1、BS ISO11533:2009ICS 73.060.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDIron ores Determination ofcobalt Flameatomic absorptionspectrometric methodThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 July
2、2009 BSI 2009ISBN 978 0 580 62729 3Amendments/corrigenda issued since publicationDate CommentsBS ISO 11533:2009National forewordThis British Standard is the UK implementation of ISO 11533:2009. Itsupersedes BS ISO 11533:1996(R06) which is withdrawn.The UK participation in its preparation was entrust
3、ed to TechnicalCommittee ISE/58, Iron Ores.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a Brit
4、ish Standard cannot confer immunityfrom legal obligations.BS ISO 11533:2009Reference numberISO 11533:2009(E)ISO 2009INTERNATIONAL STANDARD ISO11533Second edition2009-06-15Iron ores Determination of cobalt Flame atomic absorption spectrometric method Minerais de fer Dosage du cobalt Mthode par spectr
5、omtrie dabsorption atomique dans la flamme BS ISO 11533:2009ISO 11533:2009(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 an
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8、ound, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2009 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 m
9、icrofilm, without permission in writing 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 IS
10、O 2009 All rights reservedBS ISO 11533:2009ISO 11533:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv 1 Scope1 2 Normative references1 3 Principle1 4 Reagents.2 5 Apparatus.2 6 Sampling and samples3 6.1 Laboratory sample 3 6.2 Preparation of predried test samples3 7 Procedure.3 7.1
11、Number of determinations3 7.2 Test portion4 7.3 Blank test and check test .4 7.4 Determination 4 7.4.1 Decomposition of the test portion.4 7.4.2 Treatment of residue .4 7.4.3 Treatment of combined filtrate and washings4 7.4.4 Preparation of the set of calibration solutions.5 7.4.5 Adjustment of atom
12、ic absorption spectrometer 5 7.4.6 Atomic absorption measurements 5 8 Expression of results6 8.1 Calculation of mass fraction of cobalt 6 8.2 General treatment of results.6 8.2.1 Repeatability and permissible tolerances.6 8.2.2 Determination of analytical result7 8.2.3 Between-laboratories precision
13、.7 8.2.4 Check for trueness 7 8.2.5 Calculation of final result8 8.3 Oxide factor8 9 Test report9 Annex A (normative) Flowsheet of the procedure for the acceptance of analytical values for test samples 10 Annex B (informative) Derivation of repeatability and permissible tolerance equations11 Annex C
14、 (informative) Precision data obtained by international analytical trials12 BS ISO 11533:2009ISO 11533:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of prep
15、aring 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 the right to be represented on that committee. International organizations, governmental and non-governmental, in
16、liaison with ISO, also take part in the work. ISO collaborates closely with 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
17、of technical committees is to prepare International Standards. Draft International 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
18、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. ISO 11533 was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron, Subcommittee SC 2,
19、Chemical analysis. This second edition cancels and replaces the first edition (ISO 11533:1996), which has been technically revised. BS ISO 11533:2009INTERNATIONAL STANDARD ISO 11533:2009(E) ISO 2009 All rights reserved 1Iron ores Determination of cobalt Flame atomic absorption spectrometric method W
20、ARNING 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 its use. It is the responsibility of the user of this International Standard to establish appropriate healt
21、h and safety practices and determine the applicability of regulatory limitations prior to use. 1 Scope This International Standard specifies a flame atomic absorption spectrometric method for the determination of the mass fraction of cobalt in iron ores. This method is applicable to a mass-fraction
22、range of 0,000 7 % to 0,06 % of cobalt in natural iron ores, iron ore concentrates and agglomerates, including sinter products. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For
