1、BSI Standards Publication PD ISO/TR 18230:2015 Iron ores Determination of loss on ignition Non- oxidised oresPD ISO/TR 18230:2015 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TR 18230:2015. The UK participation in its preparation was entrusted to Techn
2、ical 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 its correct application. The British Standards Insti
3、tution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 80817 3 ICS 73.060.10 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and Strategy Committee on 30 September 2015. A
4、mendments issued since publication Date Text affectedPD ISO/TR 18230:2015 ISO 2015 Iron ores Determination of loss on ignition Non-oxidised ores Minerais de fer Dtermination de la perte au feu Minerais non oxyds TECHNICAL REPORT ISO/TR 18230 Reference number ISO/TR 18230:2015(E) First edition 2015-0
5、8-15PD ISO/TR 18230:2015ISO/TR 18230:2015(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 reproduced or utilized otherwise in any form or by any means, electronic or
6、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. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Gene
7、va, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgPD ISO/TR 18230:2015ISO/TR 18230:2015(E)Foreword iv Introduction v 1 Scope . 1 2 Principle 1 3 Reagents 1 4 Apparatus . 1 5 Sampling and samples 2 5.1 Laboratory sample . 2 5.2 Preparation of test samples . 2 6 Pr
8、ocedure. 2 6.1 Number of determinations . 2 6.2 Test portion 2 6.3 Determination . 2 6.3.1 Pre-treatment of crucible . 2 6.3.2 Determination of LOI . 3 7 Expression of results 3 7.1 Calculation of loss on ignition 3 7.2 General treatment of results . 3 7.2.1 Repeatability and permissible tolerances
9、3 7.2.2 Determination of analytical result 4 7.2.3 Between-laboratories precision . 4 7.2.4 Check for trueness 4 7.2.5 Calculation of final result 5 8 Test report . 5 Annex A (informative) Flowsheet of the procedure for the acceptanceof analytical values for test samples 6 Bibliography 7 ISO 2015 Al
10、l rights reserved iii Contents PagePD ISO/TR 18230:2015ISO/TR 18230:2015(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 normally carried out through ISO
11、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 work. ISO collaborates clo
12、sely 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 different approval criteria
13、 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 document may be the subject of pa
14、tent 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/patents). Any trade name us
15、ed 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 principles in the Technical B
16、arriers 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 2, Chemical analysis.iv ISO 2015 All rights reservedPD ISO/TR 18230:2015ISO/TR 18230:2015(E) Introduction Th
17、e measurement of loss on ignition (LOI) is a technique widely used in the iron ore industry. Ignition loss is the sum of contributions from the mass loss of volatile compounds such as water vapour, carbon dioxide and sulphides (due to the decomposition of goethite and carbonaceous materials), and th
18、e mass gain due to oxidation Fe(II) to Fe 2 O 3 . Its use is complementary to the determination of elemental or oxide concentrations. It serves to allow 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 es
19、sential in sinter plant and blast furnace balance calculations, as it is used to calculate calcinated elemental concentrations. ISO 2015 All rights reserved vPD ISO/TR 18230:2015PD ISO/TR 18230:2015Iron ores Determination of loss on ignition Non- oxidised ores WARNING This Technical Report may invol
20、ve hazardous materials, operations and equipment. This Technical Report does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this Technical Report to establish appropriate health and safety practices and determine the applicability o
21、f regulatory limitations prior to use. 1 Scope This Technical Report describes a gravimetric method for the determination of the loss in mass of non- oxidized iron ores, when ignited at 1 000 C. This method is applicable to a concentration range of a mass fraction of 3,0 % to 7,0 % loss on ignition
22、in natural iron ores, iron ore concentrates and agglomerates, and sinters. The method is not applicable to the following: a) processed ores containing metallic iron (direct reduced iron); b) natural or processed ores in which the sulfur content is higher than a mass fraction of 0,2 %; c) internation
23、ally traded ores with combined water greater than 2,5 %. NOTE 1 Loss on ignition can be used as an estimate of combined water. NOTE 2 This method is intended for in-house use and is not intended for referee purposes. 2 Principle A test portion is heated in a muffle furnace at 1 000 C for 60 min and
24、cooled in a desiccator. The decreased mass of the test portion is then measured. 3 Reagents During the analysis, use only reagents of recognized analytical grade. 3.1 Silica gel, dried at 105 C for 4 h. 4 Apparatus Ordinary laboratory apparatus and the following: 4.1 Silica, porcelain or platinum cr
25、ucibles, 15 ml to 25 ml capacity, with lids. The crucibles should be pre-conditioned in the muffle furnace at 1 000 C for 60 min. Crucibles and lids should be stored in the desiccator (4.4) prior to use. If platinum crucibles used for LOI analysis are to be used for flux fusions, platinum ware shoul
26、d be thoroughly cleaned to prevent cross-contamination. 4.2 Balance, capable of reading to the nearest 0,1 mg at the mass load of the crucible. TECHNICAL REPORT ISO/TR 18230:2015(E) ISO 2015 All rights reserved 1PD ISO/TR 18230:2015ISO/TR 18230:2015(E) 4.3 Muffle furnac e, capable of maintaining a t
27、emperature of 1 000 C 25 C, with provision for air circulation adequate to prevent water vapour retention. 4.4 Desiccator, of borosilicate glass, 150 mm to 250 mm internal diameter with a vacuum stopcock that will allow the evacuation of air. The desiccator plate should be metal or ceramic or simila
28、r that will not break when in contact with a crucible at 1 000 C. The rim of the desiccator should be lightly greased with silicon grease or petroleum jelly. 150 g to 200 g of silica gel (3.1) should be replaced daily. If platinum crucibles are used, metal desiccator plates should not be used. 5 Sam
