1、BS ISO 4691:2009ICS 73.060.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDIron ores Determinationof titanium DiantipyrylmethanespectrophotometricmethodThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 Jul
2、y 2009 BSI 2009ISBN 978 0 580 61880 2Amendments/corrigenda issued since publicationDate CommentsBS ISO 4691:2009National forewordThis British Standard is the UK implementation of ISO 4691:2009. Itsupersedes BS 7020-12:1988 which is withdrawn.The UK participation in its preparation was entrusted to T
3、echnicalCommittee 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 British Sta
4、ndard cannot confer immunityfrom legal obligations.BS ISO 4691:2009Reference numberISO 4691:2009(E)ISO 2009INTERNATIONAL STANDARD ISO4691Second edition2009-06-15Iron ores Determination of titanium Diantipyrylmethane spectrophotometric method Minerais de fer Dosage du titane Mthode spectrophotomtriqu
5、e au diantipyrylmthane BS ISO 4691:2009ISO 4691:2009(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 and installed on the com
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8、e 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 microfilm, without perm
9、ission 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 ISO 2009 All rights rese
10、rvedBS ISO 4691:2009ISO 4691:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references 1 3 Principle1 4 Reagents.2 5 Apparatus .3 6 Sampling and samples3 6.1 Laboratory samples.3 6.2 Preparation of predried test samples 3 7 Procedure .3 7.1 Number of determin
11、ations 3 7.2 Blank test and check test3 7.3 Test portion 4 7.4 Determination.4 7.4.1 Decomposition of the test portion .4 7.4.2 Spectrophotometric determination5 7.4.3 Preparation of calibration graph 6 8 Expression of results 6 8.1 Calculation of mass fraction of titanium .6 8.2 General treatment o
12、f results.6 8.2.1 Repeatability and permissible tolerance.6 8.2.2 Determination of analytical result7 8.2.3 Between-laboratories precision .7 8.2.4 Check for trueness 8 8.2.5 Calculation of final result9 8.3 Oxide factor 9 9 Test report 9 Annex A (normative) Flowsheet of the procedure for the accept
13、ance of analytical values for test samples.10 Annex B (informative) Derivation of repeatability and permissible tolerance equations 11 Annex C (informative) Precision data obtained by international analytical trials 12 BS ISO 4691:2009ISO 4691:2009(E) iv ISO 2009 All rights reservedForeword ISO (the
14、 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 technical committees. Each member body interested in a subject for which a technical committe
15、e 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 with the International Electrotechnical Commission (IEC) on all matters of electrotechni
16、cal 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 International Standards adopted by the technical committees are circulated to the member b
17、odies 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 be the subject of patent rights. ISO shall not be held responsible for identifying a
18、ny or all such patent rights. ISO 4691 was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron, Subcommittee SC 2, Chemical analysis. This second edition cancels and replaces the first edition (ISO 4691:1985), which has been technically revised. BS ISO 4691:2009INTERNATIONAL
19、 STANDARD ISO 4691:2009(E) ISO 2009 All rights reserved 1Iron ores Determination of titanium Diantipyrylmethane spectrophotometric method WARNING This International Standard may involve hazardous materials, operations and equipment. This International Standard does not purport to address all of the
20、safety problems associated with its use. It is the responsibility of the user of this International Standard to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use. 1 Scope This International Standard specifies a spectrophotometric
21、 method using diantipyrylmethane for the determination of the mass fraction of titanium in iron ores. This method is applicable to a mass-fraction range of 0,02 % to 4,0 % of titanium in natural iron ores, and iron ore concentrates and agglomerates including sinter products. 2 Normative references T
22、he following referenced documents are indispensable for the application 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 648, Laboratory glassware Single-volume pipett
23、es ISO 1042, Laboratory glassware One-mark volumetric flasks ISO 3082, Iron ores Sampling and sample preparation procedures ISO 7764, Iron ores Preparation of predried test samples for chemical analysis 3 Principle The test portion is decomposed by one of the following methods. a) By treatment with
24、hydrochloric, nitric and sulfuric acids, filtration and ignition of the residue, followed by treatment with hydrofluoric and sulfuric acids and fusion with potassium disulfate. Dissolution of the melt in the main solution. b) By sintering with sodium peroxide, followed by treatment with hydrochloric
25、 and sulfuric acids, filtration and ignition of the residue, followed by treatment with hydrofluoric and sulfuric acids and fusion with potassium disulfate. Dissolution of the melt in the main solution. c) By fusion with a sodium tetraborate/sodium carbonate mixture, followed by treatment with hydro
26、chloric acid. Not applicable to samples containing more than 8 % (by mass) silicon. Reduction of the iron with ascorbic acid. Colour development with diantipyrylmethane, and measurement of the absorbance at approximately 385 nm. BS ISO 4691:2009ISO 4691:2009(E) 2 ISO 2009 All rights reserved4 Reagen
27、ts During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 4.1 Potassium disulfate (K2S2O7). 4.2 Sodium peroxide (Na2O2), fine powder. 4.3 Sodium tetraborate (Na2B4O7), anhydrous. 4.4 Sodium carbonate (Na2CO3), anhydrous. 4.5 Fusi
