BS ISO 5071-1-2013 Brown coals and lignites Determination of the volatile matter in the analysis sample Two-furnace method《褐煤 分析试样中挥发物的测定 双熔炼法》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 5071-1:2013Brown coals and lignites Determination of the volatilematter in the analysis samplePart 1: Two-furnace methodBS ISO 5071-1:2013 BRITISH STANDARDNational forewor

2、dThis British Standard is the UK implementation of ISO 5071-1:2013.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/16, Solid mineral fuels.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purpor

3、t to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 81217 0ICS 73.040Compliance with a British Standard cannot confer immunity fromlegal obligations.This

4、 British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 May 2013.Amendments issued since publicationDate Text affectedBS ISO 5071-1:2013 ISO 2013Brown coals and lignites Determination of the volatile matter in the analysis sample Part 1: Two-furnace me

5、thodCharbons bruns et lignites Dtermination des matires volatiles dans lchantillon pour analyse Partie 1: Mthode avec utilisation de deux foursINTERNATIONAL STANDARDISO5071-1Second edition2013-05-01Reference numberISO 5071-1:2013(E)BS ISO 5071-1:2013ISO 5071-1:2013(E)ii ISO 2013 All rights reservedC

6、OPYRIGHT PROTECTED DOCUMENT ISO 2013All 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 per

7、mission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 5071-1:20

8、13ISO 5071-1:2013(E) ISO 2013 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents 16 Apparatus . 27 Sample . 68 Procedure. 68.1 Preliminary procedure . 68.2 Predetermination procedure 68.3 Method using ove

9、n-dried coal . 68.4 Method using air-dried coal 69 Calculation of results . 69.1 For oven-dried coal . 79.2 For air-dried coal. 710 Precision of the method 710.1 Repeatability limit 710.2 Reproducibility limit 711 Test report . 8BS ISO 5071-1:2013ISO 5071-1:2013(E)ForewordISO (the International Orga

10、nization 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 establis

11、hed 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

12、.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. Pub

13、lication 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

14、rights.ISO 5071-1 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 5071-1:1997), of which this constitutes a minor revision.ISO 5071 consists of the following parts, under the ge

15、neral title Brown coals and lignites Determination of volatile matter in the analysis sample:Part 1: Two-furnace methodiv ISO 2013 All rights reservedBS ISO 5071-1:2013ISO 5071-1:2013(E)IntroductionThe volatile matter is determined as the loss in mass, corrected for moisture, when an analysis sample

16、 of brown coal or lignite is heated out of contact with air under specified conditions. The test is empirical and, in order to obtain reproducible results, it is essential that the rate of heating, the final temperature and the overall duration of the test be carefully controlled. Due to the nature

17、of brown coals and lignites, initial heating of the sample at 400 C is necessary to minimize the possibility of ejection of sample from the test crucible.Mineral matter associated with the sample may also lose mass under the conditions of the test, the magnitude of the loss being dependent on both t

18、he nature and the quantity of the minerals present. ISO 2013 All rights reserved vBS ISO 5071-1:2013BS ISO 5071-1:2013Brown coals and lignites Determination of the volatile matter in the analysis sample Part 1: Two-furnace method1 ScopeThis part of ISO 5071 specifies a method of determining the vola

19、tile matter of brown coals and lignites.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 amendmen

20、ts) applies.ISO 1170, Coal and coke Calculation of analyses to different basesISO 1213-2, Solid mineral fuels Vocabulary Part 2: Terms relating to sampling, testing and analysisISO 5068-2, Brown coals and lignites Determination of moisture content Part 2: Indirect gravimetric method for moisture in

21、the analysis sampleISO 5069-2, Brown coals and lignites Principles of sampling Part 2: Sample preparation for determination of moisture content and for general analysis3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 1213-2 apply.4 PrincipleThe coal is

22、 heated out of contact with air for 7 min at 400 C, then immediately transferred to another furnace and heated at 900 C for a further 7 min. The percentage of volatile matter is calculated from the loss in mass of the oven-dried sample or from the loss in mass of the analysis sample corrected for mo

