1、BRITISH STANDARD BS ISO 17544:2004 Carbonaceous materials used in the production of aluminium Cold and tepid ramming pastes Determination of rammability of unbaked pastes ICS 71.100.10 BS ISO 17544:2004 This British Standard was published under the authority of the Standards Policy and Strategy Comm
2、ittee on 24 December 2004 BSI 24 December 2004 ISBN 0 580 45151 8 National foreword This British Standard reproduces verbatim ISO 17544:2004 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee CII/24, Raw materials for the alumi
3、nium industry, which has the responsibility to: 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 BSI Catalogue under th
4、e section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct applicat
5、ion. Compliance with a British Standard does not of itself confer immunity from legal obligations. 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; monit
6、or related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii and iii, pages 1 to 6 and a back cover. The BSI copyright date displayed in this document indicates when the d
7、ocument was last issued. Amendments issued since publication Amd. No. Date Comments Reference number ISO 17544:2004(E)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 unb
8、aked pastes Produits carbons utiliss pour la production de laluminium Ptes de brasquage froides et tides Dtermination de laptitude au brasquage des ptes non cuites BSISO17544:2004IS:44571 O4002(E) DPlcsid Fremia ihTs PDF file may ctnoian emdebt dedyfepcaes. In ccaocnadrw eith Aebods licensilop gnic,
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11、sneeru that the file is suitlbae fosu re yb ISO memdob rebeis. In tlnu ehikletneve y ttah lborp aem leratit gno it is f,dnuo plsaee inform ttneC ehlar Secrteiraat ta the serddaig sleb nevwo. ii BSISO17544:2004 iiiForeword ISO (the International Organization for Standardization) is a worldwide federa
12、tion 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 for which a technical committee has been established has the right to be represented on that committ
13、ee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance
14、 with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires ap
15、proval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this 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 Comm
16、ittee ISO/TC 47, Chemistry, Subcommittee SC 7, Aluminium oxide, cryolite, aluminium fluoride, sodium fluoride, carbonaceous products for the aluminium industry. BSISO17544:2004INTENRATIONAL TSANDADR IS:44571 O4002(E)1Carbonaceous materials used in the production of aluminium Cold and tepid ramming p
17、astes Determination of rammability of unbaked pastes 1 Scope This International Standard describes a method of 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 enable
18、s a ramming paste with the optimum density to be selected. 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 (in
19、cluding any amendments) applies. ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results 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 Col
20、d-ramming pastes Methods of sampling 3 Symbols h measured height of test specimen, in cm m mass of paste placed 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 t
21、he compaction curve (which decreases as increases) location parameter which shifts the origin of the distribution maxmaximum value of density, in g cm 3 0initial value of density, representative of loose compaction of the paste under its own weight, in g cm 3(N) density after N impacts, in g cm 3BSI
22、SO17544:20042 (N) first derivative of (N) (N) second derivative of (N) (N) third derivative of (N) (50) density after 50 impacts, in g cm 3(100) density after 100 impacts, in g cm 3 pre-exponential factor, in g cm 3 : = max 04 Principle Ramming paste is compacted in a laboratory rammer. The paste is
23、 subjected to a total of 350 impacts. The density of the paste is measured as a function 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 () e x p N N = (1) A ramming parameter N2, corresponding
24、to the number of impacts for which the second derivative of the Weibull function has a minimum 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)
25、5 Apparatus An example of a rammer mould is shown in Figure 1. 5.1 Rammer cylinder, made 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
26、weight mounted so that it can be dropped onto the top of the piston, and a height-measuring 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 ram
27、ming paste needed to produce one test specimen. The free space over the paste shall not be 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 poly
28、styrene), for insulation of the rammer cylinder, or thermostatically controlled surround (see Figure 1). 5.7 Balance, accurate to 0,1 g. BSISO17544:2004 36 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 tes
29、t specimen. 7 Procedure Ensure the cylinder, the ram base 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
30、 test specimen after compaction has to be (50 5) mm (see 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
31、 h to 3 h. Transfer the paste to the cylinder. Protect the 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 (t
32、o the nearest 0,1 mm) from the scale on the ramming apparatus, 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 spec
33、imen at a rate of about 1 impact per second. If the final 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 Expressi
34、on of results 8.1 Calculation of the density Calculate the 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 rh = (3) where m is the mass, in g, of the ramming paste placed in
35、the cylinder, accurate to 0,1 g; r is the inner radius of 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 g cm 3 . Plot (N) against N to give a compaction
36、curve. 8.2 Interpretation of the curve A paste showing a slow 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. BSISO17544:20044 8.3 Determination of N2 8.3.1 Fitting t
37、he data to a Weibull function 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 , , an
38、d by fitting the values of (N) calculated in 8.1 to the Weibull function: 6 10 max log () e x p 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 sta
39、rting values in Table 1 can be used. Table 1 Starting values for Equation (5) max1,500 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 deriva
40、tive (N) is used as the evaluation criterion for the rammability. The number of impacts (N2) which gives the minimum value of the second derivative of (N) (with respect to log 10 N), when the third derivative is equal to zero, is given by: 10 log 15 9 3 10 10 10 3 log log log 12 ( ) e 18 45 10 0 N N
41、NN N = + = (5) It is possible to solve Equation (5) exactly: (1 ,145 ) 21 0 N + = (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. R
42、ound the value calculated for N2 to the nearest whole 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. BSISO17544:2004 58.4 Deter
43、mination of (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
44、when compared with 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 fr
45、eedom, i.e. number 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
46、 include the following 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
47、 , , and determined 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.
48、BSISO17544:20046 Key 1 piston 2 steel cylinder 3 ramming paste 4 insulation or thermostatically controlled surround 5 ram base Figure 1 Rammer mould BSISO17544:2004BS ISO 17544:2004 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British
