BS 6043-4 11-1991 Methods of sampling and test for carbonaceous materials used in aluminium manufacture - Cold ramming pastes - Determination of the thermal expansion of baked ramm.pdf

1、BRITISH STANDARD BS 6043-4.11: 1991 Methods of sampling and test for Carbonaceous materials used in aluminium manufacture Part 4: Cold ramming pastes Section 4.11 Determination of the thermal expansion of baked rammed paste NOTEIt is recommended that this Section be read in conjunction with the gene

2、ral information in BS6043-4.0, published separately.BS6043-4.11:1991 This British Standard, having been prepared under the directionof the Chemicals Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 30 September 1991 BSI 10-1999 The following

3、BSI references relate to the work on this standard: Committee reference CIC/24 Draft for comment 90/54851 DC ISBN 0 580 19952 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Policy Committee (CIC/-) to Technical Com

4、mittee CIC/24, upon which the following bodies were represented: Aluminium Federation British Ceramic Research Ltd. Chemical Industries Association Institute of Petroleum Refractories Association of Great Britain Amendments issued since publication Amd. No. Date CommentsBS6043-4.11:1991 BSI 10-1999

5、i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Principle 1 3 Apparatus 1 4 Sampling 1 5 Preparation of test sample 1 6 Procedure 1 7 Calculation and expression of results 3 8 Test report 3 Figure 1 Thermal expansion apparatus 2 Publication(s) referred to Inside bac

6、k coverBS6043-4.11:1991 ii BSI 10-1999 Foreword This Section of BS6043has been prepared under the direction of the Chemicals Standards Policy Committee to provide a method of test for cold ramming pastes used in the production of aluminium. There is no corresponding International Standard; however,

7、it is intended, upon publication of this Section of BS6043, that it be offered to the International Organization for Standardization (ISO) for possible adoption as an International Standard. It is essential to use BS1902-5.3and BS6043-4.1, BS6043-4.6 and BS6043-4.7in conjunction with this Section of

8、 BS6043. This standard describes a method of test only, and should not be used or quoted as a specification defining the characteristics of a product. Reference to this Section should indicate that the method of test used is in accordance with BS6043-4.11:1991. A British Standard does not purport to

9、 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 legal obligations. Summary of pages This document comprises a front cover, an inside front cover,

10、pages i and ii, pages 1 to 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 on the inside front cover.BS6043-4.11:1991 BSI 10-1999 1 1 Scope This Section of BS6043 des

11、cribes a method for the measurement of the reversible linear thermal expansion of test pieces prepared from baked rammed cold ramming paste used in aluminium manufacture. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Principle A baked test pie

12、ce of known dimensions is produced from a test sample of the cold ramming paste by compaction under regulated conditions followed by baking according to a defined programme. A thermal expansion test piece, of standard dimensions, is cut from the baked test piece then heated at a specified uniform ra

13、te and its change in length and temperature measured, either continuously or at regular and frequent intervals during heating. The thermal expansion relative to the length at ambient temperature is calculated for the temperature of the thermal expansion test piece and the results are either plotted

14、as a graph or expressed as a mean coefficient of expansion for a given temperature range. 3 Apparatus 3.1 Ordinary laboratory apparatus, and the apparatus described in3.2 to 3.4. 3.2 Ramming apparatus, and the other apparatus described in clause4 of BS6043-4.7:1991. 3.3 Thermal expansion apparatus,

15、described in clause5 of BS1902-5.3:1990modified as shown inFigure 1 to allow continuous purging of the furnace with inert gas. 3.4 A supply of inert gas, e.g. oxygen-free nitrogen, to prevent oxidation of the thermal expansion test piece at temperatures up to1100 C, with means for controlling and me

16、asuring the flow rate. 4 Sampling Prepare a representative laboratory sample of cold ramming paste in accordance with BS6043-4.1. 5 Preparation of test sample Prepare a test sample from the laboratory sample (see clause4) by the method described in7.1 and7.3 of BS6043-4.7:1991. 6 Procedure 6.1 Prepa

17、ration of baked test piece Prepare a rammed test piece by ramming the test sample (see clause5) by the procedure described in8.2 of BS6043-4.7:1991using the ramming apparatus (3.2). If the cold ramming paste requires pre-curing before being baked, pre-cure the test piece in accordance with8.3 of BS6

18、043-4.7:1991. Bake the rammed test piece in accordance with8.4 of BS6043-4.7:1991. NOTEA baked test piece prepared as described in6.1 may first be used for the determination of electrical resistivity by the method described in BS6043-4.8. 6.2 Preparation of thermal expansion test pieces Cut the bake

