1、BRITISH STANDARD BS 6783-9: 1986 EN 28343:1991 ISO 8343:1985 Incorporating Amendment No. 1 Sampling and analysis of nickel, ferronickel and nickel alloys Part 9: Method for determination of silicon in ferronickel (gravimetric method) ISO title: Ferronickel Determination of silicon content Gravimetri
2、c method This European Standard EN 28343:1991 has the status of a British Standard UDC 669.1524-198:620.1:543.21:546.28BS6783-9:1986 This British Standard, having been prepared under the directionof the Non-ferrous Metals Standards Committee, waspublished under the authorityof the Board of BSIandcom
3、es into effect on 31 December 1986 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference NFM/10 Draft for comment 84/39891 DC ISBN 0 580 15528 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the
4、Non-ferrous Metals Standards Committee (NFM/-) to Technical Committee NFM/10, upon which the following bodies were represented: British Non-ferrous Metals Federation British Steel Industry Engineering Equipment and Materials Users Association Ministry of Defence Process Plant Association Stainless S
5、teel Fabricators Association of Great Britain Coopted members Amendments issued since publication Amd. No. Date of issue Comments 6995 April 1992 Indicated by a sideline in the marginBS6783-9:1986 BSI 12-1999 i Contents Page Committees responsible Inside front cover National foreword ii Text of EN 2
6、8343 3 Publication referred to Inside back coverBS6783-9:1986 ii BSI 12-1999 National foreword This Part of BS 6783 has been prepared under the direction of the Non-ferrous Metals Standards Committee. It is identical with ISO 8343:1985 “Ferronickel Determination of silicon content Gravimetric method
7、” published by the International Organization for Standardization (ISO). In 1991 the European Committee for Standardization (CEN) accepted ISO8343:1985 as European Standard EN 28343:1991 without any modifications. At present this British Standard consists of nine Parts all concerned with analysis of
8、 nickel, ferronickel and nickel alloys. Further International Standards are in preparation on sampling and analysis of nickel, ferronickel and nickel alloys and, when available, these will be published as further Parts of this British Standard. Terminology and conventions. The text of the Internatio
9、nal Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British
10、 Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “Part of BS 6783”. In British Standards it is current practice to use the symbol “L” for litre (and in i
11、ts submultiples) rather than “l” and to use the spelling “sulphur”, etc., instead of sulfur, etc. 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. Compliance with a British Standard do
12、es not of itself confer immunity from legal obligations. Cross-reference International Standard Corresponding British Standard ISO 5725:1981 BS 5497 Precision of test methods Part 1:1979 Guide for the determination of repeatability and reproducibility for a standard test method (Technically equivale
13、nt) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 4, an inside back cover andaback cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendme
14、nt table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 28343:1991 November 1991 UDC 669.1524-198:620.1:543.21:546.28 Descriptors: Ferroalloys, ferronickel, chemical analysis, determination of content, silicon, gravimetric analysis English version Ferronickel Determin
15、ation of silicon content Gravimetric method (ISO 8343:1985) Ferro-nickel Dosage du silicium Mthode gravimtrique (ISO 8343:1985) Ferronickel Bestimmung des Siliciumgehaltes Gravimetrisches Verfahren (ISO 8343:1985) This European Standard was approved by CEN on 1991-11-06. CEN members are bound to com
16、ply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Se
17、cretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the of
18、ficial versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen d
19、e Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels CEN 1991 Copyright reserved to all CEN members Ref. No. EN 28343:1991 EEN28343:1991 BSI 12-1999 2 Contents Page 1 Scope and field of application 3 2 Reference 3 3 Principle 3 4 Reagents 3 5 Appara
20、tus 3 6 Sampling and samples 3 7 Procedure 3 8 Expression of results 4 9 Test report 4 Table 4EN28343:1991 BSI 12-1999 3 1 Scope and field of application This International Standard specifies a gravimetric method for the determination of silicon in ferronickel in the range0,2 to 4,0% (m/m). 2 Refere
21、nce ISO 5725, Precision of test methods Determination of repeatability and reproducibility by inter-laboratory tests. 3 Principle Dissolution of a test portion in nitric acid and addition of perchloric acid. Formation of insoluble silica by dehydration in perchloric acid, filtration, and weighing of
22、 the calcined precipitate. Volatilization of the silica with hydrofluoric and sulfuric acids, weighing of the residue, determination of the silica by difference and calculation of the silicon content. 4 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical
23、 grade and only distilled water or water of equivalent purity. 4.1 Hydrochloric acid, 20= 1,19 g/ml. 4.2 Hydrochloric acid, 20= 1,19 g/ml, diluted 1 + 9. 4.3 Hydrochloric acid, 20= 1,14 g/ml. WARNING Hydrofluoric acid is extremely irritating and corrosive to skin and mucous membranes, producing seve
24、re skin burns which are slow to heal. In case of skin contact wash well with water and seek medical advice. 4.4 Nitric acid, 20= 1,41 g/ml, diluted1 + 1. 4.5 Perchloric acid, 20= 1,61 g/ml 70% (m/m). 4.6 Sulfuric acid, 20= 1,83 g/ml, diluted1 + 1. 5 Apparatus Ordinary laboratory apparatus, and 5.1 B
25、eaker, high form, of capacity 600 ml, unetched. 5.2 Platinum crucible, of capacity 40 ml. 5.3 Muffle furnace, capable of being maintained at1100 C. 5.4 Dessicator 6 Sampling and samples 6.1 Sampling and preparation of the laboratory sample shall be carried out by normal agreed procedures or, in case
26、 of dispute, by the relevant International Standard. 6.2 The laboratory sample normally is in the form of granules, millings or drillings and no further preparation of the sample is necessary. 6.3 If it is suspected that the laboratory sample is contaminated with oil or grease from the milling or dr
27、illing process, it shall be cleaned by washing with high purity acetone and drying in air. 6.4 If the laboratory sample contains particles or pieces of widely varying sizes, the test portion should be obtained by riffling. 7 Procedure 7.1 Test portion 7.1.1 For a silicon content greater than 1 % (m/
28、m) weigh, to the nearest 0,001 g, 2,00 g of the laboratory sample. 7.1.2 For a silicon content between 0,25 and1 % (m/m) weigh, to the nearest 0,002 g, 4,00 g of the laboratory sample. 7.1.3 For a silicon content less than 0,25% (m/m) weigh, to the nearest 0,005 g, 10,00 g of the laboratory sample.
