1、BSI Standards Publication BS ISO 8371:2015 Iron ores for blast furnace feedstocks Determination of the decrepitation indexBS ISO 8371:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO 8371:2015. It supersedes BS ISO 8371:2007 which is withdrawn. The UK par
2、ticipation in its preparation was entrusted to Technical Committee ISE/58, Iron ores. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for
3、its correct application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 79286 1 ICS 73.060.10 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Pol
4、icy and Strategy Committee on 31 August 2015. Amendments issued since publication Date Text affectedBS ISO 8371:2015 ISO 2015 Iron ores for blast furnace feedstocks Determination of the decrepitation index Minerais de fer pour charges de hauts fourneaux Dtermination de lindice de dcrpitation INTERNA
5、TIONAL STANDARD ISO 8371 Third edition 2015-08-01 Reference number ISO 8371:2015(E)BS ISO 8371:2015ISO 8371:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be repro
6、duced 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 permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester
7、. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgBS ISO 8371:2015ISO 8371:2015(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Principle 1 5 S
8、ampling, sample preparation and preparation of test portions 1 5.1 Sampling and sample preparation . 1 5.2 Preparation of test portions 2 6 Apparatus . 2 7 Procedure. 2 7.1 Number of determinations for the test 2 7.2 Heating . 2 7.3 Sieving 3 8 Expression of results 3 9 Test report . 3 10 V erificat
9、ion . 4 Bibliography 5 ISO 2015 All rights reserved iii Contents PageBS ISO 8371:2015ISO 8371:2015(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normall
10、y 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. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the
11、work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The 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 d
12、ifferent approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial 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 documen
13、t 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 identified 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/p
14、atents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO pri
15、nciples in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 102, Iron ore and direct reduced iron, Subcommittee SC 3, Physical testing. This third edition cancels and replaces the second edition (I
16、SO 8371:2007) which has been technically revised to address the care needed during hand sieving, to introduce the mechanical sieving and to exclude the reference to ISO 4701.iv ISO 2015 All rights reservedBS ISO 8371:2015ISO 8371:2015(E) Introduction This International Standard concerns one of a num
17、ber of physical test methods that have been developed to measure various physical parameters and characteristics and to evaluate the behaviour of iron ores, including reducibility, disintegration, crushing strength, apparent density, etc. This method was developed to provide a uniform procedure, val
18、idated by collaborative testing, to facilitate comparisons of tests made in different laboratories. The results of this test have to be considered in conjunction with other tests used to evaluate the quality of iron ores as feedstocks for blast furnace processes. This International Standard can be u
19、sed to provide test results as part of a production quality control system, as a basis of a contract, or as part of a research project. ISO 2015 All rights reserved vBS ISO 8371:2015BS ISO 8371:2015Iron ores for blast furnace feedstocks Determination of the decrepitation index CAUTION This Internati
20、onal Standard may involve hazardous operations and equipment. This International Standard does not purport to address all of the safety issues associated with its use. It is the responsibility of the user of this International Standard to establish appropriate safety and health practices and determi
21、ne the applicability of regulatory limitations prior to its use. 1 Scope This International Standard specifies a method to provide a relative measure for evaluating the degree of size degradation caused by rapid heating of iron ores. It specifies the determination of the decrepitation index. This In
22、ternational Standard is applicable to lump ores for blast furnace feedstocks. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated
23、references, the latest edition of the referenced document (including any amendments) applies. ISO 3082, Iron ores Sampling and sample preparation procedures ISO 3310-1, Test sieves Technical requirements and testing Part 1: Test sieves of metal wire cloth ISO 3310-2, Test sieves Technical requiremen
24、ts and testing Part 2: Test sieves of perforated metal plate ISO 11323, Iron ore and direct reduced iron Vocabulary 3 T erms a nd definiti ons For the purposes of this document, the terms and definitions given in ISO 11323 apply. 4 Principle The test portion is rapidly heated from room temperature t
25、o 700 C, maintained at this temperature for 30 min and then cooled in air down to room temperature. It is sieved with a test sieve having square openings of 6,3 mm. The decrepitation index is calculated as the mass percentage of material of size 6,3 mm. 5 Sampling, sample preparation and preparation
