ISO 12989-1:2000

INTERNATIONAL ISO
STANDARD 12989-1
First edition
2000-05-01
Carbonaceous materials used in the
production of aluminium — Baked anodes
and sidewall blocks — Determination of the
reactivity to air —
Part 1:
Loss in mass method
Produits carbonés utilisés pour la production de l'aluminium — Anodes et
blocs de façade cuits — Détermination de la réactivité à l'air —
Partie 1: Méthode par perte de masse
Reference number
©
ISO 2000
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ii © ISO 2000 – All rights reserved

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this part of ISO 12989 may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 12989-1 was prepared by Technical Committee ISO/TC 47, Chemistry, Subcommittee
SC 7, Aluminium, cryolite, aluminium fluoride, sodium fluoride, carbonaceous products for the aluminium industry.
ISO 12989 consists of the following parts, under the general title Carbonaceous materials used in the production of
aluminium — Baked anodes and sidewall blocks — Determination of the reactivity to air:
� Part 1: Loss in mass method
The thermogravimetric method will be the subject of a future part 2 to ISO 12989.
Introduction
The combustion of carbonaceous materials in air leads to undesirable losses that should be minimized in many
industrial processes.
The loss of carbonaceous anode material from burning with air is of importance in predicting the behaviour of the
anodes during the aluminium reduction process.
iv © ISO 2000 – All rights reserved

INTERNATIONAL STANDARD ISO 12989-1:2000(E)
Carbonaceous materials used in the production of aluminium —
Baked anodes and sidewall blocks — Determination of the
reactivity to air —
Part 1:
Loss in mass method
1 Scope
This part of ISO 12989 specifies a loss-in-mass method for the determination of the reactivity of carbonaceous
products to air. The method was developed especially for anodes used in the production of aluminium.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO 12989. For dated references, subsequent amendments to, or revisions of, any of these publications
do not apply. However, parties to agreements based on this part of ISO 12989 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain
registers of currently valid International Standards.
ISO 8007-2:1999, Carbonaceous materials used in the production of aluminium — Sampling plans and sampling
from individual units — Part 2: Prebaked anodes.
IEC 60584-2, Thermocouples — Part 2: Tolerances.
3Principle
A cylinder is first heated to 550 °C and then cooled with a gradient of 15 °C/h to (400� 1) °C. Frequent agitation is
necessary so that the carbon dust caused by the selective burning of the binder matrix can be collected outside the
furnace.
Loose particles on the sample are removed using a tumbling-apparatus. The reactivity residue, being the residual
body, and the reactivity loss due to burning are reported.
4 Reagents
4.1 Air, bottled or compressed, containing less than 100 μg/g of free water.
5 Apparatus
An appropriate test-apparatus arrangement is shown in Figure 1.
Normal ordinary apparatus and in particular the following:
5.1 Muffle furnace, having the dimensions given in Figure 2 with a vertical, single-zone tube ensuring good,
vertical temperature distribution and capable of heating to a maximum temperature of at least 700 °C. The tube
shall be made in a refractory steel (austenite) and have an internal diameter of 88,6 mm and a length of 486 mm.
5.2 Sample holder, to support the carbon block in the centre of the furnace with a collection plate incorporated
for catching dust falling from the specimens.
5.3 Cam m
...