ISO/FDIS 13909-6
(Main)Coal and coke — Mechanical sampling — Part 6: Preparation of test samples of coke
Coal and coke — Mechanical sampling — Part 6: Preparation of test samples of coke
ISO 13909-6:2016 describes the preparation of samples of coke from the combination of primary increments to the preparation of samples for specific tests.
Charbon et coke — Échantillonnage mécanique — Partie 6: Préparation des échantillons pour essai de coke
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FINAL DRAFT
International
Standard
ISO/TC 27/SC 4
Coal and coke — Mechanical
Secretariat: SABS
sampling —
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2025-04-18
Part 6:
Preparation of test samples of coke
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Reference number
FINAL DRAFT
International
Standard
ISO/TC 27/SC 4
Coal and coke — Mechanical
Secretariat: SABS
sampling —
Voting begins on:
Part 6:
Preparation of test samples of coke
Voting terminates on:
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 SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
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TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
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ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Precision of sample preparation . 1
5 Constitution of a sample . 2
5.1 General .2
5.2 Combination of increments .2
5.3 Combination of samples .2
6 Division . 3
6.1 General .3
6.2 Mechanical methods . 13
6.2.1 General . 13
6.2.2 Mass of cut .14
6.2.3 Interval between cuts .14
6.2.4 Division of individual increments .14
6.2.5 Minimum mass of divided increment .14
6.2.6 Division of samples. 15
6.3 Manual methods . 15
6.3.1 General . 15
6.3.2 Riffle method . 15
6.3.3 Flattened-heap method .16
6.3.4 Strip-mixing and splitting method .18
7 Preparation of samples for specific tests . 19
7.1 Types of test sample . .19
7.2 Preparation of samples for determining total moisture .21
7.2.1 General .21
7.2.2 Procedure .21
7.2.3 Wet samples .21
7.2.4 Reduction of total moisture test sample . 22
7.2.5 Division . 22
7.2.6 Determination of total moisture . 22
7.2.7 Reserve sample . 22
7.3 Preparation of sample for general analysis . 22
7.3.1 General . 22
7.3.2 Segregation errors (preparation error) . 22
7.3.3 Reduction . 23
7.3.4 Division . 23
7.3.5 Preparation errors . 23
7.4 Storage . 23
7.5 Physical test sample . 23
7.6 Samples for special properties . 23
8 Design of equipment for preparation .24
8.1 Dividers .24
8.2 Design of cutters for falling-stream dividers .24
8.2.1 General .24
8.2.2 Cutter velocity .24
8.3 Crushers . 25
8.3.1 General . 25
8.3.2 Examples of crushers . 25
8.4 Preparation systems . 25
iii
8.4.1 General . 25
8.4.2 Design criteria . 26
8.4.3 Normal operation. 26
8.4.4 Abnormal operation . 26
8.4.5 Provision for checking for precision . 26
8.4.6 Provision for testing for bias .27
Bibliography .28
iv
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 committ
...
Date: 2025-02-20
ISO/TC 27/SC 4/WG 10
Secretariat: SABS
Date: 2025-04-04
Coal and coke – — Mechanical sampling – —
Part 6:
Preparation of test samples of coke
Houille et coke — Échantillonnage mécanique — Partie 1: Introduction générale
FDIS stage
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'sISO’s member body in the country of the requester.
ISO Copyright Officecopyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Email: E-mail: copyright@iso.org
Website: www.iso.org
Published in Switzerland.
iii
ISO/DISFDIS 13909-6:2024(E2025(en)
Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Precision of sample preparation . 1
5 Constitution of a sample . 2
6 Division . 4
7 Preparation of samples for specific tests . 26
8 Design of equipment for preparation . 32
Bibliography . 36
iv
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 4, Sampling.
This third edition cancels and replaces the second edition (ISO 13909--6:20232016), which has been
technically revised.
The main changes are as follows:
— — the title has been modified and aligned with the rest of the ISO 13909 series;
— — the Scope has been revised to specifically refer to coke;
— — the references have been updated;
— — legends for Formulae (1)Formulae (1) and (3)(3) have been updated;
— — requirements have been specified throughout the document.
A list of all parts in the ISO 13909 series can be found on the ISO website.
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.
v
ISO/DISFDIS 13909-6:2024(E2025(en)
Introduction
The objective of sample preparation is to prepare one or more test samples from the primary increments for
subsequent analysis. The requisite mass and particle size of the test samples depend on the test to be carried
out.
Examples of tests which require different masses are shatter index (ISO 616), Micum and Irsid Index
(ISO 556), reactivity tests (ISO 18894), density (ISO 567, ISO 1013) and size distribution (ISO 728, ISO 2325).
The process of sample preparation may involve constitution of samples, reduction, division, mixing and
drying, or all, or a combination of these.
Primary increments may be prepared individually as test samples or combined to constitute samples either
as taken or after having been prepared by either reduction and/or division, or both. Samples may either be
prepared individually as test samples or combined on a weighted basis to constitute a further sample.
vi
FINAL DRAFT International Standard ISO/FDIS 13909-6:2025(en)
Coal and coke – — Mechanical sampling – Part 6: Preparation of test
samples of coke —
Part 6:
Preparation of test samples of coke
1 Scope
This document describes the preparation of samples of coke from the combination of primary increments to
the preparation of samples for specific tests.