28、on mixture: 1 part by mass of the sodium tetraborate (4.3) mixed with 1 part by mass of the sodium carbonate (4.4) and stored in a closed vessel. 4.6 Hydrochloric acid, 1,16 to 1,19 g/ml. 4.7 Hydrochloric acid, 1,16 to 1,19 g/ml, diluted 1 + 1. 4.8 Hydrochloric acid, 1,16 to 1,19 g/ml, diluted 1 + 4
29、. 4.9 Nitric acid, 1,4 g/ml. 4.10 Hydrofluoric acid, 1,13 g/ml, 40 % (by mass) solution. 4.11 Sulfuric acid, 1,84 g/ml, diluted 1 + 1. 4.12 Sulfuric acid, 1,84 g/ml, diluted 1 + 9. 4.13 Sulfuric acid, 1,84 g/ml, diluted 2 + 98. 4.14 Diantipyrylmethane, solution, 15 g/l. Dissolve 15 g of diantipyrylm
30、ethane monohydrate (C23H24O2N4H2O) in about 300 ml of water and 30 ml of sulfuric acid (4.11) and dilute with water to 1 litre. If a residue remains in the solution, filter off the residue. Store the solution in a brown bottle. 4.15 Ascorbic acid, 100 g/l solution. The solution should be freshly pre
31、pared. 4.16 Ammonium iron(Ill) sulfate, 100 g/l solution. Dissolve 100 g of ammonium iron(lll) sulfate in 500 ml of water acidified with 5 ml of sulfuric acid (4.11). Dilute to 1 litre and mix. 4.17 Titanium, standard solution corresponding to 0,1 mg Ti/ml. Weigh 0,167 g of titanium dioxide (TiO2) c
32、alcined previously at 900 to 950 C for about 40 min in a platinum crucible and fuse with 3 to 4 g of the potassium disulfate (4.1) at a temperature of 650 to 700 C until a clear melt is obtained. After cooling, place the crucible in a 100 ml beaker, add 50 to 60 ml of sulfuric acid (4.12) and dissol
33、ve the cooled melt with moderate heating. After washing the platinum crucible with sulfuric acid (4.12), transfer the solution to a 1 000 ml volumetric flask, dilute with sulfuric acid (4.12) to volume and mix. 1 ml of this standard solution contains 0,1 mg of titanium. BS ISO 4691:2009ISO 4691:2009
34、(E) ISO 2009 All rights reserved 34.18 Titanium, standard solution corresponding to 20 mg Ti/l. Pipette a 50 ml aliquot of the titanium standard solution (4.17) into a 250 ml volumetric flask, dilute with sulfuric acid (4.12) to volume and mix. 1 ml of this standard solution contains 0,02 mg of tita
35、nium. 5 Apparatus Ordinary laboratory apparatus, including one-mark pipettes and one-mark volumetric flasks complying with the specifications of ISO 648 and ISO 1042, respectively, and the following. 5.1 Spectrophotometer, suitable for the measurement of absorbance at a wavelength of 385 nm, togethe
36、r with 10 mm cells. 6 Sampling and samples 6.1 Laboratory samples For analysis, use a laboratory sample of minus 100 m particle size which has been taken and prepared in accordance with ISO 3082. In the case of ores with significant contents of combined water or oxidizable compounds, use a particle
37、size of minus 160 m. NOTE A guideline on significant contents of combined water and oxidizable compounds 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 manner that it is repre
38、sentative of the whole contents of the container. Dry the test sample at 105 2 C as specified in 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.
39、 NOTE The expression “independently” means that the second and any subsequent result is not affected by the previous result(s). For this particular analytical method, this condition implies that the repetition of the procedure be carried out either by the same operator at a different time or by a di
40、fferent operator including, in both cases, appropriate recalibration. 7.2 Blank 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
41、. A predried test sample of the certified reference material shall be prepared as 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 signif
42、icant changes in the analytical procedure will become necessary. BS ISO 4691:2009ISO 4691:2009(E) 4 ISO 2009 All rights reservedWhen the analysis 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 reagen
43、ts are from the same reagent bottles. When the analysis is carried out on several samples of the same type of ore at the same time, the analytical value of one certified reference material may be used. 7.3 Test portion Taking several increments, weigh, to the nearest 0,000 1 g, approximately the amo
44、unt of the predried test sample (6.2) in accordance with Table 1. Table 1 Test portion Ti mass fraction wTi% Mass of test portion g Aliquot (7.4.2) ml 0,02 u wTiC, in which case the difference between the reported result and the reference/certified value is statistically significant. where cis the f
45、inal result for the CRM/RM; Acis the 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 35:2006, Reference materials General and statistical pri
46、nciples for certification. For a CRM/RM certified by an interlaboratory test programme, C shall be calculated as follows: 222cdLc2sCNn=+ where scis the standard deviation of laboratory means (each data value for calculating the standard deviation is the average data value in each certifying laborato
47、ry) of the CRM/RM; Ncis the number of certifying laboratories; n is the number of replicate determinations carried out on the CRM/RM; dis the independent duplicate standard deviation; Lis the between-laboratories standard deviation. BS ISO 4691:2009ISO 4691:2009(E) ISO 2009 All rights reserved 9For
48、CRMs certified by only one laboratory, C shall be calculated as follows: 22 rL2Cn=+ CRMs certified by only one laboratory should be avoided unless they are known to have an unbiased certified value. 8.2.5 Calculation of final result The final result is the arithmetic mean of the acceptable analytica
49、l values for the test sample, or as otherwise determined by the operations specified in Annex A, calculated to five decimal places for mass fractions of titanium less than 1 % and to four decimal places for mass fractions greater than 1 % rounded to the third decimal place as follows: a) where the figure in the fourth decimal place is less than 5, it is discarded and the figure in the third decimal place is kept unchanged; b) where the figure in the fourth decimal place is 5 and there is a
