BS 6043-4 5-1991 Methods of sampling and test for carbonaceous materials used in aluminium manufacture - Cold ramming pastes - Determination of water content of unbaked pastes《制铝工业.pdf

1、BRITISH STANDARD BS 6043-4.5: 1991 Methods of sampling and test for Carbonaceous materials used inaluminium manufacture Part 4: Cold ramming pastes Section 4.5 Determination of water content of unbaked pastes NOTEIt is recommended that this Section be read in conjunction with thegeneral information

2、in BS 6043-4.0, published separately.BS6043-4.5:1991 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 31October1991 BSI 10-1999 The following BSI references relat

3、e to the work on this standard: Committee reference CIC/24 Draft for comment 90/54845 DC ISBN 0 580 19729 8 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Policy Committee (CIC/-) to Technical Committee CIC/24, upon

4、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 CommentsBS6043-4.5:1991 BSI 10-1999 i Contents Page Commi

5、ttees responsible Inside front cover Foreword ii 0 Introduction 1 1 Scope 1 2 Principle 1 3 Reagent 1 4 Apparatus 1 5 Sampling 3 6 Preparation of test sample 3 7 Procedure 3 8 Calculation and expression of results 3 9 Test report 3 Figure 1 Typical assembly of Dean and Stark apparatus (4.2) 1 Figure

6、 2 2 mL receiver (4.2) 2 Figure 3 Typical reflux condenser (4.2.3) 3 Publication(s) referred to Inside back coverBS6043-4.5:1991 ii BSI 10-1999 Foreword This Section of BS 6043 has been prepared under the direction of the Chemicals Standards Policy Committee to provide a method of test for cold ramm

7、ing pastes used in the production of aluminium. There is no corresponding International Standard; however, 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

8、 is essential to use BS 6043-4.1 in conjunction with this Section of 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 acco

9、rdance with BS6043-4.5:1991. 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 legal obligations. Summary of p

10、ages This document comprises a front cover, an inside front cover, pages i and ii, pages1 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

11、.BS6043-4.5:1991 BSI 10-1999 1 0 Introduction The binders used in cold ramming pastes may be coal tar or bituminous in character or may alternatively comprise one or more resins. Certain types of resins evolve water as a result of the polymerization process; this British Standard determination is no

12、t suitable for application to ramming materials containing resin binders. 1 Scope This Section of BS 6043 describes an azeotropic distillation method for the determination of the water content of unbaked cold ramming pastes used in aluminium manufacture. The method is applicable to cold ramming past

13、es made with coal tar or bituminous binders, having water contents in the range0.1% to 2% (m/m). The method is not applicable to cold ramming pastes made with resin-based binders, e.g. phenol-formaldehyde or foam types. NOTE 1Water contents in excess of2% (m/m) may be determined by using a larger re

14、ceiver. NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Principle A sample of cold ramming paste is heated under reflux with xylene. The condensate of xylene and water is collected in a graduated receiver and the volume of water which separate

15、s out in the graduated part of the receiver is measured. 3 Reagent WARNING. Refer to the reagent suppliers health and safety data sheets for the precautions which are to be observed for the safe use of the reagent. 3.1 Xylene, any of its isomers, or a mixture of these isomers in any proportion provi

16、ded that the boiling range is between130 C and 140 C, of recognized analytical grade. 4 Apparatus 4.1 Ordinary laboratory apparatus 4.2 Dean and Stark apparatus, complying with type1 of BS756:1952, comprising the items described in4.2.1 to 4.2.4. Before use, remove all traces of contamination from t

17、he graduated receiver (4.2.2) and from the interior of the reflux condenser (4.2.3) by washing them successively with, for example, a proprietary laboratory detergent, distilled water and acetone, then drying. Perfect cleanliness of the apparatus is essential. NOTEThis cleaning procedure ensures goo

18、d water wetting characteristics. 4.2.1 Distillation flask, of glass, capacity500mL, with a ground-glass joint to fit the receiver (4.2.2) (seeFigure 1). Figure 1 Typical assembly of Dean and Stark apparatus (4.2)BS6043-4.5:1991 2 BSI 10-1999 4.2.2 Graduated receiver, of capacity2mL, graduated at eve

19、ry0.05mL with a maximum error of 0.02mL (seeFigure 2). For cold ramming pastes with water contents in excess of2% (m/m) use a receiver of10mL capacity, graduated at every0.2mL with a maximum error of 0.06mL. 4.2.3 Reflux condenser, water-jacketted, with a ground-glass joint to fit the receiver (4.2.

20、2) (seeFigure 1 andFigure 3). 4.2.4 Electrically-heated mantle, or equivalent, to fit the distillation flask (4.2.1). NOTE 1All dimensions are in millimetres. NOTE 2This figure is equivalent to Figure 5 of BS 756:1952 and shows alternative connections to distillation vessel. Figure 2 2 mL receiver (

21、4.2)BS6043-4.5:1991 BSI 10-1999 3 5 Sampling Prepare a representative laboratory sample of cold ramming paste in accordance with BS6043-4.1. 6 Preparation of test sample Take 100 0.5g from the laboratory sample (seeclause5) of cold ramming paste in accordance with5.5.3 of BS 6043-4.1:1991. 7 Procedu

22、re Weigh the test sample (see clause 6) to the nearest0.1g then transfer it quantitatively to the distillation flask(4.2.1). Add100mL of the xylene(3.1) to the distillation flask containing the test portion. Attach the flask to the receiver(4.2.2) and circulate cold water through the jacket of the c

23、ondenser(4.2.3). Heat the flask gently until the test portion has dispersed in the xylene, then adjust the rate of heating so that the condensate falls from the end of the reflux condenser at a rate of two to five drops per second. Continue the distillation until condensed water is no longer visible

24、 in any part of the apparatus except in the bottom of the graduated receiver and until the volume of collected water remains constant for5min. If a persistent ring of condensed water forms in the condenser tube, remove it by increasing the rate of distillation by a few drops per second for a few min

25、utes. When the carry-over of water is complete, allow the receiver and its contents to cool to room temperature and read the volume of water to the nearest scale division. 8 Calculation and expression of results Calculate the water content, W, as a percentage by mass (see note) from the following eq

26、uation: where NOTEThe assumption that1mL of water weighs1g is sufficiently accurate for the purpose of this determination. Express the result to the nearest0.05% (m/m); if condensate is seen in the receiver for a result whichis less than0.05% (m/m), report the result as“trace less than0.05% (m/m)”.

27、9 Test report The test report shall include the following information: a) a complete identification of the sample; b) a reference to this British Standard, i.e.BS6043-4.5:1991; c) the results calculated and expressed in accordance with clause 8; d) any unusual features noted during the determination

28、; e) any operation not included in this British Standard or regarded as optional. NOTE 1All dimensions are in millimetres. NOTE 2This figure is equivalent to Figure 3 of BS 756:1952. Figure 3 Typical reflux condenser (4.2.3) M 1 is the mass of the test portion (in g); M 2 is the mass of the water co

29、llected in the receiver (in g). W 100 M 2 M 1 - =4 blankBS6043-4.5:1991 BSI 10-1999 Publication(s) referred to BS 756, Specification for Dean and Stark apparatus. BS 6043, Methods of sampling and test for carbonaceous materials used in aluminium manufacture. BS 6043-4, Cold ramming pastes. BS 6043-4

30、.0, General introduction 1) . BS 6043-4.1, Methods of sampling. 1) Referred to on the front cover only.BS 6043-4.5: 1991 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on

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