ISO 15585:2019

INTERNATIONAL ISO
STANDARD 15585
Second edition
2019-12
Hard coal — Determination of caking
index
Houille — Détermination de l'indice d'agglutination
Reference number
©
ISO 2019
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagent and materials . 1
6 Apparatus . 1
7 Preparation of test sample . 5
8 Procedure. 6
9 Expression of results . 6
10 Precision . 7
10.1 Repeatability limit . 7
10.2 Reproducibility limit . 7
11 Test report . 7
Annex A (informative) Extraction and preparation of standard anthracite
for caking index determination . 8
Annex B (informative) Quality test for standard anthracite used for caking index determination .9
Bibliography .12
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 27, Solid mineral fuels, Subcommittee
SC 5, Methods of analysis.
This second edition cancels and replaces the first edition (ISO 15585:2006), which has been technically
revised. The main changes compared to the previous edition are as follows:
— Change to test precision (both for repeatability, r, and reproducibility, R) resulting from ILS
conducted in 2016 and 2017.
— Additional information provided on anthracite sample packing and homogeneity test in Annex A
and standard deviation formula and flowchart for standard anthracite sample taking in Annex B.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2019 – All rights reserved

Introduction
Caking index is a key parameter to identify the caking power of hard coal, which is a measurement
of the agglutinating strength between the coal particles and inert constituents after heating without
the contact of air. Coal caking characteristic is important and widely used in coking, gasification,
liquefaction and combustion industries.
INTERNATIONAL STANDARD ISO 15585:2019(E)
Hard coal — Determination of caking index
1 Scope
This document specifies a method of determination of caking index of hard coal. It is applicable to the
evaluation of caking power of bituminous coal with random reflectance of vitrinite, R , greater than
r
0,6 % and less than or equal to 1,8 % (>0,6 % and ≤1,8 %).
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
caking index
measure of the magnitude of the binding strength between coal particles or between coal particles and
inert particles after coal is heated at 850 °C
4 Principle
A portion of prepared sample of coal of limited size range and the standard anthracite are mixed under
defined conditions, and the mixture is carbonized rapidly. The crucible coke thus obtained is tested
for strength in a drum conforming to certain specifications. The caking power of the test sample is
expressed by the abrasive strength, i.e. resistance to breakage of the crucible coke.
5 Reagent and materials
5.1 Standard anthracite, having a moisture of less than 2,5 % in mass fraction, air-dried basis, an
ash of less than 4 % in mass fraction, dry basis and a volatile matter of less than 8 % in mass fraction,
dry, ash free basis. The size limits are 0,1 mm to 0,2 mm. The undersize content of 0,1 mm should not be
more than 6 % in mass fraction, and the oversize content of 0,2 mm should not be more than 4 % in mass
fraction.
NOTE Annexes A and B provide information on the extraction, preparation and testing of standard
anthracite.
6 Apparatus
6.1 Balance, analytical balance with a resolution of at least 0,1 % relative of the test portion mass.
6.2 Crucible, porcelain, having the following dimensions (see Figure 1):
a) external diameter at the top: 40 mm ± 1,5 mm;
b) internal diameter at the base: 20 mm ± 1,5 mm;
c) external height: 40 mm ± 1,5 mm;
d) wall thickness: less than 2 mm.
Dimensions in millimetres
Figure 1 — Crucible and lid
6.3 Lid, porcelain, 1,5 mm to 2,0 mm thick, with a hole 2 mm in diameter in the centre (see Figure 1).
6.4 Stirrer, made of 1,0 mm to 1,5 mm diameter metal wire, having an 8 mm loop at one end (see
Figure 2).
2 © ISO 2019 – All rights reserved

Dimensions in millimetres
Figure 2 — Stirrer
1)
6.5 Heat resistant weight, composed for example of Nichrome steel , with a mass of 110 g to 115 g
(see Figure 3).
Dimensions in millimetres
Figure 3 — Heat resistant weight
6.6 Press, for compressing the mixture of coal and standard anthracite under a weight having a 6 kg
mass (see Figure 4).
1) Nichrome is an example of a suitable product available commercially. This information is given for the
convenience of users of this document and does not constitute an endorsement by ISO of this product.
Dimensions in millimetres
Key
1 bottom plate 6 dead plate 11 carriage
2 screw 7 back-up shaft 12 hand knob
3 round base 8 small shaft 13 press
4 steel tube 9 dump 14 lighting vertical shaft
5 connecting board 10 forelock 15 plug
Figure 4 — Press used for compressing the mixture of anthracite and test coal
6.7 Electric furnace, with a zone of uniform temperature and a temperature control device capable of
maintaining that zone at 850 °C ± 10 °C.
6.8 Drum, with a cover, driving shaft, transmission gear and electric motor for carrying out the
abrasion test on coke.
The drum (see Figure 5) has a 200 mm internal diameter, is 70 mm deep and is made of 3 mm thick
sheet iron. To the inside walls are welded two symmetrical sheet iron strips 70 mm long, 30 mm wide
4 © ISO 2019 – All rights reserved

and 2 mm thick. To close the drum, the cover is seated on a felt or rubber gasket and is secured by two
wing-nuts. The drum is rotated with the stub axle horizontal at (50 ± 0,5) r/min.
Dimensions in millimetres
Figure 5 — Drum used for test
6.9 Laboratory sieve, made of thin brass sheet or stainless steel sheet, with 1 mm round holes.
6.10 Stopwatch.
6.11 Brush.
6.12 Long handled tongs or rod, suitable for moving the weight.
7 Preparation of test sample
7.1 Crush the sample of air-dried coal to pass a 0,2 mm test sieve. Take care to avoid an excessive
production of particles below 0,1 mm. It is essential that 20 % to 40 % mass fraction of the total sample
consists of particles between 0,1 mm and 0,2 mm.
7.2 The test sample shall be kept in a tightly closed container. Determine caking index of the sample on
the same day after its preparation. Otherwise, refrigeration of prepared sample or maintaining it under
inert gases or other anti- oxidation method should be used to minimize oxidation, and the time between
preparation of the sample and carrying out the test shall not exceed 5 days.
7.3 Before commencing the determination, mix the analysis sample for at least 1 min.
8 Procedure
8.1 Carry out duplicate determinations on each sample of coal. These determinations shall not be
carried out simultaneously, but for convenience, the second crucible may be heated in the furnace at the
same time as the first.
8.2 Weigh a clean, dry crucible (6.2). Place in it 1,00 g of the coal and 5,00 g of the standard anthracite
(5.1). Both weighed to an accuracy of 0,01 g. Mix carefully for 2 min with the stirrer (6.4), level off the
surface and place the heat resistant weight (6.5) on it. Press the whole for at least 30 s under the weight
having a 6 kg mass (6.6). Remove the crucible from the press and cover it with the lid (6.3), leaving the
heat resistant weight in the crucible.
8.3 Raise the temperature of the furnace to about 850 °C and insert the crucible. Check the temperature
on the floor of the furnace at the side of the crucible and ensure that the temperature of 850 °C ± 10 °C
is regained within 6 min from the insertion of the crucible, then keep the temperature of 850 °C ± 10 °C,
...