ISO 20360:2020

Brown coals and lignites - Determination of the volatile matter in the analysis sample: one furnace method

This document specifies a method of determining the volatile matter of brown coals and lignites by the one furnace method.

Charbons bruns et lignites — Détermination des matières volatiles dans l'échantillon pour analyse : méthode avec utilisation d'un four

General Information

• Status: Published
• Publication Date: 29-Jun-2020
• ICS: 73.040 - Coals
• Technical Committee: ISO/TC 27/SC 5 - Methods of analysis
• Drafting Committee: ISO/TC 27/SC 5/WG 7 - Brown coals and lignites
• Current Stage: 9060 - Close of review
• Completion Date: 02-Dec-2030

Overview

ISO 20360:2020 - "Brown coals and lignites - Determination of the volatile matter in the analysis sample: one furnace method" specifies a standardized laboratory procedure to measure volatile matter in brown coals and lignites. The method determines volatile matter as the mass loss (corrected for moisture) when a prepared analysis sample is heated out of contact with air at 900 °C for a defined time. The one-furnace method is designed for repeatable, reproducible results and aligns with other coal analysis methods.

Key topics and technical requirements

• Test principle: Loss in mass of an analysis sample heated out of contact with air at 900 °C for 7 minutes, corrected for moisture.
• Sample preparation: General analysis sample reduced to nominal top size 212 µm, pressed into cakes (1.0–1.5 cm thick, ≈1.0 cm diameter) and cut into pellets of about 3 mm side length.
• Furnace and temperature control: Electric furnace with a uniform temperature zone at 900 °C ±5 °C; furnace must regain 900 °C ±10 °C within 3 minutes after insertion of cold stand and crucibles.
• Crucible and lid: Glazed porcelain (or equivalent fused silica) crucible/lid with good seal; horizontal clearance between crucible and lid ≤ 0,5 mm. Proper lid fit is critical to exclude air and prevent oxidation.
• Instrumentation:
  • Unsheathed thermocouple positioned midway between crucible base and furnace floor for temperature checks.
  • Analytical balance with resolution ≥ 0,1 mg.
  • Pellet presser capable of >100 kg force (examples in the standard show settings between 200–300 kg).
  • Desiccator with fresh desiccant (magnesium perchlorate or silica gel) - note safety warning for magnesium perchlorate.
• Moisture determination: Conduct duplicate moisture tests concurrently (ISO 5068-2 referenced) so volatile matter can be corrected to dry basis.
• Precision and reporting: The standard includes clauses on repeatability and reproducibility limits and specifies required test report content.

Applications and users

ISO 20360:2020 is used by:

• Analytical laboratories performing routine coal quality testing
• Coal and lignite producers for product specification and quality control
• Power plants and utilities assessing fuel properties for combustion and emissions planning
• Research institutions studying coal behavior and thermal decomposition
• Regulators and procurement teams requiring standardized volatile matter data for contracts and compliance

Practical benefits include consistent volatile matter values for fuel characterization, improved comparability between laboratories, and guidance on sample handling to minimize oxidation.

Related standards

• ISO 5068-2 - moisture determination (analysis sample)
• ISO 13909-4 / ISO 18283 - sampling and preparation of test samples
• ISO 1170 and ISO 1213-2 - calculation bases and terminology
• ISO 5071-1 - related volatile matter measurement methods (results agreement noted)
• ISO 562:2010 - furnace example/figures referenced

Keywords: ISO 20360:2020, volatile matter, brown coals, lignites, one furnace method, coal analysis, crucible, pellet presser, moisture correction.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20360
First edition
2020-06
Brown coals and lignites —
Determination of the volatile matter
in the analysis sample: one furnace
method
Charbons bruns et lignites — Détermination des matières volatiles
dans l'échantillon pour analyse : méthode avec utilisation d'un four
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagent and materials . 2
6 Apparatus . 2
7 Preparation of test sample . 8
7.1 Preparation of the general analysis test sample . 8
7.2 Preparation of the sample pellets . 8
8 Procedure. 8
8.1 Furnace temperature check . 8
8.2 Crucible and lid process . 9
8.3 Volatile matter determination . 9
9 Expression of results . 9
10 Precision .10
10.1 Repeatability limit .10
10.2 Reproducibility limit .10
11 Test report .10
Bibliography .12
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.
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
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see 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.
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.
iv © ISO 2020 – All rights reserved

