1、 Reference number ISO 23873:2010(E) ISO 2010INTERNATIONAL STANDARD ISO 23873 First edition 2010-11-15 Hard coal Method for the measurement of the swelling of hard coal using a dilatometer Houille Mthode pour le mesurage du gonflement de la houille au moyen dun dilatomtre ISO 23873:2010(E) PDF discla
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5、TED DOCUMENT ISO 2010 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 mem
6、ber 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 copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2010 All rights reservedISO 23873:2010(E) ISO 2010 All rights reserved iiiContents Pag
7、e Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Principle .2 5 Materials .2 6 Apparatus.2 6.1 Mould and accessories.2 6.2 Dilatometer.3 6.3 Dilatometer furnace.3 6.4 Temperature controller .4 6.5 Temperature recorder .4 6.6 Retort and piston.4 6.7 Means of
8、recording piston movement 4 6.8 Cleaning instruments4 7 Procedure.5 7.1 Temperature calibration5 7.2 Preparation of test sample and test pieces 5 7.3 Determination 6 8 Expression of results7 9 Precision 8 9.1 Repeatability 8 9.2 Reproducibility 8 10 Test report8 ISO 23873:2010(E) iv ISO 2010 All rig
9、hts reservedForeword 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 f
10、or 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
11、 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 a
12、re 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
13、responsible for identifying any or all such patent rights. ISO 23873 was prepared by Technical Committee ISO/TC 27, Solid mineral fuels, Subcommittee SC 5, Methods of analysis. ISO 23873:2010(E) ISO 2010 All rights reserved vIntroduction The dilatation of coal has been primarily measured by two diff
14、erent standard procedures: the Ruhr dilatometer and the Audibert-Arnu dilatometer. Both of the methods were very similar, having the same basic apparatus and heating rate but using different initial masses of coal arising from the method of pencil preparation. This International Standard combines th
15、e two previous procedures by adjusting the equipment specification to define a single acceptable method. INTERNATIONAL STANDARD ISO 23873:2010(E) ISO 2010 All rights reserved 1Hard coal Method for the measurement of the swelling of hard coal using a dilatometer 1 Scope This International Standard de
16、scribes a method for the measurement of the swelling of hard coal using a dilatometer. 2 Normative references The 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
17、 the referenced document (including any amendments) applies. ISO 1213-2, Solid mineral fuels Vocabulary Part 2: Terms relating to sampling, testing and analysis ISO 13909-4, Hard coal and coke Mechanical sampling Part 4: Coal Preparation of test samples 3 Terms and definitions For the purposes of th
18、is document, the terms and definitions given in ISO 1213-2 and the following apply. 3.1 softening temperature temperature of initial contraction temperature at which the downward movement of the dilatometer piston is 0,5 mm NOTE See temperature 1in Figure 3. 3.2 temperature of maximum contraction te
19、mperature at which the dilatometer piston reaches its lowest point NOTE See temperature 2in Figure 3. 3.3 temperature of maximum dilatation temperature at which the dilatometer piston reaches its highest point NOTE See temperature 3in Figure 3. 3.4 maximum contraction maximum downward movement of th
20、e dilatometer piston, measured from the zero point NOTE 1 Maximum contraction is expressed as a percentage of the initial test-piece length. NOTE 2 See c in Figures 3 and 4. ISO 23873:2010(E) 2 ISO 2010 All rights reserved3.5 maximum dilatation maximum upward movement of the dilatometer piston after
21、 contraction, measured from the zero point NOTE 1 Maximum dilatation is expressed as a percentage of the initial test-piece length. NOTE 2 See d in Figures 3 and 4. The value can be either positive or negative. 3.6 repeatability maximum acceptable difference between two determinations which are carr
22、ied out in the same laboratory, by the same operator with the same apparatus, on test pieces prepared from the same test sample and tested simultaneously in two different retorts during the same heating cycle or separately in the same retort during different heating cycles 3.7 reproducibility maximu