23、undated references, the latest edition of the referenced document (including any amendments) applies. ISO 648, Laboratory glassware Single-volume pipettes ISO 1042, Laboratory glassware One-mark volumetric flasks ISO 3082, Iron ores Sampling and sample preparation procedures ISO 3696, Water for anal
24、ytical laboratory use Specification and test methods ISO 7764, Iron ores Preparation of predried test samples for chemical analysis 3 Principle A test portion is decomposed by treatment with hydrochloric, nitric, sulfuric and hydrofluoric acids. The solution is evaporated to dryness, then dissolved
25、and filtered. The residue is ignited, then silica is removed by treatment with hydrofluoric acid and evaporation to dryness. The residue is fused with sodium carbonate. The cooled melt is dissolved with hydrochloric acid, and combined with the original filtrate. Iron is extracted with isobutyl aceta
26、te. The aqueous phase is evaporated to reduced volume, acidified with nitric acid and diluted to volume. The solution is aspirated into the flame of an atomic absorption spectrometer using an air/acetylene burner. The absorbance values obtained for cobalt are compared with those obtained from the ca
27、libration solutions. BS ISO 11533:2009ISO 11533:2009(E) 2 ISO 2009 All rights reserved4 Reagents During the analysis, use only reagents of recognized analytical grade and water that complies with grade 2 of ISO 3696. 4.1 Sodium carbonate (Na2CO3), anhydrous. 4.2 Hydrochloric acid, 1,16 g/ml to 1,19
28、g/ml. 4.3 Hydrochloric acid, 1,16 g/ml to 1,19 g/ml, diluted 1 + 1. 4.4 Nitric acid, 1,4 g/ml. 4.5 Hydrofluoric acid, 1,13 g/ml, 40 % (by mass), or 1,185 g/ml, 48 % (by mass). 4.6 Sulfuric acid, 1,84 g/ml, diluted 1 + 1. 4.7 Isobutyl acetate. 4.8 Sodium background solution. Dissolve 15 g of sodium c
29、arbonate (4.1) in 50 ml of water. While stirring, slowly add 25 ml of hydrochloric acid (4.2). Warm to eliminate carbon dioxide, then cool. Dilute to 250 ml and mix. 4.9 Cobalt standard solutions. 4.9.1 Stock solution, 1 000 g Co/ml. Dissolve 1,000 g of cobalt metal of purity 99,5 % (by mass) by hea
30、ting in 30 ml of hydrochloric acid (4.2). Add 5 ml of nitric acid (4.4) and heat to expel the oxides of nitrogen. Cool, dilute to 1 000 ml with water in a one-mark volumetric flask and mix. 4.9.2 Standard solution A, 25 g Co/ml. Transfer 25 ml of cobalt stock solution (4.9.1) to a 1 000 ml one-mark
31、volumetric flask. Dilute to volume with water and mix. 4.9.3 Standard solution B, 200 g Co/ml. Transfer 50 ml of cobalt stock solution (4.9.1) to a 250 ml one-mark volumetric flask. Dilute to volume with water and mix. 5 Apparatus Ordinary laboratory apparatus, including one-mark pipettes and one-ma
32、rk volumetric flasks complying with the specifications of ISO 648 and ISO 1042, respectively, and the following. 5.1 Separating funnels, of capacity 100 ml. 5.2 Platinum crucibles, of capacity 30 ml. 5.3 Atomic absorption spectrometer, equipped with an air/acetylene burner. WARNING To avoid possible
33、 explosion hazards, follow the manufacturers instructions for igniting and extinguishing the air/acetylene flame. Wear tinted safety glasses whenever the burner is in operation. BS ISO 11533:2009ISO 11533:2009(E) ISO 2009 All rights reserved 3The atomic absorption spectrometer used in this method sh
34、all meet the following criteria: a) Minimum sensitivity: the absorbance of the 4 g/ml cobalt calibration solution, when measured in a flame of 10 cm path length at 240,7 nm, shall be at least 0,20, and the absorbance of the 32 g/ml cobalt calibration solution, when measured in a flame of 10 cm path
35、length at 252,2 nm, shall be at least 0,60 when scale-expansion facilities are not used. b) Graph linearity: the slope of the calibration graph covering the top 20 % of the concentration range (expressed as a change in absorbance) shall not be less than 0,7 of the value of the slope for the bottom 2
36、0 % of the concentration range determined in the same way. c) Minimum stability: the standard deviation of the absorbance of the most concentrated calibration solution and that of the zero calibration solution, each being calculated from a minimum number of 10 repetitive measurements, shall be less