29、pling and samples 5.1 Laboratory sample For analysis, use a laboratory sample of 100 m particle size which has been taken and prepared in accordance with ISO 3082. 5.2 Preparation of test samples Analyses may be performed using either predried test samples (prepared in accordance with ISO 7764). 6 P
30、rocedure 6.1 Number of determinations Carry out the analysis at least in duplicate, using the procedure given in Annex A, independently, on each test sample. NOTE The expression “independently” means that the second and any subsequent result is not affected by the previous result(s). For this partic
31、ular analytical method, this condition implies that the repetition of the procedure are to be carried out either by the same operator at a different time, or by a different operator, including appropriate recalibration in either case. 6.2 Test portion Taking several increments, weigh to the nearest
32、0,000 1 g, approximately 2,0 g 0,2 g of the test sample (5.2). 6.3 Determination 6.3.1 Pre-treatment of crucible Using crucible tongs, place the crucible (4.1) into the muffle furnace ( 4.3) at 1 000 C for 60 min 10 min, ensuring that there is no loose material on the floor of the muffle furnace tha
33、t could possibly adhere to the crucible. Remove the crucible from the furnace to a desiccator (4.4), place the lid on the crucible immediately, and cool under vacuum for 30 min. Keep the lid on the crucible throughout the cooling period. Release the vacuum slowly, then weigh the cooled crucible and
34、lid to the nearest 0,000 1 g (m 1 ).2 ISO 2015 All rights reservedPD ISO/TR 18230:2015ISO/TR 18230:2015(E) 6.3.2 Determination of LOI Transfer the test portion (6.2) to the crucible and re-weigh the crucible and lid to the nearest 0,000 1 g (m 2 ). Place the crucible containing the test portion (m 2
35、 ) into the muffle furnace (4.3) at 1 000 C for 60 min 10 min. Remove the crucible from the furnace to a vacuum desiccator (4.4), place the lid on the crucible immediately, and cool under vacuum for 30 min. Keep the lid on the crucible throughout the cooling period. Release the vacuum slowly, then w
36、eigh the cooled crucible and lid to the nearest 0,000 1 g (m 3 ). 7 Expression of results 7.1 Calculation of loss on ignition The loss on ignition LOI, expressed as a percentage by mass, is calculated Formula (1): (1) wherem 1 is the mass of the crucible and lid, in grams;m 2 is the mass of the cruc
37、ible, lid and dry test portion, in grams;m 3 is the mass of the crucible, lid and test portion after ignition, in grams. 7.2 General treatment of results 7.2.1 Repeatability and permissible tolerances The precision of this analytical method is expressed by the following formulae (see also Annex A):
38、S d= 0,040 (2) S L= 0,029 1 X + 0,051 7 (3) R d= 0,114 (4) P = 0,042 7 X + 0,026 2 (5) whereX is the loss on ignition, expressed as a percentage by mass, of the sample;S d is the independent duplicate standard deviation;S L is the between-laboratories standard deviation;R d is the independent duplic
39、ate limit;P is the permissible tolerance. ISO 2015 All rights reserved 3PD ISO/TR 18230:2015ISO/TR 18230:2015(E) 7.2.2 Determination of analytical result Having computed the independent duplicate results according to Formula (2), compare them with the independent duplicate limit (R d ), using the pr
40、ocedure given in Annex A. 7.2.3 Between-laboratories precision Between-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 7.2.2. Compute the following quan
41、tity: (6) where 1 is the final result reported by laboratory 1; 2 is the final result reported by laboratory 2; 12 is the mean of final results. If 1 1 P, the final results are in agreement. 7.2.4 Check for trueness The trueness of the analytical method should be checked by applying it to a certifie
42、d reference material (CRM) or a reference material (RM). The procedure is the same as that described above. After confirmation of the precision, the final laboratory result is compared with the reference or certified value A c . There are two possibilities: a) c A c C, in which case the difference b
43、etween the reported result and the reference/certified value is statistically insignificant. b) c A c C, in which case the difference between the reported result and the reference/certified value is statistically significant. where c is the final result for the certified reference material;A c is th
44、e reference/certified value for the CRM/RM;C is a value dependent on the type of CRM/RM used. Certified reference materials used for this purpose should be prepared and certified in accordance with ISO Guide 35. For a CRM certified by an inter-laboratory test programme: L= c c+ d d= a c+ b4 ISO 2015
45、 All rights reservedPD ISO/TR 18230:2015ISO/TR 18230:2015(E) where V(A c ) is the variance of the certified value A c . For a CRM certified by only one laboratory: C = n This type of CRM should be avoided unless it is known to have an unbiased certified value. 7.2.5 Calculation of final r esult The
46、final result is the arithmetic mean of the acceptable analytical values for the test sample, or as otherwise determined by the operations provided in Annex A, calculated to four decimal places and rounded off to the second decimal place as follows: a) where the figure in the third decimal place is l
47、ess than 5, it is discarded and the figure in the second decimal place is kept unchanged; b) where the figure in the third decimal place is 5 and there is a figure other than 0 in the fourth decimal place, or when the figure in the third decimal place is greater than 5, the figure in the second deci
48、mal place is increased by one; c) where the figure in the third decimal place is 5 and the figure 0 is in the fourth decimal place, the 5 is discarded and the figure in the second decimal place is kept unchanged if it is 0, 2, 4, 6 or 8 and is increased by one if it is 1, 3, 5, 7 or 9. 8 Test report
49、 The test report should include the following information: a) the name and address of the testing laboratory; b) the date of issue of the test report; c) a reference to this Technical Report, i.e. ISO/TR 18230:2015; d) the details necessary for the identification of the sample; e) the analysis result; f) the reference number of the result; g) any characteristics noticed during
