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1、BRITISH STANDARD BS 5293:1976 Incorporating Amendment Nos. 1, 2, 3 and 4 Methods for Sampling and testing carbon black for use in the rubber industry UDC 678.046.2:661.666.4:620.1:543.7.062 Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:59:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS
2、5293:1976 This British Standard, having been approved by the Rubber Industry Standards Committee, was published under the authority of the Executive Board on 27 February 1976 BSI 10-1999 The following BSI references relate to the work on this standard: Committee references RUC/25/1 and RUC/25 Draft
3、for comment 73/54168DC ISBN 0 580 08968 1 Co-operating organizations The Rubber Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and industrial organizations: British Association of Synthet
4、ic Rubber Manufacturers British Rubber Manufacturers Association Ltd.* Department of Industry Malaysian Rubber Producers Research Association Ministry of Defence* Rubber Growers Association Rubber and Plastics Research Association of Great Britain* Society of Motor Manufacturers and Traders Ltd. The
5、 organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Association of Fatty Acid Distillers Chemical Industries Association United Kingdom Carbon Black Distributors Ass
6、ociation Zinc Pigment Development Association Amendments issued since publication Amd. No.Date of issueComments 2510March 1978 5899April 1988 6288November 1990 6378May 1991Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:59:11 GMT+00:00 2006, Uncontroll
7、ed Copy, (c) BSI BS 5293:1976 BSI 10-1999i Contents Page Co-operating organizationsInside front cover Forewordii 1Scope1 2References1 3Methods deleted 3.1Method deleted 3.2Method deleted 4Methods deleted 4.1Method deleted 4.2Method deleted 4.3Method deleted 5Chemical tests1 5.1Method deleted 5.2Meth
8、od deleted 5.3Methods for the determination of total sulphur content1 5.4Method deleted 5.5Method deleted 5.6Method deleted Appendix A Deleted Appendix B Deleted Appendix C Corresponding ISO methods which are technically equivalent4 Publications referred toInside back cover Licensed Copy: sheffieldu
9、n sheffieldun, na, Mon Dec 04 15:59:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5293:1976 ii BSI 10-1999 Foreword This British Standard has been prepared under the authority of the Rubber Industry Standards Committee. Carbon black is one of the most important non-rubber raw materials of the rub
10、ber industry and its properties are of prime technical importance in the quality of rubber products. Methods of test for carbon black for use in the rubber industry are the subject of work within Technical Committee 45, Rubber and rubber products, of the International Organization for Standardizatio
11、n (ISO). The methods in this standard correspond with those agreed internationally. (See Appendix C.) 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 Standar
12、d does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, 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 incorporate
13、d. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:59:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5293:1976 BSI 10-19991 1 Scope This British Standard specifies methods for sampling and testing carbon black for u
14、se in the rubber industry. 2 References The titles of the British Standards referred to in this standard are listed on the inside back cover. 3 Methods deleted 4 Methods deleted 5 Chemical tests 5.1 Method deleted 5.2 Method deleted 5.3 Methods for the determination of total sulphur content 5.3.1 In
15、troduction. These methods describe two procedures for the determination of the total sulphur in all types of carbon black: Method A, using an oxygen bomb calorimeter; Method B, using a combustion furnace. 5.3.2 Principle of the methods 5.3.2.1 Method A. A test portion of dried carbon black is weighe
16、d and ignited in an oxygen bomb calorimeter. The bomb is opened, the inner surfaces washed with water, and the washings collected in a beaker. The sulphur in the washings is precipitated as barium sulphate which is collected and weighed, and the percentage of sulphur is calculated. 5.3.2.2 Method B.
17、 A test portion of dried carbon black is weighed and heated at a temperature of 1 425 C in a combustion furnace in a stream of oxygen. Sulphur compounds evolved from the test portion are collected in a titration flask containing hydrochloric acid solution, then titrated with potassium iodate/potassi
18、um iodide solution, and the percentage of sulphur is calculated. 5.3.3 Method A (oxygen bomb calorimeter) 5.3.3.1 Reagents. All the reagents shall be of recognized analytical quality and water complying with BS 3978 shall be used wherever water is specified. The following reagents are required. 5.3.
