BS ISO 14435-2006 Carbonaceous materials for the production of aluminium - Petroleum coke - Determination of trace metals by inductively coupled plasma atomic emission spectrometry.pdf

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2、n spectrometryICS 71.100.10Carbonaceous materials for the production of BRITISH STANDARDBS ISO 14435:2005BS ISO 14435:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2006 BSI 2006ISBN 0 580 48630 3Cross-referencesThe British Stand

3、ards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication

4、does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the IS

5、O title page, pages ii to v, a blank page, pages 1 to 9 and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this committee can be obtained on r

6、equest to its secretary. present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Stand

7、ard reproduces verbatim ISO 14435:2005 and implements it as the UK national standard.The UK participation in its preparation was entrusted to Technical Committee CII/24, Raw materials for the aluminium industry, which has the responsibility to: aid enquirers to understand the text;Reference numberIS

8、O 14435:2005(E)INTERNATIONAL STANDARD ISO14435First edition2005-07-15Carbonaceous materials for the production of aluminium Petroleum coke Determination of trace metals by inductively coupled plasma atomic emission spectrometry Produits carbons pour la production de laluminium Coke de ptrole Dtermin

9、ation des mtaux ltat de trace par spectromtrie dmission atomique avec plasma induit par haute frquence BS ISO 14435:2005ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 2 5 Interferences . 2 6 Apparatus 3 7 Reagents 4 8 Sam

10、ple preparation 5 9 Preparation of apparatus . 5 10 Procedure 6 11 Calculation. 7 12 Test report . 7 13 Precision and bias for the dried test portion . 8 Bibliography . 9 BS ISO 14435:2005iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national stand

11、ards 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 that committee. International orga

12、nizations, 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 accordance with the rules given

13、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 requires approval by at least 75

14、% 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 14435 was prepared by Technical Committee ISO/TC 226, Mate

15、rials for the production of primary aluminium. BS ISO 14435:2005vIntroduction The presence and concentration of various metallic elements in a petroleum coke are major factors in determining the suitability of the coke for various end-uses. Users of petroleum coke require a standard procedure to det

16、ermine the concentrations of these metallic elements in a coke sample. This International Standard describes such a procedure. This International Standard is based on ASTM method D5600-98, published under the jurisdiction of ASTM Committee D2 on Petroleum Products and Lubricants and Subcommittee DO2

17、.05.01 on Petroleum Coke Sampling and Procedures. The repeatability and reproducibility information is based on an interlaboratory trial, which is reported in Research Report D02-1007 available from ASTM Headquarters. BS ISO 14435:2005blank1Carbonaceous materials for the production of aluminium Petr

18、oleum coke Determination of trace metals by inductively coupled plasma atomic emission spectrometry WARNING This International Standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropri

19、ate safety and health practices and determine the applicability of regulatory limitations prior to use. 1 Scope This International Standard applies to carbonaceous materials for the production of aluminium. This International Standard describes a test method which covers the analysis for commonly de

20、termined trace metals in test specimens of raw and calcined petroleum coke by inductively coupled plasma atomic emission spectroscopy. It can also be applied to other heat-treated carbonaceous materials e.g. coal-tar pitch coke, anthracite. Elements to which this test method applies are listed in Ta

21、ble 1. Detection limits, sensitivity, and optimum ranges of the metals will vary with the matrices and model of spectrometer. This test method is applicable only to samples containing less than a mass fraction of 1 % ash. Elements present at concentrations above the upper limit of the working ranges

22、 can be determined with additional, appropriate dilutions. 2 Normative references The 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 (in

23、cluding any amendments) applies. ISO 6375, Carbonaceous materials for the production of aluminium Coke for electrodes Sampling ISO 3696:1987, Water for analytical laboratory use Specification and test methods ISO 3310-1, Test sieves Technical requirements and testing Part 1: Test sieves of metal wir

