1、BRITISH STANDARD BS 1016-106.5: 1996 ISO 157:1996 Methods for Analysis and testing of coal and coke Part 106: Ultimate analysis of coal and coke Section 106.5 Determination of forms of sulfur in coal ICS 75.160.10BS 1016-106.5:1996 This British Standard, having been prepared under the direction of t
2、he Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes intoeffect on 15 October 1996 BSI 11-1998 The following BSI references relate to the work on this standard: Committee reference SFI/3 Draft for comment 93/508886 DC ISBN 0 580 26463 7 Comm
3、ittees 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 Association British Coal Corporation British Iron and Steel Produc
4、ers Association Electricity Association GAMBICA (BEAMA Ltd.) Power Generation Contractors Association (PGCA (BEAMA Ltd.) Amendments issued since publication Amd. No. Date CommentsBS 1016-106.5:1996 BSI 11-1998 i Contents Page Committees responsible Inside front cover National foreword ii Section 1 I
5、ntroduction 1 1.1 Scope 1 1.2 Normative references 1 1.3 Principle 1 1.4 Preparation of test sample 1 Section 2 2.1 Principle 3 2.2 Reagents 3 2.3 Apparatus 3 2.4 Procedure 4 Section 3 3.1 Principle 5 3.2 Reagents 5 3.3 Apparatus 5 3.4 Procedure 5 3.5 Blank test 6 3.6 Expression of results 6 3.7 Pre
6、cision 6 Section 4 4.1 Principle 7 4.2 Reagents 7 4.3 Apparatus 8 4.4 Procedure 8 4.5 Blank test 10 4.6 Expression of results 10 4.7 Precision 10 Section 5 5.1 Principle 11 5.2 Calculation 11 Section 6 6.1 Calculation to other bases 12 6.2 Test report 12 Annex A (informative) Derivation of factors u
7、sed in the calculations 13 Figure 1 General schematic representation of the procedure 2 Figure 2 Cold-finger condenser for the determination of sulfate and pyritic sulfur 3 Table 1 Test portion4 Table 2 Aliquot a for colorimetric finish 9 Table 3 Suitable spectrometric conditions 9 Table 4 Precision
8、 10 Table A.1 Untitled 13 List of references Inside back coverBS 1016-106.5:1996 ii BSI 11-1998 National foreword This British Standard has been prepared by SFI/3 and is identical to ISO157:1996 Coal Determination of forms of sulfur, published by the International Organization for Standardization (I
9、SO) 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 BS1016. This Section supersedes BS1016-11:1977 which is withdrawn. The three principal differences are the use of only one test portion and one treatment regime which determines sulfat
10、e sulfur and pyritic iron, the allowance of an additional procedure (atomic absorption) for the determination of iron and modification of the precision requirements for the method for pyritic sulfur with respect to higher sulfur content coals. BS 1016-106 is part of a rationalized and restructured B
11、S1016. 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 of the old series and related international standards is given in BS1016 Analysis and testing of coal and coke
12、 Part100:1994 General introduction and methods for reporting results. The technical committee has reviewed the provisions of ISO1015:1992, ISO5068:1983 and ISO5069-2:1983 to which normative reference is made in the text, and has decided that they are acceptable for use in conjunction with this stand
13、ard. British Standards related to ISO331:1983, ISO334:1992, ISO1170:1977, ISO1988:1975 and ISO2309:1980 are BS1016 Methods for analysis and testing of coal and coke Section104.1:1991 Determination of the moisture content of the general analysis sample of coal, Subsection106.4.1:1993 Eschka method, P
14、art100:1994 General introduction and methods for reporting results, BS1017 Sampling of coal and coke Part1:1989 Methods for sampling of coal and Part2:1994 Methods for sampling of coke respectively. ISO 1988 and ISO 2309 are being revised and will be published in eight Parts, and it is intended to i
15、mplement these Parts as identical British Standards, superseding BS1017. 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 i
16、mmunity from legal obligations. Cross-reference International standard Corresponding British Standard ISO 351:1995 BS 1016 Methods for analysis and testing of coal and coke Part 106: Ultimate analysis of coal and coke Section 106.4: Determination of sulfur content Subsection 106.4.1:1996 High temper
17、ature combustion method (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 14, 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 indicate
18、d in the amendment table on theinside front cover.BS 1016-106.5:1996 BSI 11-1998 1 Section 1. General Introduction For many purposes, a knowledge of the total sulfur content of a coal is sufficient, but for certain work it is also necessary to know how the sulfur is distributed between the coal subs
