ISO 501:2025
(Main)Hard coal — Determination of the crucible swelling number
Hard coal — Determination of the crucible swelling number
This document specifies a method for determining the swelling properties of hard coal when heated in a covered crucible. NOTE The "crucible swelling number" (CSN) is also known as the "free swelling index" (FSI).
Houille — Détermination de l'indice de gonflement au creuset
General Information
Relations
Standards Content (Sample)
International
Standard
ISO 501
Fifth edition
Hard coal — Determination of the
2025-05
crucible swelling number
Houille — Détermination de l'indice de gonflement au creuset
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Preparation of the test sample. 1
6 Apparatus . 2
7 Preparation of apparatus . 4
8 Procedure . 5
9 Expression of results . 6
10 Precision of the method . 7
10.1 Repeatability .7
10.2 Reproducibility .7
11 Test report . 7
iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 27, Coal and coke, Subcommittee SC 5, Methods
of analysis.
This fifth edition cancels and replaces the fourth edition (ISO 501:2012), which has been technically revised.
The main changes are as follows:
— replaced the word "should" with "shall" throughout the document;
— corrected dimension expressions e.g. 26 ± 1,0 mm to 26 mm ± 1 mm;
— standardised the reporting of ½ as 0,5.
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
International Standard ISO 501:2025(en)
Hard coal — Determination of the crucible swelling number
WARNING — Use of this document can involve hazardous materials, 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 use.
1 Scope
This document specifies a method for determining the swelling properties of hard coal when heated in a
covered crucible.
NOTE The "crucible swelling number" (CSN) is also known as the "free swelling index" (FSI).
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 13909-4, Coal and coke — Mechanical sampling — Part 4: Preparation of test samples of coal
ISO 18283, Coal and coke — Manual sampling
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
A sample of coal is heated in a covered crucible under standard conditions of time and temperature. The
shape of the coke button obtained is classified by comparison with the outlines of a set of standard profiles.
5 Preparation of the test sample
The test sample shall be the general analysis test sample prepared in accordance with ISO 13909-4 and
ISO 18283. Ensure that the moisture in the sample is in equilibrium with the laboratory atmosphere,
exposing it, if necessary, in a thin layer for the minimum time required to achieve equilibrium.
The sample used for the crucible swelling number (CSN) test shall be ground to pass a 212 μm sieve. A small
swing hammer crusher with rotary hammers is suitable for grinding samples, a mortar and pestle can be
used to grind samples of low mass, e.g. less than 60 g. Avoid very fine grinding, as CSN can be adversely
affected with pulverization level. Avoid the use of ring mills as the heat generated during very fine grinding
can potentially oxidise the sample and adversely affect the CSN result. Once the sample is prepared to this
size specifi
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.