BS ISO 13310-1997 Iron ores - Determination of zinc content - Flame atomic absorption spectrometric method《铁矿石 锌含量测定 火焰原子吸收光谱测定法》.pdf

《BS ISO 13310-1997 Iron ores - Determination of zinc content - Flame atomic absorption spectrometric method《铁矿石 锌含量测定 火焰原子吸收光谱测定法》.pdf》由会员分享，可在线阅读，更多相关《BS ISO 13310-1997 Iron ores - Determination of zinc content - Flame atomic absorption spectrometric method《铁矿石 锌含量测定 火焰原子吸收光谱测定法》.pdf（16页珍藏版）》请在麦多课文档分享上搜索。

1、BRITISH STANDARD BS ISO13310: 1997 Iron ores Determination of zinc content Flame atomic absorption spectrometric method ICS73.060.10BSISO13310:1997 This British Standard, having been prepared under the directionof the Engineering SectorBoard, was published underthe authority of the Standards Board a

2、nd comes intoeffect on 15October1997 BSI09-1999 ISBN 0 580 28728 9 National foreword This British Standard reproduces verbatim ISO13310:1997 and implements itas the UK national standard. The UK participation in its preparation was entrusted by Technical Committee ISE/58, Iron ores, to Subcommittee I

3、SE/58/2, Analysis of iron ores, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UKinterests informed; monitor related international and Europe

4、an developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Stan

5、dards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible

6、for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pagesii toiv, pages1 to6, an inside back cover and a back cov

7、er. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO13310:1997 BSI 09-1999 i Contents Page National foreword Inside fr

8、ont cover Foreword iii Text of ISO 13310 1ii blankBS ISO13310:1997 ii BSI 09-1999 Contents Page Foreword iii 1 Scope 1 2 Normative references 1 3 Principle 1 4 Reagents 1 5 Apparatus 1 6 Sampling and samples 2 7 Procedure 2 8 Expression of results 4 9 Test report 5 Annex A (normative) Flowsheet of t

9、he procedure for the acceptance of analytical values for test samples 6 Annex B (informative) Derivation of repeatability and permissible tolerance equations 6 Annex C (informative) Precision data obtained by international analytical trials Inside back cover Figure C.1 Least-squares fit of precision

10、 against X for zinc Inside back cover Table 1 Dilution guide for test solution 3 Table 2 Calibration solutions 4 Table B.1 Zinc content of test samples 6 Descriptors: Minerals and ores, metalliferous minerals, iron ores, chemical analysis, determination of content, zinc, atomic absorption spectromet

11、ric method.BS ISO13310:1997 BSI 09-1999 iii 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 technical committees. Each membe

12、r 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 with the International Elec

13、trotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees arecirculated to the member bodies for voting. Publication as an InternationalStandard requires approval by at least75% of the member bodies casting a v

14、ote. International Standard ISO13310 was prepared by Technical Committee ISO/TC102, Iron ores, Subcommittee SC2, Chemical analysis. Together with ISO13311, it cancels and replaces ISO8753:1987, of which it constitutes a technical revision. Annex A forms an integral part of this International Standar

15、d. Annex B and Annex C are for information only.iv blankBS ISO13310:1997 BSI 09-1999 1 WARNING This International Standard may involve hazardous materials, operations and equipment. This International Standard does not purport to address all of the safety issues associated with its use. It is the re

16、sponsibility of the user to establish appropriate health 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 zinc content of iron ores. T

17、his method is applicable to zinc contents between0,001% (m/m) and0,5% (m/m) in natural iron ores, iron ore concentrates and agglomerates, including sinter products. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this

18、International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated b

19、elow. Members of IEC and ISO maintain registers of currently valid International Standards. ISO648:1977, Laboratory glassware One-mark pipettes. ISO1042:1983, Laboratory glassware One-mark volumetric flasks. ISO3081:1986, Iron ores Increment sampling Manual method. ISO3082:1987, Iron ores Increment

20、sampling and sample preparation Mechanical method. ISO3083:1986, Iron ores Preparation of samples Manual method. ISO3696:1987, Water for analytical laboratory use Specification and test methods. ISO7764:1985, Iron ores Preparation of predried test samples for chemical analysis. 3 Principle Decomposi

