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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 6043-2-18:2001 ISO 593
2、1:2000 ICS 71.100.10; 75.160.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Methods of sampling and test for carbonaceous materials used in aluminium manufacture Part 2: Electrode coke Section 2.18: Determination of total sulfur by the Eschka method Licensed Copy: sheffiel
3、dun sheffieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 March 2001
4、 BSI 03-2001 ISBN 0 580 36815 7 BS 6043-2-18:2001 Amendments issued since publication Amd. No.DateComments National foreword This British Standard reproduces verbatim ISO 5931:2000 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Commi
5、ttee CII/24, Raw materials for the aluminium industry, 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 UK interests informed; monitor related
6、international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the
7、 BSI Standards 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 respons
8、ible 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, the ISO title page, pages ii to v, a blank page, pages 1 to 7 and a back cover. The BSI cop
9、yright notice displayed in this document indicates when the document was last issued. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI INTERNATIONAL STANDARD ISO 5931 First edition 2000-08-15 Reference number ISO 5931:2000(E) Carbonaceous mat
10、erials used in the production of aluminium Calcined coke and calcined carbon products Determination of total sulfur by the Eschka method Produits carbons utiliss pour la production de laluminium Coke calcin et produits carbons calcins Dosage du soufre total par la mthode Eschka Licensed Copy: sheffi
11、eldun sheffieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iii ContentsPage 1Scope .1 2Normative references .1 3Principle 1 4Reagents 1 5Apparatus .2 6Preparation
12、of test sample 2 7Procedure .3 8Expression of results 4 9Precision .5 10Test report 5 Annex ADerivation of factors used in the calculation in clause 8 .6 Bibliography.7 Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv Foreword ISO (the Int
13、ernational 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 com- mittees. Each member body interested in a subject for which a technical committee
14、has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liai- son with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechni
15、cal standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval
16、by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 5931 w
17、as prepared by Technical Committee ISO/TC 47,Chemistry, Subcommittee SC 7, Aluminium oxide, cryolite, aluminium fluoride, sodium fluoride, carbonaceous products for the aluminium industry. Annex A of this International Standard is for information only. Licensed Copy: sheffieldun sheffieldun, na, Wed
18、 Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI v Introduction Instrumental methods for a more rapid determination of total sulfur are now available. lf such a method is to be used, it is important to demonstrate that the method is free from bias when compared to this reference method an
19、d will give levels of repeatability and reproducibility which are the same as, or better than, those quoted for this reference method (see clause 9). Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na,
20、 Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ANRETNIITOLAN TSDNADRAISO 3950002:1)E( 1 Carbonaceous materials used in the production of aluminium Calcined coke and calcined carbon products Determination of total sulfur by the Eschka method 1Scope This International Standard specifi
21、es a reference method for determining the total sulfur content of calcined coke and calcined carbon products by the Eschka method, provided that they contain a minimum ofby mass and prefer- ably less thanby mass of sulfur. 2Normative references The following normative documents contain provisions wh
22、ich, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publica- tions do not apply. However, parties to agreements based on this International Standard are encouraged to investi- gate th
23、e possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 4787:1984,Laboratory glas
24、sware Volumetric glassware Methods for use and testing of capacity. ISO 4788:1980,Laboratory glassware Graduated measuring cylinders. ISO 5069-2:1983,Brown coals and lignites Principles of sampling Part 2: Sample preparation for determination of moisture content and for general analysis. ISO 6375:19
25、80,Carbonaceous materials for the production of aluminium Coke for electrodes Sampling. 3Principle A test portion is ignited in intimate contact with Eschka mixture in an oxidizing atmosphere to remove combustible matter and to convert the sulfur to sulfate. The sulfate is then extracted using a hyd
26、rochloric acid solution and the sul- fur content, in the form of sulfate, is determined gravimetrically by precipitation of the sulfate with barium chloride. 4Reagents WARNING Care should be exercised when handling the reagents, many of which are toxic and corrosive. During the analysis, unless othe
27、rwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 4.1Eschka mixture. Mix two parts by mass of light, calicined magnesium oxide with one part by mass of anhydrous sodium (or potas- sium) carbonate. Pass the mixture entirely through
28、a test sieve ofnominal size of openings. 4.2Hydrochloric acid, concentrated,approximately, approximatelyby mass. 0,1 % 4 % 212m 1,18 g/ml36 % Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO :1395(0002)E 2 4.3Potassium sulfate, solution.
