1、BS ISO 540:2008ICS 73.040; 75.160.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDHard coal and coke Determination of ashfusibilityThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 July 2008 BSI 2008ISBN 9
2、78 0 580 56507 6Amendments/corrigenda issued since publicationDate CommentsBS ISO 540:2008National forewordThis British Standard is the UK implementation of ISO 540:2008. Itsupersedes BS 1016-113:1995 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/
3、16, Solid mineral fuels.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot
4、 confer immunityfrom legal obligations.BS ISO 540:2008Reference numberISO 540:2008(E)ISO 2008INTERNATIONAL STANDARD ISO540Fourth edition2008-06-01Hard coal and coke Determination of ash fusibility Houille et coke Dtermination de la fusibilit des cendres BS ISO 540:2008ISO 540:2008(E) PDF disclaimer
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8、OCUMENT 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 ISOs member b
9、ody 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 copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2008 All rights reservedBS ISO 540:2008ISO 540:2008(E) ISO 2008 All rights reserved iiiCont
10、ents 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 Preci
11、sion of the method. 8 11.1 Repeatability limit . 8 11.2 Reproducibility limit . 8 12 Test report . 8 13 Precision statement 9 Bibliography . 10 BS ISO 540:2008ISO 540:2008(E) iv ISO 2008 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of
12、 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. Int
13、ernational 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 t
14、he 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
15、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
16、/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. BS ISO 540:2008ISO 540:2008(E) ISO 2008 All rights reserved vIntroduction The method for determination of the fusibility
17、 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 cer
18、amic 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 Fieldner, Hall
19、 and Field 1. 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,
20、 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 fi
21、eld studies were undertaken to establish that the ash fusibility test can provide a reasonable indication of the propensity of ash to form fused deposits (referred to as “clinker”) in stoker and other fuel-bed type furnaces (Nicholls and Selvig 2). Subsequently, the test has been used as a general i
22、ndicator of the tendency for ash to fuse on heating and of ash slagging propensity in pulverized coal-fired furnaces. BS ISO 540:2008BS ISO 540:2008INTERNATIONAL STANDARD ISO 540:2008(E) ISO 2008 All rights reserved 1Hard coal and coke Determination of ash fusibility 1 Scope This International Stand
23、ard 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 references The following referenced documents are indispensable f
24、or 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 doc
25、ument, the following terms and definitions apply. 3.1 deformation temperature DT 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 deformat
26、ion 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. 3.2 sphere temperature ST in the case of pyramidal and t
27、runcated-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 unchanged 3.3 hemisphere temperature HT tem
28、perature at which the test piece forms approximately a hemisphere, i.e. when the height becomes equal to half the base diameter 3.4 flow temperature FT 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 piec
29、e at the hemisphere temperature BS ISO 540:2008ISO 540:2008(E) 2 ISO 2008 All rights reserved4 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 temp
30、eratures 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 giv
31、es 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
32、.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 5
33、54 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 req
34、uired). 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
35、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 ins
36、erting, 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 p
37、ositioned 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.) BS ISO 540:2008ISO 540:2008(E) ISO 2008 All rights reserved 3
38、Dimensions in millimetres Key 1 base plate 2 mould(s) Figure 1 An example of a mould that is suitable for making a pyramidal specimen BS ISO 540:2008ISO 540:2008(E) 4 ISO 2008 All rights reserved6.4 Support for the test piece, of such a material that the support does not either become distorted or r
39、eact with or absorb the ash during the determination. Supports of sintered alumina or fine-textured mullite are generally satisfactory, but difficulties can arise with individual ashes, in which case a non-absorbent interface such as platinum foil can be used between the original support and the tes
40、t piece. 6.5 Flowmeters, two, for measuring the components of the reducing gases (see 7.1); it is not necessary to measure the flow rate when using an oxidizing gas. If the flowmeter contains a liquid, this liquid shall be a non-volatile oil. 6.6 Agate mortar and pestle. 6.7 Test sieve, of aperture
41、0,075 mm (or less) and diameter of approximately either 100 mm or 200 mm, complete with lid and receiver. 6.8 Optical instrument, which enables the profile of the test piece to be observed throughout the determination. The relative dimensions of the profile can be conveniently assessed by using a gr
42、aticule. Additional use of photographic equipment such as a camera or video equipment is optional but recommended. 7 Test conditions 7.1 Test atmosphere The reducing atmosphere is obtained by introducing into the furnace one of the following mixtures of gases at a minimum linear rate of flow past th
43、e test piece of 400 mm/min, calculated at ambient room temperature; the rate is not critical, provided that it is sufficient to prevent any leakage of air into the furnace: a) 55 volume % to 65 volume % carbon monoxide with 35 volume % to 45 volume % carbon dioxide; or b) 45 volume % to 55 volume %
44、hydrogen with 45 volume % to 55 volume % carbon dioxide. NOTE 1 If a mixture of CO/CO2is used to produce the reducing atmosphere, ensure that the contents are totally mixed in accordance with manufacturers instructions and that the temperature of the cylinder is maintained above the critical tempera
45、ture at which CO2can liquefy and separate. NOTE 2 Ashes rich in iron oxide can react with any oxygen present in the furnace, resulting in poor repeatability and reproducibility of characteristic temperatures. An oxidizing atmosphere is obtained with air or carbon dioxide; the rate of flow is not cri
46、tical. WARNING When using the reducing atmospheres given above, the gases emerging from the furnace contain a proportion of carbon monoxide. It is essential, therefore, to ensure that these gases are vented to the outside atmosphere, preferably by means of a hood or an efficient fan system. If hydro
47、gen is used in the reducing atmosphere, great care shall be taken to prevent an explosion occurring, by purging the furnace with carbon dioxide both prior to the introduction of the hydrogen and after the hydrogen supply is shut off. 7.2 Shape of test piece The test piece shall have sharp edges to f
48、acilitate observation. The mass of the test piece shall be such as to ensure equalization of the temperature within the test body. Hence, dimensions that are too large shall be avoided. BS ISO 540:2008ISO 540:2008(E) ISO 2008 All rights reserved 5The following shapes are acceptable: a) pyramid, the
49、base of which is an equilateral triangle; the height shall not exceed 12 mm and shall be two to three times the length of the side of the base (see Figure 2); b) cube of side 3 mm to 7 mm; (see Figure 3); c) upright cylinder of height 3 mm to 9 mm and with diameter equal to the height (see Figure 3); d) truncated cone of height 4 mm and with diameters 3 mm at the base and 1,5 mm at the top (see Figure 4). If, when using the pyramidal test piece, the degree of bending becomes severe enough to preclude the direct observation