19、tance and the mineral matter. In particular, such information may be required in connection with coal classification and cleaning. Sulfur is usually present in coal in three forms, viz: a) sulfate sulfur, i.e. the sulfur present in the form of inorganic sulfates; b) pyritic sulfur, i.e. the sulfur p
20、resent in the form of pyrites and marcasite; c) organic sulfur, i.e. the sulfur present in the form of organic sulfur compounds. 1.1 Scope This International Standard specifies methods of determining the sulfate and pyritic sulfur contents of coals, including brown coals and lignites, and of calcula
21、ting the amount of organic sulfur present. 1.2 Normative references The following standards contain provisions which, through 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 revi
22、sion, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying 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 Determina
23、tion of moisture in the analysis sample Direct gravimetric method. ISO 334:1993, Solid mineral fuels Determination of total sulfur Eschka method. ISO 351:1995, Solid mineral fuels Determination of total sulfur High temperature combustion method. ISO 1015:1992, Brown coals and lignites Determination
24、of moisture content Direct volumetric method. ISO 1170:1977, Coal and coke Calculation of analyses to different bases. ISO 1988:1975, Hard coal Sampling. ISO 5068:1983, Brown coals and lignites Determination of moisture content Indirect gravimetric method. ISO 5069-2:1983, Brown coals and lignites P
25、rinciples of sampling Part2: Sample preparation for determination of moisture content and for general analysis. 1.3 Principle The procedure described in this International Standard utilizes the differential solubilities of sulfates and pyrites in dilute hydrochloric and nitric acids under reflux con
26、ditions, such that each can be taken in solution successively and determined directly. A general schematic representation of the procedure is given in Figure 1. 1.4 Preparation of the test sample The test sample is the general analysis test sample prepared in accordance with ISO1988 or ISO5069-2, as
27、 appropriate. Grind about 25g of the sample to pass a sieve of aperture 75m and ensure that its moisture content is in equilibrium with the laboratory atmosphere, exposing it if necessary in a thin layer for the minimum time required to achieve equilibrium. Before commencing the determination, thoro
28、ughly mix the test sample for at least 1min, preferably by mechanical means. If the results are to be calculated other than on an air-dried basis (see6.1) then, after weighing the test portion (see2.4), determine the moisture content using a further portion of the test sample by the method described
29、 in ISO331, ISO1015 or ISO5068, as appropriate.BS 1016-106.5:1996 2 BSI 11-1998 Figure 1 General schematic representation of the procedureBS 1016-106.5:1996 BSI 11-1998 3 Section 2. Separation of sulfate and pyritic sulfur 2.1 Principle The test portion is extracted with dilute hydrochloric acid to
30、bring both the sulfate sulfur and the non-pyritic iron into solution. The pyritic iron and sulfur remain in the residue which is separated by filtration. 2.2 Reagents WARNING Care must be exercised when handling the reagents, many of which are toxic and corrosive. During the analysis, unless otherwi
31、se stated, use only reagents of recognized analytical reagent grade and only distilled water or water of equivalent quality. 2.2.1 Hydrochloric acid, concentrated, approximately 36%(m/m). 2.2.2 Hydrochloric acid, dilute, approximately15%(m/m). Dilute 420ml of the hydrochloric acid (2.2.1) to1litre w
32、ith water. 2.2.3 Nitric acid, dilute, approximately9%(m/m). Dilute 130ml of concentrated nitric acid approximately 70%(m/m) to 1litre with water. 2.3 Apparatus 2.3.1 Analytical balance, capable of weighing to the nearest 0,1mg. 2.3.2 Graduated glassware, conforming to the requirements for class A in
33、 the International Standards prepared by ISO/TC48, Laboratory glassware and related apparatus. 2.3.3 Cold-finger condenser, to fit loosely into the neck of a 250ml conical flask (seeFigure 2). Figure 2 Cold-finger condenser for the determination of sulfate and pyritic sulfurBS 1016-106.5:1996 4 BSI
34、11-1998 2.4 Procedure 2.4.1 Test portion Take a test portion of the mass given in Table 1 for the expected total sulfur content, weighing to the nearest 0,1mg. Table 1 Test portion 2.4.2 Extraction Transfer the test portion to a 250ml conical flask, add 50ml of the dilute hydrochloric acid (2.2.2) a
