ISO 18806:2019
(Main)Solid mineral fuels — Determination of chlorine content
Solid mineral fuels — Determination of chlorine content
This document specifies two methods (high temperature combustion and high pressure vessel combustion) for the determination of chlorine in solid mineral fuels. It is applicable to solid mineral fuels. The chlorine in the absorption solution can be determined using different finishes, such as coulometric or potentiometric titration, spectrophotometry or ion chromatography. The method is applicable to determine the chlorine content higher than 0,005 % mass fraction.
Combustibles minéraux solides — Dosage de la teneur en chlore
General Information
Relations
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 18806
First edition
2019-09
Solid mineral fuels — Determination
of chlorine content
Combustibles minéraux solides — Dosage de la teneur en chlore
Reference number
ISO 18806:2019(E)
©
ISO 2019
---------------------- Page: 1 ----------------------
ISO 18806:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 18806:2019(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
4.1 Method A — High temperature combustion . 1
4.2 Method B — High pressure vessel combustion . 1
5 Reagents . 2
5.1 Method A . 2
5.2 Method B . 2
6 Apparatus . 2
6.1 Method A . 2
6.2 Method B . 4
7 Test sample . 4
8 Procedure. 4
8.1 Blank value determination . 4
8.2 Method A — High temperature combustion . 4
8.2.1 General. 4
8.2.2 Preparation . 5
8.2.3 Combustion procedure . 5
8.3 Method B — High pressure vessel combustion . 5
8.3.1 Preparation . 5
8.3.2 Combustion procedure . 5
9 Determination of dissolved chloride . 6
10 Calculation and expression of results . 6
11 Precision . 7
11.1 Precision data origin . 7
11.2 Repeatability limit, r . 7
11.3 Reproducibility limit, R . 7
11.4 Quality control . 7
12 Test report . 7
Annex A (normative) Quality control . 9
Annex B (informative) Results of the interlaboratory study (precision data) .10
Bibliography .13
© ISO 2019 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 18806:2019(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
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, Solid mineral fuels, Subcommittee
SC 5, Methods of analysis.
This first edition cancels and replaces ISO/TS 18806:2014, which has been technically revised.
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 2019 – All rights reserved
---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 18806:2019(E)
Solid mineral fuels — Determination of chlorine content
1 Scope
This document specifies two methods (high temperature combustion and high pressure vessel
combustion) for the determination of chlorine in solid mineral fuels. It is applicable to solid mineral fuels.
The chlorine in the absorption solution can be determined using different finishes, such as coulometric
or potentiometric titration, spectrophotometry or ion chromatography.
The method is applicable to determine the chlorine content higher than 0,005 % mass fraction.
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 687, Solid mineral fuels — Coke — Determination of moisture in the general analysis test sample
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 11722, Solid mineral fuels — Hard coal — Determination of moisture in the general analysis test
sample by drying in nitrogen
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213-2 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/
4 Principle
4.1 Method A — High temperature combustion
The sample is combusted in an oxygen atmosphere at high temperature. The gaseous combustion
products collected in a trap filled with water include dissolved chloride compounds.
4.2 Method B — High pressure vessel combustion
The sample is combusted in an oxygen atmosphere in a high pressure vessel containing an absorption
solution. The combustion products collected in an absorption solution include dissolved chloride
compounds.
© ISO 2019 – All rights reserved 1
---------------------- Page: 5 ----------------------
ISO 18806:2019(E)
5 Reagents
5.1 Method A
5.1.1 Oxygen, pure, with an assay of at least 99,5 % volume fraction.
5.1.2 Combustion aid (optional), e.g. spectroscopic carbon, iron phosphate (FePO ), tungsten or quartz.
4
5.1.3 Deionised water, with a specific conductivity not higher than 0,2 mS/m at 25 °C.
5.2 Method B
5.2.1 Oxygen, pure, with an assay of at least 99,5 % volume fraction.
5.2.2 Combustion aid (optional), paraffin, benzoic acid, polyethylene combustion bags, acetobutyrate
capsules or other suitable materials.
5.2.3 Fuse, ignition wire (e.g. platinum) and cotton fuse (optional).
NOTE Check for a possible contribution of the cotton fuse to the chlorine content.
5.2.4 Absorption solution, either eluent used for ion chromatographic determination or alkaline
solution (e.g. 0,2 mol/l KOH or 0,1 mol/l NaOH) or deionised water (5.1.3).
6 Apparatus
6.1 Method A
An example for the equipment for high-temperature combustion is given below. This equipment is
suitable for manual determinations and is well established.
Automated systems with autosamplers can also be used if their main features comply with the manual
apparatus specified below, i.e. mainly temperature of the oven, the use of fused silica glass tubes, and
the absorption unit.
6.1.1 Fused silica combustion tube, absorber and headpiece (see Figure 1).
6.1.2 Porcelain combustion boat, with handle, e.g. 70 mm long, 10 mm wide, and 7 mm deep.
6.1.3 Silica pusher, with iron inlay (see Figure 2).
6.1.4 Magnet.
6.1.5 Electrical tube furnace, about 300 mm long, capable of being heated to preferably 1 300 °C and
maintained at the combustion temperature of (1 250 ± 25) °C.
6.1.6 Flow meter.
6.1.7 Oxygen inlet, consisting of a pierced silicon stopper with a glass tube.
2 © ISO 2019 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 18806:2019(E)
Dimensions in millimetres
Key
1 headpiece 5 VS 13 spherical joint (see ISO 641)
2 sintered glass disc (pore size of 90 µm to 150 µm) 6 oxygen inlet
3 V45/50 conical ground joint (see ISO 383) 7 absorber
4 combustion tube 8 sintered glass disc (pore size of 90 µm to 150 µm)
Figure 1 — Example of an apparatus for Method A
Dimensions in millimetres
Key
1 silica pusher
2 iron inlay
Figure 2 — Example of a silica pusher
© ISO 2019 – All rights reserved 3
---------------------- Page: 7 ----------------------
ISO 18806:2019(E)
6.2 Method B
6.2.1 Digestion unit.
6.2.1.1 Digestion vessel, capable of withstanding safely the pressures developed during combustion
and with an inner surface that is resistant to corrosion by acidic gases formed or emitted during
combustion.
6.2.1.2 Pressure regulator, to control the filling of the vessel with oxygen and discharging afterwards.
6.2.1.3 Pressure gauge, with relief valve operating at 3,5 MPa.
6.2.1.4 Ignition circuit.
6.2.2 Crucible, of silica, nickel-chromium, platinum or similar non-reactive material that is resistant to
corrosion by acidic gases formed or emitted during combustion.
6.2.3 Alternate digestion equipment.
The apparatus employed for determination of calorific value in accordance with ISO 1928 can be used
simultaneously for chlorine determination provided it meets the specifications of 6.2.1. Attention is
drawn to the fact that deionised water should be used as absorption solution.
7 Test sample
The sample used for the determ
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.