21、tion of the test portion and removal of silica by treatment with hydrochloric acid and hydrofluoric acid. Oxidation with nitric acid. Evaporation to dryness, followed by dilution and filtration. Ignition of the residue. Fusion with sodium carbonate. Dissolution of the cooled melt with hydrochloric a

22、cid. Reservation of the solution. Extraction of iron in the filtrate with4-methyl-2-pentanone. Recovery of zinc extracted. Decomposition of4-methyl-2-pentanone with nitric acid. Evaporation to dryness and dissolution of salts with the reserved solution and hydrochloric acid. Aspiration of the soluti

23、on into the flame of an atomic absorption spectrometer using an air-acetylene burner. Comparison of absorbance values obtained for zinc with those obtained from the calibration solutions. 4 Reagents During the analysis, use only reagents of recognized analytical grade and only water that complies wi

24、th grade2 of ISO3696. 4.1 Sodium carbonate (Na 2 CO 3 ), anhydrous. 4.2 4-methyl-2-pentanone (MIBK), high purity. 4.3 Hydrochloric acid, 1,16g/ml to1,19g/ml. 4.4 Hydrochloric acid, 1,16g/ml to1,19g/ml, diluted10+6. 4.5 Hydrochloric acid, 1,16g/ml to1,19g/ml, diluted1+1. 4.6 Hydrochloric acid, 1,16g/

25、ml to1,19g/ml, diluted2+98. 4.7 Nitric acid, 1,4g/ml. 4.8 Hydrofluoric acid, 1,13g/ml,40%(m/m), or 1,19g/ml,48% (m/m). 4.9 Zinc standard solutions 4.9.1 Zinc stock standard solution Dissolve1,000g of zinc metal ofpurity99,5%(m/m) in40ml of hydrochloric acid(4.5). Cool and dilute to1000ml in a one-ma

26、rk volumetric flask and mix. 1ml of the stock solution contains10004g of zinc. 4.9.2 Standard solution Transfer10,0ml of zinc stock standard solution(4.9.1) to a1000ml one-mark volumetric flask. Dilute to volume and mix. 1ml of this standard solution contains104g of zinc. 5 Apparatus Ordinary labora

27、tory apparatus, including one-mark pipettes and one-mark volumetric flasks complying with the specifications of ISO648 and ISO1042 respectively, and 5.1 Polytetrafluoroethylene (PTFE) beaker, of capacity250ml, with a PTFE cover.BS ISO13310:1997 2 BSI 09-1999 5.2 Atomic absorption spectrometer, equip

28、ped with an air-acetylene burner. The atomic absorption spectrometer shall meet the following criteria. WARNING Follow the manufacturers instructions for igniting and extinguishing the air-acetylene flame to avoid possible explosion hazards. Wear tinted safety glasses whenever the burner is in opera

29、tion. a) Minimum sensitivity the absorbance of the most concentrated calibration solution (see7.4.4) shall be at least0,25. b) Graph linearity the slope of the calibration graph covering the top20% of the concentration range (expressed as a change in absorbance) shall not be less than0,7 of the valu

30、e of the slope for the bottom20% 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 sufficient number of repetitive

31、measurements, shall be less than1,5% and0,5% respectively of the mean value of the absorbance of the most concentrated calibration solution. NOTE 1The use of a strip-chart recorder and/or digital readout device is recommended to evaluate criteriaa),b) andc) and for all subsequent measurements. NOTE

32、2Instrument parameters will vary with each instrument. The following parameters were successfully used in several laboratories and they can be used as guidelines. In systems where the values shown for gas flow rates do not apply, the ratio of the gas flow rates may still be a useful guideline. 6 Sam

33、pling and samples 6.1 Laboratory sample For analysis, use a laboratory sample of minus1004m particle size which has been taken in accordance with ISO3081 or ISO3082 and prepared in accordance with ISO3082 or ISO3083. In the case of ores having significant contents of combined water or oxidizable com

