ISO 1953:2015

Hard coal - Size analysis by sieving

ISO 1953:2015 specifies reference methods for the size analysis of coal by manual sieving (wet or dry), using test sieves of aperture sizes between 125 mm and 45 μm. A guide to sampling is given in Annex A. This International Standard is applicable to all hard coals. It is not applicable to coke or other manufactured fuels. In the case of pulverized coal which has been ground so that a high proportion passes through the test sieve of smallest aperture size, the methods described in this International Standard will determine only the percentage oversize.

Houille — Analyse granulométrique par tamisage

Črni premog - Določanje zrnatosti s sejalno analizo

Ta mednarodni standard določa referenčne metode za sejalno analizo premoga z ročnim sejanjem (mokrim ali suhim) pri uporabi preskusnih sejalnikov z velikostjo odprtine sita od 125 mm do 45 μm. Navodila za takšno vzorčenje so podana v dodatku A.
Ta mednarodni standard se uporablja za vse vrste črnega premoga. Ne uporablja se za koks ali druga proizvedena goriva.
V primeru premoga v prahu, ki je bil zmlet tako, da najmanjša velikost odprtine preskusnega sita prepusti velik delež premoga, metode, opisane v tem mednarodnem standardu, določajo le nadmerni odstotni delež.

General Information

• Status: Published
• Publication Date: 09-Nov-2015
• ICS: 73.040 - Coals
• Technical Committee: ISO/TC 27/SC 1 - Coal preparation: Terminology and performance
• Drafting Committee: ISO/TC 27/SC 1 - Coal preparation: Terminology and performance
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 02-Oct-2025
• Completion Date: 13-Dec-2025
• Ref Project: SIST ISO 1953:2016 - Hard coal - Size analysis by sieving

Relations

• Revised: ISO 1953:2025 - Coal - Size analysis by sieving
• Effective Date: 14-Oct-2023
• Revises: ISO 1953:1994 - Hard coal - Size analysis by sieving
• Effective Date: 02-Mar-2013

Overview

ISO 1953:2015 - Hard coal - Size analysis by sieving - defines reference methods for determining the particle-size distribution of hard coal by manual sieving (wet or dry). The standard covers test sieves with nominal aperture sizes between 125 mm and 45 μm, gives guidance on sampling (Annex A) and includes procedural details, apparatus and result reporting. It applies to all hard coals (but not to coke or other manufactured fuels) and notes that for highly pulverized coal the method will only determine the percentage oversize.

Key topics and technical requirements

• Scope and applicability: Reference methods for size analysis of hard coal using manual wet or dry sieving; limitations for pulverized coal and exclusion of manufactured fuels.
• Sieve series and apertures: Recommended sieve series (e.g., 125, 90, 75, 63, 50, 45, 31.5, 22.4, 16, 11.2, 8, 5.6, 4, 2, 1 mm and wire-cloth sizes down to 45 μm). Guidance on supplementary sizes when needed.
• Apparatus: Test sieves (ISO 3310 compliant), receivers, accurate weighing scale (to 0.1 %), trays, brush, vibratory shaker (for mechanical sieving), and for wet sieving: pressure-filter, Buchner funnel, filter paper and controlled oven.
• Sampling and sample mass: Sampling methods per ISO 13909 / ISO 18283 and minimum gross/sample mass requirements (Table 1) to achieve target precisions (1 % or 2%).
• Preparation and division: Drying limits (air-dry ≤ 40 °C) and procedures for dividing samples (mechanical dividers, flattened-heap or strip methods).
• Procedures: Detailed step-by-step for dry sieving (including hand-placing for large fragments) and wet sieving (used when particles agglomerate). Notes on combining wet and dry sieving and the potential influence of soluble clays/shales on wet-sieve results.
• Results and reporting: Express results as percentage mass retained on each sieve, calculation and graphical presentation conventions, and required test-report content.

Practical applications and users

ISO 1953:2015 is used for:

• Quality control in coal preparation plants and screening operations
• Design data and performance checks for crushing and screening equipment
• Yield assessment of run-of-mine coals and product grading verification
• Laboratory particle-size analysis in mining, power generation, and fuel supply chains

Primary users include coal testing laboratories, plant engineers, sampling technicians, equipment manufacturers and consultants involved in coal handling and preparation.