24、e cloth 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 petroleum coke solid, carbonaceous residue produced by thermal decomposition of heavy petroleum fractions and cracked stocks BS ISO 14435:20052 3.2 coal-tar pitch coke solid, carbonaceou

25、s residue produced by decomposition of coal-tar pitch 3.3 gross sample original, uncrushed, representative portion taken from a shipment or lot of coke 4 Principle A test sample of the petroleum coke is ashed at 700 C. The ash is fused with lithium borate. The melt is dissolved in dilute nitric acid

26、 (HNO3), and the resultant solution is analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES) using simultaneous, or sequential, multi-elemental determination of elements. The solution is introduced to the ICP instrument by free aspiration or by an optional peristaltic pump. T

27、he concentrations of the trace metals are then calculated by comparing the emission intensities from the sample with the emission intensities of the standards used in calibration. 5 Interferences For spectral interferences, follow the instrument manufacturers operating guide to develop and apply cor

28、rection factors to compensate for the interferences. To apply interference corrections, all concentrations shall be within the previously established linear-response range of each element. NOTE Spectral interferences are caused by a) overlap of a spectral line from another element, b) unresolved ove

29、rlap of molecular band spectra, c) background contribution from continuous or recombination phenomena, and d) stray light from the line emission of high-concentration elements. Spectral overlap can be compensated for by computer-correcting the raw data after monitoring and measuring the interfering

30、element. Unresolved overlap requires selection of an alternate wavelength. Background contribution and stray light can usually be compensated for by a background correction adjacent to the analyte line. Physical interferences are effects associated with the sample nebulization and transport processe

31、s. Changes in viscosity and surface tension can cause significant inaccuracies, especially in samples containing high amounts of dissolved solids or high acid concentrations. If physical interferences are present, they shall be reduced by diluting the sample, by using a peristaltic pump, or by using

32、 the standard-additions method. Another problem that can occur with high amounts of dissolved solids is build-up of salts at the tip of the nebulizer, which can affect aerosol flow rate and cause instrumental drift. This problem can be controlled by wetting the argon prior to nebulization by using a

33、 tip washer, or diluting the sample. BS ISO 14435:20053Table 1 Elements determined and suggested wavelengths Wavelengths Concentration range Element nma,bg/gcAluminium 237,313 256,799 308,215 396,152 15 to 110 Barium 455,403 493,410 1 to 65 Calcium 317,933 393,367 396,847 10 to 140 Iron 259,940 40 t

34、o 700 Magnesium 279,079 279,553 5 to 50 Manganese 257,610 294,920 1 to 7 Nickel 231,604 341,476 352,454 3 to 220 Silicon 212,412 251,611 288,159 60 to 290 Sodium 588,995 589,592 30 to 160 Titanium 334,941 337,280 1 to 7 Vanadium 292,402 2 to 480 Zinc 202,548 206,200 213,856 1 to 20 aThe wavelengths

35、listed were utilized in the interlaboratory trial because of their sensitivity. Other wavelengths can be substituted if they can provide the required sensitivity and are treated with the same corrective techniques for spectral Interference (see Clause 5). In time, other elements may be added as more

36、 information becomes available and as required. bAlternative wavelengths can be found in references such as Inductively Coupled Plasma Atomic Emission Spectroscopy,Winge, R.K., Fassel, V.A., Peterson, V.J., and Floyd, M.A., Elsevier, 1985. cBased on this interlaboratory trial. This method can be app

37、licable to other elements or concentration ranges, but precision data are not available. 6 Apparatus 6.1 Balance, top loading, with automatic tare, capable of weighing to 0,000 1 g, of capacity 150 g. 6.2 Ceramic cooling plate, desiccator plates have been found to be effective. 6.3 Crucible support,

38、 nichrome wire triangles. 6.4 Furnaces, electric, capable of temperature regulation at 700 C 10 C and 1 000 C 10 C, with allowances for exchange of combustion gases and air. 6.5 Inductively coupled plasma atomic emission spectrometer, either a sequential or simultaneous spectrometer is suitable, equ

