1、BSI Standards PublicationBS ISO 23380:2013Selection of methods forthe determination of traceelements in coalBS ISO 23380:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 23380:2013. Itsupersedes BS ISO 23380:2008 which is withdrawn.The UK participation in i
2、ts 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 purport to include all the necessaryprovisions of a contract. Users are responsible for its correc
3、tapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 81997 1ICS 73.040Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Comm
4、ittee on 30 September 2013.Amendments issued since publicationDate Text affectedBS ISO 23380:2013 ISO 2013Selection of methods for the determination of trace elements in coalSlection des mthodes de dtermination des lments en traces dans le charbonINTERNATIONAL STANDARDISO23380Second edition2013-09-0
5、1Reference numberISO 23380:2013(E)BS ISO 23380:2013ISO 23380:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT 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 mech
6、anical, 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 ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 1
7、1Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 23380:2013ISO 23380:2013(E) ISO 2013 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Abbreviations. 15 Discussion of methods 25.1 Ge
8、neral . 25.2 Arsenic and selenium 25.3 Boron . 25.4 Antimony, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, molybdenum, nickel, thallium, vanadium, zinc, thorium, and uranium 25.5 Chlorine . 35.6 Fluorine . 35.7 Mercury . 36 Use of certified reference materials . 37 Calculation of r
9、esults . 48 Sensitivity 49 Reporting of results . 510 Precision . 611 Test report . 6Annex A (informative) Scheme of analysis for trace elements 7Annex B (informative) Alternative dissolution procedures for coal 8Bibliography 9BS ISO 23380:2013ISO 23380:2013(E)ForewordISO (the International Organiza
10、tion 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
11、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
12、 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 ed
13、itorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directivesAttention 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 i
14、dentified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received. www.iso.org/patentsAny trade name used in this document is information given for the convenience of users and does not constitute an endorsement.The committee responsi
15、ble for this document is ISO/TC 27, Solid mineral fuels, Subcommittee SC 5, Methods of analysis.This second edition cancels and replaces the first edition (ISO 23380:2008), of which it constitutes a minor revision.iv ISO 2013 All rights reservedBS ISO 23380:2013ISO 23380:2013(E)IntroductionThe deter
16、mination of trace elements in coal and coke is becoming more important due to the considerable emphasis being placed on the effect of these elements on the environment. In order to have accurate and precise results for the analysis of trace elements, it is imperative that standard methods be availab
17、le and that these methods be based on reliable procedures.The objective of this International Standard is to assist in the selection of the appropriate methods available to determine the common trace elements in coal. ISO 2013 All rights reserved vBS ISO 23380:2013BS ISO 23380:2013Selection of metho
18、ds for the determination of trace elements in coal1 ScopeThis International Standard provides guidance on the selection of methods used for the determination of trace elements in coal. The trace elements of environmental interest include antimony, arsenic, beryllium, boron, cadmium, chlorine, chromi
19、um, cobalt, copper, fluorine, lead, manganese, mercury, molybdenum, nickel, selenium, thallium, vanadium, and zinc. The radioactive trace elements thorium and uranium can be added to this list.This International Standard does not prescribe the methods used for the determination of individual trace e
20、lements. The analysis of appropriate certified reference materials (CRMs) is essential to confirm the accuracy of any method used (see ISO Guide 33).2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its applicati
21、on. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 1213-2, Solid mineral fuels Vocabulary Part 2: Terms relating to sampling, testing and analysisISO 5725 (all parts), Accuracy (truene
22、ss and precision) of measurement methods and resultsISO Guide 33, Reference Materials Good practice in using reference materials3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 1213-2 apply.4 AbbreviationsAAS atomic absorption spectrometryAFS atomic fl
23、uorescence spectrometryCVAAS cold-vapour atomic absorption spectrometryGFAAS graphite-furnace atomic absorption spectrometryIC ion chromatographyICP-AES inductively coupled plasma atomic emission spectrometry often referred to as ICP-OES, i.e. inductively coupled plasma optical emission spectrometry
24、ICP-MS inductively coupled plasma mass spectrometryINAA instrumental neutron activation analysisISE ion-selective electrodeXRF x-ray fluorescence spectrometryINTERNATIONAL STANDARD ISO 23380:2013(E) ISO 2013 All rights reserved 1BS ISO 23380:2013ISO 23380:2013(E)5 Discussion of methods5.1 GeneralA s
25、ummary of techniques applicable to the determination of each of the trace elements is discussed below. A schematic of procedures used for trace element determinations is given in Annex A.It is critical that moisture be determined on the sample to enable calculation to bases other than “air-dried”.NO
26、TE 1 There are digestion procedures applicable to unashed coal. The application of these is discussed in Annex B.NOTE 2 Boron, chlorine, fluorine, mercury, and selenium are released if coal is ashed; thus, it is not possible to estimate the concentration of these elements in coal by analysing labora
27、tory-prepared ash.Where digestion procedures require ashing of the coal, it is critical to determine the ash yield to enable calculation of trace elements content in the coal sample (see Clause 7). Ashing procedures are described in ISO 152386. Coals are ashed in silica or quartz dishes, or in plati
28、num or platinum alloy crucibles/basins, in a conventional ashing furnace. The furnace temperature is ramped from ambient to a maximum of 500 C over 1 h to 3 h and held at this temperature until the carbonaceous material is completely oxidized or for a maximum of 18 h. The ramp rate is selected to av
