SIST-TS CEN/TS 15443:2007

SLOVENSKI STANDARD
SIST-TS CEN/TS 15443:2007
01-marec-2007
Trdno alternativno gorivo - Metode za pripravo laboratorijskega vzorca
Solid recovered fuels - Methods for laboratory sample preparation
Feste Sekundärbrennstoffe - Verfahren zur Herstellung von Laboratoriumsproben
Combustibles solides de récupération - Méthodes de préparation des échantillons de
laboratoire
Ta slovenski standard je istoveten z: CEN/TS 15443:2006
ICS:
75.160.10 Trda goriva Solid fuels
SIST-TS CEN/TS 15443:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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TECHNICAL SPECIFICATION
CEN/TS 15443
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
November 2006
ICS 75.160.10

English Version
Solid recovered fuels - Methods for laboratory sample
preparation
Combustibles solides de récupération - Méthodes de Feste Sekundärbrennstoffe - Verfahren zur Herstellung von
préparation des échantillons de laboratoire Laboratoriumsproben
This Technical Specification (CEN/TS) was approved by CEN on 13 May 2006 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15443:2006: E
worldwide for CEN national Members.

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CEN/TS 15443:2006 (E)
Contents Page
Foreword.3
Introduction .4
1 Scope .6
2 Normative references .6
3 Terms and definitions .6
4 Symbols and abbreviations .7
5 Principles of correct sample reduction .8
6 Apparatus .9
6.1 Apparatus for mass-reduction .9
6.2 Apparatus for size-reduction.12
6.3 Sieves.12
6.4 Balance .12
7 Procedure sample preparation.12
7.1 General structure.12
7.2 Step 1: Collection of the relevant information of the material to be sampled.13
7.3 Step 2: Making a sample preparation plan.13
7.4 Step 3: Performing the sample preparation plan .16
8 Methods for mass reduction.17
9 Methods for reducing laboratory samples to sub-samples and general analysis samples .19
9.1 General.19
9.2 Initial sample division .19
9.3 Initial mass determination .19
9.4 Pre-drying .20
9.5 Coarse cutting (size-reduction to <30 mm).20
9.6 Mass-reduction of <30 mm material .21
9.7 Size-reduction of <30 mm material to <1 mm .21
9.8 Mass-reduction of <1 mm material .22
9.9 Size-reduction of <1 mm material to <0,25 mm .22
10 Storage and labelling of sub-samples.22
11 Test report .23
Annex A (normative) Determination of the changing shape factor .24
Annex B (normative) Determination of the shape factor .26
Annex C (informative) Examples of sample preparation.27
Bibliography .30

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CEN/TS 15443:2006 (E)
Foreword
This document (CEN/TS 15443:2006) has been prepared by Technical Committee CEN/TC 343 “Solid
recovered fuels”, the secretariat of which is held by SFS.
This Technical Specification is one of series of technical specifications dealing with solid recovered fuel.
CEN/TS 15442, Solid recovered fuels — Methods for sampling
CEN/TS 15443, Solid recovered fuels — Methods for laboratory sample preparation
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this CEN Technical Specification: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.
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CEN/TS 15443:2006 (E)
Introduction
Solid recovered fuels are a major source of renewable energy. Technical Specifications are needed for
production, trade and use of solid recovered fuels. For sampling and sample preparation of solid recovered
fuels the following Technical Specifications can be used:
CEN/TS 15442, Solid recovered fuels — Methods for sampling;
CEN/TS 15443, Solid recovered fuels — Methods for laboratory sample preparation.
Current practice and the best available knowledge have been used to write these Technical Specifications.
The results of recent sampling experiments may be used to improve the sampling plans.
These Technical Specifications can be used by production and trading of solid recovered fuels. They are also
useful for buyers of solid recovered fuels, regulators, controllers and laboratories.
Figure 1 shows the links between the essential elements of a testing program.
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);
For the sample preparation of solid biofuels a Technical Specification from CEN/TC 335 is available (1). For
the characterization of waste a European standard is available from CEN/TC 292 (2).
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CEN/TS 15443:2006 (E)