29、Weigh, to the nearest, aboutof potassium sulfate, previously dried at a temperature ofto. Dissolve in water and dilute to. 4.4Barium chloride, approximatelysolution. Dissolveof barium chloride dihydrate in water and dilute to. Filter before use through a close-textured, dou- bly acid-washed filter-p
30、aper or filter-paper pad (see 5.8). 4.5Methyl red, indicator solution. Dissolveof 2-(4-dimethylaminophenylazo) benzoic acid, sodium salt (methyl red) inof water. 4.6Ammonia, concentrated solution, no less thanby mass. 4.7Silver nitrate,solution. Dissolveof silver nitrate in water and dilute to. Stor
31、e in a dark glass bottle. 5Apparatus 5.1Analytical balance, capable of weighing to the nearest. 5.2Graduated glassware, complying with the requirements for class A in ISO 4788 and in accordance with ISO 4787. 5.3Electrically heated muffle furnace, capable of being maintained at. The ventilation thro
32、ugh the muffle furnace shall be such as to give about five air changes per minute. 5.4Crucible, of platinum, silica or glazed porcelain, of approximatelycapacity. 5.5Flat plate,thick, of silica (or other suitable refractory material), which fits easily into the muffle furnace (5.3). 5.6Gooch crucibl
33、e, with a maximum pore size of, of glazed porcelain or sintered glass. Before commencing the filtration, dry the Gooch crucible and pad forin the air oven (5.7) atand weigh it to the nearest. 5.7Air oven, capable of being maintained at. 5.8Filter paper or filter-paper pad, doubly acid-washed, ashles
34、s, close-textured and/or medium-textured. To prepare the filter-paper pad, shake doubly acid-washed filter-paper clippings (cut into pieces of approximately ) with water in a bottle until the paper is thoroughly disintegrated. Place a porcelain filter cone ofin a funnel. Close the stem of the funnel
35、 with a finger and add water until the cone is immersed and the funnel stem is full. Shake sufficient paper pulp to form a padthick onto the cone and level it with a flat-ended glass rod. Allow the excess water to drain off by removing the finger from the stem and as drainage ceases, lightly tamp th
36、e pad around the edges with the glass rod. Finally wash with water to render the filter ready for use. 5.9Dessicator. 0,1 mg2 g105 C 110 C 1 l 85 g/l 100 g1 l 1 g1 l 25 % 17 g/l 17 g1 l 0,1 mg (80025) C 25 ml 6 mm 7m 1 h(13010) C 0,1 mg (13010) C 1 cm225 mm 75 mm 5 mm Licensed Copy: sheffieldun shef
37、fieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 3950002:1)E( 3 6Preparation of test sample The test sample is the representative sample prepared in accordance with ISO 6375. Expose the test sample, dis- tributed in a thin layer, to the laboratory atmosphere for the mi
38、nimum time required for the moisture content to reach approximate equilibrium. Before commencing the determination, thoroughly mix the test sample for at least, preferably by mechanical means. lf the results are to be calculated other than on an “air-dried” basis (see clause 8), then, after weighing
39、 the test por- tion (see 7.1), determine the moisture content using another portion of the test sample. 7Procedure 7.1Test portion Take two test portions of, each weighed to the nearest. Carry out the procedure given in 7.2 to 7.6 on each test portion. 7.2Loading the crucible Weighof the Eschka mixt
40、ure (4.1). Divide this mixture into three portions,and, and weigh each to the nearest. For this purpose, it may be convenient to calibrate two glass tubes for theandpor- tions. Uniformly cover the bottom of the crucible with theportion of the Eschka mixture. In another suitable vessel, mix the test
41、portion thoroughly with theportion of the Eschka mixture. Transfer this mixture to thecrucible. Level the contents by tapping the crucible gently on the laboratory benchtop and cover the contents uniformly with portion of the Eschka mixture. NOTEThe layer of Eschka mixture below the test portion mix
42、ture reduces attack on the porcelain surface, so that the extraction of sulfate with hot water is complete even when the surface deteriorates. 7.3Ignition Place the loaded crucible (or crucibles) on the cold insulating plate (5.5) and insert into the muffle furnace (5.3) main- tained at, and heat fo
43、r at least. Withdraw the crucible (or crucibles) and allow to cool. NOTEThe cracking of porcelain crucibles can be prevented, if they are slowly cooled by insertion into supports of light porous firebrick upon removal from the muffle furnace. 7.4Recovering the residue Transfer the ignited mixture fr
44、om the crucible to abeaker containingtoof water. lf unburnt parti- cles are present, stop the determination and repeat the test. Wash the crucible thoroughly with aboutof hot water, then add the washings to the contents of the beaker. 7.5Extraction Place a watch-glass on the beaker and, tilting the
45、watch-glass to leave an opening, carefully add enough hydrochloric acid (4.2) to dissolve the solid matter (will normally be required) while warming the contents of the beaker to enhance solution. Boil forto expel carbon dioxide. Filter (5.8) and collect the filtrate in aconical beaker. NOTEA medium
46、-textured, doubly acid-washed filter-paper or a filter-paper pad can be used to speed filtration. 1 min 1 g0,1 mg 4 g0,5 g 1,0 g2,5 g 0,1 mg0,5 g1,0 g 0,5 g 2,5 g25 ml 1,0 g 800 C 3 h 400 ml25 ml30 ml 50 ml 17 ml 5 min400 ml Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:47:50 GMT+00:00 2
47、006, Uncontrolled Copy, (c) BSI ISO :1395(0002)E 4 Wash the filter with fiveportions of hot water. Add 2 or 3 drops of the methyl red indicator solution (4.5) to the combined filtrate and washings, and then cautiously add the ammonia solution (4.6) until the colour of the indicator changes and a tra
48、ce of precipitate is formed. Add just enough hydrochloric acid (4.2) to redissolve the precipitate and then addin excess. 7.6Precipitation of barium sulfate After extraction, dilute the solution, if necessary, to approximatelyand cover the beaker containing the solution with a watch-glass. Heat the
49、covered beaker until the solution boils then reduce the heat slightly until the solution ceases to boil. Using a pipette, add, over a period of,of the cold barium sulfate solution to the middle of the hot, stirred solution. Keep the solution just below the boiling point for. Filter the solution using one of the following techniques: a)by gravity through an ashless, close-textured, doubly acid-washed filter-paper (see 5.8) of diameterto . Carefully fold the filter-paper and fit it into a fluted, long-stemmedfunnel, so that the stem