23、isture.5 Reagents5.1 Desiccants, fresh or freshly regenerated and preferably self-indicating. Suitable desiccants are magnesium perchlorate, silica gel, activated alumina and anhydrous calcium sulfate.WARNING Magnesium perchlorate is a strong oxidizing agent. Do not attempt to regenerate the absorbe

24、nt. Do not permit contact with organic materials or reducing agent.5.2 Nitrogen, dry, with a maximum oxygen content of 30 l per litre.INTERNATIONAL STANDARD ISO 5071-1:2013(E) ISO 2013 All rights reserved 1BS ISO 5071-1:2013ISO 5071-1:2013(E)6 Apparatus6.1 Furnace (Figure 1), heated by electricity.

25、Two such furnaces are required. One furnace shall have a zone of 160 mm 100 mm maintained at a uniform temperature of 400 C 10 C. The second shall have a zone of 160 mm 100 mm maintained at a uniform temperature of 900 C 5 C. The furnaces may be the stop-ended type or fitted at the back with a flue

26、approximately 25 mm in diameter by 150 mm long.The heat capacity of the 900 C and/or 400 C furnace shall be such that, with an initial temperature of 900 C and/or 400 C, a temperature of 900 C 10 C and/or 400 C 10 C is regained within 4 min after insertion of a cold stand and its crucibles. The temp

27、erature shall be measured with a thermocouple as described in 6.3. The furnace can be designed specifically either for multiple determinations using a number of crucibles in one stand or for receiving one crucible and its stand. A position for the crucible stand shall be chosen within the zone of un

28、iform temperature and this position used for all determinations.6.2 Oven, capable of being controlled at a temperature within the range 105 C to 110 C and with provision for passing a current of dry, oxygen-free nitrogen through it at a rate sufficient to change the atmosphere 15 times per hour. The

29、 size of the chamber is suitable for containing the crucible (6.4).6.3 Thermocouple, unsheathed, of wire not thicker than 1 mm, used to check the temperature characteristics of the furnace. The thermo-junction shall be inserted midway between the base of the crucible in its stand and the floor of th

30、e furnace. If the stand holds more than one crucible, the temperature under each crucible shall be checked in the same manner. If desired, a sheathed thermocouple may be permanently installed in the furnace with its thermo-junction as close as possible to the centre of the zone of uniform temperatur

31、e; in this case, its temperature readings shall be correlated at frequent intervals with those of the unsheathed thermocouple, which is then inserted only when necessary.NOTE The temperature/electromotive force relationship of a thermo-junction maintained at elevated temperatures gradually changes w

32、ith time.6.4 Crucible and lid, a cylindrical crucible with a well fitting lid, both made of fused silica. The crucible and lid shall weigh between 10 g and 14 g and have dimensions approximating those shown in Figure 2. The fit of the lid on the crucible is critical to the determination and a lid sh

33、all be selected to match the crucible so that the horizontal clearance between them is not greater than 0,5 mm. After selection, the crucible and the lid shall be ground together to give smooth surfaces and then be given a common distinguishing mark. Crucibles of other refractory materials, or of pl

34、atinum, can be used, provided that they give results which agree with the recommended silica crucible, within the stated precision of the method (Clause 10).6.5 Stand, on which the crucible is placed in the muffle furnace, so that the appropriate specified rate of heating can be achieved. For exampl

35、e, it may consist of the following:a) for a single determination, a ring of heat-resistant steel wire as shown in Figure 3 a), 27 mm in diameter and 1,5 mm thick, resting on the inner projection of its legs,orb) for multiple determinations, a tray of heat-resistant steel wire as shown in Figure 3 b)

36、, of appropriate size, with ceramic plates 2 mm thick supporting the crucibles.6.6 Balance, sensitive to 0,1 mg.6.7 Desiccator.2 ISO 2013 All rights reservedBS ISO 5071-1:2013ISO 5071-1:2013(E)Dimensions in millimetresKey1 heating system2 flue3 thermocoupleaChamber width is 200 mm.Figure 1 Example o