Related standards

• ISO 1213-1 / ISO 1213-2 (vocabulary)
• ISO 13909 (mechanical sampling)
• ISO 18283 (manual sampling)
• ISO 3310-1 / ISO 3310-2 (test sieve requirements)

Keywords: ISO 1953:2015, hard coal size analysis, sieving, test sieves, dry sieving, wet sieving, coal sampling, particle-size distribution, sieve aperture sizes.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2016
1DGRPHãþD
SIST ISO 1953:1998
ýUQLSUHPRJ'RORþDQMH]UQDWRVWLVVHMDOQRDQDOL]R
Hard coal - Size analysis by sieving
Houille - Analyse granulométrique par tamisage
Ta slovenski standard je istoveten z: ISO 1953:2015
ICS:
73.040 Premogi Coals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 1953
Third edition
2015-11-15
Hard coal — Size analysis by sieving
Houille — Analyse granulométrique par tamisage
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Apparatus . 1
4.1 For all methods . 1
4.2 For dry sieving . 2
4.3 For wet sieving . 2
5 Sampling of test sample . 2
5.1 General . 3
5.2 Drying . 3
5.3 Division (other than wet coal of nominal top size less than 4 mm) . 3
5.4 Division of wet coal of nominal top size less than 4 mm . 4
6 Procedure. 4
6.1 General . 4
6.2 Dry sieving . 4
6.2.1 Sample of maximum particle size greater than 22,4 mm . 4
6.2.2 Sample of maximum particle size between 4 mm and 22,4 mm—
manual method . 5
6.2.3 Sample of maximum particle size less than 4 mm—manual method . 5
6.2.4 Sample of maximum particle size between 4 mm and 22,4 mm; minus
4 mm—mechanical method . 6
6.3 Wet sieving . 6
7 Expression of results . 7
7.1 Calculation . 7
7.2 Graphical presentation . 7
8 Test report . 8
Annex A (informative) Guide to sampling .12
Annex B (informative) Example of removal by wet sieving of fine material from a sample
having a maximum particle size less than 4 mm .13
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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 27, Solid mineral fuels, Subcommittee SC 1, Coal
preparation: Terminology and performance.
This third edition cancels and replaces the second edition (ISO 1953:1994), of which it constitutes a
minor revision.
iv © ISO 2015 – All rights reserved

