Solid mineral fuels -- Determination of total sulfur by Coulomb titration method

ISO 20336:2017 specifies an alternative method of determining the total sulfur content of coal and coke by high-temperature combustion ? Coulomb titration.

Combustibles minéraux solides -- Détermination de la teneur totale en soufre par la méthode de titrage de Coulomb

General Information

Status
Published
Publication Date
12-Oct-2017
Current Stage
6060 - International Standard published
Start Date
07-Sep-2017
Completion Date
13-Oct-2017
Ref Project

Buy Standard

Standard
ISO 20336:2017 - Solid mineral fuels -- Determination of total sulfur by Coulomb titration method
English language
6 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 20336
First edition
2017-10
Solid mineral fuels — Determination
of total sulfur by Coulomb titration
method
Combustibles minéraux solides — Détermination de la teneur totale
en soufre par la méthode de titrage de Coulomb
Reference number
ISO 20336:2017(E)
ISO 2017
---------------------- Page: 1 ----------------------
ISO 20336:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, 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. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 20336:2017(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 1

5 Reagent and materials .................................................................................................................................................................................... 1

6 Apparatus ..................................................................................................................................................................................................................... 2

7 Preparation of test sample ......................................................................................................................................................................... 3

8 Procedure..................................................................................................................................................................................................................... 4

8.1 Preparation of test ............................................................................................................................................................................... 4

8.2 Calibration .................................................................................................................................................................................................. 4

8.3 Calibration procedure ....................................................................................................................................................................... 4

8.4 Procedure .................................................................................................................................................................................................... 5

8.5 Calibration check ................................................................................................................................................................................... 5

9 Expression of result ........................................................................................................................................................................................... 6

10 Precision ....................................................................................................................................................................................................................... 6

10.1 Repeatability limit ................................................................................................................................................................................ 6

10.2 Reproducibility limit .......................................................................................................................................................................... 6

11 Test report ................................................................................................................................................................................................................... 6

© ISO 2017 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 20336:2017(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 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 the following

URL: www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 27, Solid mineral fuels, Subcommittee

SC 5, Methods of analysis.
iv © ISO 2017 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 20336:2017(E)
Introduction

The objective of this document is to provide an alternative method for determining the total sulfur

content in solid mineral fuels with high-temperature combustion — Coulomb titration using automated

instruments.
© ISO 2017 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 20336:2017(E)
Solid mineral fuels — Determination of total sulfur by
Coulomb titration method
1 Scope

This document specifies an alternative method of determining the total sulfur content of coal and coke

by high-temperature combustion — Coulomb titration.
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 687, Solid mineral fuels — Coke — Determination of moisture in the general analysis test sample

ISO 5068-2, Brown coals and lignites — Determination of moisture content — Part 2: Indirect gravimetric

method for moisture in the analysis sample

ISO 11722, Solid mineral fuels — Hard coal — Determination of moisture in the general analysis test

sample by drying in nitrogen
3 Terms and definitions
No terms and definitions are listed in this document.

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

In the presence of the catalyst, a weighed sample is combusted at 1 150 °C in a stream of purified air.

The sulfur oxides are formed and dissolved in the electrolytic solution. The sulfur dioxides are titrated

by the iodine and bromine librated from the electrolysis of the potassium iodide and potassium

bromide solution. The quantity of the electricity consumed by electrolysis is integrated and used to

calculate the content of sulfur dioxides. The instrument is calibrated with certified reference materials.

The percentage of total sulfur in the sample is calculated according to the sulfur dioxides content and

the prior calibration.
5 Reagent and materials

During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only

distilled water or water of equivalent purity.
5.1 Potassium iodide.
5.2 Potassium bromide.
5.3 Glacial acetic acid.
© ISO 2017 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 20336:2017(E)
5.4 Self-indicating silica gel, industrial grade.
5.5 Sodium hydroxide, chemical grade.
5.6 Electrolytic solution.

5 g of potassium iodide (5.1) and 5 g of potassium bromide (5.2) are dissolved in (250 to 300) ml of

water, then add 10 ml of glacial acetic acid.
5.7 Glass wool.
5.8 Aluminosilicate wool.
5.9 Catalyst, tungsten trioxide.
5.10 Certified reference materials (CRMs), coal or coke.
6 Apparatus
6.1 Instrument.

For determining sulfur by Coulomb titration, commercially available, consisting of the following

...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.