1、 Reference number ISO 5418-1:2006(E) ISO 2006INTERNATIONAL STANDARD ISO 5418-1 Second edition 2006-12-01 Iron ores Determination of copper Part 1: 2,2 -Biquinolyl spectrophotometric method Minerais de fer Dosage du cuivre Partie 1: Mthode spectrophotomtrique la biquinoline-2,2 ISO 5418-1:2006(E) PDF
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6、y 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 2006 All rights reservedISO 5418-1:2006(E) ISO 2006 All rights reserved iii Contents Page Foreword iv 1 Scop
7、e 1 2 Normative references 1 3 Principle1 4 Reagents.2 5 Apparatus .3 6 Sampling and samples3 6.1 General3 6.2 Preparation of predried test samples 3 7 Procedure .3 7.1 Number of determinations 3 7.2 Test portion 3 7.3 Blank test and check test4 7.4 Determination.4 7.4.1 Decomposition of the test po
8、rtion .4 7.4.2 Treatment of the residue.4 7.4.3 Treatment of the test solution 5 7.4.4 Spectrophotometric measurement 5 7.5 Preparation of calibration curve.5 8 Expression of results 6 8.1 Calculation of mass fraction of copper .6 8.2 General treatment of results.7 8.2.1 Repeatability and permissibl
9、e tolerance.7 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 result8 8.3 Oxide factor 9 9 Test report 9 Annex A (normative) Flowsheet of the procedure for the acceptance of analytical values for test samples.10
10、Annex B (informative) Derivation of repeatability and permissible tolerance equations 11 Annex C (informative) Precision data obtained by international analytical trials 12 ISO 5418-1:2006(E) iv ISO 2006 All rights reservedForeword ISO (the International Organization for Standardization) is a worldw
11、ide 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 committee has been established has the right to be represented on th
12、at 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 electrotechnical standardization. International Standards are drafted in
13、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 bodies for voting. Publication as an International Standard r
14、equires 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 any or all such patent rights. ISO 5418-1 was prepared by Tec
15、hnical 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 5418-1:1994), which has been technically revised. It has been updated to alter the manner in which precision data are presented. ISO 54
16、18 consists of the following parts, under the general title Iron ores Determination of copper: Part 1: 2,2-Biquinolyl spectrophotometric method Part 2: Flame atomic absorption spectrometric method INTERNATIONAL STANDARD ISO 5418-1:2006(E) ISO 2006 All rights reserved 1 Iron ores Determination of cop
17、per Part 1: 2,2 -Biquinolyl spectrophotometric method WARNING This part of ISO 5418 may involve hazardous materials, operations and equipment. This part of ISO 5418 does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this part of IS
18、O 5418 to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use. 1 Scope This part of ISO 5418 specifies a 2,2 -biquinolyl spectrophotometric method for the determination of copper in iron ores. This method is applicable to mass frac
19、tions of copper between 0,005 % and 0,77 % 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.
20、For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 648, Laboratory glassware One-mark pipettes ISO 1042, Laboratory glassware One-mark volumetric flasks ISO 3082, Iron ores Sampling and sample preparation procedures ISO 3696, Water for analy
21、tical laboratory use Specification and test methods ISO 7764, Iron ores Preparation of predried test samples for chemical analysis 3 Principle The test portion is decomposed by treatment with hydrochloric, nitric and perchloric acids. Silica is dehydrated and the solution is diluted and filtered. Th
22、e residue is ignited, treated with hydrofluoric and sulfuric acids, and fused with sodium carbonate. The cooled melt is dissolved in the filtrate. Copper(II) is reduced with ascorbic acid. 2,2 -biquinolyl is added in the presence of N,N-dimethylformamide to form the red-violet complex of copper(I).
23、The absorbance of the coloured complex is measured spectrophotometrically at a wavelength of approximately 545 nm. ISO 5418-1:2006(E) 2 ISO 2006 All rights reserved4 Reagents During the analysis, use only reagents of recognized analytical grade and water that complies with grade 3 of ISO 3696. The d
24、istillation apparatus used should not contain any copper, and deionized water should not come into contact with copper tubing or taps. 4.1 Sodium carbonate (Na 2 CO 3 ), anhydrous powder. 4.2 Iron(III) oxide, minimum purity: 99,9 % (mass fraction), mass fraction of copper less than 0,000 2 %. 4.3 Hy
25、drochloric acid, 1,16 g/ml to 1,19 g/ml. 4.4 Hydrochloric acid, 1,16 g/ml to 1,19 g/ml, diluted 1 + 2. 4.5 Hydrochloric acid, 1,16 g/ml to 1,19 g/ml, diluted 1 + 10. 4.6 Nitric acid, 1,4 g/ml. 4.7 Nitric acid, 1,4 g/ml, diluted 1 + 1. 4.8 Perchloric acid, 1,54 g/ml, 60 % (m/m), or 1, 67 g/ml, 70 % (
26、m/m). 4.9 Sulfuric acid, 1,84 g/ml, diluted 1 + 1. 4.10 Hydrofluoric acid, 1,13 g/ml, 40 % (m/m), or 1,185 g/ml, 48 % (m/m). 4.11 Ascorbic acid (C 6 H 8 O 6 ), solution, 200 g/l. Prepare this solution at the time of use. 4.12 N,N-Dimethylformamide HCON(CH 3 ) 2 . WARNING Take care not to inhale toxi
27、c fumes. 4.13 2,2 -Biquinolyl (C 18 H 12 N 2 ), solution. Dissolve 0,15 g of 2,2-biquinolyl in 250 ml of N,N-dimethylformamide. Protect the solution from light and store in a brown bottle. 4.14 Copper standard solutions. 4.14.1 Standard solution A, 1 000 g Cu/ml. Dissolve 0,500 g of copper metal of
28、minimum purity 99,9% (mass fraction) in 20 ml of dilute nitric acid (4.7) in a 250 ml tall-form beaker. After elimination of the nitrous fumes by boiling, cool, transfer to a 500 ml one-mark volumetric flask, dilute to volume with water and mix. 4.14.2 Standard solution B, 50 g Cu/ml. Transfer 25,0