Introduction
The volatile matter is determined as the loss in mass, corrected for moisture, when an analysis sample
of brown coals or lignites is heated out of contact with air under specified conditions. Due to the nature
of brown coals and lignites, the sample being pressed and cut into small pellets is necessary to minimize
the possibility of ejection of sample from the test crucible when the sample is heated at 900 °C, which
has been demonstrated for its good precision and accuracy, and applied in GB/T 212 for many years.
Results obtained by this method agree with measurements of volatile matter content by ISO 5071-1.
The test of volatile matter is empirical and, in order to obtain reproducible results, it is essential that the
rate of heating, the final temperature and the overall duration of the test are carefully controlled. It is
also essential to exclude air from the coal during heating to prevent oxidation. The fit of the crucible lid
is, therefore, critical. The moisture content of the sample is determined at the same time as the volatile
matter so that the appropriate correction can be made.
To arrive at a valid comparison of volatile matter results conducted in different laboratories, it is
essential that the moisture condition of the test samples in the two laboratories is within the expected
variance of the moisture test. If a sample is re-equilibrated with the laboratory atmosphere or partially
dried in one laboratory and not the other then oxidation can and will most definitely occur for brown
coals and lignites. Oxidation will alter the, as-determined, volatile matter of a test sample.
The dry basis precision for volatile matter includes a variance contribution from the moisture
determination and potentially a covariance component, both of which can influence the precision
statistics for volatile matter on a dry basis.
Mineral matter associated with the sample may also lose mass under the conditions of the test, the
magnitude of the loss being dependent on both the nature and the quantity of the minerals present.
INTERNATIONAL STANDARD ISO 20360:2020(E)
Brown coals and lignites — Determination of the volatile
matter in the analysis sample: one furnace method
1 Scope
This document specifies a method of determining the volatile matter of brown coals and lignites by the
one furnace method.
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 1170, Coal and coke — Calculation of analyses to different bases
ISO 1213-2, Solid mineral fuels — Vocabulary — Part 2: Terms relating to sampling, testing and analysis
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, Hard coal and coke — Manual sampling
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213-2 and the following 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 http:// www .electropedia .org/
3.1
total volatile matter
w
V,T
fractional loss in mass, without correction for moisture, when a solid mineral fuel is heated out of
contact with air under specified conditions
3.2
volatile matter
loss in mass, corrected for moisture, when a solid mineral fuel is heated out of contact with air under
specified conditions
[SOURCE: ISO 1213-2:2016, 3.239]
4 Principle
A portion of the general analysis sample which is pressed and cut into pellets with the side length
of about 3 mm is heated out of contact with air at 900 °C for 7 min. The percentage mass fraction of
volatile matter is calculated from the loss in mass of the test portion after deducting the loss in mass
due to moisture.
5 Reagent and materials
5.1 Desiccant, fresh or freshly regenerated and preferably self-indicating. Suitable desiccants are
magnesium perchlorate and silica gel.
WARNING — Magnesium perchlorate is a strong oxidizing agent. Do not attempt to regenerate
the absorbent. Do not permit contact with organic materials or a reducing agent.
6 Apparatus
6.1 Furnace, heated by electricity, in which a zone of uniform temperature of 900 °C ± 5 °C can be
maintained (see Figure 1, which is the same as the one given in ISO 562:2010, Figure 1).
It may be of the stop-ended type or fitted at the back with a flue approximately 25 mm in diameter and
150 mm in length.
It is important for furnaces with flues that the furnace door seals well. The flue should not reach far out
of the oven and should be fitted with a butterfly valve to restrict airflow through the fu
...