SIST EN ISO 21646:2022
(Main)Solid recovered fuels - Sample preparation (ISO 21646:2022)
Solid recovered fuels - Sample preparation (ISO 21646:2022)
This document specifies methods for reducing combined samples to laboratory samples and laboratory samples to sub-samples and general analysis samples. The methods described in this document may be used for sample preparation, for example, when the samples are to be tested for bulk density, biomass determination, durability, particle size distribution, moisture content, ash content, ash melting behaviour, calorific value, chemical composition, and impurities. The methods are not intended to be applied to the very large samples required for the testing of bridging properties.
Feste Sekundärbrennstoffe - Probenvorbereitung (ISO 21646:2022)
Dieses Dokument legt Verfahren zur Probenvorbereitung fest, um die Repräsentativität der Proben über den gesamten Vorbereitungsprozess zur Herstellung allgemeiner Analysenproben hinweg sicherzustellen. Den Laboratoriumsproben oder allgemeinen Analysenproben können geeignete Prüfmengen entnommen werden, die für die Analyse nach den spezifischen Anforderungen der entsprechenden Analyseverfahren verwendet werden.
Dieses Dokument legt die Abfolge der richtigen Probenvorbereitung fest, die anzuwenden ist:
a) auf die Mischprobe, um eine Laboratoriumsprobe herzustellen (unter Berücksichtigung großer Stücke von festen Sekundärbrennstoffen);
b) für jeden Teilprobenahmeschritt im gesamten Prüfprogramm;
c) auf die Laboratoriumsprobe, um geeignete Prüfmengen zu erhalten;
d) um die Repräsentativität der Prüfmengen sicherzustellen, die nach dem Plan zur Probenvorbereitung vor der physikalischen Analyse, chemischen Analyse oder beiden entnommen wurden (z. B. Extrahierungen, Aufschluss, analytische Bestimmungen).
Die in diesem Dokument festgelegten Verfahren können bei der Probenvorbereitung angewendet werden, wenn an den Proben z. B. Prüfungen zur Bestimmung der Schüttdichte, des Biomassenanteils, der mechanischen Festigkeit, der Partikelgrößenverteilung, des Wassergehaltes, des Aschegehaltes, des Ascheschmelzverhaltens, des Energieinhaltes, der chemischen Zusammensetzung, von Verunreinigungen und der Eigenerwärmungseigenschaften durchzuführen sind. Die Verfahren sind nicht dafür vorgesehen, auf sehr große Proben angewendet zu werden, die zur Prüfung der Neigung zur Brückenbildung erforderlich sind.
Combustibles solides de récupération - Préparation des échantillons (ISO 21646:2022)
Le présent document spécifie des méthodes de préparation d'échantillon pour garantir la représentativité des échantillons pendant tous les modes opératoires de préparation afin de produire des échantillons pour analyse générale. Des prises d'essai adaptées peuvent être prélevées sur des échantillons de laboratoire ou ceux pour analyse générale, et utilisées pour analyses conformément aux exigences spécifiques définies dans les modes opératoires analytiques correspondants.
Le présent document spécifie la séquence correcte de préparation d'échantillon à appliquer:
a) à l'échantillon composite afin de produire un échantillon de laboratoire (en prenant en compte de morceaux de grande taille de combustible solide de récupération);
b) à chaque étape de sous-échantillonnage pendant tout le programme d'essais;
c) à l'échantillon de laboratoire afin d'obtenir des prises d'essai adaptées;
d) pour garantir la représentativité des prises d'essai qui ont été prélevées conformément au plan de préparation d'échantillon, avant une analyse physique, une analyse chimique, ou les deux (par exemple, extractions, digestion, déterminations analytiques).
Les méthodes spécifiées dans le présent document peuvent être utilisées pour la préparation d'échantillon, par exemple lorsque les échantillons doivent être soumis à des essais pour évaluer la masse volumique apparente, la teneur en biomasse, la résistance mécanique, la distribution granulométrique, la teneur en humidité, la teneur en cendres, le comportement de fusion des cendres, le pouvoir calorifique, la composition chimique, les impuretés et les propriétés d'autoéchauffement. Ces méthodes ne sont pas destinées à être appliquées aux échantillons très importants requis pour les essais de propriétés de pontage.
