1、BRITISH STANDARD CONFIRMED APRIL1993 BS1016-21: 1981 ISO1018:1975 Methods for Analysis and testing of coal and coke Part21: Determination of moisture-holding capacity of hard coal ISO title: Hard coal Determination of moisture-holding capacity UDC 662.66+662.74:662.66:543.817BS1016-21:1981 This Brit
2、ish Standard, having been prepared under the directionof the Solid Fuel Standards Committee, was published under the authority ofthe Executive Board and comesinto effect on 31August1981 BSI08-1999 The following BSI references relate to the work on this standard: Committee reference SFC/3 Draft for c
3、omment80/55220DC ISBN 0 580 12263 8 Cooperating organizations The Solid Fuel Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: Association of Consulting Engineers British Carbonization Research Association* British Ironfoun
4、ders Association Chamber of Coal Traders Chartered Institution of Building Services Coke Oven Managers Association Combustion Engineering Association Consumer Standards Advisory Committee of BSI Council of Ironfoundry Associations Department of Energy (Energy Technology) Domestic Solid Fuel Applianc
5、es Approval Scheme Electricity Supply Industry in England and Wales* Health and Safety Executive Heating and Ventilating Contractors Association Institute of Energy Low Temperature Coal Distillers Association of Great Britain Ltd. National Coal Board* Society of British Gas Industries Solid Smokeles
6、s Fuels Federation* Womens Solid Fuel Council The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: British Gas Corporation British Steel Corporation Ceme
7、nt Makers Federation Chemical Industries Association Institute of British Foundrymen Institute of Petroleum Scientific Instrument Manufacturers Association Individual experts Amendments issued since publication Amd. No. Date of issue CommentsBS1016-21:1981 BSI 08-1999 i Contents Page Cooperating org
8、anizations Inside front cover National foreword ii 0 Introduction 1 1 Scope and field of application 1 2 Reference 1 3 Principle 1 4 Reagent 1 5 Apparatus 1 6 Preparation of sample 1 7 Procedure 1 8 Expression of results 2 9 Precision of the method 3 10 Test report 3 Annex A Determination of moistur
9、e in the conditioned coal 6 Annex B Nitrogen purification train 6 Figure 1 Apparatus for determination of moisture-holding capacityofcoal(atmospheric pressure method) 4 Figure 2 Apparatus for determination of moisture-holding capacityofcoal(reduced pressure method) 5 Publications referred to Inside
10、back coverBS1016-21:1981 ii BSI 08-1999 National foreword This British Standard, which has been prepared under the direction of the Solid Fuel Standards Committee, is identical with ISO1018 Hard coal Determination of moisture-holding capacity, published in1975 by the International Organization for S
11、tandardization (ISO), and prepared by ISO/TC27, Solid mineral fuels. This British Standard is one of a series issued under the same number, BS1016, dealing with methods for analysis and testing of coal and coke; the other Parts are as follows: Part1: Total moisture of coal 1) ; Part2: Total moisture
12、 of coke; Part3: Proximate analysis of coal; Part4: Moisture, volatile matter and ash in the analysis sample of coke; Part5: Gross calorific value of coal and coke; Part6: Ultimate analysis of coal; Part7: Ultimate analysis of coke; Part8: Chlorine in coal and coke; Part9: Phosphorus in coal and cok
13、e; Part10: Arsenic in coal and coke; Part11: Forms of sulphur in coal; Part12: Caking and swelling properties of coal; Part13: Tests special to coke; Part14; Analysis of coal ash and coke ash; Part15: Fusibility of coal ash and coke ash; Part16: Reporting of results 1) ; Part17: Size analysis of coa
14、l; Part18: Size analysis of coke; Part19: Determination of the index of abrasion of coal; Part20: Determination of Hardgrove grindability index of hard coal. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard withou
15、t deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is especially drawn to the following. The comma has been used throughout as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the
16、 decimal marker. Where the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. Cross-references. The Technical Committee has reviewed the provisions of ISO589:1974, to which reference is made in the footnote on page1, and ISO1988:1975, to whi
17、ch reference is made in clauses2 and6, and has decided that they are suitable for use in conjunction with this standard. The related British Standards for ISO589 and ISO1988 are BS1016 “Methods for the analysis and testing of coal and coke” Part1:1973 “Total moisture of coal” and BS1017 “Methods for
