1、BRITISH STANDARD BS 6043-2.6: 1986 ISO 8004:1985 Methods of sampling and test for Carbonaceous materials used in aluminium manufacture Part 2: Electrode coke Section 2.6 Determination of the density in xylene of calcined cokes ISO title: Carbonaceous materials for the production of aluminium Calcine
2、d coke and calcined carbon products Determination of the density in xylene Pyknometric method UDC 665.777:669.713.7:531.754.4BS6043-2.6:1986 This British Standard, having been prepared under thedirectionof the ChemicalsStandards Committee,waspublished underthe authorityof theBoardof BSI and comesint
3、oeffect on28February1986 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference CIC/24 Draft for comment 83/56065 DC ISBN 0 580 14974 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Chemicals
4、Standards Committee (CIC/-) to Technical Committee CIC/24 upon which the following bodies were represented: Aluminium Federation British Ceramic Research Association British Tar Industry Association Chemical Industries Association Institute of Petroleum Standardization of Tar Products Tests Committe
5、e Amendments issued since publication Amd. No. Date of issue CommentsBS6043-2.6:1986 BSI 11-1999 i Contents Page Committees responsible Inside front cover National foreword ii 0 Introduction 1 1 Scope and field of application 1 2 References 1 3 Principle 1 4 Reagents and materials 1 5 Apparatus 1 6
6、Sampling and samples 2 7 Procedure 2 8 Expression of results 3 9 Test report 3 Figure Typical degassing apparatus 4 Publications referred to Inside back coverBS6043-2.6:1986 ii BSI 11-1999 National foreword This British Standard has been prepared under the direction of the Chemical Standards Committ
7、ee to provide methods of sampling and test for carbonaceous materials used in the production of aluminium. The standard will be published in two Parts, each Part being divided into Sections. The two Parts are: Part 1: Electrode pitch; Part 2: Electrode coke. Initially, it is proposed that Part2 will
8、 comprise the following Sections applicable to green and/or calcined coke as indicated: Other international methods of test for electrode coke are under consideration and, subject to approval by the United Kingdom, will be published as they become available. This Section is identical with ISO8004:19
9、85 “Carbonaceous materials for the production of aluminium Calcined coke and calcined carbon products Determination of the density in xylene Pyknometric method”, published by the International Organization for Standardization (ISO). Terminology and conventions. The text of the International Standard
10、 has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards i
11、t is current practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. In British Standards it is current practice to use the symbol “L” for litre (and its submultiple
12、s) rather than “l” and to use the spelling “sulphur”, etc., instead of“sulfur”, etc. Section Subject Identical with 2.1 Sampling ab ISO 6375 2.2 Ash content ab ISO 8005 2.3 Ash analysis (AAS) ab ISO . . . . c 2.4 Ash analysis (XRF) ab ISO . . . . c 2.5 Apparent density and porosity ab ISO . . . . c
13、2.6 Density (xylene method) b ISO 8004 2.7 Oil content (gravimetric method) b ISO 6997 2.8 Oil content (extraction method) b ISO . . . . c 2.9 Sieve analysis b ISO . . . . c 2.10 Electrical resistivity b ISO . . . . c 2.11 Volatile matter content a ISO . . . . c a Applicable to green coke. b Applica
14、ble to calcined coke. c In preparation.BS6043-2.6:1986 BSI 11-1999 iii The Technical Committee has reviewed the provisions of ISO5725:1981, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A related British Standard for ISO57
15、25:1981 is BS5497 “Precision of test methods” Part1:1979 “Guide for the determination of repeatability for a standard test method”. The reference to ISO8723 is for reference only and does not form part of the standard. Additional information. This standard describes methods of test only, and should
16、not be used or quoted as a specification defining limits of purity. Reference to this Section should state that the method of test used is in accordance with BS6043-2.6:1986. In clause5 and the Figure, the numerical references to parts of the apparatus have omitted numbers1 to4 inclusive and number9
17、. 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. Cross-references International Standard
18、 Corresponding British Standard ISO 3507:1977 BS 733 Pyknometers Part 1:1983 Specification (Identical) ISO 6375:1980 BS 6043 Methods of sampling and test for carbonaceous materials used in aluminium manufacture Part2Electrode coke Section 2.1:1985 Sampling (Identical) Summary of pages This document