Trdna alternativna goriva - Priprava vzorca (ISO 21646:2022)
Ta dokument določa metode za zmanjšanje kombiniranih vzorcev na laboratorijske vzorce in laboratorijskih vzorcev na podvzorce ter splošne analizne vzorce. Metode, ki so opisane v tem dokumentu, se lahko uporabijo za pripravo vzorcev, ko potrebno preskusiti na primer masno gostoto, določanje biomase, odpornost, porazdelitev velikosti delcev, vsebnost vlage, vsebnost pepela, lastnosti pepela pri taljenju, kalorično vrednost, kemično sestavo in nečistoče. Te metode niso namenjene za uporabo pri zelo velikih vzorcih, ki so potrebni za preskušanje premostitvenih lastnosti.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 21646:2022
01-julij-2022
Nadomešča:
SIST EN 15413:2011
SIST EN 15443:2011
Trdna alternativna goriva - Priprava vzorca (ISO 21646:2022)
Solid recovered fuels - Sample preparation (ISO 21646:2022)
Feste Sekundärbrennstoffe - Probenvorbereitung (ISO 21646:2022)
Combustibles solides de récupération - Préparation des échantillons (ISO 21646:2022)
Ta slovenski standard je istoveten z: EN ISO 21646:2022
ICS:
75.160.10 Trda goriva Solid fuels
SIST EN ISO 21646:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 21646:2022
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SIST EN ISO 21646:2022
EN ISO 21646
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2022
EUROPÄISCHE NORM
ICS 75.160.10 Supersedes EN 15443:2011, EN 15413:2011
English Version
Solid recovered fuels - Sample preparation (ISO
21646:2022)
Combustibles solides de récupération - Préparation des Feste Sekundärbrennstoffe - Probenvorbereitung (ISO
échantillons (ISO 21646:2022) 21646:2022)
This European Standard was approved by CEN on 25 March 2022.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21646:2022 E
worldwide for CEN national Members.
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SIST EN ISO 21646:2022
EN ISO 21646:2022 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 21646:2022
EN ISO 21646:2022 (E)
European foreword
This document (EN ISO 21646:2022) has been prepared by Technical Committee ISO/TC 300 "Solid
recovered materials, including solid recovered fuels" in collaboration with Technical Committee
CEN/TC 343 “Solid recovered materials, including solid recovered fuels” the secretariat of which is held
by SFS.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2022, and conflicting national standards
shall be withdrawn at the latest by November 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 15443:2011 and EN 15413:2011.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 21646:2022 has been approved by CEN as EN ISO 21646:2022 without any modification.
3
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SIST EN ISO 21646:2022
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SIST EN ISO 21646:2022
INTERNATIONAL ISO
STANDARD 21646
First edition
2022-05
Solid recovered fuels — Sample
preparation
Combustibles solides de récupération — Préparation des échantillons
Reference number
ISO 21646:2022(E)
© ISO 2022
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SIST EN ISO 21646:2022
ISO 21646:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
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
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
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SIST EN ISO 21646:2022
ISO 21646:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Safety remarks . 4
6 Principles of correct sample preparation . 4
7 Quality control and sources of error .6
8 Apparatus . 7
8.1 Selection of equipment . 7
8.2 Apparatus for sample division . 8
8.2.1 Scoops and shovels (sampling tools) . 8
8.2.2 Riffle boxes . 9
8.2.3 Rotary sample dividers . 10
8.3 Apparatus for particle size reduction . 11
8.3.1 Shredder . 11
8.3.2 Coarse cutting mill . 11
8.3.3 Cutting mill . 11
8.4 Sieves . 11
8.5 Balance . 11
9 Sample preparation procedure .12
9.1 General .12
9.2 Step 1: Collecting the relevant information of the material for sample preparation .12
9.3 Step 2: Making a sample preparation plan .12
9.3.1 General .12
9.3.2 Sample division . . .12
9.3.3 Particle size reduction of a sample .12
9.3.4 Retaining the minimum (sub-)sample mass . 15
9.4 Step 3: Performing the sample preparation plan . 16
10 Methods for homogenization and sample division .16
10.1 General . 16
10.2 Homogenization. 16
10.3 Sample division methods . 16
10.3.1 General . 16
10.3.2 Riffling . 16
10.3.3 Strip division . . 17
10.3.4 Long strip . 18
10.3.5 Manual increment division . 18
10.3.6 Rotary sample divider . 19
10.3.7 Fractional shovelling . 19
10.3.8 Quartering . 20
11 Methods for mass and particle size reduction of laboratory samples and general
analysis samples .21
11.1 General . 21
11.2 Initial sample division . 21
11.3 Initial mass determination . 21
