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1、 Reference number ISO 17544:2004(E) ISO 2004 INTERNATIONAL STANDARD ISO 17544 First edition 2004-07-15 Carbonaceous materials used in the production of aluminium Cold and tepid ramming pastes Determination of rammability of unbaked pastes Produits carbons utiliss pour la production de laluminium Pte
2、s de brasquage froides et tides Dtermination de laptitude au brasquage des ptes non cuites ISO 17544:2004(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
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5、t a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO 2004 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and
6、 microfilm, without permission in writing from either ISO at the 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
7、ISO 2004 All rights reserved ISO 17544:2004(E) ISO 2004 All rights 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
8、ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates
9、 closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards.
10、 Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this
11、document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 17544 was prepared by Technical Committee ISO/TC 47, Chemistry, Subcommittee SC 7, Aluminium oxide, cryolite, aluminium fluoride, sodium fluoride, carbonaceous products
12、for the aluminium industry. -,-,- INTERNATIONAL STANDARD ISO 17544:2004(E) ISO 2004 All rights reserved 1 Carbonaceous materials used in the production of aluminium Cold and tepid ramming pastes Determination of rammability of unbaked pastes 1 Scope This International Standard describes a method of
13、producing a compaction curve indicating the rammability of carbonaceous ramming pastes used to line cathodes utilized in the production of aluminium. Determination of the rammability enables a ramming paste with the optimum density to be selected. 2 Normative references The following referenced docu
14、ments 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 5725-2, Accuracy (trueness and precision) of measurement methods and resul
15、ts Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method ISO 14422, Carbonaceous materials used in the production of aluminium Cold-ramming pastes Methods of sampling 3 Symbols h measured height of test specimen, in cm m mass of paste placed
16、 in cylinder, in g N number of impacts N2 minimum value of second derivative of (N) r inner radius of rammer cylinder, in cm scaling or normalization parameter describing the steepness of the compaction curve (which decreases as increases) location parameter which shifts the origin of the distributi
17、on max maximum value of density, in gcm3 0 initial value of density, representative of loose compaction of the paste under its own weight, in gcm3 (N) density after N impacts, in gcm3 ISO 17544:2004(E) 2 ISO 2004 All rights reserved (N) first derivative of (N) (N) second derivative of (N) (N) third
18、derivative of (N) (50) density after 50 impacts, in gcm3 (100) density after 100 impacts, in gcm3 pre-exponential factor, in gcm3: = max 0 4 Principle Ramming paste is compacted in a laboratory rammer. The paste is subjected to a total of 350 impacts. The density of the paste is measured as a functi
19、on of the number of impacts. The data is fitted to a three- parameter cumulative Weibull distribution function given by the following equation: 6 10 max log ()exp N N = (1) A ramming parameter N2, corresponding to the number of impacts for which the second derivative of the Weibull function has a mi
20、nimum value, is then calculated. An alternative method of evaluation is to determine the ratio of the density after 50 impacts to the density after 100 impacts, as shown by the following formula: (50) (100) (2) 5 Apparatus An example of a rammer mould is shown in Figure 1. 5.1 Rammer cylinder, made
21、of steel, with an inner diameter of 50 mm. 5.2 Ram base, made of steel. The ram base shall fit into the rammer cylinder and act as the bottom of the cylinder. 5.3 Rammer, consisting of a steel piston, a falling weight mounted so that it can be dropped onto the top of the piston, and a height-measuri
22、ng device accurate to 0,1 mm. The mass of the falling weight shall be 6,35 kg and the weight shall travel a constant distance to impact of (50 0,1) mm. 5.4 Box (with lid), capable of containing the amount of ramming paste needed to produce one test specimen. The free space over the paste shall not b
23、e more than 50 % of the volume of the paste. 5.5 Heating/cooling cabinet, capable of being maintained at a constant temperature 0,5 C in the range 5 C to 100 C. 5.6 Insulation layer (for example, 1-cm-thick polystyrene), for insulation of the rammer cylinder, or thermostatically controlled surround
24、(see Figure 1). 5.7 Balance, accurate to 0,1 g. ISO 17544:2004(E) ISO 2004 All rights reserved 3 6 Sampling Sample the paste in accordance with ISO 14422. NOTE Experience has shown that 150 g to 200 g of ramming paste is necessary for each test specimen. 7 Procedure Ensure the cylinder, the ram base
25、 and the piston are clean. Weigh the necessary amount of ramming paste (to the nearest 0,1 g) into a suitable box (5.4). If the amount of ramming paste to be used is not known, determine the required mass by preliminary tests the height of the test specimen after compaction has to be (50 5) mm (see
26、below). Seal the box. Heat or cool the box together with the rammer cylinder (5.1), the ram base (5.2) and the insulation/surround (5.6) to the test temperature (agreed between the interested parties) in the heating/cooling cabinet (5.5) for 2 h to 3 h. Transfer the paste to the cylinder. Protect th