19、comprises a front cover, an inside front cover, pages i to iv, pages1to 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.iv blankBS6043-2.6:1
20、986 BSI 11-1999 1 0 Introduction Calcined coke may be treated with different types of oil in order to avoid the formation of dust during loading and transportation. The present method does not provide for the elimination of traces of oil which may be present in the sample. An oil-free sample of coke
21、 may be derived from the coke obtained after the determination of oil by the extraction method specified in ISO8723. 1 Scope and field of application This International Standard specifies a pyknometric method for the determination of the density in xylene of calcined coke and calcined carbon product
22、s used for the production of aluminium. 2 References ISO 3507, Pyknometers. ISO 5725, Precision of test methods Determination of repeatability and reproducibility by inter-laboratory tests. ISO 6375, Carbonaceous materials for the production of aluminium Cokes for electrodes Sampling. ISO 8723, Carb
23、onaceous materials for the production of aluminium-calcined coke Determination of oil content Extraction method 1) . 3 Principle Measurement of the density at25 C of calcined coke and calcined carbon products by a pyknometric method after degassing under vacuum. 4 Reagents and materials During the d
24、etermination, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity degassed by boiling for1h. Use this water immediately after degassing. 4.1 Ethanol, 95 % (V/V). 4.2 Acetone 4.3 Xylene, commercial grade, about0,860g/ml. WAR
25、NING This product burns the skin and can be absorbed into the system through the skin. Inhalation of the vapour from hot material is to be avoided. 4.4 Sulfuric acid, approximately1,84g/ml, about96% (m/m) solution. 5 Apparatus Ordinary laboratory apparatus, and 5.1 Pyknometer, Gay-Lussac, type3, cap
26、acity25ml (seeISO3507). 5.2 Degassing apparatus (see the Figure), comprising the following items: a) Container (5) for the pyknometer (5.1), consisting of a glass beaker (6) with removable lid(7) and O-ring (8), capable of containing the pyknometer without stopper. The outlet (10) is connected to th
27、e pumping device. b) Filling device (11), fitted to the container by the conical ground joint (12). A tube (13) reaches into the pyknometer bottle. The reservoir (14) with ground stopper (15) contains the pyknometer liquid which is allowed to flow into the pyknometer bottle by the teflon valve (16).
28、 c) Support (17), to maintain the beaker in place when no vacuum is applied to the degassing apparatus. The rod (18) with spring (19) allows the beaker (6) to be shaken with the pyknometer to facilitate the evolution of gas bubbles during evacuation. The apparatus is made of glass. A rotary pump is
29、connected via the outlet and the oil trap (20) to the apparatus. Between the pump and oil trap, a manometer (21) is connected to the vacuum system. The vacuum is adjusted so that the manometer, which is about600mm from the joint (12), registers1,3 0,3kPa 2) . With the valve (22), the apparatus can b
30、e filled with air. This must be done slowly and with due care. NOTEAt a pressure of1,3 0,3kPa and an ambient temperature of25 C, a light vaporization of xylene may occur, until equilibrium is obtained, but this is of no consequence. The above-mentioned apparatus is only an example; any other apparat
31、us with these characteristics may be used. 5.3 Electric oven, capable of being controlled at120 2 C. 5.4 Thermostatically controlled bath, capable of being controlled at25 0,05 C. 1) At present at the stage of draft. 2) 1 kPa = 10 mbarBS6043-2.6:1986 2 BSI 11-1999 5.5 Grinder, capable of grinding th
32、e sample to less than634m size. The parts coming in contact with the sample are made of refractory hardmetals, to avoid contamination. 6 Sampling and samples Sample in accordance with ISO6375. 7 Procedure 7.1 General instructions Weighing should be carried out with a precision of 0,0001g. The buoyan
33、cy correction is neglected so that apparent and real masses are assumed to be identical. This approximation is sufficient for the purpose and affects the results by less than1 10 3 . When the pyknometer contains a liquid, stabilize it in the thermostatically controlled bath (5.4) at25 0,05 C. 7.2 Pr
34、eparation of the sample Grind the sample to a particular size u 634m using the grinder (5.5). Store the ground material in an air-tight container until the measurement is made. Before the measurement, dry the sample in the electric oven (5.3), controlled at120 2 C for8h. Then cool the sample in a de
