ISO 5072:2021

INTERNATIONAL ISO
STANDARD 5072
Third edition
2021-12
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
Reference number
ISO 5072:2021(E)
© ISO 2021

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ISO 5072:2021(E)
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© ISO 2021
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ISO 5072:2021(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Determination of the true relative density by the water method . 1
4.1 Principle . 1
4.2 Reagents . 2
4.3 Apparatus . 2
4.4 Sample . 2
4.5 Procedure . 3
4.5.1 Calibration of the mass of the pycnometer(s) . 3
4.5.2 Determination of true relative density . 3
4.6 Calculation of results . 3
4.7 Precision . . . 4
4.7.1 Repeatability limit . 4
4.7.2 Reproducibility limit . 4
4.8 Test report . 4
5 Determination of the apparent relative density . 4
5.1 Principle . 4
5.2 Reagents . 5
5.3 Apparatus . 5
5.4 Sample . 5
5.5 Procedure . 5
5.6 Calculation of results . 7
5.7 Precision . . . 7
5.7.1 Repeatability limit . 7
5.7.2 Reproducibility limit . 7
5.8 Test report . 7
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ISO 5072:2021(E)
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
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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
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 27, Coal and Coke, Subcommittee SC 5,
Methods of analysis.
This third edition cancels and replaces the second edition (ISO 5072:2013), of which it constitutes a
minor revision. The changes compared to the previous edition are as follows:
— referenced documents have been updated;
— terms and definitions have been added;
— sample has been added;
— calculation and expression of results have been amended;
— precision has been amended;
— test report has been amended.
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
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INTERNATIONAL STANDARD ISO 5072:2021(E)
Brown coals and lignites — Determination of true relative
density and apparent relative density
1 Scope
This document describes methods for the determination of true relative density and the apparent
relative density of brown coals and lignites.
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 5068-1, Brown coals and lignites — Determination of moisture content — Part 1: Indirect gravimetric
method for total moisture
ISO 5068-2, Brown coals and lignites — Determination of moisture content — Part 2: Indirect gravimetric
method for moisture in the analysis sample
ISO 13909-4, Hard coal and coke — Mechanical sampling — Part 4: Coal — Preparation of test samples
ISO 18283, Coal and coke — Manual sampling
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
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 https:// www .electropedia .org/
3.1
true relative density
ratio of the mass of a sample of dry coal ground to pass through a 212 μm 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.
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ISO 5072:2021(E)
4.2 Reagents
4.2.1 Distilled or deionized water, freshly boiled.
4.2.2 Wetting agent, 5
...