Figure 1 — Links between the essential elements of a testing program
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CEN/TS 15443:2006 (E)
1 Scope
This Technical Specification describes methods for reducing combined samples to laboratory samples and
laboratory samples to sub-samples and general analysis samples, and is applicable to solid recovered fuels
that are either:
 fine and regularly-shaped particulate materials, particle sizes up to about 10 mm that can be sampled
using a scoop or pipe, for example: soft and hard pellets;
 coarse or irregularly-shaped particulate materials, particle sizes up to about 200 mm that can be sampled
using a shovel, for example: fluff, chips and chunks;
 large pieces with nominal top size above 200 mm.
The methods described in this Technical Specification 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.
2 Normative references
The following referenced documents are indispensable for the application 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.
CEN/TS 15357:2006, Solid recovered fuels — Terminology, definitions and descriptions
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
CEN/TS 15414-3, Solid recovered fuels —Determination of moisture content using the oven dry method —
Part 3: Moisture in general analysis sample
CEN/TS 15415, Solid recovered fuels — Determination of particle size and distribution by screen method
CEN/TS 15442, Solid recovered fuels — Methods of sampling
3 Terms and definitions
For the purposes of this document, the terms and definitions given in CEN/TS 15357:2006 and the following
apply.
3.1
lot
defined quantity of fuel for which the quality is to be determined
3.2
increment
portion of solid recovered fuel extracted in a single operation of the sampling device
3.3
sample
quantity of fuel, representative of a larger mass for which the quality is to be determined
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CEN/TS 15443:2006 (E)
3.4
combined sample
sample consisting of all the increments taken from a lot or a sub-lot
NOTE The increments may be reduced by division before being added to the combined sample.
3.5
moisture analysis sample
sample taken specifically for the purpose of determining total moisture
3.6
sub-sample
portion of a sample
3.7
laboratory sample
combined sample or a sub-sample of a combined sample or an increment or a sub-sample of an increment
sent to a laboratory
3.8
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
3.9
test portion
sub-sample of a laboratory sample consisting of the quantity of material required for a single execution of a
test method
3.10
mass-reduction
reduction of the mass of a sample or sub-sample
3.11
size-reduction
reduction of the nominal top size of a sample or sub-sample
3.12
nominal top size
d
95
aperture size of the sieve used in CEN/TS 15415 through which at least 95 % by mass of the material passes
4 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviated terms apply.
d is the nominal top size in mm
95
m is the mass of a sample
M is moisture in percent by weight
s is the shape factor
α is a constant in third power law
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CEN/TS 15443:2006 (E)
5 Principles of correct sample reduction
The main purpose of sample preparation is that a sample is reduced to one or more test portions that are in
general smaller than the original sample. The main principle for sample reduction is that the composition of
the sample as taken on site shall not be changed during each step of the sample preparation. Each
sub-sample shall be representative for the original sample. To reach this goal every particle in the sample
before mass-reduction shall have an equal probability of being included in the sub-sample retained after
mass-reduction during a mass-reduction step. Two basic methods are used during the sample preparation.
These methods are:
 mass-reduction of the sample by division;
 particle size-reduction of the sample.
For granular materials, generally the principle of the third-power law is accepted and shall be respected at
each mass-reduction step. The equation for this third power law is shown in Equation 1:
3
m > α×d (1)
95
where
m  is the mass retained after each mass-reduction step in g;
d is the nominal top size in mm;
95
3
α is a constant over the whole sample preparation procedure for a particular material in g/mm .
The value and dimension of constant α is fixed by the nominal particle size, d , and the sample size, m, of the
95
sample before sample preparation.