Introduction
Size analysis involves the separation of a sample of coal into size fractions having defined limits. In the
methods described in this International Standard the results are expressed in terms of the percentage
mass of coal remaining on sieves of different aperture sizes. This information can be of use in a number
of applications, including the following: assessing the yields of products from run-of-mine coals;
providing design data for coal preparation plants; checking that products from screening plants are
within the required limits; assessing the performance of coal-crushing plants; and selecting coals for
particular processes and equipment.
INTERNATIONAL STANDARD ISO 1953:2015(E)
Hard coal — Size analysis by sieving
1 Scope
This International Standard specifies reference methods for the size analysis of coal by manual sieving
(wet or dry), using test sieves of aperture sizes between 125 mm and 45 μm. A guide to sampling is
given in Annex A.
This International Standard is applicable to all hard coals. It is not applicable to coke or other
manufactured fuels.
In the case of pulverized coal which has been ground so that a high proportion passes through the test
sieve of smallest aperture size, the methods described in this International Standard will determine
only the percentage oversize.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 1213-1, Solid mineral fuels — Vocabulary — Part 1: Terms relating to coal preparation
ISO 1213-2, Solid mineral fuels — Vocabulary — Part 2: Terms relating to sampling, testing and analysis
ISO 13909 (all parts), Hard coal and coke — Mechanical sampling
ISO 18283, Hard coal and coke — Manual sampling
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
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213-1 and ISO 1213-2 apply.
4 Apparatus
4.1 For all methods
4.1.1 Test sieves, exclusively round-hole or exclusively square-hole, complying with ISO 3310-1 or
ISO 3310-2, as appropriate.
The recommended series of test sieves for general purposes is 125 mm, 90 mm, 75 mm, 63 mm, 50 mm,
45 mm, 31,5 mm, 22,4 mm, 16 mm, 11,2 mm, 8 mm, 5,6 mm, 4 mm, 2 mm and 1 mm nominal aperture
sizes, square-hole, or the same sizes of round-hole sieves. If this series is inadequate for the sizing of
graded coals, sieves from the supplementary sizes 100 mm, 80 mm, 40 mm, 25 mm, 20 mm, 12,5 mm,
10 mm and 6,3 mm may be included. For samples greater than 125 mm, single square-hole gauges of the
required dimensions may be used for the larger pieces. Test sieves of nominal aperture size 4 mm and
less should be of metal wire cloth; the recommended series of nominal aperture sizes is 4 mm, 2,8 mm,
2 mm, 1,4 mm, 1 mm, 710 μm, 500 μm, 355 μm, 250 μm, 180 μm, 125 μm, 90 μm, 63 μm and 45 μm.
When a complete size analysis is required, it is preferable, subject to the range of sieve aperture sizes
available, that the mass of coal in any size fraction does not exceed 30 % of the total mass of sample
being sieved. The largest aperture size sieve should be that on which not more than 5 % mass fraction
of the sample is retained and the smallest aperture size sieve should be that through which not more
than 5 % mass fraction of the sample passes.
It is important to check the sieves from time to time, by the methods described in ISO 3310-1 and
ISO 3310-2, to ensure that the aperture dimensions are within the specified tolerances. Worn or
damaged sieves can give rise to serious errors in size analysis and should be discarded.
4.1.2 Receivers, for collecting material passing through the sieves.
4.1.3 Weighing scale, capable of measuring the mass of the sample to be sieved to the nearest 0,1 %.
4.1.4 Trays, smooth, of non-corrodible material, of at least 400 mm × 400 mm, depending on the mass
of sample and number of analysis required.
4.1.5 Watch- or clock-glasses.
4.2 For dry sieving
4.2.1 Lids, to fit the test sieves.
4.2.2 Flat brush, for cleaning the sieves and for brushing dust from the trays.
4.2.3 Hardwood block, about 150 mm long with a 10 mm × 10 mm cross-section, for tapping the sieves.
4.2.4 Shovel or scoop.
4.2.5 Vibratory sieve shaker for mechanical sieving.
4.3 For wet sieving
4.3.1 Pressure filter.
4.3.2 Buchner funnel and Buchner flask.
4.3.3 Filter paper.
4.3.4 Oven, capable of being controlled to ± 5 °C in the range 30 °C to 110 °C.
5 Sampling of test sample
The sample shall be taken in accordance with ISO 13909 or ISO 18283, subject to the following provision:
a) the number of increments and the increment masses, for both manual and mechanical sampling,
should comply with the requirements of ISO 13909 or ISO 18283.
or
b) the minimum mass of the gross sample should comply with Table 1.
2 © ISO 2015 – All rights reserved

