BS 1016-106 1 1-1996 Methods for analysis and testing of coal and coke - Ultimate analysis of coal and coke - Determination of carbon and hydrogen content - High temperature combus.pdf

1、BRITISH STANDARD BS 1016-106.1.1: 1996 ISO 609:1996 Methods for Analysis and testing of coal and coke Part 106: Ultimate analysis of coal and coke Section 106.1 Determination of carbon and hydrogen content Subsection 106.1.1 High temperature combustion method ICS 75.160.10BS 1016-106.1.1:1996 This B

2、ritish Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 October 1996 BSI 11-1998 The following BSI references relate to the work on this standard: Committee referen

3、ce SFI/3 Draft for comment 93/508888 DC ISBN 0 580 26460 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee SFI/3, Analysis and testing of coal and coke, upon which the following bodies were represented: British Cement Ass

4、ociation British Coal Corporation British Iron and Steel Producers Association Electricity Association GAMBICA (BEAMA Ltd.) Power Generation Contractors Association (PGCA (BEAMA Ltd.) Amendments issued since publication Amd. No. Date CommentsBS 1016-106.1.1:1996 BSI 11-1998 i Contents Page Committee

5、s responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Normative references 1 3 Principle 1 4 Reagents and materials 1 5 Apparatus 2 6 Preparation of the apparatus 6 7 Preparation of test sample 6 8 Procedure 8 9 Blank test 8 10 Expression of results 8 11 Precision 9 12 Tes

6、t report 9 Annex A (informative) Derivation of factors used in calculations in clause 10 10 Figure 1 Typical temperature-distribution curve for furnace 3 Figure 2 Midvale tube 4 Figure 3 Absorption train 5 Figure 4 Arrangement of apparatus for the location of the silver gauze roll 7 Table 1 9 Table

7、A.1 10BS 1016-106.1.1:1996 ii BSI 11-1998 National foreword This British Standard has been prepared by SFI/3 and is identical to ISO609:1996 Solid mineral fuels Determination of carbon and hydrogen High temperature combustion method, including Corrigendum 1:1996, both published by the International

8、Organization for Standardization (ISO) and in the preparation of which the UK played a full part. BS 1016-106 will form a revision of Parts 6 to 11 of BS 1016. This Subsection supersedes the following: in BS 1016-6:1977, clauses 5 and 6 and that part of clause 11 relating to carbon and hydrogen; in

9、BS 1016-7:1977, clauses 5 and 6 and that part of clause 10 relating to carbon and hydrogen. Principal differences are that coal and coke are now considered together, the method follows a different procedure for conditioning the absorption train and the precision data has been revised. An alternative

10、 method is given in Subsection 106.1.2 Liebig method. BS 1016-106 is part of a rationalized and restructured BS 1016. The Parts numbered from 1 to 21 are gradually being withdrawn and replaced by Parts in the new series. The full list of Parts in the new series, together with corresponding numbering

11、 of the old series and related international standards is given in BS 1016 Analysis and testing of coal and coke Part 100:1994 General introduction and methods for reporting results. The technical committee has reviewed the provisions of ISO 1015:1992, ISO5068:1983 and ISO 5069-2:1983 to which norma

12、tive reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. British Standards related to ISO 331:1983, ISO 687:1974, ISO 925:1980 and ISO1170:1977 are BS 1016 Methods for analysis and testing of coal and coke Section 104.1:1991 Determinatio

13、n of the moisture content of the general analysis sample of coal, Section 104.2:1991 Determination of the moisture content of the general analysis sample of coke, Part 6:1991 Ultimate analysis of coal and Part100:1994 General introduction and methods for reporting results respectively. British Stand

14、ards related to ISO 1988:1975 and ISO 2309:1980 are BS1017 Sampling of coal and coke Part 1:1989 Methods for sampling of coal and Part2:1994 Methods for sampling of coke. ISO 1988 and ISO 2309 are being revised and will be published in eight Parts, and it is intended to implement these parts as iden

15、tical British Standards, superseding BS 1017. 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 obligati

16、ons. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 10 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 theinside front cover.BS

17、1016-106.1.1:1996 BSI 11-1998 1 Introduction An alternative method to that specified in this International Standard is given in ISO625:1996, Solid mineral fuels Determination of carbon and hydrogen Liebig method. 1 Scope This International Standard specifies a method of determining the total carbon

18、and the total hydrogen in hard coal, brown coal and lignite, and coke, by a high temperature combustion method. The results include the carbon in the carbonates and the hydrogen combined in the moisture and in the water of constitution of silicates. A determination of moisture is carried out at the