29、oid ignition and mechanical loss of sample.5.2 Arsenic and seleniumArsenic and selenium are determined by hydride generation/atomic absorption or atomic fluorescence techniques following the ashing of the coal at 800 C in the presence of Eschka mixture and dissolution with hydrochloric acid. ISO 117
30、233is the recommended method for the determination of arsenic and selenium in coal.Arsenic can be determined in coal by the analysis of ash prepared in a laboratory at a temperature no greater than 500 C. Selenium is vaporized at quite low temperatures and is not recovered in ash. There is no Intern
31、ational Standard for the determination of arsenic in coal ash. A suitable procedure is the dissolution of the ash either by fusion or by mixed acids (nitric, hydrochloric, and hydrofluoric acids) and determination of the analyte by hydride/AAS or hydride/AFS. This element can also be determined by I
32、CP-MS if the interference caused by argon chloride is eliminated.5.3 BoronBoron is determined by ICP-AES following the ashing of the coal at 800 C in the presence of Eschka mixture and dissolution with hydrochloric acid (see AS 1038-10.3). This dissolution procedure is the same as that used for arse
33、nic and selenium. The procedure is set out in ISO 117233.5.4 Antimony, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, molyb-denum, nickel, thallium, vanadium, zinc, thorium, and uranium5.4.1 GeneralAntimony, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, molybdenum, n
34、ickel, thallium, vanadium, zinc, thorium, and uranium are determined by various spectrometric techniques (see ASTM D6357).NOTE 1 A number of these trace elements can be determined by XRF. However, in general, the sensitivity is too low to accurately determine beryllium, cadmium, thallium, thorium, a
35、nd uranium by XRF.Recommended procedures are summarized below.a) The coal sample is ashed at a maximum temperature of 500 C to remove the carbonaceous matter.2 ISO 2013 All rights reservedBS ISO 23380:2013ISO 23380:2013(E)b) The laboratory-prepared ash is dissolved either by fusion (see AS 1038-14.1
36、) or by mixed acids (nitric, hydrochloric, and hydrofluoric acids). These dissolution procedures are applicable to the analysis of coal ash. Note that thorium and uranium can form insoluble fluorides and precautions shall be taken to prevent this in the presence of hydrofluoric acid. Thorium and ura
37、nium can be determined within 2 h of the preparation of a mixed-acid solution of the coal ash or the fluoride can be removed by evaporation.The solution obtained by dissolution procedures in which fluoride is complexed with boric acid can be used for the determination of trace elements by ICP-AES an
38、d ICP-MS.c) The concentrations of the analytes in the solution are determined by spectrometric techniques. Traditionally, AAS has been used. This has generally been replaced by ICP-AES, which is used to determine the majority of these elements with the exception of antimony, cadmium, lead, thallium,
39、 thorium, and uranium. These latter six elements occur in coals at concentrations too low to be determined by ICP-AES but can be accurately determined by ICP-MS.NOTE 2 Cadmium (see ISO 15238) and lead can also be determined by GFAAS.5.4.2 RadionuclidesRadionuclides are naturally present in coal. The
40、 radioactivity of these can be measured using high-resolution gamma spectrometry; refer to Fardy, et al.14. This radioactivity is due to the decay of 238U, 235U, and 232Th and their daughters, as well as 40K and 87Rb.5.5 ChlorineChlorine can be determined by a number of methods, including ISO 5871an
41、d ASTM D42089. These procedures require that the coal be burnt and the chlorine trapped either in Eschka mixture or in an alkaline solution. The methods lack sensitivity and, with these procedures, repeatability levels are high. The solution obtained by pyrohydrolysis (see 5.6) can be used for the m
42、easurement of chlorine by IC or ICP-AES. The use of XRF can provide a practical and accurate method for the determination of chlorine directly on the coal.NOTE Chlorine is generally reported not as a trace element but as a minor element and expressed as a percentage.5.6 FluorineFluorine is determine
43、d using ISO 117244. This method is a pyrohydrolysis/ISE or pyrohydrolysis/IC procedure. This procedure can be used for the analysis of coal ash. There is significant evidence in the scientific literature that methods based on the decomposition of coal with an oxygen bomb combustion procedure can giv
44、e low results.5.7 MercuryMercury is determined using ISO 152375. In this procedure, coal is combusted in an oxygen bomb and the released mercury absorbed in a solution of dilute nitric acid. A number of accurate alternative procedures exist for the determination of mercury. It is possible to digest
45、coal with acids, either in a pressure vessel in a microwave oven or closed vessel in a heated water bath, or by refluxing with a mixture of nitric and sulfuric acids (see ASTM D6414). There are instrumental techniques in which the coal is combusted and the released mercury adsorbed onto a gold colle
46、ctor. The mercury is subsequently thermally released and concentrated (see ASTM D6722).6 Use of certified reference materialsThe use of appropriate CRMs is absolutely essential when checking the accuracy of methods for the determination of trace elements in coal (see ISO Guide 33). CRMs of coal are
47、available and are required to ascertain that there are no losses of analytes during the ashing procedure of any method. CRMs of coal ash can be used for those methods that require the ashing of the coal as a part of the procedure. ISO 2013 All rights reserved 3BS ISO 23380:2013ISO 23380:2013(E)It is
48、 mandatory that verification of the method selected to determine trace elements be confirmed by using the procedures in ISO 5725 (all parts) and that this verification be documented.It is recommended that a CRM be analysed with each batch of samples and that the result of this analysis be reported o
49、n the test report, together with the certified or recommended values.7 Calculation of resultsThe concentration of element X, CX,coal dry, expressed in milligrams per kilogram of coal on a dry basis, where the analyte has been determined without ashing of the sample, is calculated using Formula (1):CCMXX,coaldry ,coaladad=100100(1)where:Madis the moisture in coal, air-dried basis, as a percentage;CX,coal adis the concentration of element X in coal, in milligrams per kilogram, air-dried basis.The calculation of CX,coal adto an ai