EXAMPLE
A sample of 10 kg of SRF fluff has d of 50 mm. For the analysis is a test portion of 5 g required.
95
The third power law results in α = 10 000 g divided by 50 mm to the third power. The value of α is now
3
0,08 g/mm . Using this value in Equation 1 for a reduced sample size results in a nominal top size for the particles in the
3
test portion of 3,97 mm (cube root of 5,0 g divided by 0,08 g/mm ). Below in the table are shown the figures.
m αα d
αα 95
3
in g in g/mm  in mm
10 000 0,08 50
5 0,08 3,97


Table 5a shows the resulting reduction factors for the minimum (sub-)sample size, if a certain reduction of the
nominal top size is chosen and the third-power law is respected. The reduction factor of the nominal top size
can be calculated by dividing the current nominal top size by the proposed nominal top size after size
reduction.
Table 5b shows the resulting reduction factors for the minimum nominal top size, if a certain reduction of the
(sub-)sample size is chosen and the third-power law is respected. The reduction factor of the minimum
(sub-)sample size can be calculated by dividing the current minimum (sub-)sample size by the proposed
minimum (sub-)sample top size after size reduction.
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CEN/TS 15443:2006 (E)
Equation 1 can be used to calculate the exact values for each specific situation.

Table 5a – Common values for desired
reduction factor minimum Table 5b – Common values for desired
(sub-)sample size reduction factor nominal top size


Chosen reduction Resulting reduction Desired reduction factor Necessary reduction
factor of the nominal factor for the minimum for the minimum factor of the nominal
top size (sub-)sample size (sub-)sample size top size

1,5 3,4 2 1,3

2 8 3 1,4

3 27 4 1,6

4 64 5 1,7

5 125 10 2,2

6 216 20 2,7

7 343 50 3,7

8 512 80 4,3

9 729 100 4,6

10 1 000 200 5,8

20 8 000 500 7,9

30 27 000 1 000 10,0

For SRF, however, many materials turn out to be far from granular. For example in fluff the particles turn out
to be predominantly flat. Therefore for solid recovered fuels a correction can made for non-granular materials.
Care is needed to avoid loss of fine particles during milling and other operations.
If a sub-sample is required for the determination of moisture content, then the sample reduction shall be
carried out by a procedure that does not conflict with the requirements of CEN/TS 15414-1,
CEN/TS 15414-2 or CEN/TS 15414-3. It is recommended that, if moisture content of the material (as
sampled) is to be determined, a separate moisture analysis sample is taken (as there is a risk of changing the
moisture content by sample reduction operations).
For materials that have to be examined for moisture content, care shall be taken for any significant heat build-
up and risk of drying.
6 Apparatus
6.1 Apparatus for mass-reduction
6.1.1 Riffle boxes
A riffle box shall have at least 16 slots, with adjacent slots directing material into different sub-samples, and
the width of the slots shall be at least 2,5 times the nominal top size of the material to be riffled (see Figure 2).
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CEN/TS 15443:2006 (E)

Key
1 sample
2 slot, width is at least 2,5 times the nominal top size of the material
Figure 2 — Example of a riffle box
6.1.2 Rotary sample dividers
A rotary sample divider shall have a feeder device adjusted so that the divider rotates at least 20 times while
the sample is being divided. See Figure 3 for an example of a rotating divider.
The manufacturer’s manual shall always be followed. The inner dimensions of the equipment where the
sample is feed shall be at least 2,5 times as wide as the nominal top size of the material to be processed.

Key
1 feeder
2 funnel
3 rotating receiver
4 divided sample
Figure 3 — Example of a rotary sample divider
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CEN/TS 15443:2006 (E)
6.1.3 Shovels and scoops
A shovel or scoop used for manual mass-reduction shall have a flat bottom, edges raised high enough to
prevent particles rolling off, and shall be at least 2,5 times as wide as the nominal top size of the material to be
processed. See Figures 4 and 5 for examples of a scoop and a shovel respectively.