37、f a suitable furnace ISO 2013 All rights reserved 3BS ISO 5071-1:2013ISO 5071-1:2013(E)Dimensions in millimetresFigure 2 Silica crucible and lid4 ISO 2013 All rights reservedBS ISO 5071-1:2013ISO 5071-1:2013(E)Dimensions in millimetresa) Suitable for a single determinationb) Suitable for multiple de

38、terminationsKey1 three legs spaced 120 apart 3 handle2 ring 4 ceramic platesFigure 3 Crucible stands ISO 2013 All rights reserved 5BS ISO 5071-1:2013ISO 5071-1:2013(E)7 SamplePrepare the sample for the determination of volatile matter in the analysis sample in accordance with ISO 5069-2.8 Procedure8

39、.1 Preliminary procedureAdjust the temperature of the zone in the furnaces (6.1), loaded with a stand and empty crucibles where appropriate, to 400 C 10 C and 900 C 5 C respectively, as indicated by the correctly unsheathed thermocouple (6.3). Remove the stand and crucibles and close the doors of th

40、e furnace. Heat, in a furnace (6.1) at 900 C for 7 min, either one crucible and lid (6.4) or the requisite number of crucibles and lids to fill the multiple stand. Remove the crucible(s) from the furnace and cool them, first on a metal slab and finally in a desiccator (6.7) located next to the balan

41、ce. As soon as they are cool, weigh each empty crucible and lid. Record the mass(es) of the preconditioned crucibles and lids to the nearest 0,1 mg (8.4, Note 1).8.2 Predetermination procedureBefore commencing the determination, mix the analysis sample for at least 1 min, preferably by mechanical me

42、ans. Accurately weigh 1,00 g to 1,01 g of sample (Clause 7) to the nearest 0,1 mg into each preconditioned crucible. Replace the lid and tap the crucible on a clean hard surface until the sample forms a layer of even thickness on the bottom of the crucible. Proceed in accordance with either 8.3 or 8

43、.4 depending on whether or not the coal has been oven-dried or air-dried.8.3 Method using oven-dried coalPlace the charged crucible(s), with lid(s) removed, in the oven (6.2) at 105 C to 110 C. Dry the sample(s) to constant mass in accordance with the procedure for moisture determination specified i

44、n ISO 5068-2. Record the mass(es) of the oven-dried crucible(s), lid(s) and sample(s) to the nearest 0,1 mg.Place the crucible(s) fitted with lid(s) containing the oven-dried sample(s) in a suitable stand (8.4, Note 2) and transfer to the furnace set at 400 C for 7 min. Immediately transfer to the f

45、urnace set at 900 C for a further 7 min.Remove the crucible(s) and cool and weigh them in the same manner as for empty crucible(s) (see 8.1). If ash deposits are visible on the stand or crucible(s) then discard the test and repeat (8.4, Note 3).8.4 Method using air-dried coalPlace the charged crucib

46、le(s) with the lid(s) in a suitable cool stand (Note 2) and transfer to the muffle furnace set at 400 C for 7 min. Immediately transfer to the furnace set at 900 C for a further 7 min. Remove the crucible(s) and cool and weigh them in the same manner as for the empty crucible(s) (see 8.1).NOTE 1 Pre

47、cisely similar treatment of the crucible(s) and lid(s) before and after the determination minimizes the effect of any film of water absorbed on its surface, while the rapid cooling reduces absorption of moisture by the coal residue.NOTE 2 If multiple determinations are being made, fill any vacant pl

48、aces in the stand with empty crucibles.NOTE 3 Certain brown coals and lignites may consistently produce ash deposits either on the crucible lid or the sample tray when tested using the two-furnace procedure. In such a case, it is recommended to press the air-dried sample into small pellets, then det

49、ermine the volatile matter.9 Calculation of resultsCalculate the percentage by mass of volatile matter on a dry basis, Vd, according to the formulas in 9.1 and 9.2.6 ISO 2013 All rights reservedBS ISO 5071-1:2013ISO 5071-1:2013(E)9.1 For oven-dried coalVmmmmd=1002321()wherem1is the mass, in grams, of the empty crucible and lid (8.1);m2is the mass, in grams,of crucible, lid and oven-dried sample (8.3;m3is the mass, in grams, of crucible, lid and sample after heatin