ISO 540:2008
(Main)Hard coal and coke -- Determination of ash fusibility
Hard coal and coke -- Determination of ash fusibility
ISO 540:2008 specifies a method of determining the characteristic fusion temperatures of ash from coal and coke.
Houille et coke -- Détermination de la fusibilité des cendres
General Information
RELATIONS
Standards Content (sample)
INTERNATIONAL ISO
STANDARD 540
Fourth edition
2008-06-01
Hard coal and coke — Determination of
ash fusibility
Houille et coke — Détermination de la fusibilité des cendres
Reference number
ISO 540:2008(E)
ISO 2008
---------------------- Page: 1 ----------------------
ISO 540:2008(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT© ISO 2008
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2008 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 540:2008(E)
Contents Page
Foreword............................................................................................................................................................ iv
Introduction ........................................................................................................................................................ v
1 Scope ..................................................................................................................................................... 1
2 Normative references ........................................................................................................................... 1
3 Terms and definitions........................................................................................................................... 1
4 Principle................................................................................................................................................. 2
5 Reagents................................................................................................................................................ 2
6 Apparatus .............................................................................................................................................. 2
7 Test conditions ..................................................................................................................................... 4
7.1 Test atmosphere ................................................................................................................................... 4
7.2 Shape of test piece ............................................................................................................................... 4
8 Calibration check.................................................................................................................................. 7
9 Preparation of the test piece ............................................................................................................... 7
10 Procedure .............................................................................................................................................. 7
11 Precision of the method....................................................................................................................... 8
11.1 Repeatability limit ................................................................................................................................. 8
11.2 Reproducibility limit ............................................................................................................................. 8
12 Test report ............................................................................................................................................. 8
13 Precision statement.............................................................................................................................. 9
Bibliography ..................................................................................................................................................... 10
© ISO 2008 – All rights reserved iii---------------------- Page: 3 ----------------------
ISO 540:2008(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 540 was prepared by Technical Committee ISO/TC 27, Solid mineral fuels, Subcommittee SC 5, Methods
of analysis.This fourth edition cancels and replaces the third edition (ISO 540:1995), which has been technically revised.
iv © ISO 2008 – All rights reserved---------------------- Page: 4 ----------------------
ISO 540:2008(E)
Introduction
The method for determination of the fusibility temperatures of coal ash and coke ash described in this
International Standard provides information about the fusion and melting behaviour of the composite inorganic
constituents of the ash at high temperatures. The standard method is based on the “Seger Cone” method,
which is well known in the ceramic industry, the use of which predates the year 1900. The conditions of the
test, as well as basic studies on the influence of ash chemistry and of gas composition on ash fusibility
temperatures (which have led to the standardization of the method), arose from the pioneering work of
[1]Fieldner, Hall and Field .
In the laboratory, the ash used for the test is a homogeneous mixture prepared from a representative sample
of the coal or coke, and the determination is performed at a controlled rate of heating in either a reducing or
an oxidizing atmosphere. In contrast, under industrial conditions, the complex processes of combustion and
fusion involve heterogeneous mixtures of particles, heating rates (that can be several orders of magnitude
greater than those used in the standard test) and variable gas composition.During the first quarter of the 20th century, laboratory, pilot-scale and field studies were undertaken to
establish that the ash fusibility test can provide a reasonable indication of the propensity of ash to form fused
[2]deposits (referred to as “clinker”) in stoker and other fuel-bed type furnaces (Nicholls and Selvig ).
Subsequently, the test has been used as a general indicator of the tendency for ash to fuse on heating and of
ash slagging propensity in pulverized coal-fired furnaces.© ISO 2008 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 540:2008(E)
Hard coal and coke — Determination of ash fusibility
1 Scope
This International Standard specifies a method of determining the characteristic fusion temperatures of ash
from coal and coke.NOTE Descriptors: fossil fuels, solid fuels, ash, ashes, tests, high temperature tests, determination, and fusibility.
2 Normative referencesThe 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.ISO 1171, Solid mineral fuels — Determination of ash
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
deformation temperature
temperature at which the first signs of rounding, due to melting, of the tip or edges of the test piece occur
NOTE Shrinkage or distortion of the test piece, or rounding of cracks and fins, are not criteria for deformation and
should be ignored if the tip and edges remain sharp. However, for some solid mineral fuels, the temperature at which the
test piece shrinkage begins can be of interest and should be reported as a feature noted during the determination.
3.2sphere temperature
in the case of pyramidal and truncated-cone test pieces, the temperature at which the height is equal to the
width of the base, and in the case of cubical or cylindrical test pieces, the temperature at which the edges of
the test pieces become completely round with the height remaining unchanged3.3
hemisphere temperature
temperature at which the test piece forms approximately a hemisphere, i.e. when the height becomes equal to
half the base diameter3.4
flow temperature
temperature at which the ash melt is spread out over the supporting tile in a layer, the height of which is
one-third of the height of the test piece at the hemisphere temperature© ISO 2008 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 540:2008(E)
4 Principle
A test piece made from the ash is heated under standard conditions and continuously observed. The
temperatures at which characteristic changes of shape occur are recorded. The characteristic temperatures
are defined in Clause 3. (See also Figures 2, 3 and 4.)Although the determination is usually performed in a reducing atmosphere, additional information can
sometimes be obtained by performing a further determination in an oxidizing atmosphere. In general, the
reducing atmosphere in 7.1 gives the lowest characteristic temperatures.5 Reagents
5.1 Dextrin, 100 g/l solution.
Dissolve 10 g of dextrin in 100 ml of water.
5.2 Petroleum jelly.
5.3 Gold wire, of diameter 0,5 mm or larger, or gold plate, of thickness 0,5 mm to 1,0 mm, with a purity of
99,99 % and a melting point of 1 064 °C.5.4 Nickel wire, of diameter 0,5 mm or larger, or nickel plate, of thickness 0,5 mm to 1,0 mm, with a purity
of 99,9 % and a melting point of 1 455 °C.5.5 Palladium wire, of diameter 0,5 mm or larger, or palladium plate, of thickness 0,5 mm to 1,0 mm with
a purity of 99,9 % and a melting point of 1 554 °C.5.6 Carbon dioxide.
5.7 Hydrogen or carbon monoxide.
6 Apparatus
6.1 Furnace, electrically heated, which satisfies the following conditions.
a) It shall be capable of reaching the maximum temperature at which the properties of the ash are
determined (a temperature of 1 500 °C or more can be required).NOTE Some furnaces can have a practical upper operating temperature, e.g. 1 480 or 1 540 °C, due to the type of
heating elements used in their manufacture.b) It shall provide an adequate zone of uniform temperature in which to heat the test piece(s).
c) It shall provide means of heating the test piece(s) at a uniform rate from 815 °C upwards.
d) It shall be capable of maintaining the required test atmosphere (see 7.1) around the test piece(s).
e) It shall provide a means of observing the change of shape of the test piece(s) during heating.
It is recommended to provide a facility for inserting, between the end window of the furnace and the optical
viewing instrument, a piece of cobalt-blue or similar glass to protect the retina of the operator from radiation
emitted at elevated temperatures.6.2 Pyrometer, comprised of a platinum/platinum-rhodium thermocouple.
The thermocouple is positioned so that the thermo-junction is on the longitudinal axis in the centre of the zone
of uniform temperature.6.3 Mould, of brass, stainless steel, or other suitable material, for preparing the test piece. (See example in
Figure 1.)2 © ISO 2008 – All rights reserved
----------
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.