1、BRITISH STANDARD BS 4993-9: 1980 BS 5050-12: 1980 ISO 5938:1979 Methods of test for Aluminium fluoride for industrial use Part9: Determination of sulphur content (X-ray fluorescence spectrometric method) Methods of test for Cryolite Part12: Determination of sulphur content (X-ray fluorescence spectr
2、ometric method) ISO title: Cryolite, natural and artificial, and aluminium fluoride for industrial use Determination of sulphur content X-ray fluorescence spectrometric method UDC 661.862.361+622.363.414:543.062:546.22BS4993-9:1980 BS 5050-12:1980 This British Standard, having been prepared under th
3、e directionof the Chemicals Standards Committee, was published under the authority ofthe Executive Board and comesinto effect on 31December1980 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference CIC/24 Draft for comment 77/54319 DC ISBN 0 580 11667 0 Co
4、operating organizations The Chemicals Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: Association of Fatty Acid Distillers British Tar Industry Association Chemical Industries Association* Chemical Society, Analytical Div
5、ision* Consumer Standards Advisory Committee of BSI Department of Health and Social Security Department of Industry (Laboratory of the Government Chemist) Fertiliser Manufacturers Association Ltd. Hydrocarbon Solvents Association Ministry of Agriculture, Fisheries and Food Ministry of Defence Nation
6、al Sulphuric Acid Association Paintmakers Association of Great Britain Ltd. Royal Institute of Public Health and Hygiene Soap and Detergent Industry Association Standardization of Tar Products Tests Committee The organizations marked with an asterisk in the above list, together with the following, w
7、ere directly represented on the committee entrusted with the preparation of this British Standard: Aluminium Federation British Ceramic Research Association Royal Institute of Chemistry Amendments issued since publication Amd. No. Date of issue CommentsBS4993-9:1980 BS5050-12:1980 BSI 09-1999 i Cont
8、ents Page Cooperating organizations Inside front cover National foreword ii 1 Scope 1 2 Field of application 1 3 References 1 4 Principle 1 5 Reagents 1 6 Apparatus 1 7 Procedure 2 8 Expression of results 3 9 Test report 3 Annex ISO publications relating to cryolite, natural and artificial, andalumi
9、nium fluoride for industrial use 4 Table 1 2 Table 2 2 Publications referred to Inside back coverBS4993-9:1980 BS5050-12:1980 ii BSI 09-1999 National foreword These Parts of these British Standards have been prepared under the direction of the Chemicals Standards Committee. They are identical with I
10、SO5938:1979 “Cryolite, natural and artificial, and aluminium fluoride for industrial use Determination of sulphur content X-ray fluorescence spectrometric method”. ISO5938 was originally disapproved by the United Kingdom at Member Body stage. The standard, as published, has been amended in respect o
11、f the main UnitedKingdom criticisms and this has led to a reversal of the original vote. Terminology and conventions. The text of the International Standard has been approved as suitable for publication, without deviation, as a British Standard. Some terminology and certain conventions are not ident
12、ical with those used in British Standards; attention is especially drawn to the following. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. The comma has been used throughout as a decimal marker. In British Standards, it is cu
13、rrent practice to use a full point on the baseline as the decimal marker. There is no British Standard identical with ISO1619:1976, referred to in the text. However, a related British Standard for ISO1619 is BS5050:1974 “Methods of test for cryolite”, clause2, “Preparation and storage of test sample
14、s”. The other International Standards listed in the Annex are for information only. Corresponding British Standards are listed below. Cross-references International Standard Corresponding British Standard ISO2925:1973 BS4993 Methods of test for aluminium fluoride for industrial use Part4:1980 Prepar
15、ation and storage of test samples (Identical) International Standard Corresponding British Standard BS4993 Methods of testfor aluminium fluoridefor industrialuse BS5050:1974 Methods of test for cryolite Title ISO1620:1976 Clause3 Determination of silica content (Related) ISO1693:1976 Clause4 Determi
16、nation of fluorine content (Related) ISO1694:1976 Clause5 Determination of iron content (Related) ISO2362:1972 Part1:1974 Determination of fluorine content (Related) ISO2366:1974 Clause6 Determination of sodium content (Related) ISO2367:1972 Clause7 Determination of aluminium content (gravimetric me
17、thod) (Related)BS4993-9:1980 BS5050-12:1980 BSI 09-1999 iii ISO5930, referred to in the Annex and published in July1979, was disapproved by the UnitedKingdom at Member Body stage and it is likely that this disapproval will be sustained. International Standard Corresponding British Standard BS4993 Me
