1、BSI Standards PublicationBS ISO 11536:2015Iron ores Determination ofloss on ignition GravimetricmethodBS ISO 11536:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 11536:2015.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/58
2、, Iron ores.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 correctapplication. The British Standards Institution 2015. Published by
3、BSI StandardsLimited 2015ISBN 978 0 580 82614 6ICS 73.060.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 July 2015.Amendments issued since publicationDate Te
4、xt affectedBS ISO 11536:2015 ISO 2015Iron ores Determination of loss on ignition Gravimetric methodMinerais de fer Dtermination de la perte au feu Mthode gravimtriqueINTERNATIONAL STANDARDISO11536First edition2015-08-01Reference numberISO 11536:2015(E)BS ISO 11536:2015ISO 11536:2015(E)ii ISO 2015 Al
5、l rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll 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 intern
6、et 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 officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrig
7、htiso.orgwww.iso.orgBS ISO 11536:2015ISO 11536:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 16 Sampling and samples Laboratory sample 27 Procedure. 27.1 General . 27.2 Number of determinations . 27.3 Determination of hygroscopic moisture c
8、ontent. 27.4 Test portion 27.5 Determination . 38 Expression of results 38.1 Calculation of loss on ignition 38.2 General treatment of results . 38.2.1 Repeatability and permissible tolerances 38.2.2 Determination of analytical result 48.2.3 Between-laboratories precision . 48.2.4 Check for trueness
9、 48.2.5 Calculation of final result 59 Test report . 5Annex A (normative) Flowsheet of the procedure for the acceptance of analytical values for test samples . 6Bibliography 7 ISO 2015 All rights reserved iiiContents PageBS ISO 11536:2015ISO 11536:2015(E)ForewordISO (the International Organization f
10、or 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 th
11、e 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 proce
12、dures 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 editoria
13、l rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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. 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 (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanati
15、on on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document
16、is ISO/TC 102, Iron ore and direct reduced iron, Subcommittee SC 2, Chemical analysis.iv ISO 2015 All rights reservedBS ISO 11536:2015ISO 11536:2015(E)IntroductionThe measurement of loss on ignition (LOI) is a technique widely used in the iron ore industry. Ignition loss is the sum of contributions
17、from the mass loss of volatile compounds water vapour, carbon dioxide and sulfides (due to the decomposition of goethite and carbonaceous materials), and the mass gain due to oxidation Fe(II) to Fe2O3. Its use is complementary to the determination of elemental or oxide concentrations. It serves to a
18、llow for an addition of the oxides, generated at the ignition temperature, and the LOI, to arrive at total (oxide + LOI). The determination of LOI is essential in sinter plant and blast furnace balance calculations, as it is used to calculate calcinated elemental concentrations. ISO 2015 All rights
19、reserved vBS ISO 11536:2015BS ISO 11536:2015Iron ores Determination of loss on ignition Gravimetric methodWARNING This International Standard may involve hazardous materials, operations and equipment. This International Standard does not purport to address all of the safety problems associated with
20、its use. It is the responsibility of the user of this International Standard to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use.1 ScopeThis International Standard specifies a gravimetric method for the determination of the loss
21、 in mass of fully-oxidized iron ores, when ignited at 1 000 C.This method is applicable to a concentration range of 1,0 % (m/m) to 10,0 % (m/m) loss on ignition in natural iron ores, iron ore concentrates and agglomerates.The method is not applicable to the following:a) Processed ores containing met
22、allic iron (direct reduced iron);b) Natural or processed ores in which the sulfur content is higher than 0,2 % (m/m);c) Natural or processed ores in which the content of partially-oxidized iron is more than 1,0 % (m/m).2 Normative referencesThe following documents, in whole or in part, are normative
23、ly referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 2596, Iron ores Determination of hygroscopic moisture in analyt
24、ical samples Gravimetric, Karl Fischer and mass-loss methodsISO 3082, Iron ores Sampling and sample preparation procedures3 PrincipleA test portion is heated in a muffle furnace at 1 000 C for 60 min and cooled in a desiccator (5.4). The mass loss of the test portion is determined, and expressed as
25、a mass fraction percentage relative to the original weight.4 ReagentsDuring the analysis, use only reagents of recognized analytical grade.4.1 Silica gel, dried at 105 C for 4 h.5 ApparatusOrdinary laboratory apparatus and, in particular, the following:INTERNATIONAL STANDARD ISO 11536:2015(E) ISO 20
26、15 All rights reserved 1BS ISO 11536:2015ISO 11536:2015(E)5.1 Silica (porcelain or platinum crucibles), 15 ml to 25 ml capacity, with lids.The crucibles and their lids shall be pre-conditioned in the muffle furnace at 1 000 C for 60 min. Crucibles and lids shall be stored in the desiccator (5.4) pri
27、or to use.If platinum crucibles used for LOI analysis are to be used for flux fusions, platinum ware should be thoroughly cleaned to prevent cross-contamination.5.2 Balance, capable of reading to the nearest 0,1 mg at the mass load of the crucible.5.3 Muffle furnace, capable of maintaining a tempera
28、ture of 1 000 C 25 C, with provision for air circulation adequate to prevent water vapour retention.5.4 Vacuum desiccator, of borosilicate glass, 150 mm to 250 mm internal diameter with a vacuum stopcock that will allow the equilibrium of air pressure.The desiccator plate shall be metal, ceramic or
29、similar that will not break when in contact with a crucible at 1 000 C. The rim of the desiccator shall be lightly greased with silicon grease or petroleum jelly. 150 g to 200 g of silica gel (4.1) shall be replaced daily.If platinum crucibles are used, metal desiccator plates should not be used.6 S