18、 sampling of coal and coke” Part1:1977 “Sampling of coal” respectively. NOTEISO1988 and BS1017-1 have some technical differences but both are under revision; it is expected that the BS will be identical with the ISO Standard when the revision is complete. 1) Under revision.BS1016-21:1981 BSI 08-1999
19、 iii HAZARD WARNING. This British Standard method does not necessarily detail all precautions necessary to meet the requirements of the Health and Safety at Work etc. Act1974. Attention should be paid to any appropriate safety precautions, particularly with regard to the use of vacuum desiccators, a
20、nd the method should be operated only by trained personnel. NOTETextual errors. When adopting the text of the International Standard the errors given below were noticed. They have been marked in this British Standard and have been reported to ISO in a proposal to amend the text of the International
21、Standard. In the plan view of Figure 1, the top positioning stud on the top right hand dish has been omitted. In7.3.1 the lid of the dish should be stored in a desiccator whilst the dish is in the conditioning vessel. In A.3 the lid of the dish should be placed in the oven with the dish and not in a
22、 desiccator. 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 pages This docume
23、nt comprises a front cover, an inside front cover, pagesi toiv, pages1to6, 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 blankBS1016-21:19
24、81 BSI 08-1999 1 0 Introduction The moisture-holding capacity indicates the rank of hard coals and is used in coal classification for correcting the calorific value of the sample to the moist mineral matter-free basis. The full moisture-holding capacity is that of the coal in equilibrium with an atm
25、osphere saturated with water vapour. Since there are insuperable experimental difficulties in working with such an atmosphere, the determination is carried out at96% relative humidity. 1 Scope and field of application This International Standard specifies a method of determining the moisture-holding
26、 capacity of hard coals. 2 Reference ISO1988, Hard coal Sampling. 3 Principle The coal is brought to equilibrium with an atmosphere of96% relative humidity at30 C and then dried to constant mass at105 to110 C. The conditioning of the coal may be carried out either at atmospheric pressure or under re
27、duced pressure. The moisture-holding capacity is reported as a percentage, by mass, of the conditioned moist coal. 4 Reagent Potassium sulphate pulp. Add sufficient potassium sulphate to water to form a pulp. 5 Apparatus 5.1 Atmospheric pressure method 5.1.1 Conditioning vessel (see Figure 1). A dou
28、ble-walled vessel, manufactured of copper sheet, with a double-walled lid made in two pieces. The lid and vessel are covered by a foam rubber insulation jacket. Each half of the lid is secured by three equally spaced clamps, or by the addition of a2kg weight. 5.1.2 Electric motor, capable of driving
29、 a two-blade propeller at approximately1500rev/min. 5.1.3 Pump, for circulating water through the conditioning vessel to maintain it at a temperature of30 0,1 C. 5.1.4 Dishes, made of glass or corrosion-resistant metal, approximately50mm diameter by10mm deep, with well-fitting lids. 5.2 Reduced pres
30、sure method 5.2.1 Conditioning vessel (see Figure 2). A vacuum desiccator weighted to overcome its buoyancy when immersed in water. The desiccator is fitted with a mercury vacuum manometer, and a glass or corrosion-resistant metal stand is provided to carry dishes above the level of the pulp, so tha
31、t the dishes are protected from spray due to frothing. The volume of free space in the desiccator is kept to a minimum by the choice of a suitable design, by increasing the volume of the pulp material or by adding inert material such as glass beads or washed sand to the pulp. 5.2.2 Water bath (see F
32、igure 2), thermostatically controlled at a temperature of30 0,1 C. 5.2.3 Dishes made of glass or corrosion-resistant metal, approximately22mm diameter by15mm deep. The lids for these dishes should form a sliding fit. 5.3 For both methods 5.3.1 Vacuum pump 5.3.2 Filter crucible or funnel 5.3.3 Filter
33、 flask 5.3.4 Apparatus for determining moisture by a method which precludes oxidation of the coal. 2) 5.3.5 Filter paper, diameter about200mm. 6 Preparation of sample It is essential that the coal be in a fresh, unchanged state. If the sample cannot be examined immediately, it shall be protected fro
34、m oxidation by storing under water. Crush the sample to pass a sieve of0,2mm aperture, using the procedures described in ISO1988. The production of an excessive amount of fines shall be avoided. 7 Procedure 7.1 Preparation of apparatus 7.1.1 Both methods Fill the conditioning vessel with the potassi