19、3.1.1 Barium chloride solution, 100 g/l. Dissolve 100 g of barium chloride (BaCl2.2H2O) in water and dilute to 1 litre. 5.3.3.1.2 Hydrochloric acid, 20 = 1.19 g/ml. 5.3.3.1.3 Picric acid solution, saturated. Add an excess of picric acid to water in a glass-stoppered bottle. Shake the bottle well to
20、dissolve enough picric acid to saturate the solution. A few crystals of picric acid should remain in contact with the solution after saturation. 5.3.3.1.4 Oxygen. A supply of oxygen, such as from commercial cylinders, of adequate purity (free from sulphur compounds). 5.3.3.2 Apparatus. The following
21、 apparatus is required. 5.3.3.2.1 Oxygen bomb calorimeter, complete with ignition transformer, ignition wire, fuel capsule crucibles, oval type bucket, calorimeter jacket, electric stirrer for water circulation around bomb, and calorimeter thermometers covering the range 19 C to 35 C, in intervals o
22、f 0.02 C. The calorimeter bomb shall comply with the requirements of BS 4791 and the calorimeter thermometers shall comply with the requirements of BS 791. 5.3.3.2.2 Oxygen cylinder, with regulator and connector for oxygen bomb calorimeter. 5.3.3.2.3 Crucible, porcelain, 30 ml capacity, complying wi
23、th the requirements of BS 4244. 5.3.3.2.4 Oven, complying with the requirements of BS 2648. 5.3.3.2.5 Muffle furnace, capable of maintaining a temperature of 925 25 C, 5.3.3.2.6 Filter funnels, analytical type. 5.3.3.3 Procedure. Before making the determination check that the safety precautions when
24、 using oxygen filled calorimeter bombs have been met (see clause 9 of BS 4791:1972). Dry at least 0.5 g of the sample for 1 h at a temperature of 105 2 C. Weigh, to the nearest 0.1 mg, about 0.5 g of the dried sample in the fuel capsule. Place the crucible in the loop electrode and attach a fuse wir
25、e as described in the manufacturers instructions for the oxygen filled bomb calorimeter. Bend the fuse wire so that the wire extends just below the surface of the carbon black. Pipette 5 ml of water into the bomb cylinder. Assemble the bomb and fill with oxygen (pressure: 30 bar). Put 2 000 ml of wa
26、ter, at room temperature, in the calorimeter bucket. Place the bucket in the calorimeter, set the bomb in the bucket, attach the ignition lead to the bomb, close the calorimeter with the thermometer in place, and start the electric stirrer. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:5
27、9:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5293:1976 2 BSI 10-1999 Allow the electric stirrer to operate for 2 min, then record the water temperature. Close the ignition circuit momentarily to fire the charge. If the ignition system has no pilot light hold the ignition switch button for 5 s
28、before releasing. Observe the rise in water temperature. The temperature should rise about 2 C in approximately 5 min (if the temperature fails to rise the test should be abandoned and a fresh determination begun). Allow the electric stirrer to operate for a total of 10 min after ignition. Remove th
29、e bomb and release the pressure gradually over a period of time of at least 1 min. Open the bomb and wash all the inner surfaces of the bomb with water, catching all the washings in a 250 ml beaker. Filter the solution into a 400 ml beaker, washing the filter paper with three 5 ml portions of water.
30、 Add 5 ml of the hydrochloric acid, 5 ml of the saturated picric acid solution, and 10 ml of the barium chloride solution to the filtrate. Digest the mixture on an electric hotplate at low temperature for approximately 15 min. Filter through a low ash paper and wash the precipitate on the paper with
31、 10 ml portions of boiling water. Continue washing until a test with silver nitrate shows absence of chloride in the filtrate. Transfer the filter paper with the precipitate to the porcelain crucible, weighed to the nearest 0.1 mg. Char and ignite over the low flame of a high temperature gas burner.
