ISO 12987:2004

INTERNATIONAL ISO
STANDARD 12987
First edition
2004-07-01
Carbonaceous materials for the
production of aluminium — Anodes,
cathodes blocks, sidewall blocks and
baked ramming pastes — Determination
of the thermal conductivity using a
comparative method
Produits carbonés utilisés pour la production de l'aluminium — Anodes,
cathodes blocs, blocs de façade et pâtes de brasquage cuites —
Détermination de la conductivité thermique à température ambiante par
une méthode comparative
Reference number
©
ISO 2004
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ii ISO 2004 – All rights reserved

Contents Page
1 Scope . 1
2 Terms and definitions . 1
3 Reagents and materials . 2
4 Apparatus . 2
5 Sampling . 2
6 Procedure . 4
7 Calculation . 4
8 Precision . 4
9 Test report . 5
Bibliography . 6
©
ISO 2004 – All rights reserved 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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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 document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 12987 was prepared by Technical Committee ISO/TC 47, Chemistry, Subcommittee SC 7, Aluminium
oxide, cryolite, aluminium fluoride, sodium fluoride, carbonaceous products for the aluminium industry.
©
iv ISO 2004 – All rights reserved

Introduction
Knowledge of the thermal conductivity of carbonaceous materials allows calculations of the heat transfer and
losses in electrolysis cells.
©
ISO 2004 – All rights reserved v

.
vi
INTERNATIONAL STANDARD ISO 12987:2004(E)
Carbonaceous materials for the production of aluminium —
Anodes, cathodes blocks, sidewall blocks and baked ramming
pastes — Determination of the thermal conductivity using a
comparative method
1Scope
This International Standard specifies a method for the determination of thermal conductivity of carbonaceous
◦ ◦
material in the temperature range of 20C6 to 0 C. The typical range of thermal conductivity for these
materials is 2 W/(K·m) to 100 W/(K·m).
This method can be used for other carbon materials, such as graphitized electrodes for other applications.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
thermal conductivity
λ
dQ
material property, expressed in W/(K·m), obtained by determining the heat flow at a given temperature
dt
difference ∆ϑh through a body with height and cross-sectional area A as follows:
dQ 1 h
× × (1)
λ=
dt ∆ϑ A
where
dQ
is the heat flow, expressed in watts;
dt
∆ϑ is the temperature difference, expressed in kelvins;
h is the height, expressed in metres, of the body;
A is the cross-sectional area, expressed in square metres
NOTE 1 For cylindrical test specimens:
d
A =π× (2)
where d is the diameter of the test specimens, expressed in metres
NOTE 2 This temperature difference is compared to those obtained with reference specimens thereby allowing the
determination of the thermal conductivity of the test specimen.
©
ISO 2004 – All rights reserved 1

3 Reagents and materials
3.1 Contact agent, for testing, consisting of Vaseline, glycerol or contact pas
...