19、d test piece (see6.1) to produce a minimum of three thermal expansion test pieces of length75 2mm and cross-sectional dimension either10 2mm square or10 2mm in diameter. Carefully place the thermal expansion test pieces in an oven controlled at110 5 C for2h then allow them to cool to ambient tempera

20、ture in a desiccator. Weigh the test pieces to the nearest0.001g, then repeat the operations of heating for2h at110 5 C, cooling and weighing until consecutive weighings do not differ by more than0.01g. Store the thermal expansion test pieces in the desiccator until required. 6.3 Determination 6.3.1

21、 Connect the supply of inert gas (3.4) to the inlet tube on the thermal expansion apparatus (3.3). 6.3.2 Calibrate the apparatus (3.3) by the method described in clause7 of BS1902-5.3:1990whilst purging the apparatus with the inert gas (3.4) at a flow rate of100mL/min, at normal temperature and pres

22、sure, after the insertion of the test piece of reference material. NOTEThe calibration procedure described in6.3.2 should be carried out at the start of a series of tests and subsequently at intervals not exceeding five test runs, or whenever the apparatus is serviced or parts replaced. 6.3.3 Determ

23、ine the coefficient of thermal expansion and any permanent linear change in dimensions of the thermal expansion test piece (see6.2) in accordance with clause8 of BS1902-5.3:1990, whilst purging the apparatus(3.3) with the inert gas (3.4) at a flow rate of100mL/min, at normal temperature and pressure

24、, after the insertion of the thermal expansion test piece. 6.3.4 Perform the operations described in6.3.1 to6.3.3 on at least three thermal expansion test pieces (see6.2).BS 6043-4.11:1991 2 BSI 10-1999 NOTEModified version of apparatus described in BS 1902-5.3:1990. Figure 1 Thermal expansion appar

25、atusBS6043-4.11:1991 BSI 10-1999 3 7 Calculation and expression of results 7.1 Calculate the thermal expansion of each test piece (see6.2) and the mean value for all the test pieces in accordance with7.2 and, if appropriate, 7.3. 7.2 Correct the expansion data recorded for the thermal expansion test

26、 piece (see6.2) by use of the calibration data (6.3.2) in accordance with clause7 of BS1902-5.3:1990 and calculate the expansion as a percentage of the initial length of the test piece. Present the percentage expansion values against the corresponding temperatures either as a graph or in tabulated f

27、orm. 7.3 Calculate a mean expansion coefficient (a), for a particular temperature range (see note), using the following equation: where NOTEUnless material exhibits an almost linear expansion curve it is not appropriate to calculate a mean expansion coefficient. 8 Test report The test report shall i

28、nclude the following information: a) a complete identification of the sample of cold ramming paste and any other treatment which it has received; b) a reference to this British Standard, i.e. BS6043-4.11:1991; c) the reference material used to calibrate the apparatus (see6.3.2); d) the test result e

29、xpressed in accordance with clause7, including the temperature range over which measurement was made; e) the initial and final length of each test piece, indicating any permanent linear change (see6.3.3); f) any unusual features noted during the test; g) any operation not included in this British St

30、andard or regarded as optional. L 1 is the initial length of the thermal expansion test piece (see 6.2) (in mm); L 2 is the corrected change in length (see 7.2) of the thermal expansion test piece (see 6.2) (in mm), over the temperature range T 2 T 1 , in K; T 1 is the lower temperature of the range

31、 (in C); T 2 is the upper temperature of the range (in C);4 blankBS6043-4.11:1991 BSI 10-1999 Publication(s) referred to BS 1902, Methods of testing refractory materials. BS 1902-5, Refractory and thermal properties. BS 1902-5.3, Determination of thermal expansion (horizontal method to 1 100 C) (met

32、hod 1902-503). BS 6043, Methods of sampling and test for carbonaceous materials used in aluminium manufacture. BS 6043-4, Cold ramming pastes. BS 6043-4.0, General introduction 1) . BS 6043-4.1, Methods of sampling. BS 6043-4.6, Determination of maximum rammed apparent density of unbaked paste 2) .

33、BS 6043-4.7, Preparation of baked rammed test pieces and determination of baked apparent density, change in volume and loss in mass. BS 6043-4.8, Determination of electrical resistivity of baked rammed paste. 1) Referred to on the front cover only. 2) Referred to in the foreword only.BS 6043-4.11: 1

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