ISO 15237:2016

INTERNATIONAL ISO
STANDARD 15237
Second edition
2016-11-15
Solid mineral fuels — Determination
of total mercury content of coal
Combustibles minéraux solides — Dosage du mercure total dans le
charbon
Reference number
ISO 15237:2016(E)
©
ISO 2016

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ISO 15237:2016(E)

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ii © ISO 2016 – All rights reserved

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ISO 15237:2016(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definition . 1
4 Principle . 1
5 Reagents . 1
6 Apparatus . 2
7 Preparation of sample . 3
8 Oxygen bomb combustion procedure . 3
8.1 General . 3
8.2 Combustion of coal . 3
9 Preparation of test solution . 3
10 Atomic absorption analysis . 4
10.1 Calibration . 4
10.2 Analytical procedure . 4
11 Expression of results . 5
12 Precision . 5
12.1 Repeatability limit . 5
12.2 Reproducibility critical difference . 5
13 Test report . 5
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ISO 15237:2016(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.
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described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
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The committee responsible for this document is ISO/TC 27, Solid mineral fuels, Subcommittee SC 5,
Methods of analysis.
This second edition cancels and replaces the first edition (ISO 15237:2003), which has been technically
revised. This document incorporates changes related to dated references and other minor items
following its systematic review.
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ISO 15237:2016(E)

Introduction
Mercury occurs naturally in coal. It is an element that can be released during the combustion process.
The determination of the total mercury content of coal cannot be accomplished satisfactorily by
traditional ashing and digestion procedures because of the volatility of the element.
Quantitive recovery can be achieved by strict adherence to the procedure set out in this document.
Instrumental methods for a more rapid determination of total mercury content are available. If such a
method is to be used, it is important to demonstrate that the method is free from bias, when compared
with this reference method and will give levels of repeatability and reproducibility which are the same,
or better than, those quoted for the reference method (see Clause 10).
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INTERNATIONAL STANDARD ISO 15237:2016(E)
Solid mineral fuels — Determination of total mercury
content of coal
1 Scope
This document specifies a procedure for the determination of the total mercury content of coal.
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 1928, Solid mineral fuels — Determination of gross calorific value by the bomb calorimetric method
and calculation of net calorific value
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 5068-2, Brown coals and lignites — Determination of moisture content — Part 2: Indirect gravimetric
method for moisture in the analysis sample
ISO 5069-2, Brown coals and lignites — Principles of sampling — Part 2: Sample preparation for
determination of moisture content and for general analysis
ISO 13909-4, Hard coal and coke — Mechanical sampling — Part 4: Coal — Preparation of test samples
3 Terms and definition
No terms and definitions are defined in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
4 Principle
The sample is burned in an oxygen bomb, the mercury species formed during combustion being
absorbed in water. The mercury species present in the water are reduced by stannous chloride and
quantified by flameless cold vapour atomic absorption spectroscopy.
It is reported that lithium borohydride (LiBH ) and sodium borohydride (NaBH ) are satisfactory for
4 4
the reduction instead of stannous chloride; laboratories using these reductants should demonstrate
that the performance is equivalent to that using stannous chloride.
5 Reagents
WARNING — Care should b
...