32、 Transfer to the muffle furnace at a temperature of 925 25 C for 30 min. Remove the crucible and contents to a desiccator, allow to cool to room temperature, and weigh to the nearest 0.1 mg. 5.3.3.4 Expression of results. Calculate the percentage of sulphur from the following formula: where A is the
33、 mass of the crucible (g); B is the mass of the crucible and precipitate after ignition (g); C is the mass of the dried test portion (g). 5.3.3.5 Test report. The test report shall include the following information. a) Identification of the sample. b) Results obtained from two individual determinati
34、ons and their average. c) A reference to this British Standard, i.e. BS 5293-5.3:method A. 5.3.4 Method B (combustion furnace) 5.3.4.1 Reagents. All the reagents shall be of recognized analytical quality and water complying with BS 3978 shall be used wherever water is specified. The following reagen
35、ts are required. 5.3.4.1.1 Hydrochloric acid. Mix 2 volumes of concentrated hydrochloric acid (20 = 1.19 g/ml) with 13 volumes of water. 5.3.4.1.2 Potassium iodate/potassium iodide solution. Dry at least 1.5 g of potassium iodate in an oven for 1 h at a temperature of 120 5 C. Dissolve 1.1125 g of t
36、he dried potassium iodate (KIO3), 100 g of potassium iodide (KI), and 5 g of potassium hydroxide in approximately 500 ml of water. Dilute to 1 litre in a volumetric flask. NOTEThe solution should be stored in a brown or green glass bottle. It is advisable to prepare a fresh solution every 30 days. 5
37、.3.4.1.3 Starch indicator solution. Stir 2.5 g of powdered, water-soluble starch and 2 mg of mercuric iodide (HgI2) in 25 ml of water in a 50 ml beaker. Add the starch/mercuric iodide suspension immediately to 1 litre of boiling water while stirring. Boil the resulting starch solution for at least 5
38、 min to ensure proper solution. Allow to cool to room temperature and to settle, and decant the clear portion into stoppered bottles. 5.3.4.1.4 Oxygen.A supply of oxygen, such as from commercial cylinders, of adequate purity (free from sulphur compounds). 5.3.4.2 Apparatus. The following apparatus i
39、s required. 5.3.4.2.1 Combustion furnace, suitable for use at a temperature of 1 425 25 C. 5.3.4.2.2 Combustion tube about 75 cm in length, with one end tapered. 5.3.4.2.3 Combustion boats, either of fused aluminium oxide or of porcelain. NOTEAll new combustion boats should be fired for 1 h at 1 425
40、 25 C prior to use. 5.3.4.2.4 Pressure regulator and flowmeter 5.3.4.2.5 Oxygen purification train, consisting of a gas washing bottle, complying with the requirements of BS 2461, containing concentrated sulphuric acid (H2SO4, 20 = 1.84 g/ml) and a water absorbing bottle filled with a mixture of sod
41、a asbestos and anhydrous calcium sulphate that has been saturated with carbon dioxide. 5.3.4.2.6 Gas distribution tube, coarse, sintered glass. 5.3.4.2.7 Titration flask, about 500 ml capacity. 5.3.4.2.8 Rubber stopper equipped with a high-temperature heat reflector or baffle made of either metal or
42、 a refractory material. Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:59:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5293:1976 BSI 10-19993 5.3.4.2.9 Oven, complying with the requirements of BS 2648. 5.3.4.3 Procedure. Dry at least 1 g of carbon black for 1 h at a temperature of 105
43、 2 C. Weigh, to the nearest 1 mg, about 1 g of the dried sample and transfer to a combustion boat. Fill the titration flask one-third full with the hydrochloric acid, add 2 ml of the starch indicator and, while agitating the solution, add just enough of the potassium iodate/potassium iodide solution
44、 to give a perceptible colour. Place the gas distribution tube in the titration flask. With the combustion furnace at a temperature of 1 425 C and the oxygen flowing at 1 litre/min (see note), insert the combustion boat containing the carbon black into the hot zone of the combustion tube. Stopper th
45、e combustion tube, immediately so as to pass the combustion gases evolved through the gas distribution tube. Titrate the solution in the titration flask with the potassium iodate/potassium iodide solution to maintain the blue colour in the titration flask. Consider the final point to be reached when
46、, after 3 min of bubbling, it is not necessary to add potassium iodate/potassium iodide solution to maintain the blue colour in the titration flask. NOTEPrior to each series of determinations the combustion system should be purged for 30 min with the oxygen flowing and with the furnace temperature a
47、t 1 425 25 C. 5.3.4.4 Expression of results. Calculate the percentage of total sulphur from the following formula: Total sulphur (%) = where A is the volume of potassium iodate/potassium iodide solution required for the titration (ml); B is the mass of the test portion (g), 5.3.4.5 Test report. The
48、test report shall include the following information: a) Identification of the sample. b) Results obtained from two individual determinations and their average. c) A reference to this British Standard, i.e. BS 5293-5.3:method B. 5.4 Method deleted 5.5 Method deleted 5.6 Method deleted A 20B - - Licen
49、sed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:59:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5293:1976 4 BSI 10-1999 Appendix A Deleted Appendix B Deleted Appendix C Corresponding ISO methods which are technically equivalent BS 5293 clause reference ISO standard or recommendation Title 5.3ISO 1138Carbon black for the rubber industry Determination of total sulphur content Licensed Copy: sheffieldun sheffieldun, na, Mon Dec 04 15:59:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5293:1976 BSI 10-1999 Publications refe
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