30、ampling and samples Laboratory sampleFor analysis, use a laboratory sample of minus 160 m particle size which has been taken and prepared in accordance with ISO 3082.7 Procedure7.1 GeneralThoroughly mix the laboratory sample and, taking multiple increments, extract a test sample in such a way that i
31、t is representative of the whole contents of the container.Test samples shall be air-equilibrated.7.2 Number of determinationsCarry out the analysis at least in duplicate in accordance with Annex A, independently, on each test sample.NOTE The expression “independently” means that the second and any
32、subsequent result is not affected by the previous result(s). For this particular analytical method, this condition implies that the repetition of the procedure is to be carried out either by the same operator at a different time, or by a different operator, including appropriate recalibration in eit
33、her case.7.3 Determination of hygroscopic moisture contentThe hygroscopic moisture shall be determined in accordance with ISO 2596. Two test portions shall be taken simultaneously, one for the ignition loss determination and the other for the hygroscopic moisture determination.7.4 Test portionTaking
34、 several increments, weigh to the nearest 0,000 1 g, approximately (2,0 0,2) g of the test sample (see 7.1).2 ISO 2015 All rights reservedBS ISO 11536:2015ISO 11536:2015(E)7.5 DeterminationUsing crucible tongs, place the crucible (5.1) covered with the lid into the muffle furnace (5.3) at 1 000C for
35、 60 min 10 min, ensuring that there is no loose material on the floor of the muffle furnace that could possibly adhere to the crucible.Remove the crucible from the furnace and place in the desiccator (5.4), and place the lid on the crucible immediately. Allow the crucible to cool for 30 min. Keep th
36、e lid on the crucible throughout the cooling period.Release the vacuum slowly, then weigh the cooled crucible and lid to the nearest 0,000 1 g.Transfer the test portion to the crucible and re-weigh the crucible and lid to the nearest 0,000 1 g.Repeat the determination as described above.8 Expression
37、 of results8.1 Calculation of loss on ignitionThe loss on ignition (LOI), expressed as a percentage by mass, is calculated to a dry basis as indicated below.The total mass loss after ignition (TMLw), including moisture, is calculated from Formula (1):TMLmmmmwm/m%( )=2321100 (1)wherem1is the mass of
38、the ignited crucible and lid, in grams;m2is the mass of the crucible and lid plus the air-equilibrated test portion, in grams;m3is the mass of the crucible and lid plus test portion after ignition, in grams.The loss on ignition (LOI), moisture corrected, is calculated from Formula (2)LOITMLAAwwm/m%(
39、 )=()100100(2)where A is the hygroscopic moisture content as a percentage by mass, determined in accordance with ISO 2596.8.2 General treatment of results8.2.1 Repeatability and permissible tolerancesThe precision of this analytical method is expressed by the following formulae:SXd=+0 01825 0 00114,
40、 (3)SL=0 025, (4)RXd=+0 05164 0 00323, (5) ISO 2015 All rights reserved 3BS ISO 11536:2015ISO 11536:2015(E)PX=+0 05302 0 00509, (6)whereX is the loss on ignition, expressed as a percentage by mass, of the sample;Sdis the independent duplicate standard deviation;SLis the between-laboratories standard
41、 deviation;Rdis the independent duplicate limit;P is the permissible tolerance.8.2.2 Determination of analytical resultHaving computed the independent duplicate results according to Formula (1), compare them with the independent duplicate limit (Rd), using the procedure given in Annex A, to obtain t
42、he final laboratory result, .8.2.3 Between-laboratories precisionBetween-laboratories precision is used to determine the agreement between the final results reported by two laboratories. The assumption is that both laboratories followed the same procedure described in 8.2.2.Compute the following qua
43、ntity:12122=+(7)where1is the final result reported by laboratory 1;2is the final result reported by laboratory 2;12is the mean of final results.If 1 2 P, the final results are in agreement.8.2.4 Check for truenessThe present method is not suitable to measure any certified reference material, unless
44、it is of the same mineralogical type, and preferably of the same geological origin as the samples used in the test. If that is the case, the trueness of the analytical method may be checked in the same way as in other ISO methods. For this, calculate the analytical result () for the CRM/RM using the
45、 procedures in 8.2.2, and compare it with the reference or certified value Ac. There are two possibilities:a) C AC C in which case the difference between the reported result and the certified/reference value is statistically insignificant.b) C AC C in which case the difference between the reported r
46、esult and the certified/reference value is statistically significant.4 ISO 2015 All rights reservedBS ISO 11536:2015ISO 11536:2015(E)whereCis the final result for the certified reference material;ACis the certified/reference value for the CRM/RM;C is a value dependent on the type of CRM/RM used.NOTE
47、 Certified reference materials used for this purpose are to be prepared and certified in accordance with ISO Guide 35.For a CRM certified by an inter-laboratory test programCnVA=+()222LdC(8)wheren is the number of replicate determinations carried out on the CRM/RM;V(AC) is the variance of the certif
48、ied value AC(= 0 for a CRM certified by only one laboratory, see Note below).NOTE This type of CRM is to be avoided unless it is known to have an unbiased certified value.8.2.5 Calculation of final resultThe final result is the arithmetic mean of the acceptable analytical values for the test sample,
49、 or as otherwise determined by the operations specified in Annex A, calculated the nearest 0,001 % and reported to the nearest 0,01 %, as follows:a) where the figure in the fifth decimal place is less than 5, it is discarded and the figure in the fourth decimal place is kept unchanged;b) where the figure in the fifth decimal place is 5 and there is a figure other than 0 in the sixth decimal place, or when the figure in the fifth decimal place is greater than 5, the figure i
