1、BRITISH STANDARD BS 5072-8: 1980 ISO 3566:1976 Methods of Test for sodium fluoride for industrial use Part 8: Determination of chlorides content ISO title: Sodium fluoride primarily used for the production of aluminium Determination of chlorides content Turbidimetric method UDC 661.833.361:546.33161
2、:543.436.062:546.131BS5072-8:1980 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authority ofthe Executive Board and comesinto effect on 30April1980 BSI 12-1999 The following BSI references relate to the work on this stand
3、ard: Committee reference CIC/24 Draft for comment 74/54500 DC ISBN 0 580 11219 5 Cooperating organizations The Chemicals Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial
4、organizations: Association of Fatty Acid Distillers British Tar Industry Association Chemical Industries Association* Chemical Society, Analytical Division* Consumer Standards Advisory Committee of BSI Department of Health and Social Security Department of Industry (Laboratory of the Government Chem
5、ist) Fertiliser Manufacturers Association Ltd Hydrocarbon Solvents Association Ministry of Agriculture, Fisheries and Food Ministry of Defence National Sulphuric Acid Association Paintmakers Association of Great Britain Ltd Royal Institute of Public Health and Hygiene Soap and Detergent Industry Ass
6、ociation Standardization of Tar Products Tests Committee The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Aluminium Federation British Ceramic Research Associa
7、tion Royal Institute of Chemistry Amendments issued since publication Amd. No. Date of issue CommentsBS5072-8:1980 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii 1 Scope and field of application 1 2 Reference 1 3 Principle 1 4 Reagents 1 5 Apparatus 1 6
8、 Procedure 1 7 Expression of results 2 8 Test report 2 Annex ISO Publications relating to sodium fluoride for industrialuseandsodiumfluoride primarily used for theproductionofaluminium 3 Publications referred to Inside back coverBS5072-8:1980 ii BSI 12-1999 National foreword WARNING NOTE. Sodium flu
9、oride is toxic and is irritant, particularly in the form of dust. Carry out operations involving its use in a fume cupboard and wear suitable protective clothing to prevent inhalation of the dust and contact with the eyes, skin and clothing. This British Standard has been prepared under the directio
10、n of the Chemicals Standards Committee in order to provide methods for the analysis of sodium fluoride for industrial use. For some years the United Kingdom has participated in the work of preparing methods of test applicable to this material, organized by Subcommittee7(formerly WG8), Aluminium oxid
11、e and related compounds of Technical Committee47, Chemistry, of the International Organization for Standardization (ISO). As international agreement is reached on the methods, it is proposed to publish them as Parts of this British Standard. This Part is identical with ISO3566 “Sodium fluoride used
12、for the production of aluminium Determination of chlorides content Turbidimetric method”. 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 iden
13、tical with those used in British Standards; attention is especially drawn to the following. The comma has been used throughout as a decimal marker. In British Standards, it is current practice to use a full point on the baseline as the decimal marker. Where the words “International Standard” appear,
14、 referring to this standard, they should be read as “British Standard”. Related British Standards for ISO 2831 1) , ISO 2832 1)and ISO 2833 1)are BS5072-1, BS 5072-2 and BS 5072-3 respectively. NOTEThe title and clause1 of ISO 3429, ISO 3430, ISO 3431, ISO 3566 and ISO 4278 (seetheAnnex) state that
15、the sodium fluoride is “primarily used for the production of aluminium”. This is incorrect, at least for the United Kingdom. This has been brought to the attention of ISO Technical Committee 47, in a proposal to amend the International Standards concerned. Additional information Water. Water complyi
16、ng with the requirements of clause4 is specified in BS3978“Water for laboratory use”. Nitric acid. approximately 1.42 g/ml, about70% (m/m) solution, which is the corresponding reagent normally obtainable in the United Kingdom, is suitable for use in place of the approximately1.40g/ml solution specif
17、ied in4.1. Cross-references International Standard Corresponding British Standard BS 5072 Methods of test for sodium fluoride for industrial use ISO 3428:1976 Part 4:1980 Preparation and storage of test samples (Identical) ISO 3429:1976 a Part 5:1980 Determination of iron content (Identical) ISO 343
18、0:1976 a Part 6:1980 Determination of silica content (Identical) ISO 3431:1976 a Part 7:1980 Determination of soluble sulphates content (Identical) ISO 4278:1977 a Part 9:1980 Determination of carbonate content (Identical) a Referred to in theAnnex, for information only. 1) Referred to in theAnnex,