11.4 Pre-drying . 21
11.5 Particle size reduction to < 30 mm. 22
11.6 Sample division of < 30 mm material . 23
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SIST EN ISO 21646:2022
ISO 21646:2022(E)
11.7 Particle size reduction of < 30 mm material to < 1 mm . 23
11.8 Sample division of < 1 mm material . 24
11.9 Particle size reduction of < 1 mm material to < 0,25 mm . 24
12 Handling considerations of the general analysis sample and the test portion .25
12.1 Key concepts . 25
12.2 Sequence of preparation procedures . 26
13 Storage, preservation and labelling of samples .26
14 Sample preparation report .26
15 Precision .27
Annex A (normative) Determination of the shape factor .28
Annex B (normative) Determination of the changing shape factor .29
Annex C (informative) Examples of sample preparation procedures .31
Annex D (normative) Guidelines for choosing sample preparation procedures .35
Annex E (informative) Relationship between minimum amount of sample and particle
size – Formula for the estimation of the minimum amount of sample . 44
Annex F (normative) Sample preparation equipment .47
Annex G (normative) Characteristics of the laboratory sample for chemical analysis of solid
recovered fuel .48
Annex H (informative) Data on the precision of sample preparation .50
Annex I (informative) Results of ruggedness testing .53
Bibliography .61
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SIST EN ISO 21646:2022
ISO 21646:2022(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 300, Solid recovered materials, including
solid recovered fuels, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 343, Solid recovered materials, including solid recovered fuels, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
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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SIST EN ISO 21646:2022
ISO 21646:2022(E)
Introduction
Solid recovered fuels are a major source of renewable energy. International Standards facilitate
the production, trade and use of solid recovered fuels. For sampling and sample preparation of solid
recovered fuels, ISO 21645 and this document, respectively, can be used (in conjunction) by different
types of organizations, including but not limited to:
— solid recovered fuel production and trading companies;
— energy companies;
— regulatory bodies;
— conformity assessment bodies;
— laboratories.
The sample preparation technique adopted depends on a combination of different characteristics of the
material and circumstances encountered at the sampling location. The determining factors are:
— the type of solid recovered fuel;
— the physical behaviour of the specific solid recovered fuel;
— the (expected) degree of heterogeneity (e.g. monostreams, mixed fuels, blended fuels).
In laboratory practice, different analytical procedures often need to be applied to the laboratory
sample that has been taken according to the sampling plan. For this purpose, sub-sampling is applied
in a way that the different test portions are representative of the laboratory sample with respect to the
compounds of interest and the specific analytical procedures. The representativeness of the laboratory
sample and of the test portions is of major importance to guarantee the quality and accuracy of
analytical results. The representativeness of the laboratory sample is specified by the sampling plan.
This document is largely based on the work done by CEN/TC 343, Solid recovered fuels, and CEN/
TC 292, Characterization of waste (now integrated in CEN/TC 444, Environmental characterization of
solid matrices), and in particular EN 15002, which was developed for the majority of waste samples.
Most of its concepts and specifications are also applicable to solid recovered fuel samples. However,
the foundations of EN 15002 are not completely applicable to solid recovered fuel, as the nature of this
material is substantially different and can lead to misrepresentation of the fuel quality.
The main characteristic that makes solid recovered fuel samples significantly different from other
kinds of waste is that very often solid recovered fuels are solid, but neither ‘granular’ nor monolithic.
It often happens that solid recovered fuel samples are fibrous-like materials, so that the statistical
formula for sampling as defined in EN 15002 is not applicable. One additional term in the statistical
formula is needed, namely the ‘shape factor’ ( f ).
This document is part of the testing programme for solid recovered fuels. This programme consists of
various steps leading to the analysis sample for fuel quality testing as outlined in Figure 1.
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SIST EN ISO 21646:2022
ISO 21646:2022(E)
a
ISO 21645:2021, B.2, steps 5) and 6).