23、m acceptable difference between the means of two determinations which are carried out in each of two laboratories, on representative portions taken from the same gross sample, after the last stage of sample preparation 4 Principle A test piece, in the form of a pencil, prepared from powdered coal is
24、 heated at a constant rate in a steel retort positioned in a furnace, the temperature monitoring system having been previously calibrated using two reference metals of known melting points. The change in level of a piston resting upon the test piece is observed continuously, and a record is produced
25、 which is charateristic of the swelling properties of the coal. 5 Materials The following materials are required for temperature calibration (7.1). 5.1 Graphite pencils, 30 mm long, base diameter 7,4 mm, top diameter 6,8 mm, with a small cylindrical reservoir drilled in the narrow end of each pencil
26、. 5.2 Metal balls, of the following reference metals: a) lead, of analytical reagent grade, assay (Pb) 99,98 % minimum, melting point 327,0 C; b) zinc, assay (Zn) 99,87 % minimum, melting point 419,3 C. 5.3 Water-based blacking. 6 Apparatus 6.1 Mould and accessories 6.1.1 Mould (see Figure 1), made
27、from steel, case-hardened after machining. The bore shall be polished after hardening and the bore and uniformity of taper (i.e 1 in 50) shall conform to the dimensions given in Table 1. 6.1.2 Mallet, plastics head, mass about 200 g. 6.1.3 Ram (see Figure 1). ISO 23873:2010(E) ISO 2010 All rights re
28、served 36.1.4 Press (see Figure 1). 6.1.5 Load cell (see Figure 1), capable of registering a load of 0 to 15 kN. 6.1.6 Pencil gauge (see Figure 1). Table 1 Dimensions of mould Distance from wide end Bore (tolerance: 0,00, +0,005) 0 10 20 30 40 50 60 70 7,4 7,2 7,0 6,8 6,6 6,4 6,2 6,0 6.2 Dilatometer
29、 A general arrangement of suitable dilatometer apparatus giving critical dimensions is shown in Figure 2. 6.3 Dilatometer furnace A furnace capable of heating two or more retorts (6.6) to a temperature of 550 C at a rate of 3 C/min is used. A suitable furnace (for heating three retorts) is illustrat
30、ed in Figure 2 and consists of a casing fitted with a base and a top cover. The cover supports a cylindrical block of copper-aluminium alloy CA 104, of 65 mm diameter and 460 mm long. The block has three holes of 380 mm minimum depth and 15,0 mm 0,1 mm diameter, drilled as shown in Figure 2. The top
31、 surface may be insulated by an appropriately shaped piece of board. The block is heated electrically by an insulated resistance winding, capable of raising the temperature of the block to 550 C at a rate of 3C/min. The space between the block and the casing is filled with a thermal insulating mater
32、ial. A suitable temperature sensor is positioned in the third retort in such a way that the sensor tip lies centrally 30 mm above the internal base of the retort. The distance of 30 mm is established by using a graphite pencil (5.1) as a means of measurement. The furnace shall comply with the follow
33、ing operating conditions. Heat the furnace to 400 C, measuring the temperature at the standard sensing point, i.e. at a position equivalent to that of the centre of a normally sited test piece 30 mm above the internal base of the sensing retort. Place a second temperature-measuring device (e.g. a pr
34、obe), of similar precision, in one of the other retorts at the same height above its base. If the two devices differ, apply a correction. Heat the furnace at a rate of 3 C/min and, when the temperature has reached about 450 C, measure the temperature over the lower 250 mm of the retort using the pro
35、be. The difference between the corrected probe temperature and the mean temperature shown at the standard temperature-sensing position shall be not more than: 2 C in the lower 120 mm; 5 C from 120 mm to 180 mm; 10 C from 180 mm to 250 mm. ISO 23873:2010(E) 4 ISO 2010 All rights reservedThe instrumen
36、t used to measure the temperature can be either the temperature recorder described in 6.5 or another of at least equal precision. 6.4 Temperature controller The temperature controller shall be a separate instrument from that used to record the rise of temperature during the test. It shall be of the
