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1、 Reference number ISO 4700:2007(E) ISO 2007 INTERNATIONAL STANDARD ISO 4700 Third edition 2007-09-01 Iron ore pellets for blast furnace and direct reduction feedstocks Determination of the crushing strength Boulettes de minerais de fer pour charges de haut fourneaux et rduction directe Dtermination
2、de la rsistance lcrasement ISO 4700:2007(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer perfor
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5、cretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2007 All rights reserved. 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 wr
6、iting from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2007 All rights reserved ISO 470
7、0:2007(E) ISO 2007 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope 1 2 Normative references1 3 Terms and definitions .1 4 Principle1 5 Sampling, sample preparation and preparation of test portions1 6 Apparatus .2 7 Procedure .3 8 Expression of results 4 9 Test report4 10 Ver
8、ification .5 -,-,- ISO 4700:2007(E) iv ISO 2007 All rights reserved 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 normally carried out through ISO technica
9、l 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 work. ISO collaborates closely wit
10、h the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. 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 Inter
11、national Standards adopted by the technical committees are circulated to the member bodies for voting. Publication 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
12、 be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 4700 was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron, Subcommittee SC 3, Physical testing. This third edition cancels and replaces the second editio
13、n (ISO 4700:1996), which has been revised to homogenise with other physical test standards. -,-,- ISO 4700:2007(E) ISO 2007 All rights reserved v Introduction This International Standard concerns one of a number of physical test methods that have been developed to measure various physical parameters
14、 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, validated by collaborative testing, to facilitate comparisons of tests made in different laboratories. The results
15、of this test should be considered in conjunction with other tests used to evaluate the quality of iron ores as feedstocks for blast furnace and direct reduction processes. This International Standard may be used to provide test results as part of a production quality-control system, as a basis of a
16、contract, or as part of a research project. -,-,- INTERNATIONAL STANDARD ISO 4700:2007(E) ISO 2007 All rights reserved 1 Iron ore pellets for blast furnace and direct reduction feedstocks Determination of the crushing strength CAUTION This International Standard may involve hazardous operations and
17、equipment. This 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 determine the applicability of regulatory limitations prior to its use.
18、1 Scope This International Standard specifies a method to provide a measure of the compressive load attained to cause breakage of pellets. This International Standard is applicable to hot bonded pellets. 2 Normative references The following referenced documents are indispensable for the application
19、of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3082:20001), Iron ores Sampling and sample preparation procedures ISO 11323:2002, Iron ore and direct reduced iron Voc
20、abulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 11323 apply. 4 Principle A single pellet of a specific size range is compressed at a specific speed. The procedure is repeated on all pellets in the test portion. The crushing strength is calcul
21、ated as the arithmetic mean of all the measurements obtained. 5 Sampling, sample preparation and preparation 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 pellets shall be 12,5 mm + 10,
22、0 mm. 1) Under revision to incorporate ISO 10836, Iron ores Method of sampling and sample preparation for physical testing. -,-,- ISO 4700:2007(E) 2 ISO 2007 All rights reserved A test sample of at least 1 kg, on a dry basis, of sized pellets shall be obtained. Oven-dry the test sample to constant m
23、ass at 105 C 5 C and cool it to room temperature before 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 One test portion comprising at least 60 pe
24、llets, as agreed upon at the time of order, shall be taken from the test sample by random selection. NOTE A method of determining the exact number of pellets to obtain a specific precision in the test results is to use the following equation: 2 2 n = where n is the number of pellets; is the standard
25、 deviation, in newtons, derived from several experiments; is the required precision, in newtons, for 95 % confidence levels. 6 Apparatus 6.1 General The test apparatus shall comprise: a) ordinary laboratory equipment, such as an oven, hand tools and safety equipment; b) loading unit; c) load transmi
26、ssion system; d) load indicator or recorder. 6.2 Loading unit, formed by two compressive flat platens made of steel, installed in mutual parallel planes. The surface of the platens that will be in contact with the sample shall be made of surface-hardened steel. A device capable of setting the speed
27、of the compressive platen between 10 mm/min and 20 mm/min over the entire test period shall be used. NOTE If the platen speed is not constant during the test cycle, results may differ depending upon the test machine used. More uniform results may be obtained using a test machine that applies a const
28、ant load increase. 6.3 Load transmission system, which shall be either a load cell or a lever. The capacity of the load cell for transmission of the applied load to the indicating unit shall be at least 10 kN. 6.4 Load indicator or recorder, which shall be either an electric indicator (digital read-
29、out device, recording chart, meter with needle rider or other suitable device) for the load-cell type, or a mechanical indicator (gauge equipped with a needle rider or other suitable device) for the lever type. When using a load cell, the chart-recorder pen-response time shall be 1,0 s or less for a
30、 full-scale deflection. The minimum graduation shall be 1/100 of the full scale. The compression device shall be calibrated regularly. -,-,- ISO 4700:2007(E) ISO 2007 All rights reserved 3 7 Procedure 7.1 Number of determinations for the test Carry out the test on 60 or more single pellets (see the
31、Note in 5.2). 7.2 Load application Place a test piece (single pellet) at the approximate centre of the surface-hardened portion of the lower platen. Apply the load at a constant platen speed between 10 mm/min and 20 mm/min throughout the test period. The test is complete when either the load falls t
32、o a value of 50 % or more of the maximum load recorded (see Figure 1), or the platen gap has reduced to 50 % of the initial mean test-piece diameter (see Figure 2). In either case, the crushing strength is the maximum load attained in the test. Key X contraction, % Y load 1 1st peak 2 2nd peak 3 3rd
33、 peak 4 stop 5 strength Figure 1 Measurement of crushing strength as explained in Example 1 in the procedure -,-,- ISO 4700:2007(E) 4 ISO 2007 All rights reserved Key X contraction, % Y load 1 strength 2 stop Figure 2 Measurement of crushing strength as explained in Example 2 in the procedure 8 Expr
34、ession of results The crushing strength, CS, is the arithmetic mean of all the measurements obtained. Express the result, in decanewtons per pellet, to one decimal place. 9 Test report The test report shall include the following information: a) a reference to this International Standard, i.e. ISO 47
35、00:2007; 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; g) details of any operation and any test conditions not specified
36、in this International Standard or regarded as optional, as well as any incident which may have had an influence on the results; ISO 4700:2007(E) ISO 2007 All rights reserved 5 h) the crushing strength, CS; i) the standard deviation of the measurements; j) the size distribution of the sample for phys
37、ical testing and the size range(s) of the pellets; k) a table of the relative frequency, in percent, of the measurements, classified at 50 daN intervals; l) the number of pellets in each specified size range tested; m) the platen speed used, expressed in mm/min. 10 Verification Regular checking of t
38、he apparatus is essential to ensure test result reliability. The frequency of checking is a matter for each laboratory to determine. The conditions of the following items shall be checked: compressive plates; compressive device; load cell or lever; load indicator; recording system. It is recommended that internal reference material be prepared and used periodically to check test repeatability. Appropriate records of verification activities shall be maintained. -,-,- ISO 4700:2007(E) ICS 73.060.10 Price based on 5 pages ISO 2007 All rights reserved -,-,-