Figure 1 — Links between the essential elements of a testing programme
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SIST EN ISO 21646:2022
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SIST EN ISO 21646:2022
INTERNATIONAL STANDARD ISO 21646:2022(E)
Solid recovered fuels — Sample preparation
1 Scope
This document specifies methods for sample preparation to ensure representativeness of the samples
throughout the preparation procedures to produce general analysis samples. Suitable test portions can
be taken from the laboratory or general analysis samples and used for analysis according to the specific
requirements defined in the corresponding analytical procedures.
This document specifies the correct sample preparation sequence to be applied to:
a) the composite sample, in order to produce a laboratory sample (taking into account large pieces of
solid recovered fuel);
b) each sub-sampling step throughout the testing programme;
c) the laboratory sample, in order to obtain suitable test portions;
d) ensure the representativeness of the test portions that have been taken according to the sample
preparation plan, prior to physical analysis, chemical analysis or both (e.g. extractions, digestion,
analytical determinations).
The methods specified in this document can be used for sample preparation, for example, when the
samples are to be tested for bulk density, biomass content determination, mechanical durability,
particle size distribution, moisture content, ash content, ash melting behaviour, calorific value, chemical
composition, impurities and self-heating properties. The methods are not intended to be applied to the
very large samples required for the testing of bridging properties.
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 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
ISO 3310-2, Test sieves — Technical requirements and testing — Part 2: Test sieves of perforated metal
plate
ISO 21637:2020, Solid recovered fuels — Vocabulary
ISO 21660-3, Solid recovered fuels — Determination of moisture content using the oven dry method — Part
3: Moisture in general analysis sample
CEN/TS 15414-1, Solid recovered fuels —Determination of moisture content using the oven dry method —
Part 1: Determination of total moisture by a reference method
CEN/TS 15414-2, Solid recovered fuels — Determination of moisture content using the oven dry method —
Part 2: Determination of total moisture by a simplified method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21637 and the following apply.
1
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SIST EN ISO 21646:2022
ISO 21646:2022(E)
ISO and IEC maintain terminology 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
composite sample
sample (3.12) consisting of all the increments (3.6) taken from a lot (3.8) or a sub-lot
Note 1 to entry: The increments can be reduced by division before being added to the composite sample.
Note 2 to entry: The minimum sample mass shall be retained during the collection of increments to form the
composite sample.
3.2
drying
process of removing water from a sample (3.12)
Note 1 to entry: For the purpose of test portion (3.16) preparation, it can be useful to remove just the amount
of water that can possibly interfere with other processes involved (e.g. during crushing or milling). In order
to minimize the alteration of the sample during test portion preparation, removing the total amount of water
present in the sample is not necessarily needed.
[SOURCE: ISO 21637:2020, 3.19, modified — “solid fuel” was replaced with “sample” in Note 1 to entry.]
3.3
fraction separation
process of dividing components, particles or layers if homogenization (3.5) of the sample (3.12) is
practically not applicable and/or the analyses of different fractions or phases are appropriate
[SOURCE: ISO 21637:2020, 3.32]
3.4
general analysis sample
sub-sample (3.14) of a laboratory sample (3.7) having a nominal top size (3.10) of 1 mm or less and used
for a number of chemical and physical analyses
3.5
homogenization
process of combining of increments (3.16) making up a combined sample, components, particles or
layers into a more homogeneous state than in the samples (in the case of composite samples) or pre-
treated fractions of samples in order to ensure equal distribution of substances in and properties of the
sample (3.12)
3.6
increment
portion of solid recovered fuel extracted from a lot (3.8) or sub-lot in a single operation of the sampling
device
[SOURCE: ISO 21637:2020, 3.39]
3.7
laboratory sample
composite sample (3.1) received by the laboratory on which sample (3.12) preparation procedures are
undertaken
Note 1 to entry: When the laboratory sample is further prepared (reduced) by subdividing,
...
