1、 Reference number ISO 8005:2005(E) ISO 2005INTERNATIONAL STANDARD ISO 8005 Second edition 2005-10-01 Carbonaceous materials used in the production of aluminium Green and calcined coke Determination of ash content Produits carbons utiliss pour la production de laluminium Coke cru et coke calcin Dterm
2、ination du taux de cendres ISO 8005:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer perfor
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6、address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2005 All rights reservedISO 8005:2005(E) ISO 2005 All rights
7、reserved iii Foreword ISO (the International 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 committees. Each member body interested in a subject
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11、 responsible for identifying any or all such patent rights. ISO 8005 was prepared by Technical Committee ISO/TC 226, Materials for the production of primary aluminium. This second edition cancels and replaces the first edition (ISO 8005:1984), which has been technically revised. ISO 8005:2005(E) iv
12、ISO 2005 All rights reservedIntroduction The content of ash or inorganic materials in coke is an important property, as ash will accumulate in the electrolyte when the coke is used for anodes. Constant ash content may also be an indication that the same raw materials are used. INTERNATIONAL STANDARD
13、 ISO 8005:2005(E) ISO 2005 All rights reserved 1 Carbonaceous materials used in the production of aluminium Green and calcined coke Determination of ash content 1 Scope This International Standard specifies a method for the determination of ash in green and calcined coke used in the production of al
14、uminium. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 6375, Carbona
15、ceous materials for the production of aluminium Cokes for electrodes Sampling ASTM Practice E69199, Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method 3 Principle Heating of a test portion of a dry, finely ground sample in a tared dish in a furnace
16、at 700 C, to constant mass. 4 Apparatus 4.1 Jaw crusher, or another suitable crusher, faced with a very hard alloy that will not be abraded and therefore will not contaminate the sample. 4.2 Pestle and mortar, or a suitable mill, of hard material that will not be abraded and therefore will not conta
17、minate the sample. Suitable materials are agate, tungsten or silicon carbide. Porcelain should not be used. 4.3 Sieve, 750 m. 4.4 Laboratory balance. 4.5 Desiccator, containing a drying agent (e.g. activated alumina or molecular sieves). 4.6 Platinum dish, of capacity 50 ml to 60 ml, diameter about
18、65 mm to 72 mm, height about 15 mm; or an appropriate porcelain dish. 4.7 Oven, capable of maintaining a temperature of (105 5) C. 4.8 Electric furnace, capable of being controlled at (700 10) C, with an adequate air circulation. ISO 8005:2005(E) 2 ISO 2005 All rights reserved5 Sampling and sample S
19、ample in accordance with ISO 6375. 6 Procedure 6.1 Preparation of the test sample Use any suitable means to crush a representative portion of the material (Clause 5) to approximately 25 mm or smaller size and dry until it is totally dry e.g. at (105 5) C for 3 h. Further crush the dry material, by m
20、eans of the crusher (4.1), to approximately 6 mm or smaller size. Thoroughly mix the dried crushed material; reduce it by quartering to a test sample of at least 50 g. Grind the entire 50 g test sample with the pestle and mortar or in a mill (4.2) to such a fineness that it all passes through the 75
21、0 m sieve (4.3). 6.2 Test portion 6.2.1 Heat the platinum or porcelain dish (4.6) for 1 h in the furnace (4.8), controlled at (700 10) C, allow it to cool to ambient temperature in the desiccator containing the drying agent (4.5) and weigh to the nearest 0,000 2 g. 6.2.2 Weigh, to the nearest 0,000
22、2 g, a test portion of about 20 g of the dry, sieved test sample (6.1), or a quantity sufficient to provide a minimum of 0,020 g of ash, in the previously tared dish (6.2.1). 6.3 Determination 6.3.1 Place the dish containing the test portion (6.2.2) into the cold furnace (4.8) and raise the temperat
23、ure of the furnace to (700 10) C. Gradually heat to redness at such a rate as to avoid mechanical loss (in the case of green coke, this prevents a too rapid expulsion of volatile matter). Maintain at (700 10) C overnight, or for an adequate time to completely burn off the carbonaceous matter in the
24、test portion. Remove the dish containing the ash from the furnace and cool it to room temperature in the desiccator containing the drying agent (4.5). 6.3.2 Weigh the dish and ash as rapidly as possible; replace them in the furnace and repeat heating, cooling and weighing until the mass of the dish
25、and contents does not differ by more than 0,000 5 g for two consecutive weighings. 7 Expression of results 7.1 Method of calculation The ash content, expressed as a percentage by mass, w a , is given by the formula: () 21 0 100 a wmm m = where m 0is the mass, in grams, of the test portion (6.2.2); m
26、 1is the mass, in grams, of the empty dish (6.2.1); m 2is the mass, in grams, of the dish containing the ash (6.3.2). ISO 8005:2005(E) ISO 2005 All rights reserved 3 Report the result in weight percent to the nearest 0,01 %. 7.2 Precision 7.2.1 Laboratories, materials and determinations The number o
27、f laboratories, materials, and determinations met the minimum requirements for determining precision specified in ASTM Practice E691 (see Table 1): Table 1 Laboratories, materials and determinations This study ASTM E691 Minimum Laboratories 8 6 Materials 6 4 Determinations: 4 2 7.2.2 Precision state
28、ment for test method Repeatability r = 0,03 % (weight percent) Reproducibility R = 0,06 % (weight percent) 8 Test report The test report shall include the following information: a) an identification of the sample; b) a reference to this International Standard; c) the results and the method of expres
29、sion 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; f) date of the test. ISO 8005:2005(E) ICS 71.100.10 Price based on 3 pages ISO 2005 All rights reserved