37、automatic, programmed type capable of maintaining a mean rate of temperature rise of 3 C/min 0,05 C/min between 250 C and 550 C with a variation of not more than 1 C per 30 C rise in any 10 min period, with a precision of 1 C. 6.5 Temperature recorder A suitable means of producing a complete record
38、of the temperature variation during the test. 6.6 Retort and piston A cylindrical retort of cold-drawn seamless tube of steel fitted with a gastight threaded plug at its base and a collar at its top. When inserted in a hole in the furnace, the retort shall be supported only by the collar with the th
39、readed plug clear of the bottom of the hole. When new, the internal diameter of the retort shall be 8,00 mm 0,05 mm and the external diameter shall be 14,5 mm 0,1 mm. Check the internal diameter with a suitable ball gauge when new, and again after 100, 150, 200, etc., tests. If the internal diameter
40、 of the lower third of the retort has increased at any point to more than 8,075 mm, discard the retort. The piston is machined from rod made of steel. Adjust the combined mass of the piston and pen assembly to 150 g 5 g by machining cut-out portions from the piston. The difference between the diamet
41、er of the piston and the internal diameter of the retort shall be 0,2 mm 0,05 mm on manufacture. If this difference exceeds 0,275 mm in use, the piston shall be replaced. The piston shall slide freely in the retort. A stand shall be provided to allow the retorts and pistons to cool in a vertical pos
42、ition after removal from the furnace. 6.7 Means of recording piston movement A suitable means of recording piston movement versus time on a chart shall be used. The horizontal scale (time) shall be such that, when converted to temperature (see 7.3.3), a range of 180 C will occupy a length of at leas
43、t 150 mm. On the vertical scale, 5 % expansion or contraction shall occupy at least 3 mm. This may be achieved either by a mechanical pen/chart system or a transducer/electrical signal recorder. A simple mechanical system is illustrated in Figure 2. In this example, two tests are recorded simultaneo
44、usly on opposite sides of the chart by means of pens clipped firmly to the tops of the pistons. The chart is fixed to a cylinder which is rotated at uniform speed by either a clockwork or a synchronous motor and is mounted on a stand which is clamped to the top of the dilatometer outer casing. 6.8 C
45、leaning instruments 6.8.1 Auger, of diameter approximately 7,8 mm and stem length 400 mm. 6.8.2 Wire brush, of diameter 8 mm and stem length 400 mm. NOTE A wear-resistant steel reamer, of diameter 7,95 mm and stem length 400 mm, can also be used. ISO 23873:2010(E) ISO 2010 All rights reserved 57 Pro
46、cedure 7.1 Temperature calibration Check that the standard temperature sensor is accurate by either of the following procedures. Carry out the operations for each retort in the furnace, other than the retort used for the standard temperature sensor. a) Coat the lower 30 mm of the internal wall and t
47、he screw thread and the sealing plug of the retort, as well as the lower face of the piston (6.6), with a thin layer of blacking (5.3) prior to testing in order to prevent the molten reference metals adhering to the steel construction material. Dry by gentle warming. Place a lead ball 5.2 a) in the
48、recess at the narrow end of a graphite pencil (5.1). Place the pencil in a retort, replace the screw plug and assemble the piston and recording mechanism. Insert the retort assembly into the furnace at a temperature of approximately 280 C and determine the melting point of the lead using the procedu
49、re described in 7.3.3, replacing the test piece (7.2.2) by a prepared graphite pencil. Repeat this procedure using a zinc ball 5.2 b). Before re-using graphite pencils, heat the narrow end of each pencil in a bunsen flame for a few seconds and shake the molten metal from the cylindrical reservoir. b) Place an independently calibrated reference-temperature-measuring device in the retort, with the measurement point 30 mm from the internal base of the retort. Starting at 300 C, ra