35、nd fit the cold-finger condenser (2.3.3) into the neck of the flask. Boil for 30min, ensuring that a slow stream of water is passing through the cold finger. Remove the condenser and thoroughly rinse back into the flask. Filter the mixture through a medium-textured, doubly acid-washed filter paper i
36、nto a tall-form beaker. Wash the residue three times with the dilute hydrochloric acid (2.2.2) and a further three times with hot distilled water, using a total volume of approximately 30ml. Retain the filtrate for the determination of sulfate sulfur (seeSection3). Immediately transfer the washed, u
37、ndissolved residue and filter paper to a 250ml conical flask, add 50ml of the dilute nitric acid (2.2.3) and retain for the determination of pyritic sulfur (seeSection4). Total sulfur content % (m/m) Mass of test portion g2,0 2BS 1016-106.5:1996 BSI 11-1998 5 Section 3. Determination of sulfate sulf
38、ur 3.1 Principle The sulfate sulfur extracted by dilute hydrochloric acid from the test portion is determined gravimetrically by precipitation with barium chloride. 3.2 Reagents WARNING Care must be exercised when handling the reagents, many of which are toxic and corrosive. During the analysis, unl
39、ess otherwise stated, use only reagents of recognized analytical reagent grade and only distilled water or water of equivalent purity. 3.2.1 Hydrogen peroxide, solution, approximately30%(m/m). 3.2.2 Methyl red, indicator solution. Dissolve 1g of 2-(4-dimethylaminophenylazo) benzoic acid, sodium salt
40、 (methyl red) in 1litre of water. 3.2.3 Ammonia, concentrated, solution not less than25%(m/m). 3.2.4 Hydrochloric acid, concentrated, approximately 36%(m/m). 3.2.5 Potassium sulfate, approximately 2g/l solution. Dissolve approximately 2g of potassium sulfate in water and dilute to 1litre. 3.2.6 Bari
41、um chloride, approximately 85g/l solution. Dissolve 100g of barium chloride dihydrate in water and dilute to 1litre. Filter before use through a close-textured, doubly acid-washed filter-paper or filter-pad. 3.2.7 Silver nitrate, approximately 17g/l solution. Dissolve 17g of silver nitrate in water
42、and dilute to1litre. Store in a dark glass bottle. 3.3 Apparatus 3.3.1 Analytical balance, capable of weighing to the nearest 0,1mg. 3.3.2 Graduated glassware, conforming to the requirements for class A in the International Standards prepared by ISO/TC48. 3.3.3 Electrically-heated muffle furnace, ca
43、pable of being maintained at 800C 25C, with an adequate ventilation rate. 3.3.4 Crucible, of platinum, silica or glazed porcelain, of capacity approximately 25ml. 3.3.5 Flat plate, 6mm thick, of silica or other suitable refractory material, which fits easily into the muffle furnace (3.3.3). 3.3.6 Go
44、och crucible, of glazed porcelain or sintered glass. 3.3.7 Air oven, capable of being maintained at a temperature of 130C 10C. 3.3.8 Filter cone, made of porcelain, of diameter25mm. 3.4 Procedure To the filtrate from the hydrochloric acid extraction (see2.4.2), add 5ml of the hydrogen peroxide solut
45、ion (3.2.1) and boil for 5min to convert all the soluble iron to the +3 oxidation state. While still hot, add 2 or 3 drops of the methyl red indicator solution (3.2.2) followed by the ammonia solution(3.2.3), drop by drop, until the solution is just alkaline (yellow colour) and then add a further5 d
46、rops in excess. Filter the resultant precipitate on a toughened fast filter paper into a250ml beaker. Wash thoroughly with hot water, discarding the precipitate. Cautiously add the concentrated hydrochloric acid (3.2.4) to the filtrate, drop by drop, until the colour of the solution changes to pink
47、and then add a further 1ml in excess. The volume of the solution shall be between 150ml and250ml. Add 25,0ml of the potassium sulfate solution (3.2.5) from a one-mark pipette. Cover the beaker with a watch glass, heat the covered beaker until the solution boils and then reduce the heating slightly u
48、ntil ebullition ceases. Add 10ml of the cold barium chloride solution (3.2.6) from a pipette with a delivery time of approximately 20s, held so that the barium chloride falls into the centre of the hot solution, whilst this is being agitated. Keep the solution just below boiling point, without agita
49、tion, for 30min.BS 1016-106.5:1996 6 BSI 11-1998 Filter the solution using one of the following techniques. a) By gravity through an ashless, close-textured, doubly acid-washed filter paper of diameter100mm to 125mm. Carefully fold the filter paper and fit it into a fluted, long-stemmed 60 funnel, so that the stem remains full of liquid during the filtration. b) By gravity through a filter-paper pad prepared from ashless, doubly acid-washed filter paper. To prepare the filter-paper pad, shake doubly
