO , standard volumetric solution, 0,001 042 mol/l.
3
The potassium iodate should be previously dried for 2 h at 130 °C.
Weigh, to the nearest 0,000 2 g, 0,223 g of dried potassium iodate and dissolve in water. Cool, transfer
to a 1 l volumetric flask, dilute to volume and mix.
1 ml of this standard volumetric solution is equivalent to 0,10 mg of sulfur.
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. See Figure 1.
5.1 Nitrogen supply.
5.2 Drying tower, containing sodium hydroxide coated silica (4.4) and magnesium perchlorate (4.1).
5.3 Flowmeter, graduated from 0 to 1 l/min.
5.4 Resistance furnace, capable of maintaining a temperature of 1 200 °C ± 25 °C.
5.5 Refractory combustion tube, capable of withstanding a temperature of 1 200 °C ± 25 °C.
5.6 Refractory combustion boat, with loose-fitting lid, or a suitable refractory combustion boat
capable of accommodating a porous cartridge, as shown in Figure 2 a) or b) respectively. The following
dimensions can be used as guidelines.
Combustion boat Cartridge
Length 80 mm Length 50 mm
Width 13 mm Internal diameter 15 mm
Depth 9 mm
5.7 Tin(II) chloride absorption tube, of narrow glass tubing containing approximately of solid tin(II)
chloride (4.3), suitably plugged with inert wool to prevent the reagent being blown into the absorption
2 © ISO 2015 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 4689-2:2015(E)

vessel. A U-tube is suitable. Where necessary, this is inserted in the train at the exit of the combustion
tube at point X in Figure 1.
If the sample is known or thought to contain chloride, e.g. in the form of sodium chloride, chlorapatite,
or scapolite, the chlorine formed during combustion of the sample should be removed by passing the gas
stream through solid tin(II) chloride in a suitable tube or vessel (5.7) prior to absorption and titration.
If numerous samples having chloride contents >1 (mass fraction) are to be analysed, it is advisable to
determine the absorption capacity of the tin(II) chloride in order to be able to judge the most suitable
interval for reagent replacement. In such cases, a larger absorption vessel may be preferred.
The tin(II) chloride absorption tube should also be fitted if the chloride content of the test sample is
unknown.
5.8 Cylinder, 100 ml, tall form, to hold the absorbing solution.
5.9 Bubbler, multi-hole, to reach to the bottom of the cylinder (5.8).
5.10 Burette, conforming to ISO 385-1, graduated in divisions of 0,05 ml.
For determination of low sulfur contents [<0,005 % (mass fraction)], alternative titration devices such
as a piston
...

SLOVENSKI STANDARD
SIST ISO 4689-2:2016
01-maj-2016
1DGRPHãþD
SIST ISO 4689-2:2005
äHOH]RYHUXGH'RORþHYDQMHåYHSODGHO0HWRGDVVHåLJDQMHPWLWUDFLMR
Iron ores - Determination of sulfur content - Part 2: Combustion/titration method
Minerais de fer - Dosage du soufre - Partie 2: Méthode par combustion et titration
Ta slovenski standard je istoveten z: ISO 4689-2:2015
ICS:
73.060.10 Železove rude Iron ores
SIST ISO 4689-2:2016 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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

SIST ISO 4689-2:2016

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

SIST ISO 4689-2:2016
INTERNATIONAL ISO
STANDARD 4689-2
Second edition
2015-08-01
Iron ores — Determination of sulfur
content —
Part 2:
Combustion/titration method
Minerais de fer — Dosage du soufre —
Partie 2: Méthode par combustion et titration
Reference number
ISO 4689-2:2015(E)
©
ISO 2015

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

SIST ISO 4689-2:2016
ISO 4689-2:2015(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 4689-2:2016
ISO 4689-2:2015(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 . 4
6.1 Laboratory sample . 4
6.2 Preparation of predried test samples . 4
7 Procedure. 4
7.1 Number of determinations . 4
7.2 Test portion . 5
7.3 Blank test and check test . 5
7.4 Determination . 5
8 Expression of results . 6
8.1 Calculation of sulfur content . 6
8.2 General treatment of results . 6
8.2.1 Repeatability and permissible tolerance . 6
8.2.2 Determination of analytical result . 7
8.2.3 Between-laboratories precision . 7
8.2.4 Check for trueness . 7
8.2.5 Calculation of final result . 8
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 4689-2:2016
ISO 4689-2:2015(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 SC 2, Chemical analysis.
This second edition cancels and replaces the first edition (ISO 4689-2:2004), of which 4.4, 5.2, 8.2.4 and
Figure 1 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 4689-2:2016
ISO 4689-2:2015(E)