26、 of test portions 5.1 Sampling and sample preparation Sampling of a lot and preparation of a test sample shall be in accordance with ISO 3082. The size range for lump ores shall be 25,0 mm +20,0 mm. A test sample of at least 5,0 kg, on a dry basis, of the sized lump ores shall be obtained. INTERNATI
27、ONAL ST ANDARD ISO 8371:2015(E) ISO 2015 All rights reserved 1BS ISO 8371:2015ISO 8371:2015(E) Oven-dry the test sample to constant mass at 105 C 5 C and cool it to room temperature. Screen the sized sample again on a 20,0 mm sieve to remove any adhering fines, and keep the test material in a desicc
28、ator until testing. NOTE Constant mass is achieved when the difference in mass between two subsequent measurements becomes less than 0,05 % of the initial mass of the test sample. 5.2 Preparation of test portions Only particles taken at random shall be used to constitute a test portion. At least 10
29、test portions, each of approximately 500 g (the mass of 1 particle) shall be prepared from the test sample. Weigh the test portions to the nearest 1 g and register the mass of each test portion on its recipient label. 6 Apparatus 6.1 General The test apparatus shall comprise: a) ordinary laboratory
30、equipment, such as an oven, hand tools, time-control device and safety equipment; b) a furnace; c) a test-portion holder; d) test sieves; e) a weighing device. 6.2 Furnace, having a heating capacity and temperature control able to heat the test portion from room temperature to 700 C in 30 min. 6.3 T
31、est portion holder, made of non-scaling, heat-resistant metal to withstand temperatures higher than 700 C, equipped with a thermocouple to measure the temperature of the sample. The cover shall be of the loose fitting type and shall not provide a gas-tight seal. 6.4 Test sieves, conforming to ISO 33
32、10-1 or ISO 3310-2 and having square apertures of the following nominal sizes: 6,30 mm; 3,15 mm and 500 m. 6.5 Weighing device, capable of weighing the test sample and test portions to an accuracy of 1 g. 7 Procedure 7.1 Number of determinations for the test Owing to the heterogeneity of lump ores,
33、carry out the test 10 times on each test sample. 7.2 Heating WARNING This test involves handling of hot apparatus. In addition, for some iron ores, spitting may occur when loading the sample into the hot container. Suitable hand and eye protection shall be used by the operator.2 ISO 2015 All rights
34、reservedBS ISO 8371:2015ISO 8371:2015(E) Turn on the furnace and begin heating. When its temperature reaches 700 C, keep it constant for a further 20 min. Place the test portion in the sample holder, cover and put the set in the furnace. After 30 min, remove the holder and the test portion from the
35、furnace and allow the test portion to cool to below 50 C. 7.3 Sieving Discharge the test portion carefully from the sample holder, determine and record its mass (m 1 ). Hand sieve with care on the 6,30 mm, 3,15 mm and 500 m sieves (6.4). Determine and record the mass passing 6,30 mm (m 2 ), 3,15 mm
36、and 500 m to one decimal place. NOTE 1 Equivalent mechanical sieving can be used provided that preliminary test programme is carried out according to ISO 3086, the hand sieving being the reference method. NOTE 2 Sieving results are influenced by the sieve shaker characteristics. Therefore in cases w
37、here two or more laboratories need to compare their results for commercial or research purposes, the sieving conditions are to be adjusted until identical results are obtained for the same test sample. 8 Expression of results The decrepitation index, DI -6,3 , expressed as a percentage by mass, is c
38、alculated from the following equation: , m m where m 1 is the mass, in grams, of the test portion after thermal treatment; m 2 is the mass, in grams, of the undersize fraction passing the 6,30 mm sieve. Express the result to one decimal place. 9 Test report The test report shall include the followin
39、g information: a) a reference to this International Standard, i.e. ISO 8371; b) all details necessary for the identification of the sample; c) the name and address of the test laboratory; d) the date of the test; e) the date of the test report; f) the signature of the person responsible for the test
40、; g) the details of any operation and any test conditions not specified in this International Standard or regarded as optional, as well as any incident which may have had an influence on the results; h) the decrepitation index, DI -6,3and the individual results of the 10 tests; i) the mean values of
41、 the decrepitation index for the whole 10 tests; j) the type of sieve used. ISO 2015 All rights reserved 3BS ISO 8371:2015ISO 8371:2015(E) 10 V erifica tion Regular checking of apparatus is essential to ensure test-result reliability. The frequency of checking is a matter for each laboratory to dete
42、rmine. The conditions of the following items shall be checked: sieves; weighing device; temperature control and measurement device; time control device. It is recommended that internal reference material be prepared and used periodically to check test repeatability. Appropriate records of verificati
43、on activities shall be maintained.4 ISO 2015 All rights reservedBS ISO 8371:2015ISO 8371:2015(E) Bibliography 1 ISO 3086, Iron ores Experimental methods for checking the bias of sampling ISO 2015 All rights reserved 5BS ISO 8371:2015ISO 8371:2015(E) ISO 2015 All rights reserved IC S 73.060.10 Price
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