Table 1 — Minimum mass of sample for size analysis
Minimum mass for a Minimum mass for a
Nominal top size of coal
precision of 1 % precision of 2 %
mm kg kg
300 54 000 13 500
200 16 000 4 000
150 6 750 1 700
125 4 000 1 000
90 1 500 400
75 950 250
63 500 125
50 280 70
45 200 50
38 130 30
31,5 65 15
22,4 25 6
16,0 8 2
11,2 3 0,70
10,0 2 0,50
8,0 1 0,25
5,6 0,50 0,25
4,0 0,25 0,25
2,8 0,25 0,25
2,0 0,25 0,25
1,0 0,25 0,25
< 0,5 0,25 0,25
Preparation of test sample
5.1 General
Drying is necessary if the coal is wet and dry sieving is to be performed. The gross sample may be
divided if its mass greatly exceeds the value given in Table 1. If the gross sample is to be dried and
divided, the division shall be carried out first whenever practicable. If no preparation is necessary, the
test sample is the gross sample.
5.2 Drying
Air-dry the sample either at ambient temperature or at an elevated temperature not exceeding 40 °C.
Cool, if necessary, and allow the moisture content to come to equilibrium with the laboratory atmosphere.
If caking or swelling tests are to be carried out subsequently on the sample, the drying temperature
should not exceed 40 °C.
5.3 Division (other than wet coal of nominal top size less than 4 mm)
Divide the sample by means of a suitable mechanical sample divider or riffle avoiding size degradation
and loss of dust. For sample that contains larger pieces of particle size greater than say 50 mm, where
a suitable mechanical sample divider or riffle is not available, use either the flattened heap method,
the strip mixing and splitting method described in ISO 13909-4 and ISO 18283. Weigh all the coal not
included as part of the test sample and retain it until all analyses and calculations are complete.
5.4 Division of wet coal of nominal top size less than 4 mm
Spread the gross sample on a clean flat surface, form into a cake 15 mm to 25 mm thick and extract a
2 kg sample by taking not less than 50 increments, evenly spread over the cake, using an appropriate
sampling scoop and bump plate. If further division is necessary, air-dry the divided sample first, as
described in 6.2 and then proceed as described in 6.3.
6 Procedure
6.1 General
The analysis shall be carried out by dry sieving (7.2) or by wet sieving (7.3).
In general, dry sieving is suitable for most types of coal but wet sieving should be used if particles tend
to agglomerate.
NOTE 1 A combination of wet sieving (to remove fine material) and dry sieving can be appropriate and an
example is given in Annex B.
NOTE 2 When sieving coals, wet sieving may produce different results compared to dry sieving because the
coals may contain percentages of clay and/or shales which may be soluble in water.
The range of sieves used will depend on the type of coal and the purpose of the test. For example, a
complete size analysis may be required for a run-of-mine coal or, in the simplest case, the amount of
undersize in a graded product may be required. If the results are to be presented graphically, the range
of sieves should comprise at least five different aperture sizes.
During sieving it may be convenient either to weigh separately each container with its size fraction and
to subtract the mass of the empty container or to weigh one container with the fraction corresponding
to the largest aperture size and to add successively all the other fractions, noting the cumulative
mass after each addition. The first technique is preferred for samples having a maximum particle size
of 4 mm, so that the end point of sieving may be checked. The second technique is normally used for
samples containing pieces having a particle size greater than 4 mm. Howe
...

INTERNATIONAL ISO
STANDARD 1953
Third edition
2015-11-15
Hard coal — Size analysis by sieving
Houille — Analyse granulométrique par tamisage
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Apparatus . 1
4.1 For all methods . 1
4.2 For dry sieving . 2
4.3 For wet sieving . 2
5 Sampling of test sample . 2
5.1 General . 3
5.2 Drying . 3
5.3 Division (other than wet coal of nominal top size less than 4 mm) . 3
5.4 Division of wet coal of nominal top size less than 4 mm . 4
6 Procedure. 4
6.1 General . 4
6.2 Dry sieving . 4
6.2.1 Sample of maximum particle size greater than 22,4 mm . 4
6.2.2 Sample of maximum particle size between 4 mm and 22,4 mm—
manual method . 5
6.2.3 Sample of maximum particle size less than 4 mm—manual method . 5
6.2.4 Sample of maximum particle size between 4 mm and 22,4 mm; minus
4 mm—mechanical method . 6
6.3 Wet sieving . 6
7 Expression of results . 7
7.1 Calculation . 7
7.2 Graphical presentation . 7
8 Test report . 8
Annex A (informative) Guide to sampling .12
Annex B (informative) Example of removal by wet sieving of fine material from a sample
having a maximum particle size less than 4 mm .13
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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 27, Solid mineral fuels, Subcommittee SC 1, Coal
preparation: Terminology and performance.
This third edition cancels and replaces the second edition (ISO 1953:1994), of which it constitutes a
minor revision.
iv © ISO 2015 – All rights reserved