18、thods of testfor aluminium fluoridefor industrialuse BS5050:1974 Methods of test for cryolite Title ISO2368:1972 Part2:1974 Determination of iron content (Related) ISO2369:1972 Part3:1974 Determination of silica content (Related) ISO2830:1973 Clause8 Determination of aluminium (atomic absorption met
19、hod) (Related) ISO3391:1976 Part8:1980 Determination of calcium content (Identical) ISO3392:1976 Part5:1980 Part9:1980 Determination of water content (Karl Fischer method) (Identical) ISO3393:1976 Part6:1980 Part10:1980 Gravimetric determination of moisture content (Identical) ISO4277:1977 (ISO4277
20、disapproved by United Kingdom) ISO4279:1977 Part7:1980 Determination of sodium content (Identical) ISO4280:1977 Part8:1980 Part11:1980 Determination of sulphate content (Identical) ISO6374 a Part10 b Part13 b Determination of phosphorus content (atomic absorption spectrophotometric method) b (Identi
21、cal) a In preparation. b Subject to approval by the UK.BS4993-9:1980 BS5050-12:1980 iv BSI 09-1999 The first seven international test methods in the cryolite series were published in combined form as BS5050:1974 and were modified both to take into account UnitedKingdom comments made during their dev
22、elopment and to conform to BSI layout. In accordance with current policy, the remaining standards are to be published without alteration, as separate dual-numbered (BSI/ISO) Parts of this British Standard. In order to establish a uniform and acceptable overall layout, it is intended, in conjunction,
23、 to revise the1974 edition, progressively replacing it by the International Standards, without alteration, as separate Parts of this British Standard. The change will be made, for each Part, immediately following the routine five-yearly review of the International Standard concerned. This will ensur
24、e that the revised standard satisfies current requirements and will allow the UnitedKingdom to propose changes if the International Standards are not completely acceptable as they stand. It is expected, however, that such changes will be minimal. When the process of revision has been completed, the1
25、974 edition will be withdrawn. BS4993-1, BS4993-2 and BS4993-3, although published in separate Parts, differ from the corresponding International Standards in a similar manner to the methods in BS5050:1974 and will therefore be revised, with the same objective, i.e.of complete identity with the corr
26、esponding International Standards. Additional information Water. Water complying with the requirements of clause5 is specified in BS3978 “Water for laboratory use”. WARNING. Sodium fluoride, referred to in5.3 and5.4, is toxic and is irritant in the form of dust. Avoid inhalation of dust. Prevent con
27、tact with eyes and skin. NOTETextual errors. In Table 2, “Proportional gas type” should be read as “Proportional gas flow type”. In the note to7.3.3, line3, insert “to” before “eliminate”. These standards prescribe methods of test only, and should not be used or quoted as a specification defining li
28、mits of purity. Reference to the standards should state that the methods of test used conform to BS4993, or BS5050, as appropriate. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Com
29、pliance 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, pagesi toiv, pages1to4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have ha
30、d amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS4993-9:1980 BS5050-12:1980 BSI 09-1999 1 1 Scope This International Standard specifies an X-ray fluorescence spectrometric method for the determination of the sulphur content of natural and artificia
31、l cryolite and of aluminium fluoride for industrial use. 2 Field of application The method is applicable to products having sulphur contents, expressed as , between0,01 and2%(m/m). 3 References ISO1619, Cryolite, natural and artificial Preparation and storage of test samples. ISO2925, Aluminium fluo
32、ride for industrial use Preparation and storage of test samples. 4 Principle Preparation of tablets from a mixture of the test portion and a binder. Measurement of the intensity of the K !line emitted by the sulphur at a wavelength of0,5373nm by means of avacuum X-ray fluorescence spectrometer fitte
33、d with a tube having a rhodium, chromium or tungsten anticathode. Comparison of the measured intensity with the intensity of emission of standard tablets of knowncontent. 5 Reagents During the analysis, unless otherwise specified, use only reagents of recognized analytical grade and only distilled w
34、ater or water of equivalent purity. 5.1 Binder Crystalline cellulose for use in chromatography, or other equivalent binder. 5.2 Aluminium fluoride Use either: a) very pure (96,4%) aluminium fluoride, containing only traces of ; or b) the sublimate obtained by subliming technical grade aluminium fluo