Key
d is the nominal top size
Figure 4 — Example of a scoop

Key
l is the length of the shovel
A - A sectional view
Figure 5 — Example of a shovel
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CEN/TS 15443:2006 (E)
6.2 Apparatus for size-reduction
6.2.1 Coarse cutting mill or wood crusher
Coarse cutting mills are used for cutting materials into lengths of about 10 mm to 30 mm (depending on the
solid recovered fuel and the analyses to be performed). The equipment shall have a minimum of drying effect
either by heating the materials or blowing air through them. The equipment shall be designed so that it does
not lose dust or contaminate the material with pieces of metal, and shall be easy to clean. A cutting mill with
no screens may be suitable for small quantities.
6.2.2 Cutting mill
Cutting mills are used for reducing the nominal top size of materials used as solid recovered fuels from about
10 mm to 30 mm down to about 1 mm or less (depending on the solid recovered fuel and the analyses to be
performed). The mill shall be provided with screens of various aperture sizes covering this range, including an
appropriate sieve to control the nominal top size of the material produced. Other apparatus may be used
provided that they are designed so that they do not get blocked with the material that is being processed.
Avoid the use of cutting mills whose cutting faces contain significant quantities of an element that is to be
determined in the analysis.
NOTE Cross beater mills can be used without any excessive dusting, when fitted with dust filters (like a filter sock)
between the mill and the receiving container. They are suitable for final grinding of hard, wood type materials after the
pre-grinding with cutting type mills.
6.2.3 Shredder
A shredder is an apparatus with a rotor equipped with hammers that shred the material which is fed to the
shredder. Shredders are used for reducing the particle size down to 30 mm. The use of shredders for particle
size reduction causes a risk of losing moisture and fine fractions. Therefore the use of shredders shall be
avoided when possible. Unfortunately many types of solid recovered fuel contain plastics and metals and
make therefore the use of a shredder necessary.
6.3 Sieves
A wire-mesh sieve with an aperture size of 1,00 mm is required to check the nominal top size of general
analysis samples. A wire-mesh sieve with an aperture size of 0,250 mm will be required if sub-samples with
this as the nominal top size are required.
6.4 Balance
A balance is required that is capable of determining the mass of samples to an accuracy of 0,1 % of the
sample mass, and the mass of sub-samples to an accuracy of 0,1 % of the sub-sample mass.
7 Procedure sample preparation
7.1 General structure
Figure 6 outlines the general procedure that shall be followed in order to perform the sample preparation
according to this Technical Specification.
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CEN/TS 15443:2006 (E)