Introduction
Size analysis involves the separation of a sample of coal into size fractions having defined limits. In the
methods described in this International Standard the results are expressed in terms of the percentage
mass of coal remaining on sieves of different aperture sizes. This information can be of use in a number
of applications, including the following: assessing the yields of products from run-of-mine coals;
providing design data for coal preparation plants; checking that products from screening plants are
within the required limits; assessing the performance of coal-crushing plants; and selecting coals for
particular processes and equipment.
INTERNATIONAL STANDARD ISO 1953:2015(E)
Hard coal — Size analysis by sieving
1 Scope
This International Standard specifies reference methods for the size analysis of coal by manual sieving
(wet or dry), using test sieves of aperture sizes between 125 mm and 45 μm. A guide to sampling is
given in Annex A.
This International Standard is applicable to all hard coals. It is not applicable to coke or other
manufactured fuels.
In the case of pulverized coal which has been ground so that a high proportion passes through the test
sieve of smallest aperture size, the methods described in this International Standard will determine
only the percentage oversize.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 1213-1, Solid mineral fuels — Vocabulary — Part 1: Terms relating to coal preparation
ISO 1213-2, Solid mineral fuels — Vocabulary — Part 2: Terms relating to sampling, testing and analysis
ISO 13909 (all parts), Hard coal and coke — Mechanical sampling
ISO 18283, Hard coal and coke — Manual sampling
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
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1213-1 and ISO 1213-2 apply.
4 Apparatus
4.1 For all methods
4.1.1 Test sieves, exclusively round-hole or exclusively square-hole, complying with ISO 3310-1 or
ISO 3310-2, as appropriate.
The recommended series of test sieves for general purposes is 125 mm, 90 mm, 75 mm, 63 mm, 50 mm,
45 mm, 31,5 mm, 22,4 mm, 16 mm, 11,2 mm, 8 mm, 5,6 mm, 4 mm, 2 mm and 1 mm nominal aperture
sizes, square-hole, or the same sizes of round-hole sieves. If this series is inadequate for the sizing of
graded coals, sieves from the supplementary sizes 100 mm, 80 mm, 40 mm, 25 mm, 20 mm, 12,5 mm,
10 mm and 6,3 mm may be included. For samples greater than 125 mm, single square-hole gauges of the
required dimensions may be used for the larger pieces. Test sieves of nominal aperture size 4 mm and
less should be of metal wire cloth; the recommended series of nominal aperture sizes is 4 mm, 2,8 mm,
2 mm, 1,4 mm, 1 mm, 710 μm, 500 μm, 355 μm, 250 μm, 180 μm, 125 μm, 90 μm, 63 μm and 45 μm.
When a complete size analysis is required, it is preferable, subject to the range of sieve aperture sizes
available, that the mass of coal in any size fraction does not exceed 30 % of the total mass of sample
being sieved. The largest aperture size sieve should be that on which not more than 5 % mass fraction
of the sample is retained and the smallest aperture size sieve should be that through which not more
than 5 % mass fraction of the sample passes.
It is important to check the sieves from time to time, by the methods described in ISO 3310-1 and
ISO 3310-2, to ensure that the aperture dimensions are within the specified tolerances. Worn or
damaged sieves can give rise to serious errors in size analysis and should be discarded.
4.1.2 Receivers, for collecting material passing through the sieves.
4.1.3 Weighing scale, capable of measuring the mass of the sample to be sieved to the nearest 0,1 %.
4.1.4 Trays, smooth, of non-corrodible material, of at least 400 mm × 400 mm, depending on the mass
of sample and number of analysis required.
4.1.5 Watch- or clock-glasses.
4.2 For dry sieving
4.2.1 Lids, to fit the test sieves.
4.2.2 Flat brush, for cleaning the sieves and for brushing dust from the trays.
4.2.3 Hardwood block, about 150 mm long with a 10 mm × 10 mm cross-section, for tapping the sieves.
4.2.4 Shovel or scoop.
4.2.5 Vibratory sieve shaker for mechanical sieving.
4.3 For wet sieving
4.3.1 Pressure filter.
4.3.2 Buchner funnel and Buchner flask.
4.3.3 Filter paper.
4.3.4 Oven, capable of being controlled to ± 5 °C in the range 30 °C to 110 °C.
5 Sampling of test sample
The sample shall be taken in accordance with ISO 13909 or ISO 18283, subject to the following provision:
a) the number of increments and the increment masses, for both manual and mechanical sampling,
should comply with the requirements of ISO 13909 or ISO 18283.
or
b) the minimum mass of the gross sample should comply with Table 1.
2 © ISO 2015 – All rights reserved