37、than 1,5 % and 0,5 %, respectively, of the mean value of the absorbance of the most concentrated calibration solution. The use of a strip-chart recorder and/or digital read-out device is recommended to evaluate criteria a), b) and c) and for all subsequent measurements. NOTE Instrument parameters ca
38、n vary with each instrument. The following parameters have been successfully used in several laboratories and they can be used as guidelines. Solutions were aspirated into an air/acetylene flame. Hollow cathode lamp, mA 7 Wavelength, nm 240,7 252,2 Air flow rate, l/min 20 Acetylene flow rate, l/min
39、5 In systems where the values shown for gas flow rates do not apply, the ratio of the gas flow rates can still be a useful guideline. Criteria b) and c) should be determined separately at wavelengths of 240,7 nm and 252,2 nm. 6 Sampling and samples 6.1 Laboratory sample For analysis, use a laborator
40、y sample of minus 100 m particle size which has been taken and prepared in accordance with ISO 3082. In the case of ores having significant contents of combined water or oxidizable compounds, use a particle size of minus 160 m. NOTE Guidance on significant contents of combined water and oxidizable c
41、ompounds is incorporated in ISO 7764. 6.2 Preparation of predried test samples Thoroughly mix the laboratory sample and, taking multiple increments, extract a test sample in such a way that it is representative of the whole contents of the container. Dry the test sample at 105 C 2 C as specified in
42、ISO 7764. (This is the predried test sample.) 7 Procedure 7.1 Number of determinations Carry out the analysis at least in duplicate in accordance with Annex A, independently, on one predried test sample. NOTE The expression “independently” means that the second and any subsequent result is not affec
43、ted by the previous result(s). For this particular analytical method, this condition implies that the repetition of the procedure is carried BS ISO 11533:2009ISO 11533:2009(E) 4 ISO 2009 All rights reservedout either by the same operator at a different time or by a different operator, including appr
44、opriate recalibration in both cases. 7.2 Test portion Taking several increments, weigh, to the nearest 0,000 2 g, approximately 2 g of the predried test sample obtained in accordance with 6.2. The test portion should be taken and weighed quickly in order to avoid reabsorption of moisture. 7.3 Blank
45、test and check test In each run, one blank test and one analysis of a certified reference material of the same type of ore shall be carried out in parallel with the analysis of the ore sample(s) under the same conditions. A predried test sample of the certified reference material shall be prepared a
46、s specified in 6.2. The certified reference material should be of the same type as the sample to be analysed and the properties of the two materials should be sufficiently similar to ensure that, in both cases, no significant changes in the analytical procedure will become necessary. Where the analy
47、sis is carried out on several samples at the same time, the blank value may be represented by one test, provided that the procedure is the same and the reagents used are from the same reagent bottles. Where the analysis is carried out on several samples of the same type of ore at the same time, the
48、analytical value of one certified reference material may be used. 7.4 Determination 7.4.1 Decomposition of the test portion Transfer the test portion (7.2) to a 250 ml beaker. Moisten with a few millilitres of water, add 50 ml of hydrochloric acid (4.2), cover with a watch-glass, and heat at 95 C fo
49、r 1 h. If after this digestion the amount of insoluble residue is high, raise the hotplate temperature to about 105 C and continue heating, avoiding boiling. Add 5 ml of nitric acid (4.4) and 0,5 ml of sulfuric acid (4.6) and heat at 105 C for 15 min. Displace the watch-glass to provide a gap of approximately 5 mm, and add 1 ml of hydrofluoric acid (4.5). Evaporate to dryness and heat for a further 15 min. Add 20 ml of hydrochloric acid (4.3) and heat gently to dissolve the soluble salts. Wash th
