ISO 924:2024

International
Standard
ISO 924
Third edition
Coal preparation plant — Principles
2024-08
and conventions for flowsheets
Ateliers de préparation du charbon — Principes et conventions
relatifs aux schémas de traitement
Reference number
© ISO 2024
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
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Types of basic flowsheet . 1
5 Grouping of operations and products. 1
6 Conventions for use on flowsheets . 2

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 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).
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.
This third edition cancels and replaces the second edition (ISO 924:1989), of which it constitutes a minor
revision.
The main changes are as follows:
— changes to update other nominated standards in the text;
— minor changes to some units and ISO normal set up;
— the list of informative terms in Clause 3 were deleted.
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
Introduction
At various stages in the design of a complete plant, it is necessary to illustrate by flowsheets the process
steps covering the operations to which the raw coal will be subjected in the preparation plant. In order that
these may be more readily and universally understood, it is desirable that flowsheets should conform to a
standard pattern and that various conventions should be well understood and adopted.

v
International Standard ISO 924:2024(en)
Coal preparation plant — Principles and conventions for
flowsheets
1 Scope
This document sets out principles and conventions for use in the preparation of basic process and equipment
flowsheets for the design of a coal preparation plant.
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 561, Coal preparation plant — Graphical symbols
ISO 1213-1, Solid mineral fuels — Vocabulary — Part 1:Terms relating to coal preparation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213-1 and the symbols in
ISO 561 apply.
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 Types of basic flowsheet
In order to cover the various stages leading to the final design of a plant, two basic flowsheets are needed,
one based on the process and the ot
...