35、siccator with silica gel as drying agent. NOTEIn order to avoid the need for verifying the particle sizes of each sample, it is advisable to determine the most convenient grinding conditions which allow the desired particle size to be reached with each sample type (petroleum coke, anthracite, graphi
36、te) and with the available grinding apparatus. In particular, this control can be done with an apparatus of the“elutriateur” type. 7.3 Calibration of the pyknometer Commercial pyknometers are usually calibrated at20 C, whereas the present determination is carried out at25 C. It is therefore necessar
37、y to calibrate the pyknometer at this temperature. 7.3.1 Determination of the mass of the pyknometer Wash the pyknometer (5.1) with the warm sulfuric acid solution (4.4), taking all necessary precautions. Wash carefully first with running water then with distilled water, then with the ethanol (4.1),
38、 and finally with the acetone (4.2). Eliminate the electrostatic charges by rubbing the pyknometer with a lint-free cloth moistened with acetone immediately before weighing. Weigh the dry pyknometer as specified in7.1 (mass m 0 ). 7.3.2 Determination of the volume of the pyknometer Fill the pyknomet
39、er with distilled water degassed at a temperature of23to24 C, with the ground stopper firmly inserted and the pyknometer cleaned from excess water with filter paper. Place the filled pyknometer into the thermostatically controlled bath (5.4) and heat to a temperature of25 0,05 C. During heating, rem
40、ove the liquid which leaves the capillary bore carefully with filter paper. When no more water runs out, the pyknometer has reached the test temperature. Remove it from the thermostatically controlled bath and dry it carefully. To avoid running over due to the warmth of the hand or when the ambient
41、temperature is greater than25 C, brief chilling in cooler water or with the acetone(4.2) can take place beforehand. Weigh the pyknometer, which is completely dry on the outside as specified in7.1 (mass m 1 ). The volume V, in millilitres, of the pycnometer is given by the formula where m 0 is the ma
42、ss, in grams, of the clean, dry, empty pyknometer; m 1 is the mass, in grams, of the pyknometer filled with distilled and degassed water; 0,995 87is the apparent density of water, in grams per millilitre at25 C. The volume V of the pyknometer is rounded off to0,001ml. The calibration of the pyknomet
43、er should be repeated every3 months and the mass m 0should remain constant to 0,001g. The volume of the pyknometer, when calibration is repeated, shall be carried out several times and on different days to eliminate the effects of outside influences as well as the small differences in regulations of
44、 the thermostatically controlled bath. Finally, it shall represent the mean of8 to10 determinations. The maximum permissible difference between two determinations is0,0015ml. NOTEDuring the period of validity of the calibration of the pyknometer (3 months), the pyknometer may be used for numerous de
45、terminations. In this case, it should be verified that the mass m 0remains constant to within0,001g. m 1 m 0 0,995 87 -BS6043-2.6:1986 BSI 11-1999 3 7.4 Determination of the density of commercial grade xylene The procedure is the same as described in7.3.2. The density of xylene x , expressed in gram
46、s per millilitre, is given by the formula where m 0and V are as defined in7.3.2; m 2 is the mass, in grams, of the pyknometer filled with xylene (4.3). The value of xshall be the mean of8 to10 determinations. The determinations shall be carried out several times and on different days to eliminate th
47、e effect of outside influences and also each time the thermostatically controlled bath has been stopped or changed. 7.5 Determination of the density of calcined coke and calcined carbon products 7.5.1 Test portion Weigh, as specified in7.1,5 0,1g of the sample (see7.2) (mass m 3 ) into the clean, dr
48、y, empty pyknometer, prepared according to7.3.1. 7.5.2 Determination Place the pyknometer without stopper, containing the test portion (7.5.1) in the container (5 of theFigure) of the degassing apparatus (5.2). Before adding xylene, evacuate for15min at a residual pressure of1,3 0,3kPa with the xyle
49、ne feed closed(16 of the Figure). This pressure is necessary for a precision of 0,004g/ml (see8.2). If only a precision of 0,01g/ml is required, a pressure of2,6 0,3kPa is sufficient. Thereafter add xylene drop by drop to the pyknometer. After the substance in the pyknometer is covered with20mm xylene at the most, interrupt the addition of xylene. Continue the evacuation of air, occasionally shaking the pyknometer and suport until the evolution of air bubbles has stopped. In general
