1、BRITISH STANDARD BS 6043-1.8: 1986 ISO 8006:1985 Methods of sampling and test for Carbonaceous materials used in aluminium manufacture Part 1: Electrode pitch Section 1.8 Determination of ash (ISO title: Carbonaceous materials used in the production of aluminium Pitch for electrodes Determination of
2、 ash) UDC 661.66:669.71.012.23:620.1BS6043-1.8:1986 This British Standard, having been prepared under the directionof the Chemicals Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 29 August 1986 BSI 10-1999 The following BSI references relate to the
3、work on this standard: Committee reference CIC/24 Draft for comment 83/56064 DC ISBN 0 580 15315 0 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Committee (CIC/-) to Technical Committee CIC/24, upon which the follow
4、ing bodies were represented: Aluminium Federation British Ceramic Research Association British Tar Industry Association Chemical Industries Association Institute of Petroleum Refractories Association of Great Britain Standardization of Tar Products Tests Committee Amendments issued since publication
5、 Amd. No. Date of issue CommentsBS6043-1.8:1986 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope and field of application 1 2 References 1 3 Principle 1 4 Apparatus 1 5 Sampling and samples 1 6 Procedure 1 7 Expression of results 2 8 Test report 2 Fi
6、gure Graph of repeatability r jand of reproducibility R jas a function of mean level 3 Publications referred to Inside back cover x jBS6043-1.8:1986 ii BSI 10-1999 National foreword This British Standard has been prepared under the direction of the Chemicals Standards Committee to provide methods of
7、 sampling and test for carbonaceous materials used in the production of aluminium. The standard is published in two Parts, each Part being divided into Sections. The two Parts are: Part 1: Electrode pitch; Part 2: Electrode coke. Initially it is proposed that Part1will comprise the following Section
8、s: The UK did not approve the determination of density (by pyknometer) method given inISO6999:1983 and a national version is being prepared. Other international methods of test for electrode pitch are under consideration and, subject to approval by the United Kingdom, will be published as they becom
9、e available. This Section is identical withISO8006 “Carbonaceous materials used in the production of aluminium Pitch for electrodes Determination of ash”, published by the International Organization for Standardization (ISO). Terminology and conventions. The text of the International Standard has be
10、en 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 throughout as a decimal marker. In British Standar
11、ds 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 “British Standard”. The Technical Committee has reviewed the provisions ofISO5725, to which reference is made in
12、7.2, and has decided that they are acceptable for use in conjunction with this standard. A related British Standard for ISO5725 isBS5497, “Precision of test methods” Part1 “Guide for the determination of repeatability and reproducibility for a standard test method”. Section Subject Identical with 1.
13、1 Sampling ISO 6257 1.2 Water content (Dean and Stark method) ISO 5939 1.3 Softening point (ring and ball method) ISO 5940 1.4 Content of toluene-insoluble material ISO 6376 1.5 Content of quinoline-insoluble material ISO 6791 1.6 Coking value ISO 6998 1.7 Density 1.8 Ash content ISO 8006 1.9 Sulphu
14、r content ISO a a In preparation. Cross-references International Standard Corresponding British Standard ISO 6257:1980 BS 6043 Methods of sampling and test for carbonaceous materials used in aluminium manufacture Part1Electrode pitch Section 1.1:1981 Sampling (Identical) ISO 5939:1980 Section 1.2:19
15、81 Determination of water content (Dean and Stark method) (Identical)BS6043-1.8:1986 BSI 10-1999 iii Additional information. This standard describes methods of test only, and should not be used or quoted as a specification defining limits of purity. Reference to this Section should state that the me
16、thod of test used is in accordance withBS6043-1.8:1986. 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 does not of itself confer immunity from lega
17、l obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages1to 4, 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
18、on the inside front cover.iv blankBS6043-1.8:1986 BSI 10-1999 1 1 Scope and field of application This International Standard specifies a method for the determination of ash in the pitch for electrodes used in the production of aluminium. The method is applicable to products (tar pitch, petroleum pit
19、ch, etc.) producing a quantity of ash greater than or equal to0,05% (m/m). If it is required to express the result on the dry product, carry out the water determination by azeotropic distillation as specified in ISO5939. Refer the result of the determination of ash obtained on the product as such, t
20、o the dry product. NOTEThis ash may be utilised for subsequent elemental analysis. 2 References ISO 5725, Precision of test methods Determination of repeatability and reproducibility by inter-laboratory tests. ISO 5939, Carbonaceous materials for the production of aluminium. Determination of water c
21、ontent Azeotropic distillation (Dean and Stark). ISO 6257, Carbonaceous materials for the production of aluminium Pitch for electrodes Sampling. 3 Principle Heating of a test portion in a tared platinum crucible, in a furnace at 700 C, under oxidizing and specified conditions, to constant mass. 4 Ap