19、for information only.BS5072-8:1980 BSI 12-1999 iii This standard prescribes methods of test only and should not be used or quoted as a specification defining limits of purity. Reference to the standard should indicate that the methods of test comply with the requirements of BS5072-8. A British Stand
20、ard 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 does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover,
21、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 had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS5072-8:1980 BSI 12-1999 1 1 Scope and
22、field of application This International Standard specifies a turbidimetric method for the determination of the chlorides content of sodium fluoride primarily used for the production of aluminium. The method is applicable to products having a chlorides content, expressed as chlorine (Cl), equal to or
23、 greater than0,005% (m/m). 2 Reference ISO 3428, Sodium fluoride for industrial use Preparation and storage of test samples. 3 Principle Precipitation, in the presence of boric acid, of chloride ions with silver nitrate and turbidimetric evaluation of the mass of precipitate. 4 Reagents During the a
24、nalysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 4.1 Nitric acid, approximately1,40g/ml, about68% (m/m) solution. 4.2 Boric acid, 40g/l solution. 4.3 Silver nitrate, approximately0,1N solution. 4.4 Chloride, standard solution, correspo
25、nding to0,050g of Cl per litre. Place14,10ml of 0,100N hydrochloric acid solution in a 1000ml one-mark volumetric flask, dilute to the mark and mix. 1ml of this standard solution contains0,050mg ofCl. 5 Apparatus Ordinary laboratory apparatus and 5.1 Nessler tubes, of capacity50ml. 6 Procedure 6.1 T
26、est portion Weigh, to the nearest0,01g, 1g of the dried test sample. (See ISO 3428, sub-clause2.3.) 6.2 Preparation of the standard matching solutions Place12,5ml of the boric acid solution (4.2) into six of the Nessler tubes (5.1) and then the volumes of the standard chloride solution (4.4) shown i
27、n the following table: Dilute to50ml, introduce1,0ml of the nitric acid solution (4.1) and mix. 6.3 Preparation of the test solution Place the test portion (6.1) in a100ml one-mark volumetric flask and add60ml of water and25ml of the boric acid solution (4.2). Shake until dissolved, dilute to the ma
28、rk, and mix. Filter if necessary. Place50,0ml of this solution in one of the Nessler tubes (5.1), add1,0ml of the nitric acid solution(4.1) and mix. 6.4 Reaction and turbidimetric evaluation Add rapidly to the standard matching solutions(6.2) and to the test solution (6.3)1,0ml of the silver nitrate
29、 solution (4.3), mix and allow to stand in the dark for5min. Compare the opalescence of the test solution with that of each standard matching solution, examining through the axis of the Nessler tubes against a black background and under a diffuse lateral illumination. Deduce the chlorides content of
30、 the test solution. NOTEA photometer can also be used to measure the degrees of opalescence. Standard chloride solution(4.4) Corresponding mass of Cl ml mg 0 0,50 1,00 2,00 3,00 4,00 5,00 0 0,025 0,050 0,100 0,150 0,200 0,250BS5072-8:1980 2 BSI 12-1999 7 Expression of results The chlorides content (
31、Cl) of the dried product, expressed as a percentage by mass, is given by the formula where m 0 is the mass, in grams, of the test portion(6.1); m 1 is the mass, in milligrams, of chloride found in the test solution. 8 Test report The test report shall include the following particulars: a) the refere
32、nce of the method used; b) the results and the method of expression used; c) any unusual features noted during the determination; d) any operation not included in this International Standard or in the International Standard to which reference is made, or regarded as optional. m 1 1 1000 - 100 50 - 1
33、00 m 0 - m 1 5 m 0 - = BS5072-8:1980 BSI 12-1999 3 Annex ISO Publications relating to sodium fluoride for industrial use and sodium fluoride primarily used for the production of aluminium Sodium fluoride for industrial use ISO 2831, Determination of water-insoluble matter. ISO 2832, Determination of
34、 moisture content. ISO 2833, Determination of fluorine content Modified Willard-Winter method. ISO 3428, Preparation and storage of test samples. Sodium fluoride primarily used for the production of aluminium ISO 3429, Determination of iron content 1,10-Phenanthroline photometric method. ISO 3430, D
35、etermination of silica content Reduced molybdosilicate spectrophotometric method. ISO 3431, Determination of soluble sulphates content Turbidimetric method. ISO 3566, Determination of chlorides content Turbidimetric method. ISO 4278, Determination of carbonates content Gravimetric method.4 blankBS50
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