SLOVENSKI STANDARD
oSIST prEN ISO 21646:2021
01-marec-2021
Trdna alternativna goriva - Priprava vzorca (ISO/DIS 21646:2020)
Solid recovered fuels - Sample preparation (ISO/DIS 21646:2020)
Feste Sekundärbrennstoffe - Probenvorbereitung (ISO/DIS 21646:2020)
Combustibles solides de récupération - Préparation des échantillons (ISO/DIS
21646:2020)
Ta slovenski standard je istoveten z: prEN ISO 21646
ICS:
75.160.10 Trda goriva Solid fuels
oSIST prEN ISO 21646:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO 21646:2021
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oSIST prEN ISO 21646:2021
DRAFT INTERNATIONAL STANDARD
ISO/DIS 21646
ISO/TC 300 Secretariat: SFS
Voting begins on: Voting terminates on:
2021-01-04 2021-03-29
Solid recovered fuels — Sample preparation
Combustibles solides de récupération — Préparation des échantillons
ICS: 75.160.10
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 21646:2021(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2021
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oSIST prEN ISO 21646:2021
ISO/DIS 21646:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
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
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
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oSIST prEN ISO 21646:2021
ISO/DIS 21646:2021(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Safety remarks . 4
6 Principles of correct sample preparation . 4
7 Quality control and sources of error . 7
8 Apparatus . 8
8.1 Selection of equipment . 8
8.2 Apparatus for sample division. 8
8.2.1 Shovels and scoops (sampling tools) . 8
8.2.2 Riffle boxes . 9
8.2.3 Rotary sample dividers . 9
8.3 Apparatus for particle size reduction .10
8.3.1 Shredder .10
8.3.2 Coarse cutting mill or wood crusher .10
8.3.3 Cutting mill .10
8.4 Sieves .11
9 Sample preparation procedure .11
9.1 General .11
9.2 Step 1: Collection of the relevant information of the material for sample preparation .11
9.3 Step 2: Making a sample preparation plan .11
9.3.1 General.11
9.3.2 Sample division .12
9.3.3 Particle size reduction of a sample.12
9.3.4 Retaining the minimum (sub-)sample mass .14
9.4 Step 3: Performing the sample preparation plan .14
10 Methods for homogenization and sample division .15
10.1 General .15
10.2 Homogenization .15
10.3 Sample division methods .15
10.3.1 General.15
10.3.2 Riffling .15
10.3.3 Strip division .15
10.3.4 Long pile .16
10.3.5 Manual increment division .17
10.3.6 Rotary sample divider .17
10.3.7 Fractional shovelling .17
10.3.8 Quartering .18
11 Methods for mass and particle size reduction of laboratory samples and general
analysis samples .19
11.1 General .19
11.2 Initial sample division .19
11.3 Initial mass determination .19
11.4 Pre-drying .19
11.5 Coarse cutting (particle size reduction to < 30 mm) .20
11.6 Sample division of < 30 mm material .21
11.7 Particle size reduction of < 30 mm material to < 1 mm .21
© ISO 2021 – All rights reserved iii
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oSIST prEN ISO 21646:2021
ISO/DIS 21646:2021(E)
11.8 Sample division of < 1 mm material .22
11.9 Particle size reduction of < 1 mm material to < 0,25 mm .22
12 Handling considerations of the general analysis sample and the test portion .23
12.1 Key concepts .23
12.2 Sequence of preparation procedures.24
13 Storage, preservation and labelling of samples .24
14 Sample preparation report .24
15 Precision .25
Annex A (normative) Determination of the shape factor.26
Annex B (normative) Determination of the changing shape factor .27
Annex C (informative) Examples of sample preparation procedures .29
Annex D (normative) Guidelines for choosing sample preparation procedures .34
Annex E (informative) Relationship between minimum amount of sample and particle
size – Formula for the estimation of the minimum amount of sample .43
Annex F (normative) Sample preparation equipment .46
Annex G (normative) Characteristics of the laboratory sample for chemical analysis of solid
recovered fuel .47
Annex H (informative) Data on the precision of sample preparation .48
Annex I (informative) Results of ruggedness testing .51
Bibliography .60
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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 300, Solid recovered fuels.
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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Introduction
Solid recovered fuels (SRF's) are a major source of renewable energy. International Standards facilitate
the production, trade and use of solid recovered fuels. For sampling and sample preparation of solid
recovered fuels, ISO 21645 and this document, respectively, can be used (in conjunction) by different
types of organizations, including but not limited to:
— solid recovered fuel production and trading companies;
— energy companies;
— regulatory bodies;
— conformity assessment bodies;
— laboratories.