19、same time, and an appropriate correction is applied to the hydrogen value obtained by combustion. A determination of carbon dioxide may also be made and the total carbon value corrected for the presence of mineral carbonates. 2 Normative references The following standards contain provisions which, t

20、hrough reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of a

21、pplying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 331:1983, Coal Determination of moisture in the analysis sample Direct gravimetric method. ISO 687:1974, Coke Determination of moisture in the

22、analysis sample. ISO 925:1980, Solid mineral fuels Determination of carbon dioxide content Gravimetric method. ISO 1015:1992, Brown coals and lignites Determination of moisture content Direct volumetric method. ISO 1170:1977, Coal and coke Calculation of analyses to different bases. ISO 1988:1975, H

23、ard coal Sampling. ISO 2309:1980, Coke Sampling. ISO 5068:1983, Brown coals and lignites Determination of moisture content Indirect gravimetric method. ISO 5069-2:1983, Brown coals and lignites Principles of sampling Part 2: Sample preparation for determination of moisture content and for general an

24、alysis. 3 Principle A known mass of coal or coke is burnt in a stream of oxygen, at a temperature of 1 350 C, in a tube impervious to gases. All the hydrogen is converted to water and all the carbon to carbon dioxide. These products are absorbed by suitable reagents and determined gravimetrically. T

25、he chlorine and oxides of sulfur which are formed are retained by a silver gauze roll at the outlet end of the tube. 4 Reagents and materials WARNING Care should be exercised when handling reagents, many of which are toxic and corrosive. During the analysis, unless otherwise stated, use only reagent

26、s of recognized analytical grade and only distilled water or water of equivalent purity. 4.1 Magnesium perchlorate, anhydrous, less than1,2 mm in size and preferably within the size range 1,2 mm to 0,7 mm. WARNING Due regard must be taken of local regulations when disposing of exhausted magnesium pe

27、rchlorate. Regeneration of magnesium perchlorate must not be attempted, owing to the risk of explosion. 4.2 Sodium hydroxide on an inert base, preferably of a coarse grading, for example 3,0mm to 1,5 mm, but not finer than the grading 1,2mm to0,7mm, and preferably of the self-indicating type. 4.3 Al

28、uminium oxide (alumina), finely divided, approximately 0,1 mm in size. 4.4 Sodium tetraborate, standard volumetric solution, c(Na 2 B 4 O 7 ) = 0,025 mol/l. Dissolve 9,534 2 g of sodium tetraborate decahydrate in water and dilute to 1 litre. Mix thoroughly. 4.5 Hydrogen peroxide, approximately 30% (

29、m/m). 4.6 Pure silver gauze, of mesh approximately1mm, made of wire approximately0,3 mm in diameter. 4.7 Oxygen, hydrogen-free, preferably prepared from liquid air and not by electrolysis. Electrolytically prepared oxygen shall be passed over red-hot copper oxide before use to remove any trace of hy

30、drogen.BS 1016-106.1.1:1996 2 BSI 11-1998 4.8 Mixed indicator solution 4.8.1 Solution A Dissolve 0,125 g of 2-(4-dimethylaminophenylazo)benzoic acid, sodium salt (methyl red) in 100 ml of water. 4.8.2 Solution B Dissolve 0,083 g of 3,7-bis(dimethylamino)phenothiazine-5-ylium chloride (methylene blue

31、) in 100 ml of water. Store in a dark bottle. 4.8.3 Mixed solution Mix equal volumes of solution A and solution B. Store in a dark bottle. Discard the mixed solution after 1 week. 4.9 Air, compressed. 4.10 Glass wool 5 Apparatus 5.1 Analytical balance, capable of weighing to the nearest 0,1 mg. 5.2

32、Graduated glassware, conforming to the requirements for class A in the International Standards prepared by ISO/TC 48, Laboratory glassware and related apparatus. 5.3 Two purification trains, one for absorbing water vapour and carbon dioxide from the oxygen used for the combustion and the other for s

33、imilarly treating the air used for sweeping out the absorption train before and after a determination. Assemble each train using a series of U-tubes or Midvale tubes containing the following reagents in the order stated, in the direction of flow: a) magnesium perchlorate (4.1) for absorbing water; b

34、) sodium hydroxide on an inert base (4.2) for absorbing carbon dioxide; c) magnesium perchlorate for absorbing the water evolved in the reaction between carbon dioxide and sodium hydroxide. The purification trains shall be large enough to render frequent recharging unnecessary, even with continuous