29、7.2 Blank test Carry out a blank test in parallel with the determination, following the same procedure and using the same quantities of all the reagents. 7.3 Determination WARNING Fuming perchloric acid is a powerful oxidant and can cause an explosive mixture when in contact with organic materials.
30、All evaporations should be done in fume cupboards suitable for use with perchloric acid. 7.3.1 Transfer the test portion (7.1) to a beaker (5.1), add 50 ml of nitric acid (4.4) and cover with a watch-glass. Heat moderately and when dissolution is almost complete, add 50 ml of perchloric acid(4.5). N
31、OTEIf a 10 g test portion is used, add the nitric acid with care in small portions to prevent too great an effervescence. After dissolution add 70 ml of perchloric acid. 7.3.2 Heat gently and then progressively more strongly until the appearance of white fumes of perchloric acid. Continue heating un
32、til the residue reaches the point of crystallization. Remove from the hotplate and allow to cool. Add 100 ml of near boiling water to dissolve the salts, then add 15 ml of hydrochloric acid (4.1). Dilute to 250 ml with boiling water. Stir and heat for 2 min at just below boiling. 7.3.3 Filter on a 1
33、25 mm folded filter paper of medium porosity. Rinse the beaker using hot water and clean with a rubber policeman. Wash the filter and contents with hot hydrochloric acid diluted 1 + 9 (4.2) until the yellow colour of iron salts disappears. Finally wash with hot water until the filtrate is acid free.
34、 Discard the filtrate and washings.EN28343:1991 4 BSI 12-1999 WARNING The filter shall be thoroughly washed to eliminate any trace of perchloric acid which could cause an explosion during incineration. 7.3.4 Place the filter containing the precipitate in a platinum crucible (5.2). Dry on a hotplate
35、or in an oven and ignite in a muffle furnace (5.3) first at low temperature to char the paper. Calcine at 1 100 C for at least 30 min. Allow to cool in a desiccator(5.4) and weigh the crucible containing the calcined precipitate to the nearest 0,1 mg. Repeat the calcination for 30 min intervals unti
36、l a constant mass is obtained. 7.3.5 Wet the calcined precipitate with several drops of water. Add about 0,5 ml of sulfuric acid(4.6) followed by about 5 ml of hydrofluoric acid(4.3). Evaporate gently to dryness on a hotplate until sulfuric acid fumes are eliminated. Calcine in a muffle furnace at 1
37、 100 C for 10 min. Allow to cool in a desiccator and weigh the crucible containing the impurities to the nearest 0,1 mg. Repeat the calcination for 10 min intervals until a constant mass is obtained. 8 Expression of results 8.1 Calculation The silicon content, expressed as a percentage by mass, in t
38、he test portion, is given by the formula where m 0 is the mass, in grams, of the test portion; m 1 is the mass, in grams, of the crucible and impure silica; m 2 is the mass, in grams, of the crucible plus residual impurities; NOTEThe difference m 1 m 2is the mass, in grams, of the pure silica volati
39、lized. m 3 is the mass, in grams, of the pure silica given by the blank test; 0,467is the conversion factor for silica to silicon. 8.2 Precision This International Standard was subjected to a limited inter-laboratory test programme involving only five laboratories in four countries. Repeatability an
40、d reproducibility were calculated according to the principles of ISO 5725 with the results given in the Table. Table 9 Test report The test report shall include the following information: a) the reference to the method used; b) the results of the analysis; c) the number of independent replications;
41、d) any unusual features noted during the analysis; e) any operation not included in this International Standard or regarded as optional. Silicon content % (m/m) 0,26 1,01 2,56 Standard deviations within laboratory, s w 0,005 0,022 0,014 between laboratories, s b 0,001 0,012 0,027 Repeatability, r 0,
42、013 0,062 0,039 Reproducibility, R 0,014 0,071 0,087BS6783-9:1986 BSI 12-1999 Publication referred to See national foreword.BS 6783-9: 1986 EN 28343:1991 ISO 8343:1985 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for prepari
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