The sample preparation technique adopted depends on a combination of different characteristics of the
material and circumstances encountered at the sampling location. The determining factors are:
— the type of solid recovered fuel;
— the physical behaviour of the specific solid recovered fuel;
— the (expected) degree of heterogeneity (e.g. monostreams, mixed fuels, blended fuels).
In laboratory practise, different analytical procedures often need to be applied to the laboratory
sample that has been taken according to the sampling plan. For this purpose, sub-sampling is applied
in a way that the different test portions are representative of the laboratory sample with respect to the
compounds of interest and the specific analytical procedures. The representativeness of the laboratory
sample and of the test portions is of major importance to guarantee the quality and accuracy of
analytical results. The representativeness of the laboratory sample is specified by the sampling plan.
This document is largely based on the work done by CEN/TC 343 "Solid recovered fuels" and CEN/
TC 292 "Characterization of waste" (now integrated in CEN/TC 444 “Environmental characterization
of solid matrices”), and in particular EN 15002:2015 which was developed for the majority of waste
samples. Most of its concepts and specifications are also applicable to solid recovered fuel samples.
However, the foundations of EN 15002 are not completely applicable to solid recovered fuel as the
nature of this material is substantially different and can lead to misrepresentation of the fuel quality.
The main characteristic that makes solid recovered fuel samples significantly different from other kinds
of waste is that very often solid recovered fuels are solid, but neither ‘granular’ nor monolithic. It often
happens that solid recovered fuel samples are fibrous-like materials, so that the statistical formula for
sampling as defined in EN 15002:2015 is not applicable. One additional term in the statistical formula is
needed, namely the ‘shape factor’ ( f ).
This document is part of the testing program for solid recovered fuels. This program consists of various
steps leading to the analysis sample for fuel quality testing as outlined in Figure 1.
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Figure 1 — Links between the essential elements of a testing program
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DRAFT INTERNATIONAL STANDARD ISO/DIS 21646:2021(E)
Solid recovered fuels — Sample preparation
1 Scope
This document specifies methods for sample preparation to ensure representativeness of the samples
throughout the preparation procedures to produce general analysis samples. Suitable test portions can
be taken from the laboratory or general analysis samples and used for analysis in conformance with the
specific requirements defined in the corresponding analytical procedures.
This document specifies the correct sample preparation sequence to be applied to:
a) the field sample in order to produce a laboratory sample (taking into account large pieces of solid
recovered fuel);
b) each sub-sampling step throughout the testing program;
c) the laboratory sample in order to obtain suitable test portions;
d) ensure the representativeness of the test portions that have been taken according to the sample
preparation plan, prior to physical and/or chemical analysis (e.g. extractions, digestion and/or
analytical determinations).
The methods described in this document can be used for sample preparation, for example, when the
samples are to be tested for bulk density, biomass content determination, mechanical durability,
particle size distribution, moisture content, ash content, ash melting behaviour, calorific value, chemical
composition, impurities and self-heating properties. The methods are not intended to be applied to the
very large samples required for the testing of bridging properties.
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 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
ISO 3310-2, Test sieves — Technical requirements and testing — Part 2: Test sieves of perforated metal plate
ISO 21637:2020, Solid recovered fuels — Vocabulary
1)
ISO 21660-3:— , Solid recovered fuels — Determination of moisture content using the oven dry method —
Part 3: Moisture in general analysis sample
CEN/TS 15414-1, Solid recovered fuels —Determination of moisture content using the oven dry method —
Part 1: Determination of total moisture by a reference method
CEN/TS 15414-2, Solid recovered fuels — Determination of moisture content using the oven dry method —
Part 2: Determination of total moisture by a simplified method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21637:2020 and the
following apply.
1) Under preparation. (Stage at the time of publication: ISO/FDIS 21660-3.)
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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
composite sample
sample consisting of all the increments taken from a lot or a sub-lot
Note 1 to entry: The increments can be reduced by division before being added to the composite sample.
Note 2 to entry: The minimum sample mass shall be retained during the collection of increments to form the
composite sample.
3.2
drying
process of removing water from a sample
Note 1 to entry: For the purpose of test portion preparation, it can be useful to remove just the amount of water
that could interfere with other processes involved (e.g. during crushing or milling). In order to minimize the
alteration of the sample during test portion preparation, removing the total amount of water present in the
sample is not necessarily needed.