29、ml of standard solution A (4.14.1) to a 500 ml one-mark volumetric flask and dilute to volume with water. ISO 5418-1:2006(E) ISO 2006 All rights reserved 3 5 Apparatus Ordinary laboratory equipment, including one-mark pipettes and one-mark volumetric flasks complying with the specifications of ISO 6
30、48 and ISO 1042 respectively (unless otherwise indicated), and the following. 5.1 Platinum crucible, of capacity 25 ml to 30 ml. 5.2 Muffle furnace, suitable for heating at 1 000 C. 5.3 Spectrophotometer, suitable for measurement of an absorbance of approximately 545 nm. 6 Sampling and samples 6.1 G
31、eneral 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 having significant contents of combined water or oxidizable compounds, use a particle size of minus 160 m. NOTE A guideline on significant cont
32、ents 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 representative of the whole contents of the container. Dry the
33、 test sample at 105 C 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. NOTE The expression “independently” means that the sec
34、ond 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 is carried out either by the same operator at a different time or by a different operator, including appropriate recalibration i
35、n either case. 7.2 Test portion Taking several increments, weigh, to the nearest 0,000 2 g, approximately 0,5 g or 1 g of the test sample (see Table 1) obtained in accordance with 6.2. The test portion should be taken and weighed quickly, to avoid reabsorption of moisture. ISO 5418-1:2006(E) 4 ISO 2
36、006 All rights reservedTable 1 Measurement guide for test solution Mass fraction of copper in test sample % Mass of test portiong Volumetric flask ml Cell cm 0,004 to 0,05 0,05 to 0,4 0,4 to 0,8 1,0 0,5 0,5 50 100 100 5 2 1 7.3 Blank test and check test In each run, one blank test and one analysis o
37、f 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 as specified in 6.2. The certified reference material should be of
38、the same type as the sample to be analysed, and the properties of the two materials should be sufficiently similar to ensure that, in either case, no significant changes in the analytical procedure will become necessary. Where the analysis is carried out on several samples at the same time, the blan
39、k 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 analytical value of one certified reference material may be used
40、. 7.4 Determination 7.4.1 Decomposition of the test portion Place the test portion (7.2) in a 250 ml tall-form beaker, and moisten with 5 ml of water. Add 20 ml of hydrochloric acid (4.3), cover the beaker with a watch-glass, and heat the solution gently without boiling until decomposition of the te
41、st portion is complete. Add 5 ml of nitric acid (4.6), followed by 10 ml of perchloric acid (4.8) and 0,2 ml of sulfuric acid (4.9), cover the beaker with a watch-glass, and heat until perchloric acid fumes are evolved. Continue heating for a further 3 min to 5 min. Allow the beaker to cool and add
42、20 ml of hydrochloric acid (4.4). Boil for 1 min to remove chlorine, and dilute with 10 ml of water. Filter the solution through a medium-texture filter paper, collecting the filtrate in a 300 ml beaker. Wash the paper with hydrochloric acid (4.5), using as small a volume as possible, until the yell
43、ow colour due to iron(III) can no longer be detected. Finally, wash with hot water until the washings are free from acid. Reserve the filtrate and washings as the main solution. Transfer the filter paper containing the residue to a platinum crucible (5.1). 7.4.2 Treatment of the residue Dry and burn
44、 off the filter paper at a low temperature, and ignite the residue at about 800 C in a muffle furnace (5.2). Allow the crucible to cool, moisten the residue with a few drops of water, and add 5 drops of sulfuric acid (4.9) and 5 ml of hydrofluoric acid (4.10). Heat gently in a fume cupboard to volat
45、ilize silica as the tetrafluoride, and evaporate the sulfuric acid to dryness. Finally, heat the crucible at a high temperature for several seconds to ensure complete removal of sulfuric acid. Allow to cool and add 1 g of sodium carbonate (4.1). Heat gently for several minutes, then at between 900 C
46、 and 1 000 C until decomposition of the residue is complete. ISO 5418-1:2006(E) ISO 2006 All rights reserved 5 NOTE With a large amount of residue, additional sodium carbonate may be required. If so, the amount of sodium carbonate taken in 7.5 will have to be increased correspondingly. Allow the cru
47、cible to cool and transfer it to the beaker containing the main solution from 7.4.1, heating gently to dissolve the melt. Remove the crucible and rinse with water. Evaporate the solution as necessary and cool to room temperature. Transfer to a 50 ml or 100 ml one-mark volumetric flask, as indicated
48、in Table 1, dilute to volume with water and mix. (This is the test solution.) 7.4.3 Treatment of the test solution Transfer 10,0 ml aliquots of the solution from 7.4.2 to two 50 ml one-mark volumetric flasks. Add the following reagents, mixing well after each addition: for the test solution, 5 ml of
49、 ascorbic acid solution (4.11) and 25 ml of 2,2 -biquinolyl solution (4.13); for the reference solution, 5 ml of ascorbic acid solution (4.11) and 25 ml of N,N-dimethylformamide (4.12). Similarly, transfer 10 ml aliquots of the blank test solution to two 50 ml one-mark volumetric flasks. Add the following reagents, mixing well after each addition: for the blank test solution, 5 ml of ascorbic acid solution (4.11) and 25 ml of 2,2 -biquinolyl solution (4.13); for