22、paratus Ordinary laboratory apparatus and 4.1 Platinum crucible, low form, of capacity approximately50ml. 4.2 Electric furnace, capable of being controlled at700 10 C and provided with air circulation. 4.3 Electric oven, capable of being controlled at150 5 C. 5 Sampling and samples Sample in accorda
23、nce withISO6257. 6 Procedure 6.1 Test portion Heat the crucible (4.1) for1h in the furnace (4.2), controlled at700 10 C. Allow the crucible to cool, first in air to about100and150 C, and then in a desiccator charged with diphosphorus pentaoxide, to room temperature. Weigh the crucible to the nearest
24、0,0002 g (m 1 ). Weigh into the crucible, to the nearest0,0002 g, approximately5g of the test sample (see clause5) (m 0 ). 6.2 Determination Place the crucible containing the test portion (6.1) into the electric furnace (4.2) set at a temperature close to but not exceeding300 10 C. Increase heating
25、following the heating rule indicated below. In periods of not less than30min each, but whichmay, without prejudice, be increased toapproximately60min, raise the temperature atauniform rate first to350 10 C, then to400 10 C and finally to450 10 C, inspecting regularly to ensure that no mechanical los
26、s of the test portion occurs due to over-vigorous volatilization. If losses are observed, repeat the determination on another test portion and following the procedure specified below. If the water content of the sample is high, place the crucible containing the test portion (6.1) in the electric ove
27、n (4.3), controlled at150 5 C, and allow to stand at this temperature for about 2h. Remove the crucible and its content from the oven and place it directly in the electric furnace (4.2), controlled at300 10 C. Continue heating following the heating rule already specified. If even in such conditions
28、some losses of the testportion are observed (over-vigorous volatilization), reduce the rate of heating, in the range 300to450 C by suitably increasing the relevant periods of heating. Raise the temperature of the furnace to700 10 C and heat the crucible and contents at this temperature until the ash
29、ing process appears to be complete (conveniently overnight). Remove the crucible and contents, allow to cool, first in air to about 100 to150 C and then in a desiccator, charged with diphosphorus pentaoxide, to room temperature. Weigh the crucible and contents to the nearest0,0002 g. Transfer the cr
30、ucible and contents to the furnace maintained at700 10 C and heat for30min. Cool and weigh as specified in the previous paragraph. Repeat the heating, cooling and weighing operations until the mass of the crucible and contents does not differ by more than 0,0002g on two consecutive weighings. NOTE 1
31、The furnace (4.2) should be located in a well-ventilated fume cupboard. NOTE 2The number of tests which may be carried out simultaneously is dependent on the performance characteristics of the furnace used. Particular attention should be paid to the temperature profile within the furnace in position
32、ing the crucibles for a multiple determination.BS6043-1.8:1986 2 BSI 10-1999 7 Expression of results 7.1 Method of calculation The ash, determined on the normal product, x, expressed as a percentage by mass, is given by the equation where Report the result to the nearest0,01% (m/m). 7.2 Precision Th
33、e repeatability and reproducibility were calculated according toISO5725. From the data obtained a connection is observed between both repeatability and reproducibility and the average value (see the Figure). The graph shows, as abscissae, the average values as percentages, obtained for each level, a
34、nd as ordinates the corresponding values, as percentages, of repeatability and reproducibility. Calculate these values for each level using the two linear equations: r =0,0126 + 0,081 7 R =0,00126 +0,427 8 Test report The test report shall include the following particulars: a) an identification of t
35、he sample; b) the reference of the method used; c) the results and the method of expression used; d) any unusual features noted during the determination; e) any operation not included in this International Standard or in the International Standards to which reference is made, or regarded as optional
36、. m 0 is the mass, in grams, of the test portion(6.1); m 1 is the mass, in grams, of the empty crucible; m 2 is the mass, in grams, of the crucible containing the ash. xm 2 m 1 () 100 m 0 - = x xBS6043-1.8:1986 BSI 10-1999 3 Figure Graph of repeatability r jand of reproducibility R jas a function of
37、 mean level x j4 blankBS6043-1.8:1986 BSI 10-1999 Publications referred to See national foreword.BS 6043-1.8: 1986 ISO8006:1985 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK
38、view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve t
39、he quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:0208996740
40、0. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel:02089969001. Fax
41、:02089967001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as BritishStandards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and internatio
42、nal standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also available which give details on all its products and services. Contact the Information Centre. Tel:02089967111. Fax:02089967048. Subscribing members of BSI are kept up
43、to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Membership Administration. Tel:02089967002. Fax:02089967001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, i
44、n the UK, of the publications of the international standardization bodies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise with
45、out prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