34、pounds, use a particle size of minus1604m. NOTEA guideline on significant contents of combined water and oxidizable compounds is incorporated in ISO7764. 6.2 Preparation of predried test samples Thoroughly mix the laboratory sample and, taking multiple increments, extract a test sample in such a man

35、ner that it is representative of the whole contents of the container. Dry the test samples at105 C 2 C as specified in ISO7764. (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

36、predried test sample. NOTEThe 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 is carried out either by the same operator at a diffe

37、rent time or by a different operator including, in either case, appropriate recalibration. 7.2 Test portion Taking several increments, weigh, to the nearest0,0002g, approximately2g of the predried test sample obtained in accordance with6.2. NOTEThe test portion should be taken and weighed quickly in

38、 order to avoid reabsorption of moisture. 7.3 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 ofthe ore sample(s) under the same conditions. Apredried test sample of th

39、e certified reference material shall be prepared as specified in6.2. NOTEThe 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 either case, no significant changes in the analy

40、tical procedure become necessary. When 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 reagents are from the same reagent bottles. When the analysis is carried out on several samples of t

41、he same type of ore at the same time, the analytical value of one certified reference material may be used. Hollow cathode lamp, mA 8 Wavelength, nm 213,9 Air flow rate, l/min 14 Acetylene flow rate, l/min 3BS ISO13310:1997 BSI 09-1999 3 7.4 Determination 7.4.1 Decomposition of the test portion Tran

42、sfer the test portion(7.2) to a250ml PTFE beaker(5.1). Moisten with a few millilitres of water, add40ml of hydrochloric acid(4.3) and10ml of hydrofluoric acid(4.8), and cover with a PTFE cover. Heat on a hotplate at100 C, then increase the heat to200 C. Evaporate to dryness. Add5ml of nitric acid(4.

43、7) and evaporate to nearly1ml. Dissolve the salts with10ml of hydrochloric acid(4.3) and evaporate to dryness again. Dissolve the salts with5ml of hydrochloric acid(4.3). Add10ml of water and filter through a close-texture paper into a250ml beaker. Remove all adhering particles from the beaker with

44、a rubber-tipped rod, wash with hydrochloric acid(4.6) until the paper is free from iron stains, and wash the paper three times with hot water. Reserve the residue and combined filtrate and washings. 7.4.2 Treatment of residue Place the paper and residue in a platinum crucible, dry and char the paper

45、 at a low temperature and ignite in a muffle furnace at550 C. Add0,5g of sodium carbonate(4.1) and fuse over a Bunsen burner (about900 C to1000 C) until a clear melt is obtained. Dissolve the cooled melt with5ml of hydrochloric acid(4.5), heat to remove carbon dioxide and reserve the solution. 7.4.3

46、 Treatment of combined filtrate and washings Evaporate the filtrate and washings(7.4.1) just to dryness. Dissolve the salts with20ml of hydrochloric acid(4.4), and transfer to a200ml separating funnel. Rinse the beaker with20ml of hydrochloric acid(4.4) and combine these washingswith the main soluti

47、on. Add50ml of4-methyl-2-pentanone(4.2) and shake thoroughly for1min. Allow the layers to separate, then run the lower aqueous solution into a250ml beaker. Wash the organic phase by extracting with10ml of hydrochloric acid(4.4), and transfer the washings to the beaker. Heat the solution gently and e

48、xpel almost all of the4-methyl-2-pentanone in the solution. Then add5ml of nitric acid(4.7) and evaporate to dryness. Dissolve the salts with15ml of hydrochloric acid(4.5). Combine this solution with the reserved solution from7.4.2. Transfer the solution to a50ml one-mark volumetric flask, and dilut

49、e to volume with water and mix. Depending on the concentration (see Table 1), use the solution for atomic absorption measurement either without dilution or as specified. If dilution is required, transfer the appropriate aliquot to a250ml beaker. Add the amount of sodium carbonate(4.1) and hydrochloric acid(4.5) indicated in Table 1. Heat the solution to remove carbon dioxide. Cool and dilute to100ml in a one-mark volumetric flask with water. (See the note to Table 1.) (This solution is the final test