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 579, Coke — Determination of total moisture
ISO 687, Coke — Determination of moisture in the general analysis test sample
ISO 13909--1, Coal and coke — Mechanical sampling — Part 1: General introduction
ISO 13909--5, Coal and coke — Mechanical sampling — Part 5: Sampling of coke from moving streams
ISO 13909--7, Coal and coke — Mechanical sampling — Part 7: Methods for determining the precision of
sampling, sample preparation and testing
ISO 13909--8, Coal and coke — Mechanical sampling — Part 8: Methods of testing for bias
ISO 21398, CoalHard coal and coke — Guidance to the inspection of mechanical sampling systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13909--1 apply.
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/
4 Precision of sample preparation
From the formulae given in ISO 13909--7, the estimated absolute value of the precision of the result obtained
for the lot at the 95 % confidence level, P , for continuous sampling is given by Formula (1)Formula (1)::
L
(1)
𝑉𝑉
𝐼𝐼
+𝑉𝑉
𝑃𝑃𝑃𝑃
𝑛𝑛
�
𝑃𝑃 = 2 (1)
𝐿𝐿
𝑚𝑚
where
2 is a conversion factor from the sample estimate of the population standard deviation to an index of
precision, dimensionless;
V is the primary increment variance;
I
n is the number of increments in the sample;
V is the variance of preparation and testing for both off-line and on-line systems;
PT
m is the number of sub-lots.
The procedures given in this document are designed to achieve levels of V of 0,05 or less for moisture tests.
PT
Better levels may be expected for other chemical characteristics.
For some preparation schemes, however, practical restrictions maycan prevent the preparation and testing
variance being as low as this. Under these circumstances, the user shall decide whether to achieve the desired
overall precision by improving the preparation scheme or by dividing the lot into a greater number of sub-
lots.
The errors occurring in the various stages of preparation and analysis, expressed in terms of variance, can be
checked by the methods given in ISO 13909--7.
5 Constitution of a sample
5.1 General
Examples of the constitution of samples are shown in Figure 1Figure 1.
Primary increments shall be taken in accordance with the procedures specified in ISO 13909--5.
Individual increments are usually combined to form a sample. A single sample may be constituted by
combination of increments taken from a complete sub-lot or by combining increments taken from individual
parts of a sub-lot. Under some circumstances, e.g. size analysis or bias testing, the sample consists of a single
increment which is prepared and tested.
Samples may also be prepared by the combination of other samples.
5.2 Combination of increments
The mass of the primary increments shall be proportional to the flow rate at the time of sampling. The primary
increments may be combined into a sample, either directly as taken or after having been prepared individually
to an appropriate stage by fixed-ratio division (see Clause 6Clause 6).).
5.3 Combination of samples
When combining samples, the mass of the individual samples shall be directly proportional to the mass of the
coke from which they were taken in order to obtain a weighted mean of the quality characteristic for the sub-
lot. Prior to combination, division shall be by fixed-ratio (see Clause 6Clause 6).).
a) Example 1
b) Example 2
Figure 1 — Examples of the constitution of samples
6 Division
6.1 General
Since the cutter aperture will be at least three times the nominal top size, this will result in a very large
increment mass in many cases. The handling and preparation of such large increments would be either
manpower or equipment intensive. Division prior to further treatment may be necessary to provide a
manageable sample mass.
Sample division can be:
— — on-line mechanically,; or
— — off-line mechanically or manually.
Whenever possible, mechanical methods are preferred to manual methods to minimize human error.
Examples of dividers are shown in Figures 2 to 10Figure 2.
Mechanical dividers are designed to extract a part of the coke in a number of cuts of relatively small mass.
When the smallest mass of the divided sample that can be obtained in one pass through the divider is greater
than that required, further passes through the same divider or subsequent passes through further dividers
are necessary.
Manual division is normally applied when mechanical methods would result in loss of integrity (e.g. loss of
moisture or size degradation). Manual division of coke is also applied when the nominal top size of the coke is
such as to make the use of a mechanical divider impracticable. Manual methods may themselves result in bias,
particularly if the mass of coke to be divided is large.
In the rotating disc type of mechanical divider in Figure 2Figure 2(a),, the material from a mixing container is
fed by scrapers to the centre of the dividing disc. From there it is discharged over the range of the disc through
special clearing arms. The sample falls through adjustable slots into chutes; the reject is carried away through
a cleaning conduit. The whole interior space is cleaned by scrapers.
For the rotating cone type of divider in Figure 3Figure 2(b),, a stream of coke is allowed to fall onto a rotating
cone, the adjustable slot with lips in the cone allows the stream to fall directly onto the sample receiver for
part of each revolution.
In the container type dividers in Figure 4Figure 2(c),, the coke stream flows to the hopper and this flow is
intercepted by the top edge of a number of sector-shaped containers dividing the flow into equal parts. Either
the hopper or the containers may rotate. The machine can be controlled for the following operations:
1) for dividing;
2) for collecting duplicates:
3) for collecting replicates.
Figure 3(d),, a chain mechanism as shown is equipped with
For the chain bucket type divider in Figure 5
buckets spread at equal pitch. The buckets travel in a single direction or change direction at preset time
periods. The bucket intercepts the free-falling coke stream to extract cuts which discharge to sample as the
bucket inverts.
The slotted-belt type divider in Figure 6Figure 3(e) comprises an endless belt
...
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