ISO 9088:1997

SLOVENSKI STANDARD
01-januar-1998
2JOMLNRYLPDWHULDOL]DSURL]YRGQMRDOXPLQLMD.DWRGQLEORNLLQSUHGSHþHQHDQRGH
'RORþHYDQMHJRVWRWHYNVLOHQXVSLNQRPHWURP
Carbonaceous materials used for the production of aluminium -- Cathode blocks and
prebaked anodes -- Determination of the density in xylene by a pyknometric method
Produits carbonés utilisés pour la production de l'aluminium -- Blocs cathodiques et
anodes précuites -- Détermination par pycnométrie de la masse volumique en xylène
Ta slovenski standard je istoveten z: ISO 9088:1997
ICS:
71.100.10 Materiali za proizvodnjo Materials for aluminium
aluminija production
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL
STANDARD
First edition
1997-03-01
Carbonaceous materials used for the
production of aluminium - Cathode blocks
and prebacked anodes - Determination of
the density in xylene by a pyknometric
method
Produits carbon& utilisks pour la production de I’aluminium - Blocs
cathodiques et anodes prkuites - DGtermination par pycnom6trie de la
masse volumique en xykne
Reference number
IS0 9088: 1997(E)
IS0 9088:1997(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work of
preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
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.
International Standard IS0 9088 was prepared by Technical Committee
ISOnC 47, Chemisty, Subcommittee SC 7, Aluminium oxide, cryolite, a/u-
minium fluoride, sodium fluoride, carbonaceous products for the alu-
minium industry.
0 IS0 1997
All rights reserved. Unless otherwise specified, no part of this publication may be
reproduced or utilized in any form or by any means, electronic or mechanical, including
photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Internet: central@iso.ch
x.400: c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii
INTERNATIONAL STANDARD o Iso IS0 9088:1997(E)
Carbonaceous materials used for the production of aluminium -
Cathode blocks and prebaked anodes - Detemination of the
density in xylene by pyknometric method
1 Scope
This International Standard specifies a pyknometric method for the determination of the true density in xylene of
cathode blocks and prebacked anodes used for the production of aluminium.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain
registers of currently valid International Standards.
IS0 3507: 1976, Pyknometers.
IS0 8007: 1985, Carbonaceous materials used in the production of aluminium - Sampling from cathodic blocks and
prebaked anodes - General.
3 Principle
The true density of cathode blocks and prebaked anodes is measured in xylene in a pyknometer after degassing
under a vacuum.
4 Reagents and materials
During the determination, unless otherwise stated, use only reagents of recognized analytical grade and only
distilled water, or water of equivalent purity, degassed by boiling for 1 h.
4.1 Ethanol, 95 % (V/V).
4.2 Acetone.
4.3 Sulfuric acid, density approx. I,84 g/ml, about 98 % (m/m) solution.
@ IS0
ISO9088:1997(E)
4.4 Xylene, commercial grade, density about 0,86 g/ml.
WARNING - Xylene burns the skin and can also be absorbed into the system through the skin. In addition,
inhalation of the vapour from hot material is to be avoided.
5 Apparatus
5.1 Pyknometer, type 3 as defined in IS0 3507 (Gay-Lussac), capacity 25 ml.
5.2 Degassing apparatus (see figure I), comprising the following items:
52.1 Container (1) for the pyknometer, consisting of a glass beaker (2) with removable lid (3) and O-ring (4),
capable of containing the pyknometer without its stopper. The container outlet (5) is connected to a pump (not
+
shown).
5.2.2 Filling device (6), fitted to the container by a ground-glass joint (7). A tube (8) extends down into the
pyknometer. A reservoir (9) with a ground-glass stopper (10) contains the pyknometer liquid which is allowed to
flow into the pyknometer through a teflon valve (11).
5.2.3
Stand (12), to support the beaker when no vacuum is applied to the degassing apparatus. A rod (13) with a
spring (14) allows the beaker (Z),with the pyknometer in it, to be shaken to facilitate the evolution of a gas bubbles
during degassing.
The apparatus is made of glass. A rotary pump is connected to the outlet of the apparatus via an oil trap (15). A
manometer (16) is connected to the vacuum system between the pump and the oil trap. The vacuum is adjusted
so that the manometer, which is about 600 mm from the joint (7) between the container and the filling device,
registers I,3 kPa + 0,3 kPa. A valve (17) is fitted to allow air back into the apparatus. This has to be done slowly and
with due care.
At a pressure of I,3 kPa + 0,3 kPa and an ambient temperature of 25 OC, slight vapourization of xylene may occur
NOTE -
until equilibrium is reached, but this is of no consequence.
The apparatus described above is only an example; other apparatus with the same characteristics may be used.
5.3 Drying oven, capable of being maintained at 120 “C + 2 “C.
5.4 Thermostatically controlled bath, capable of being maintained at 25 “C k 0,05 OC.
5.5 Grinder, capable of grinding the sample to a particle size of less than 63 pm. The parts which come into
contact with the sample shall be made of hardmetal to avoid contamination.
5.6 Filter paper.
5.7 Jaw-type crusher.
6 Sampling
Sample in accordance with IS0 8007.
IS0 9088:1997(E)
Dimensions in millimetres
Volume 50 ml
Voiume 330 ml
-12
Ground-glass stopper
10)
Container
I)
Teflon valve
11)
Glass beaker
2)
Stand
12)
Lid
3)
Rod
13)
O-ring
4)
Spring
14)
Outlet
5)
Oil trap
15)
Filling device
6)
Manometer
16)
Ground-glass joint
7)
Valve
17)
Tube
8)
Reservoir
9)
Figure 1 - Typical degassing apparatus

@ IS0
IS0 9088:1997(E)
7 Procedure
7.1 General
Carry out all weighings to an accuracy of 0,l mg. When the py
...