27、e cylinder with the insulation or surround (5.6). Place the cylinder in the rammer (5.3) and lower the piston until it is resting on the paste. Compact the ramming paste with a total of 350 impacts, reading the height h of the test specimen (to the nearest 0,1 mm) from the scale on the ramming appar
28、atus, with the piston head resting on the specimen, after 1, 2, 3, 4, 5, 7, 10, 15, 20, 25, 30, 35, 40, 50, 60, 80, 100, 120, 150, 180, 230, 280 and 350 impacts. Where several impacts are made between height measurements, compact the test specimen at a rate of about 1 impact per second. If the final
29、 height of the compacted test specimen is not equal to (50 5) mm, discard the results and repeat the test with another sample mass. Remove the test specimen. Clean the cylinder, the ram base and the piston carefully after each test. 8 Expression of results 8.1 Calculation of the density Calculate th
30、e density of the paste (N) corresponding to each specimen height measured (i.e. to each number of impacts N at which a height measurement was made) from Equation (3): 2 () m N r h = (3) where m is the mass, in g, of the ramming paste placed in the cylinder, accurate to 0,1 g; r is the inner radius o
31、f the ramming cylinder, in cm, accurate to 0,01 cm; h is the height of the unbaked test specimen as read from the rammer scale, in cm, accurate to 0,01 cm. Round the results to the nearest 0,001 gcm3. Plot (N) against N to give a compaction curve. 8.2 Interpretation of the curve A paste showing a sl
32、ow asymptotic approach towards its maximum density is said to be a dry paste, whereas a paste showing a rapid asymptotic approach towards its maximum density is said to be a wet paste. ISO 17544:2004(E) 4 ISO 2004 All rights reserved 8.3 Determination of N2 8.3.1 Fitting the data to a Weibull functi
33、on The data fit is based on the similarities between compaction curves presented with a logarithmic abscissa and statistical cumulative distribution functions. A general three-parameter cumulative Weibull distribution function is chosen. Determine the parameters max, , and by fitting the values of (
34、N) calculated in 8.1 to the Weibull function: 6 10 max log ()exp N N = (4) The fitting can be done by the least-squares method, for which various commercial computer programmes are available. Normally, a set of starting values for the four parameters is needed. The starting values in Table 1 can be
35、used. Table 1 Starting values for Equation (5) max 1,500 0,500 3 2 8.3.2 Calculation of N2 Putting the third derivative of (N) equal to zero i.e. (N) = 0 enables the turning point of the density distribution curve to be determined. The minimum value of the second derivative (N) is used as the evalua
36、tion criterion for the rammability. The number of impacts (N2) which gives the minimum value of the second derivative of (N) (with respect to log10N), when the third derivative is equal to zero, is given by: 10 log 1593 101010 3 logloglog12 ()e1845100 N NNN N =+= (5) It is possible to solve Equation
37、 (5) exactly: (1,145) 210N + = (6) Calculate the number of impacts N2 which gives the minimum value of the second derivative of (N) (third derivative = 0) using Equation (6) and the parameters from the curve-fitting operation carried out in 8.3.1. Round the value calculated for N2 to the nearest who
38、le number. NOTE Typically, values lie in the range 65 N2 130. Such values were found to give good rammability when compared with practical work at one smelter. The range may, however, depend on the ramming technology used. -,-,- ISO 17544:2004(E) ISO 2004 All rights reserved 5 8.4 Determination of (
39、50)/(100) Alternatively, calculate the density after 50 impacts divided by the density after 100 impacts, (50)/(100), using the values of (50) and (100) determined in 8.1. NOTE Typically, values lie in the range 0,960 (50)/(100) 0,975. Such values were found to give good rammability when compared wi
40、th practical work at one smelter. The range may, however, depend on the ramming technology used. 9 Precision (determined in accordance with ISO 5725-2) 9.1 N2 Repeatability (r) = 0,18 material average 3,71 Reproducibility (R) = 0,34 material average + 2,65 The number of degrees of freedom, i.e. numb
41、er of laboratories (5) number of samples (4), was 20. 9.2 (50)/(100) Repeatability (r) = 0,004 9 Reproducibility (R) = 0,496 material average 0,473 1 The number of degrees of freedom, i.e. number of laboratories (6) number of samples (4), was 24. 10 Test report The test report shall include the foll
42、owing information: a) a reference to this International Standard; b) all details necessary for identification of the sample tested; c) the temperature used for the test; d) the results of the test: 1) the curve of density versus number of impacts, 2) the values of the parameters max, , and determine
43、d by fitting the curve to the Weibull function, 3) the value obtained for N2 or (50)/(100); e) the date of the test; f) details of any unusual features noted during the determination; g) details of any operation not included in this International Standard or regarded as optional. ISO 17544:2004(E) 6 ISO 2004 All rights reserved Key 1 piston 2 steel cylinder 3 ramming paste 4 insulation or thermostatically controlled surround 5 ram base Figure 1 Rammer mould -,-,- ISO 17544:2004(E) ICS 71.100.10 Price based on 6 pages ISO 2004 All rights reserved