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1、4B51903 O583233 174 9 I N T E R NAT I O NA L STA N DAR D IS0 837 1 First edition 1994-1 1-1 5 Iron ores - Determination of decrepitation index Minerais de fer - Dtermination de lindice de dcrpitation I Reference number IS0 8371 :I 994(E) COPYRIGHT International Organization for Standardization Licen
2、sed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services W 4853903 0583234 O00 IS0 8371:1994(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0
3、 member bodies). The work of preparing International Standards is normally carried out through IS0 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, gover
4、nmental and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the
5、 member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard IS0 8371 was prepared by Technical Committee ISO/TC 1 O!, iron ores, Subcommittee SC 3, Physical testing. Q IS0 1994 All rights reserved.
6、 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 the publisher. International Organization for Standardization Case Postale 56 CH-1 21
7、 1 Genve 20 Switzerland Printed in Switzerland II COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services 4853903 0583235 T47 = IS0 8371:1994(E) 0 IS0 Introdu
8、ction The decrepitation index test is used to evaluate the behaviour of lump iron ore when it is subject to rapid heating. The specific conditions involved in this test are a) a sample having a specified size range; b) a specified sample mass; c) heating to 700 O C ; d) sieving to determine decrepit
9、ation index. . 111 COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services g851903 0583236 983 INTERNATIONAL STANDARD 0 IS0 IS0 8371:1994(EI Iron ores - Deter
10、mination of decrepitation index 1 Scope This International Standard specifies a method for the determination of the decrepitation index of lump iron ore. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this Internation
11、al Standard. At the time of publi- cation, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most re- cent editions of the standards indicated below. M
12、embers of IEC and IS0 maintain registers of cur- rently valid International Standards. IS0 3081:1986, Iron ores - Increment sampling - Manual method. IS0 30821 987, Iron ores - Increment sampling and sample preparation - Mechanical method. IS0 3083: 1986, Iron ores - Preparation of samples - Manual
13、method. IS0 33 1 0-1 : 1 990, Test sieves - Technical require- ments and testing - Part 7: Test sieves of metal wire cloth. IS0 331 0-2: 1990, Test sieves - Technical require- ments and testing - Part 2: Test sieves of perforated metal plate. IS0 11323:-), Iron ores - Vocabulary. 3 Definitions For t
14、he purposes of this International Standard, the definitions given in IS0 11 323 apply. 4 Principle This method evaluates the effect of rapid heating from room temperature to 700 “C in 30 min on the sized test portion. This is done by measuring the mass of material passing a 6.30 mm screen after the
15、heating cycle. 5 Apparatus 5.1 Electrically heated furnace, with heat capacity and thermal response characteristics sufficient to heat the sample from room temperature to 700 “C in 30 min. 5.2 Sample holder, made of non-scaling, heat- resistant metal capable of withstanding a temperature greater tha
16、n 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. 5.3 Test sieves, with square mesh openings of 25,O mm, 20,O mm. 6,30 mm, 3.15 mm and 0,50 mm in accordance with IS0 3310-1 or IS0 3310
17、-2. 1) To be published 1 COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services IS0 8371:1994(E) W 4853903 0583237 83T W 8 IS0 NOTE 1 It is recommended that
18、the set of sieves used for sieving should include a sieve of suitable aperture size between 10,O mm and 6.30 mm (for example 8,OO mm) in order to improve the efficiency of the 6.30 mm sieve by decreasing the test portion retained on it. 6 Preparation of test sample Prepare the test sample according
19、to IS0 3083 from the sample for physical testing which has been taken in accordance with IS0 3081 and IS0 3082. A quan- tity of sample sufficient to provide at least ten 500 g test portions shall be prepared. Screen the sample on 25,O mm and 20,O mm sieves (5.3) and oven dry the 20 mm to 25 mm test
20、sample at 105 “C k 5 “C for at least 12 h. Screen the sized sample again on 25,O mm and 20,O mm sieves to re- move any adhering fines and oven dry the sample again at 105 “C f 5 “C for 12 h. After drying, keep the test material in a desiccator until testing. Only par- ticles taken at random shall be
21、 used to constitute a test portion. 7 Procedure 7.1 Number of tests Owing to the heterogeneity of natural ores, the test shall be carried out 10 times. 7.2 Test portions Weigh the test portions each consisting of approxi- mately 500 g (k 1 particle) of the predried test sample to provide the test po
22、rtion (mass m , , ) . 7.3 Heating WARNING - This test involves the 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 pro- tection shall be used by the operator. Place the sample holder (5.2) in the fur
23、nace (5.1) and begin heating. When the temperature of the holder has reached 700 “C keep it in the furnace for a further 20 min. Place the test portion in the sample holder and cover. After 30 min remove the holder and test portion from the furnace and allow to cool to room temperature. Discharge th
24、e test portion carefully from the sample holder and determine its mass (m?). Hand sieve with care in 6,30 mm, 3,15 mm and 0,50 mm sieves (5.3). Determine and record the masses of the 6,30 mm, 3,15 mm and 0,50 mm fractions (-1. NOTE 2 Mechanical sieving may be used provided that preliminary tests giv
25、e results similar to those obtained by hand sieving, within the permissible tolerance of 2 % abso- lute. 8 Expression of results Calculate the decrepitation index (DI, 3), expressed as a percentage by mass, from the following formula: m, x 100 “6,3 = m, where m, is the mass, in grams, of the test po
26、rtion after thermal treatment; m, is the mass, in grams, of the - 6,30 mm fraction obtained after sieving. Express the result to one decimal place. Report also the percentage mass passing 3,15 mm and 0,50 mm. 9 Test report The test report shall include the following information: reference to this In
27、ternational Standard; description of the sample; the decrepitation index and the individual results of the 10 tests; the mean values of the decrepitation index for the whole 10 tests, for each sieve size; reference number of the results; any characteristics noted during the test and any operations w
28、hich may have had an influence on the results, for example sampling point, scalping sieves used, method of sieving or loss of mass during tests. 2 COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardizati
29、on Licensed by Information Handling Services IS0 8371:1994(E) Li851903 0583238 756 Q IS0 ICs 73.060.00 Descriptors: minerals and ores, metalliferous minerals, iron ores, tests, high temperature tests, determination, physical properties Price based on 2 pages COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services