35、um sulphate pulp to the level indicated in Figure 1 or Figure 2. 7.1.2 Atmospheric pressure method Connect the conditioning vessel to the pump and circulate the water at a rate sufficient to maintain a temperature of30 0,1 C in the vessel. 2) The apparatus and procedure of Method B described in ISO5
36、89, Hard coal Determination of total moisture, are suitable for this purpose and the description is reproduced in Annex A.BS1016-21:1981 2 BSI 08-1999 7.1.3 Reduced pressure method Evacuate the desiccator several times until frothing ceases. To minimize subsequent frothing, the desiccator should be
37、kept evacuated when not in use. 7.2 Preliminary treatment of the sample Place about20g of the sample, crushed to pass a sieve of0,2mm aperture, into a conical flask, add about100ml of distilled water, shake several times and filter on a filter crucible or funnel. Wash the filtered coal with two or t
38、hree separate portions of25ml of distilled water, taking care that the surface of the coal is not dried by excessive suction. Remove the coal from the filter and spread out between two layers of the filter paper, each layer consisting of eight sheets of the filter paper. The thickness of the coal la
39、yer should not be more than4mm. Place a weight of about10kg on the top layer of filter paper; a considerable part of the adherent surface water is removed by this pressure. After about10min, remove the weight and thoroughly mix the coal with a spatula. 7.3 Conditioning 7.3.1 Atmospheric pressure met
40、hod 3) Weigh the empty dish and lid and spread uniformly into it approximately2g of the treated coal (see7.2). Place the dish in the conditioning vessel, controlled to a temperature of30 0,1 C, so that it is below an air circulation exit. Replace the two halves of the lid and secure by means of clam
41、ps or weights. Start the propeller motor and pass air for a period of3 to6h (see7.3.2, note1). Switch off the motor, remove the dish and securely replace its lid. Transfer the dish on a metal tray to a balance and weigh quickly to within0,2mg. 7.3.2 Reduced pressure method Weigh the empty dish and l
42、id and spread uniformly into it approximately1g of the treated coal (see7.2). Cover the loaded dish loosely with its lid and place in the conditioning vessel. Replace the lid of the conditioning vessel and evacuate it to a pressure of2 to2,5kPa. Place the vessel into the water bath, maintained at a
43、temperature of30 0,1 C, and re-evacuate. The pressure should rise quickly to about4kPa, which is the vapour pressure of the saturated solution of potassium sulphate at30 C. If the pressure rises above4kPa, re-evacuate the vessel without otherwise disturbingit. After a period of24 2h, with the vessel
44、 still in the water bath, restore the pressure to atmospheric by slowly admitting dry air at30 C through the train, consisting of a capillary tube, a tower charged with dry magnesium perchlorate (see note2) and a coiled copper tube immersed in the water bath and connected to the inlet of the vessel
45、(see Figure 2). In order to avoid changes in the moisture content it is essential to ensure that there is no disturbance of the local atmosphere immediately adjacent to the conditioned coal. This may be achieved by adjusting the length and diameter of the capillary tube G (seeFigure 2), so that the
46、time taken to restore atmospheric pressure is approximately15min. Remove the vessel from the bath, remove the lid, transfer the covered dish immediately to a balance and weigh quickly to within0,2mg. NOTE 1The period required for equilibrium to be reached will depend on the rank of the coal. In the
47、case of an “unknown” coal, several samples of the coal should be placed in the vessel and the moisture-holding capacity determined after various conditioning times. NOTE 2Regeneration of magnesium perchlorate should not be attempted, owing to the risk of explosion. When exhausted, the magnesium perc
48、hlorate should be washed down the sink with a stream of water. 7.4 Determination of moisture content Determine the moisture content of the conditioned sample by the method described in Annex A, using the dish in which the coal was conditioned. 8 Expression of results The moisture-holding capacity, M
49、HC, of the sample as analysed, expressed as a percentage, is given by the formula The result, preferably the mean of duplicate determinations (see clause9), shall be reported as follows: 3) See national foreword. where m 1 is the mass, in grams, of empty dish and lid; m 2 is the mass, in grams, of coal, dish and lid after conditioning; m 3 is the mass, in grams, of dried coal, dish and lid. Moisture-holding capacity Report result to the nearest Less than5% 5% and over 0,1% 0,5%BS1016-21:1981 BSI 08-
