ISO 14428:2019

INTERNATIONAL ISO
STANDARD 14428
Second edition
2019-11
Carbonaceous materials for the
production of aluminium — Cold and
tepid ramming pastes — Expansion/
shrinkage during baking
Produits carbonés utilisés pour la production de l'aluminium —
Pâtes de brasquage froides et tièdes — Expansion/rétrécissement
durant la cuisson
Reference number
©
ISO 2019
© ISO 2019
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and materials. 1
6 Samples . 3
7 Procedure. 3
7.1 Cleaning . 3
7.2 Preparation of vitreous silica materials . 4
7.3 Calibration . 4
7.4 Test procedure . 4
8 Results . 4
8.1 Calculation of the correction term . 4
8.2 Calculation of the expansion/shrinkage . 5
8.2.1 Calculation of expansion or shrinkage for each temperature . 5
8.2.2 Calculation of reference points . 5
8.2.3 Calculation of shrinkage . 5
9 Test report . 7
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 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 226, Materials for the production of
primary aluminium.
This second edition cancels and replaces the first edition (ISO 14428:2005), which has been technically
revised.
The main changes to the previous edition are as follows:
— Clause 8: new calculation concept based on average expansion/shrinkage within newly defined
temperature ranges
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 © ISO 2019 – All rights reserved

Introduction
The expansion/shrinkage of ramming pastes used in the production of aluminium is an important
property, because excessive shrinkage can cause cracks in the baked paste serving as a lining material
in alumina electrolysis cells. These cracks can cause leakage of the liquid bath, destroying the sidewall
lining and the steel shell and thus leading to shutdown of the cell. Ramming pastes change phase from
plastic to non-plastic between 400 °C and 600 °C (200 °C and 300 °C for resin binders). The shrinkage
which occurs between the temperature at which the paste becomes non-plastic and the operating
temperature (950 °C) is an important factor. Apparent shrinkage in the viscous range is due to slumping
rather than actual shrinkage.
INTERNATIONAL STANDARD ISO 14428:2019(E)
Carbonaceous materials for the production of
aluminium — Cold and tepid ramming pastes —
Expansion/shrinkage during baking
1 Scope
This document specifies the determination of expansion/shrinkage during baking of cold and tepid
ramming pastes used in the production of aluminium.
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 14422, Carbonaceous materials used in the production of aluminium — Cold-ramming pastes —
Methods of sampling
ISO 14427, Carbonaceous materials used in the production of aluminium — Cold and tepid ramming
pastes — Preparation of unbaked test specimens and determination of apparent density after compaction
ISO 17034, General requirements for the competence of reference material producers
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
The change in height of a rammed
...