Figure 6 — General sample preparation procedure
7.2 Step 1: Collection of the relevant information of the material to be sampled
In the first step of sample preparation information shall be collected about the material to be sampled:
a) the minimum sample size out of the sampling plan;
b) the actual size of the sample, m ;
0
c) the nominal top size of the sample;
d) the shape factor of the sample;
e) the requirements in terms of size reduction for the analysis that need to be performed;
f) the required amounts for each of the size fractions and their restrictions to the sample preparation
methods. Sample preparation prepares a sample for a number of tests which will be performed on the
sample. Some of these tests require no comminution or drying of the material in the sample. Other tests
require very tiny homogenized sub-samples with small particle sizes. A sample preparation plan shall have
to meet all these requirements.
7.3 Step 2: Making a sample preparation plan
7.3.1 General
This subclause specifies the making of a sample preparation plan. The actual making of the sample
preparation plan is the most crucial phase during sample preparation. Sample preparation is a combination of
mass reduction of a sample, particle size reduction of a sample and splitting a sample. Until what level a
sample of solid recovered fuel shall be prepared on site depends on available equipment on site and the
preferences of the client of the sampling activities. Below these two essential activities are specified:
Splitting a sample or mass reduction of a sample
The aim of mass-reduction of a sub-sample is to reduce the mass remaining sub-sample. The aim of splitting
a sub-sample is to make several duplicate sub-samples out of one original sub-sample. During the
performance of splitting a sample or mass reduction of a sample it is of eminent importance that the minimum
sub-sample size shall be retained in order to sustain the representatively of the sub-sample for the original
combined sample. Clause 7 describes the available methods for mass reduction.
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CEN/TS 15443:2006 (E)
Particle size reduction of a sample
The aim of particle-size reduction is to reduce the nominal top size of the particles in order to reduce the
minimum sub-sample size without losing representatively. During the performance of particle size reduction it
is important that all materials are included. Leaving out metals causes significant errors in the measured
values of these and possibly accompanying metals.
In order to make a valid sample preparation plan, the plan shall contain at least the information as shown in
Table 7. All information of this table shall be completed. Table 7 can be used as a sample preparation plan. It
specifies all activities that shall be performed during the whole process of sample preparation. The actual
structure of Table 7 shall be adjusted to the properties of the investigated SRF and the equipment selected in
the laboratory takes place. This means that e.g. steps can be skipped or added if the nominal top size is
already smaller than e.g. 30 mm or the coarse shredder results in a nominal top size different from
30 mm. Some of the information used to complete Table 7 such as techniques, shape factors, nominal top
sizes and comminution steps shall be chosen or determined. The determination of the changing shape factor
is specified in 7.3.2. The determination of mass and particle size reduction techniques and apparatus are
specified in Clause 8. In Annex C an example is given on how a sample preparation plan is made. In Clause 8
the methods of mass reduction before particle size reduction are described. Clause 9 describes how the
sampling preparation plan of Table 7 shall be implemented.
A sample preparation plan can be used multiple times for a specific product as long as the physical
composition of the solid recovered fuel does not change.
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CEN/TS 15443:2006 (E)
Table 7 — Sample preparation plan
Purpose of product of
Description Method of Used Mass Mass Nominal Nominal Shape Shape Mass to
reduction technique before after top size top size factor factor be this reduction step
and reduction reduction before after before after withheld
apparatus reduction reduction reduction reduction for
analysis
Step 1 splitting the combined sample in a mass     Determination of bulk
sub-sample for further sample reduction density, durability of
preparation and a sub-sample of pellets, particle size
untreated material distribution etc.
Step 2 reducing the particle size in order to particle size   30 mm
make further mass reduction and/or reduction to

splitting possible <30 mm
Step 3 reducing and/or splitting the sample mass  30 mm 30 mm  Sub-samples for
size in order to make further particle reduction determination of particle

size reduction and/or splitting size distribution, abrasion
possible resistance, moisture
Step 4 splitting the remaining sub-sample in particle size  30 mm 1,0 mm 1,0
a sub-sample for further sample reduction to

preparation and sub-samples for <1,0 mm
analyses
Step 5 split the remaining sample material mass  1,0 mm 1,0 mm 1,0 1,0 Sub-samples for
into the required test portions reduction determination of ash,
calorific value, chemical
analysis etc.
Step 6 reducing the particle size in order to particle size  1,0 mm 0,25 mm 1,0 1,0
make splitting possible reduction to
<0,25 mm
Step 7 split the remaining sample material mass  0,25 mm 0,25 mm 1,0 1,0 Sub-samples for analysis
into the required test portions reduction where <0,25 mm is
required
NOTE  Mass can only be withheld during a mass reduction step and not during a size reduction step.
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CEN/TS 15443:2006 (E)
7.3.2 Retaining the minimum (sub-)sample size
During every mass-reduction step, every particle in the sample before mass-reduction shall have an equal
probability of being included in the sub-sample retained after mass-reduction. For non-granular materials with
a shape factor significantly smaller than 1,0 a correction shall be made for the changing shape factor. How
this correction shall be calculated is specified in Annex A.
Each step a sample preparation shall comply with Equation 2:
3
 
m s d
1 1 1
 
≥ × (2)
 
m s d
2 2  2
where,
m  is the sample size of sample to be reduced;
1
m is the sample size of sample after reduction;
2
s  is the shape factor of sample to be reduced;
1
s  is the shape factor of sample after reduction;
2
d  is the nominal top size of sample to be reduced;
1
d  is the nominal top size of sample after reduction.
2
For more or less granular materials the shape factors s and s will be close to 1. In this case it is easier and
1 2
cheaper
...