Table 1 — Minimum mass of sample for size analysis
Minimum mass for a Minimum mass for a
Nominal top size of coal
precision of 1 % precision of 2 %
mm kg kg
300 54 000 13 500
200 16 000 4 000
150 6 750 1 700
125 4 000 1 000
90 1 500 400
75 950 250
63 500 125
50 280 70
45 200 50
38 130 30
31,5 65 15
22,4 25 6
16,0 8 2
11,2 3 0,70
10,0 2 0,50
8,0 1 0,25
5,6 0,50 0,25
4,0 0,25 0,25
2,8 0,25 0,25
2,0 0,25 0,25
1,0 0,25 0,25
< 0,5 0,25 0,25
Preparation of test sample
5.1 General
Drying is necessary if the coal is wet and dry sieving is to be performed. The gross sample may be
divided if its mass greatly exceeds the value given in Table 1. If the gross sample is to be dried and
divided, the division shall be carried out first whenever practicable. If no preparation is necessary, the
test sample is the gross sample.
5.2 Drying
Air-dry the sample either at ambient temperature or at an elevated temperature not exceeding 40 °C.
Cool, if necessary, and allow the moisture content to come to equilibrium with the laboratory atmosphere.
If caking or swelling tests are to be carried out subsequently on the sample, the drying temperature
should not exceed 40 °C.
5.3 Division (other than wet coal of nominal top size less than 4 mm)
Divide the sample by means of a suitable mechanical sample divider or riffle avoiding size degradation
and loss of dust. For sample that contains larger pieces of particle size greater than say 50 mm, where
a suitable mechanical sample divider or riffle is not available, use either the flattened heap method,
the strip mixing and splitting method described in ISO 13909-4 and ISO 18283. Weigh all the coal not
included as part of the test sample and retain it until all analyses and calculations are complete.
5.4 Division of wet coal of nominal top size less than 4 mm
Spread the gross sample on a clean flat surface, form into a cake 15 mm to 25 mm thick and extract a
2 kg sample by taking not less than 50 increments, evenly spread over the cake, using an appropriate
sampling scoop and bump plate. If further division is necessary, air-dry the divided sample first, as
described in 6.2 and then proceed as described in 6.3.
6 Procedure
6.1 General
The analysis shall be carried out by dry sieving (7.2) or by wet sieving (7.3).
In general, dry sieving is suitable for most types of coal but wet sieving should be used if particles tend
to agglomerate.
NOTE 1 A combination of wet sieving (to remove fine material) and dry sieving can be appropriate and an
example is given in Annex B.
NOTE 2 When sieving coals, wet sieving may produce different results compared to dry sieving because the
coals may contain percentages of clay and/or shales which may be soluble in water.
The range of sieves used will depend on the type of coal and the purpose of the test. For example, a
complete size analysis may be required for a run-of-mine coal or, in the simplest case, the amount of
undersize in a graded product may be required. If the results are to be presented graphically, the range
of sieves should comprise at least five different aperture sizes.
During sieving it may be convenient either to weigh separately each container with its size fraction and
to subtract the mass of the empty container or to weigh one container with the fraction corresponding
to the largest aperture size and to add successively all the other fractions, noting the cumulative
mass after each addition. The first technique is preferred for samples having a maximum particle size
of 4 mm, so that the end point of sieving may be checked. The second technique is normally used for
samples containing pieces having a particle size greater than 4 mm. However, if a detailed analysis of
the individual size fractions is required, it is essential to use the first technique.
A preliminary sieving on the smallest aperture size sieve is recommended when the sample contains a
large proportion of very fine material.
6.2 Dry sieving
6.2.1 Sample of maximum particle size greater than 22,4 mm
The following procedure applies:
a) Weigh the sample to be
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