39、ipped with a quartz ICP torch and radio frequency (RF) generator to form and sustain the plasma. 6.6 Magnetic stirring bars, polytetrafluoroethylene (PTFE) coated, approximately 12 mm in length. 6.7 Magnetic stirring hotplate. 6.8 Meker-type forced air burner. 6.9 Nebulizer, a high-solids nebulizer

40、is recommended. 6.10 Peristaltic pump, a peristaltic pump is recommended. BS ISO 14435:20054 6.11 Platinum dish, of capacity 50 ml to 58 ml, recommended type Pt II (Pt containing 5 % mass fraction Au). 6.12 Platinum dish, of capacity 100 ml to 200 ml, recommended type Pt II. 6.13 Platinum-tipped ton

41、gs. 6.14 Ring stand, with crucible support. 6.15 Sieves, 0,250 mm and 0,075 mm, conforming to ISO 3310-1. 6.16 Tungsten carbide mill, laboratory size. 6.17 Vacuum filtration apparatus. 6.18 Filter paper, sized to fit a vacuum filtration apparatus, of fine porosity, slow flow rate, 2,5 m particle ret

42、ention. 6.19 Ultrasonic bath. 7 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and distilled or demineralized water, or water of equivalent purity. 7.1 Water, complying with grade 2 of ISO 3696:1987. 7.2 Argon gas supply, welding grade. 7.3 Li

43、thium metaborate (LiB02), powder (high purity) or lithium tetraborate (Li2B407), powder (high purity). The use of a blend containing 66 % lithium metaborate (LiB02) and 34 % lithium tetraborate (Li2B407) is recommended: a commercially available product is known as “Spectromelt A12“1). 7.4 Nitric aci

44、d, 65 % mass fraction (high purity). 7.5 Solution No. 1, nitric acid, prepared by diluting 400 ml of concentrated HNO3(65 % mass fraction) to 2 000 ml with water. NOTE The mass fraction of concentrated HNO3is 65 %. The dilution of 400 ml HNO3(65 % mass fraction) to 2 000 ml with water gives a mass f

45、raction of 13 % HNO3with a density of 1,072. The result is a mass fraction of 12,1 %. 7.6 Solution No. 2, standard and sample solution additive. Weigh 20 0,1 g, of lithium borate into a 100 ml to 200 ml platinum dish. Place in a furnace at 1000 C for 5 min, to fuse to a liquid. Remove and cool. Plac

46、e the cooled platinum dish containing the fused recrystallized lithium borate and a magnetic stirring bar (6.6) into a 2 litre glass beaker. Add 1 000 ml of Solution No. 1. Heat gently and stir the solution on the magnetic stirring hotplate (6.7) until the lithium borate completely dissolves. After

47、dissolution, remove the platinum dish with a glass rod. Rinse the platinum dish and glass rod with water into the lithium borate solution. Immediately transfer the warm solution quantitatively to a 2 litre volumetric flask. Dilute to about 1 800 ml with water to avoid crystallization. Mix the soluti

48、on and cool to room temperature. Dilute to volume with water, mix thoroughly, and vacuum-filter the entire solution through filter paper. 1)Spectromelt A12 is an example of a suitable product available commercially. This information is given for the convenience of users of this International Standar

49、d and does not constitute an endorsement by ISO of this product.BS ISO 14435:2005550 ml of Solution No. 2 contains exactly 0,5 g of lithium borate and 25 ml of Solution No. 1. 7.7 Standard stock solutions, use certified ready-to-use single- or multi-element standard stock solutions with a concentration of 1 000 g/ml for each element in nitric acid. CAUTION To minimize the potential of contamination, prepare the platinum ware by boiling in dilute HNO35 % HNO3(volume fraction) + 95 % water (v