35、use. NOTE 1Midvale tubes that have been freshly packed with absorbent and used in the purification train are thereby conditioned for subsequent use in the absorption train. 5.4 Combustion assembly 5.4.1 Heating unit, an electrically heated furnace or furnaces, designed to carry a combustion tube(5.4

36、.2) and heat it to 1 350 C over a distance of125mm in the hot zone, and yield a temperature-distribution profile similar to that shown in Figure 1. The heating unit normally requires an auxiliary furnace to ensure that the silver gauze roll (5.9) is maintained at the correct temperature (approximate

37、ly 600 C to 800 C). Suitable furnaces are, for example: a) molybdenum or tungsten wire wound; b) platinum or platinum-rhodium wire wound; c) heated by silicon carbide rods. NOTE 2Type c) has the lowest initial cost and has proved satisfactory in use. NOTE 3Furnaces of the type normally used for the

38、determination of carbon or sulfur in steel are not suitable because of the absence of the auxiliary section required to maintain the silver gauze roll at the correct temperature. 5.4.2 Combustion tube, of approximately 28mm external diameter, 3 mm wall thickness and650mm length, made of refractory a

39、luminous porcelain which is impervious to gases up to a temperature of 1 400 C. The end of the combustion tube shall be lagged with a suitable heat-resistant mineral fibre to prevent condensation in the tube. 5.4.3 Combustion boat, of iron-free, unglazed porcelain, approximately 60 mm long, 12,5 mm

40、wide and 10 mm deep, for hard coal and coke samples and approximately 75 mm long, 15 mm wide and 10mm deep for brown coal and lignite, capable of withstanding a temperature of 1 350 C. NOTE 4Combustion boats should not blister, discolour or change in mass on heating in oxygen at 1 350 C for 3 h. A s

41、uitable boat lasts for about 10 to 20 determinations and should then be discarded because of the accumulation of fused ash. For coals with a high ash content, it may be convenient to line the boat with alumina before adding the sample, in order to prevent fusion of the ash to the boat. 5.5 Absorptio

42、n train, for absorbing the water and carbon dioxide evolved by the combustion of the sample. Midvale tubes (Figure 2), which provide a large area of reaction, are used in order to reduce the back-pressure in the apparatus, and so obviate the danger of leakage through the rubber sleeve carrying the p

43、usher. Assemble the train using the following reagents in the order stated, in the direction of flow: a) magnesium perchlorate (4.1) for absorbing the water evolved during the combustion; b) sodium hydroxide on an inert base (4.2) for absorbing the carbon dioxide; c) magnesium perchlorate for absorb

44、ing the water evolved in the reaction between carbon dioxide and sodium hydroxide.BS 1016-106.1.1:1996 BSI 11-1998 3 Figure 1 Typical temperature-distribution curve for furnaceBS 1016-106.1.1:1996 4 BSI 11-1998 Place glass wool (4.10), previously dried at 105 C for 1 h, above and below the absorbent

45、s to prevent the carry-over of dust by the flow of oxygen, and to prevent the cracking of the Midvale tube by the heat of reaction. A typical absorption train with details of the packing is shown in Figure 3. A is the absorber for water; B and C are the absorbers for carbon dioxide, C serving as a c

46、ontrol to indicate when the packing in B is in need of replacement. Any water released in B by the reaction between sodium hydroxide and carbon dioxide is absorbed in C. The inlet of the water-absorption tube shall be inserted through the heat-resistant stopper so that it is flush with the inner end

47、 of the stopper. All connections between the tubes shall be made of glass-to-glass, using the rubber connecting sleeves merely as seals. Figure 2 Midvale tubeBS 1016-106.1.1:1996 BSI 11-1998 5 5.6 Two flowmeters, both capable of measuring rates of flow up to 300 ml/min of air. 5.7 Heat-resistant sto

48、pper (acrylonitrile or chloroprene) for connecting the absorption train to the combustion tube. 5.8 Silica or steel pusher, made from rod or sealed tube, approximately 6 mm in diameter and 450mm long, with a disc end, 12 mm in diameter, for pushing the boat into the hot zone of the combustion tube.

49、The pusher passes loosely through a glass or metal T-piece, one end of which fits into the stopper which closes the inlet end of the combustion tube, the other being sealed by a rubber sleeve (seenote5), through which the pusher slides. The sleeve prevents the escape of oxygen which enters at the stem of the T-piece. The pusher is usually marked from the disc end, for convenience in ascertaining the position of the boat in the combustion tube during pushing. NOTE 5The rubber sleeve should be changed periodic