[SOURCE: ISO 21637:2020, 3.19, modified: "solid fuel" was replaced with "sample" in Note 1 to entry]
3.3
fraction separation
process of dividing components, particles or layers if homogenization of the sample is practically not
applicable and/or the analyses of different fractions or phases are appropriate
[SOURCE: ISO 21637:2020, 3.32]
3.4
general analysis sample
sub-sample of a laboratory sample having a nominal top size of 1 mm or less and used for a number of
chemical and physical analyses
3.5
homogenization
process of combining of increments making up a combined sample, components, particles or layers
into a more homogeneous state than in the samples (in the case of composite samples) or pre-treated
fractions of samples in order to ensure equal distribution of substances in and properties of the sample
3.6
increment
portion of solid recovered fuel extracted from a lot or sub-lot in a single operation of the sampling device
[SOURCE: ISO 21637:2020, 3.39]
3.7
laboratory sample
combined sample received by the laboratory on which sample preparation procedures are undertaken
Note 1 to entry: When the laboratory sample is further prepared (reduced) by subdividing, mixing, grinding,
or by combinations of these operations, leading to a nominal top size ≤ 1 mm, the result is the general analysis
sample. A test portion is removed from the general analysis sample for the performance of the test or for analysis.
When no preparation of the laboratory sample is required, the laboratory sample may become the test portion.
Note 2 to entry: The combined sample becomes the laboratory sample when it is delivered into the laboratory for
commencement of the sample preparation procedures.
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3.8
lot
defined quantity of fuel for which the quality is to be determined
[SOURCE: ISO 21637:2020, 3.40]
3.9
minimum sample mass
minimum sample mass or dimension of the sample required during sampling and sample preparation
from the point of view of preserving its representativeness
Note 1 to entry: The minimum sample mass is equal to the increment mass multiplied by the number of
increments and is linked directly to the nominal top size.
3.10
nominal top size
d
95
aperture size of the sieve used for determining the particle size distribution of solid recovered fuels
through which at least 95 % by mass of the material passes
[SOURCE: ISO 21637:2020, 3.48 – modified: "Smallest" and "through the sieve" were removed]
3.11
particle size reduction
reduction of the nominal top size of a sample or sub-sample
3.12
sample
quantity of material, representative of a larger quantity for which the quality is to be determined
3.13
sample division
reduction of the mass of a sample or sub-sample
[SOURCE: ISO 21637:2020, 3.64, modified: "by mass" was deleted from term]
3.14
sub-sample
portion of a sample
Note 1 to entry: A sub-sample is obtained by procedures in which the particles are randomly distributed in part
of equal or unequal size.
Note 2 to entry: A sub-sample may be either a portion of the sample obtained by selection, or division of the
sample itself, or the final sample of a multistage sample preparation procedure.
[SOURCE: ISO 21637:2020, 3.82, modified – "items of interest" was replaced by "particles" in Note 1 to
entry and Note 2 to entry was added]
3.15
sub-sampling
process of selecting one or more sub-samples from a sample
3.16
test portion
sub-sample of a laboratory or general analysis sample consisting of the quantity of material required
for a single execution of a test method
Note 1 to entry: The test portion may be taken from the laboratory sample directly, if no preparation of sample is
required (e.g. for bulk density determination or particle size distribution).
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3.17
total moisture sample
sample taken specifically for the purpose of determining the total moisture content
4 Symbols
For the purposes of this document, the following symbols apply.
3
α constant in third power law, in g/mm
d is the nominal minimum particle size (a mass fraction of 5 % of the particles are smaller than
05
d ), in mm
05
d nominal top size of a particle (a mass fraction of 95 % of the particles are smaller than d ), in mm
95 95
3 3
f shape factor, in m /m
M moisture, in percent by weight
m mass of a sample, in g
5 Safety remarks
The safety in handling of potentially hazardous materials is dealt with relevant national and
international regulations, to which every laboratory should refer.
In addition, the following applies:
a) The apparatus for grinding, cutting, milling, and homogenization can be harmful for the users.
They shall be operated by skilled persons strictly according to the manufacturer's instructions
b) All operations shall be performed in a hood or in closed fo
...
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