35、ride in the electric vacuum furnace(6.4), controlled at860 20 C, under a vacuum of0,01 to0,1Pa 1) . 5.3 Sodium fluoride, prepared by calcination, at about600 C, of sodium fluoride obtained by crystallization from an aqueous solution. 5.4 Cryolite, prepared by fusing, in the nickel crucible(6.1), a s
36、toichiometric mixture of the aluminium fluoride(5.2) and the sodium fluoride(5.3), in the electric furnace(6.3), controlled at1000 20 C, for2h. In order to prevent evaporation of fluorides during fusion, place the nickel crucible in the iron container(6.2), and close the latter hermetically with its
37、 lid. 5.5 Acetone 5.6 Sodium sulphate, anhydrous. 5.7 Sodium sulphate, standard solution corresponding to20,0g of Na 2 SO 4per litre. Weigh, to the nearest0,0001g,20,0g of the anhydrous sodium sulphate(5.5) and dissolve in water. Transfer the solution quantitatively to a1000ml one-mark volumetric fl
38、ask, dilute to the mark and mix. 1ml of this standard solution contains20,0mg of Na 2 SO 4 , corresponding to0,01352g of 5.8 Sodium sulphate, standard solution corresponding to100,0g of Na 2 SO 4per litre. Weigh, to nearest0,001g,100,0g of the anhydrous sodium sulphate(5.5) and dissolve in water. Tr
39、ansfer the solution quantitatively to a1000ml one-mark volumetric flask, dilute to the mark andmix. 1ml of this standard solution contains100,0mg of Na 2 SO 4 , corresponding to0,0676g of 6 Apparatus Ordinary laboratory apparatus and 6.1 Nickel crucible 6.2 Iron container, having a threaded lid with
40、 which it may be hermetically sealed, and capable of containing the crucible(6.1). 6.3 Electric furnace, capable of being controlled at1000 20 C. 6.4 Electric vacuum furnace, capable of being controlled at860 20 C. 6.5 Laboratory mixer 6.6 Grinder, capable of grinding the powders used for tablet pre
41、paration to a particle size smaller than204m. 6.7 Press, for preparing tablets of thickness at least8mm and diameter40mm. 6.8 Electric oven, capable of being controlled at110 5 C. 1) 1Pa=1N/m 2 =104bar; 133Pa=1torr SO 2 4 SO 2 4 SO 2 4 SO 2 4 . SO 2 4 .BS4993-9:1980 BS5050-12:1980 2 BSI 09-1999 6.9
42、Vacuum X-ray fluorescence spectrometer, fitted with a tube having a rhodium, chromium or tungsten anticathode, a sodium chloride or pentaerythritol crystal analyser, a physical pulse height analyser and a proportional gas flow detector. 7 Procedure 7.1 Test portion Weigh, to the nearest0,10g,15g of
43、the dried test sample, prepared as specified in ISO1619 for cryolite, or in ISO2925 for aluminium fluoride. 7.2 Grinding and preparation of tablets Carefully mix the binder(5.1) with the test portion(7.1) in the proportion of1,5g of binder to5g of cryolite or aluminium fluoride, using the mixer(6.5)
44、 in order to obtain a homogeneous mixture. Add10 to15 drops of the acetone(5.5) to prevent compacting of the product and grind for1min in the grinder(6.6). Then press the powder into tablets using the press(6.7) for15s at250MPa. 2) 7.3 Calibration 7.3.1 Preparation of the standard tablets Into a ser
45、ies of seven watch-glasses of suitable size, place20g of the ground aluminium fluoride(5.2) or cryolite(5.4). Add the volumes of the standard sodium sulphate solution(5.7 or5.8) specified in Table 1. Table 1 Add the standard solution, drop by drop, on to the centre of the surface of the powder, taki
46、ng care not to wet the surface of the glass. Dry for about12h in the electric oven(6.8), controlled at110 5 C. Allow to cool in a desiccator. Mix each powder carefully in an agate mortar. Prepare tablets by the procedure specified in7.2, using15g of powder from each dried and mixed standard. NOTEIn
47、the special case of aluminium fluoride having a highcontent, the sodium sulphate may be added directly in the form of the solid sodium sulphate(5.6). 7.3.2 Spectrometric measurements Switch on the current to the apparatus(6.9) and allow to stabilize. Adjust the current according to the type of antic
48、athode (seeTable 2). Place the standard tablets in position and adjust the vacuum to a value equal to or less than1,33Pa. Then, under the operating conditions specified, for example, in Table 2, measure the intensity of the sulphur K !line emitted for each standard tablet. Table 2 2) 1MPa=10 6 N/m 2
49、 Standard sodium sulphate solution Volume added Corresponding mass of Corresponding content ml g % (m/m) 5.7 0 0,5 1,0 1,5 0 0,00676 0,01352 0,02028 0 0,0338 0,0676 0,1014 5.8 0,5 1,0 1,5 0,03380 0,06760 0,10140 0,1690 0,3380 0,5070 SO 2 4 SO 2 4 Characteristic or element ofapparatus Specification Tube voltage 50kV aa Current: rhodium anticathode tungsten anticathode chromium anticathode 40mA aa 50mA aa 20mA aa Vacuum u 1,33Pa Sulphur K !wavelength 0,5373nm Analyser NaCl or pentaerythritol crystal Detecto
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