ISO 5072:1997

SLOVENSKI STANDARD
SIST ISO 5072:1998
01-februar-1998
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Brown coals and lignites -- Determination of true relative density and apparent relative
density
Charbons bruns et lignites -- Détermination de la densité relative vraie et de la densité
relative apparente
Ta slovenski standard je istoveten z: ISO 5072:1997
ICS:
73.040 Premogi Coals
SIST ISO 5072:1998 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 5072:1998

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SIST ISO 5072:1998
IS0
INTERNATIONAL
5072
STANDARD
First edition
1997-07-01
Brown coals and lignites - Determination
of true relative density and apparent
relative density
Charbons bruns et /ignites - Dktermination de /a densit relative vraie et
de la densit relative apparente
Reference number
IS0 5072: 1997(E)

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SIST ISO 5072:1998
IS0 5072: 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 5072 was prepared by Technical Committee
ISOnC 27, So/id mineral fuels, Subcommittee SC 5, Methods of analysis.
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 @ isoch
x.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii

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SIST ISO 5072:1998
INTERNATIONAL STANDARD o Is0 IS0 5072: 1997(E)
Brown coals and lignites - Determination of true relative density
and apparent relative density
1 Scope
This International Standard describes methods for the determination of true relative density and the apparent
relative density of brown coals and Iignites.
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 1015: 1992, Brown coals and /ignites - Determination of moisture content - Direct volumetric method.
IS0 5068:1983, Brown coals and /ignites - Determination of moisture - Indirect gra vime tric method.
IS0 506921983, Brown coals and /ignites - Principles of sampling - Par? 2 . Sample preparation for
determination of moisture content and for general analysis.
3 Definitions
3.1 True relative density: Ratio of the mass of a sample of dry coal ground to pass through a 212 pm sieve to the
mass of an equal volume of water at a specified temperature.
3.2 Apparent relative density: Ratio of the mass of a dry coal to the mass of a volume of water equal to the
apparent volume of the coal at a specified temperature.
4 Determination of the true relative density by the water method
4.1 Principle
The true relative density is determined pycnometrically by water displacement, with the inclusion of a wetting agent
to ensure dispersion of the solid in the displacement medium.
NOTE - The use of other displacement media such as methanol is not recommended because of possible swelling of SOme
brown coals and lignites in such liquids.
4.2 Reagents
4.2.1 Distilled or deionized water, freshly boiled.

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SIST ISO 5072:1998
@ IS0
IS0 5072: 1997(E)
4.2.2 Wetting agent, 5 % (V/V) solution of detergent (such as sodium dodecyl sulfate) is suitable.
4.2.3 Potassium dichromate-sulfuric acid mixture, for cleaning pycnometers.
4.3 Apparatus
4.3.1 Analytical balance, sensitive to 0,l mg.
4.3.2 Camel hair brush, of such a diameter that bristles can pass completely through the stem of the funnel
(4.3.4).
4.3.3 Filter paper, for drying the necks of the pycnometers.
4.3.4 Funnel, with a stem of sufficient length to reach the middle of the pycnometer flask.
Glass cloth, fibre free for polishing the pycnometers prior to weighing.
4.3.5
4.3.6 Glass syringe, with a needle to bring the pycnometer liquid to the mark of the pycnometer.
Earthing point, to remove static charge from pycnometers.
4.3.7
4.3.8 Mercury thermometer, capable of measuring the temperature in the range of 20 “C to 30 “C with a
minimum scale spacing of 0,l “C.
4.39 Pycnometers, of capacity 50 ml with capillary-bored ground stoppers, internal diameter of the neck no
greater than 5 mm.
4.3.10 Vacuum desiccator, with protective cage.
NOTE - The use of vacuum desiccator is preferable for the purpose of degassing samples.
4.3.11 Vacuum pump, capable of attaining a vacuum of residual pressure from 0 kPa to 5 kPa.
4.3.12 Water bath, thermostatically controlled, the temperature of which shall be maintained at 25 OC + 0,l OC as
measured by a thermometer (4.3.8) permanently placed in the water bath.
4.3.13 Weighing boat, with a capacity of not less than 2 g.
4.4 Sample
The sample for the determination of true relative density shall be the general analysis sample (ground to pass
through a 212 pm sieve) prepared in accordance with IS0 5068-2.
4.5 Procedure
4.5.1 Calibration of the mass of the pycnometer(s)
Pipette 10 ml of wetting agent into the pycnometer(s) (4.3.9). Pipette 10 ml of water (4.2.1) into the pycnometer(s).
Swirl to mix the solution. Place the pycnometer(s) in the vacuum desiccator (4.3.10) and evacuate to 0 Pa to 500 Pa
for 15 min. Release the vacuum and fill the pycnometer(s) with water (4.2.1) using a glass syringe (4.3.6) to 3 mm
from the top of the neck.
2

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SIST ISO 5072:1998
@ IS0
IS0 5072: 1997(E)
Place the pycnometer(s) in a water bath (4.3.12) thermostatically controlled at 25 OC + 0,l “C. Allow to equilibrate
for at least 1 h 45 min. Top up the pycnometer(s) to the meniscus using a glass syringe without removing them from
the water bath. Leave the pycnometer(s) in the water bath for a further 5 min.
Remove the pycnometer(s) from the water bath and insert the capillary-bored stopper(s) such that no air is trapped
in the pyc
...