Introduction
This part of ISO 4689 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 this document as ISO 4689-2.
It was further decided to introduce a combustion/infrared method, numbered ISO 4689-3.
When next revised, ISO 4689:1986 will be re-designated as ISO 4689-1.
© ISO 2015 – All rights reserved v

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

SIST ISO 4689-2:2016

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

SIST ISO 4689-2:2016
INTERNATIONAL STANDARD ISO 4689-2:2015(E)
Iron ores — Determination of sulfur content —
Part 2:
Combustion/titration 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/titration method 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
results are not affected by the presence of fluoride.
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 385-1, Laboratory glassware — Burettes — Part 1: General requirements
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 tungsten(VI) oxide and heated at 1 200 °C in a resistance furnace, using
nitrogen as a carrier gas.
The evolved sulfur dioxide is absorbed in dilute hydrochloric acid solution containing starch and
potassium iodide, and the solution is titrated continuously during evolution with a standard volumetric
solution of potassium iodate.
4 Reagents
During analysis, use only reagents of recognized analytical grade, and only distilled water or water of
equivalent purity.
4.1 Magnesium perchlorate, Mg(ClO ) , anhydrous, free flowing, particle size 0,5 mm to 2 mm.
4 2
© ISO 2015 – All rights reserved 1

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

SIST ISO 4689-2:2016
ISO 4689-2:2015(E)

4.2 Tungsten(VI) oxide, (WO ).
3
4.3 Tin(II) chloride, SnCl ·2H O, particle size 0,5 mm to 2 mm.
2 2
4.4 Sodium hydroxide coated silica, particle size 0,5 mm to 2 mm.
4.5 Hydrochloric acid, ρ, 1,16 g/ml to 1,19 g/ml, diluted 1 + 66.
4.6 Potassium iodide, KI, 3 % (mass fraction) solution.
4.7 Starch, 2 % (mass fraction) solution.
Make a suspension of 2,0 g of starch in 10 ml of water, add to 50 ml of boiling water and stir. Cool, dilute
to 100 ml and mix.
Prepare this solution immediately prior to use.
4.8 Potassium iodate, KIO , standard volumetric solution, 0,001 042 mol/l.
3
The potassium iodate should be previously dried for 2 h at 130 °C.
Weigh, to the nearest 0,000 2 g, 0,223 g of dried potassium iodate and dissolve in water. Cool, transfer
to a 1 l volumetric flask, dilute to volume and mix.
1 ml of this standard volumetric solution is equivalent to 0,10 mg of sulfur.
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. See Figure 1.
5.1 Nitrogen supply.
5.2 Drying tower, containing sodium hydroxide coated silica (4.4) and magnesium perchlorate (4.1).
5.3 Flowmeter, graduated from 0 to 1 l/min.
5.4 Resistance furnace, capable of maintaining a temperature of 1 200 °C ± 25 °C.
5.5 Refractory combustion tube, capable of withstanding a temperature of 1 200 °C ± 25 °C.
5.6 Refractory combustion boat, with loose-fitting lid, or a suitable refractory combustion boat
capable of accommodating a porous cartridge, as shown in Figure 2 a) or b) respectively. The following
dimensions can be used as guidelines.
Combustion boat Cartridge
Length 80 mm Length 50 mm
Width 13 mm Internal diameter 15 mm
Depth 9 mm
5.7 Tin(II) chloride absorption tube, of narrow glass tubing containing approximately of solid tin(II)
chloride (4.3), suitably plugged with inert wool to prevent the reagent being blown into the absorption
2 © ISO 2015 – All rights reserved

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

SIST ISO 4689-2:2016
ISO 4689-2:2015(E)

vessel. A U-tube is suitable. Where necessary, this is inserted in the train at the exit of the combustion
tube at point X in Figure 1.
If the sample is known or thought to contain chloride, e.g. in the form of sodium chloride, chlorapatite,
or scapolite, the chlorine formed during combustion of the sample should be removed by passing the gas
stream through solid tin(II) chloride in a suitable tube or vessel (5.7) prior to absorption and titration.
If numerous samples having chloride contents >1 (mass fraction) are to be analysed, it is advisable to
determine the absorption capacity of the tin(II) chloride in order to be able to judge the most suitable
interval for reagent replacement. In such cases, a larger absorption vessel may be preferred.
The t
...