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1、BRITISH STANDARD BS 1016-112: 1995 ISO 5074:1994 Methods for Analysis and testing of coal and coke Part 112: Determination of Hardgrove grindability index of hard coal Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:08:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1016-112:1995 This Bri
2、tish Standard, having been prepared under the direction of the Materials and Chemicals Sector Board (I/-), was published under the authority of the Standards Board and comes into effect on 15 April 1995 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference
3、 SFI/3 Draft for comment 93/502545 DC ISBN 0 580 23957 8 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 Assoc
4、iation British Coal Corporation British Gas plc British Steel Industry Electricity Association GAMBICA (BEAMA Ltd.) Power Generation Contractors Association PGCA (BEAMA Ltd.) Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:08:13 GMT+
5、00:00 2006, Uncontrolled Copy, (c) BSI BS 1016-112:1995 BSI 07-1999i Contents Page Committees responsibleInside front cover National forewordii 1 Scope1 2 Normative references1 3 Definition1 4 Principle1 5 Apparatus1 6 Sampling2 7 Preparation of test sample2 8 Procedure2 9 Expression of results5 10
6、Precision5 11 Test report5 Annex A (normative) Calibration charts6 Annex B (normative) Preparation of national standard reference coal samples with certified Hardgrove grindability indices7 Annex C (informative) Calibration of national Hardgrove machines7 Figure 1 Hardgrove grindability machine3 Fig
7、ure 2 Sectional view of the ginding elements with an indication of the essential tolerances4 Figure A.1 Specimen calibration chart6 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:08:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1016-112:1995 ii BSI 07-1999 National foreword This Britis
8、h Standard has been prepared by Technical Committee SFI/3 and is identical to ISO 5074:1994 Hard coal Determination of Hardgrove grindability index, published by the International Organization for Standardization (ISO) and in the preparation of which the United Kingdom played a full part. This Briti
9、sh Standard is a revision of BS 1016-20 which is withdrawn. BS 1016-20 is renumbered as Part 112 under a scheme for rationalizing and restructuring 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
10、, together with corresponding numbering of the old series and related ISO standards is given in BS 1016 Analysis and testing of coal and coke Part 100:1994 General introduction and sampling report. Cross-references. A British Standard related to ISO 1988:1975 is BS 1017-1:1989 Methods for sampling o
11、f coal. ISO 1988 is being revised in conjunction with ISO 2309 Coke Sampling, ISO 9411 Solid mineral fuels Mechanical sampling from moving streams Part 1: Coal and Part 2: Coke. This revision will be published in eight Parts, and it is intended to implement these Parts as identical British Standards
12、 superseding BS 1017. A British Standard related to ISO 3310-1:1990 is BS 410:1986 Specification for test sieves. 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 Bri
13、tish Standard 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 7 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This wi
14、ll be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:08:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5074:1994(E) BSI 07-19991 1 Scope This International Standard specifies the method for determining the grindability index o
15、f hard coal1) using the Hardgrove machine. It also specifies the procedure for calibrating the test machine and for preparing the standard reference coal samples. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this In
16、ternational 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 applying the most recent editions of the standards indicated bel
17、ow. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1988:1975, Hard coal Sampling. ISO 3310-1:1990, Test sieves Technical requirements and testing Part 1: Test sieves of metal wire cloth. 3 Definition For the purposes of this International Standard, the foll
18、owing definition applies. 3.1 hard coal coal having a gross calorific value of more than 24 MJ/kg on a moist, ash-free basis 4 Principle Treatment of a prepared sample of coal of limited size range under defined conditions in a laboratory apparatus of standardized design (calibrated Hardgrove machin
19、e). Derivation of the grindability index from sieve analysis of the ground product and by reference to a calibration chart prepared from standard reference material. 5 Apparatus 5.1 Balance, capable of weighing up to 100 g to an accuracy of 0,01 g. 5.2 Balance, capable of weighing up to 1 500 g to a
20、n accuracy of 1 g. 5.3 Sample divider, as specified in A.6.3 of ISO 1988:1975. 5.4 Crusher, a laboratory crusher capable of reducing 4,75 mm coal particles to 1,2 mm with the production of a minimum of material finer than 600 4m. In the case of a plate mill, the plates shall be serrated and about 10
21、0 mm in diameter, the distance between the plates being adjustable and the relative frequency of rotation of the plates not exceeding 200 min1. Roll mills or hammer mills shall not be used. 5.5 Sieves 5.5.1 Wire-cloth test sieves, complying with the requirements of ISO 3310-1, Series R 40/3, of aper
22、ture sizes 1,18 mm, 600 4m and 75 4m respectively, and having a cover and receiver of diameter about 200 mm. 5.5.2 Protective sieve, with round or square apertures in the range 6 mm to 19 mm, capable of nesting in the test sieves. A plate sieve with round holes is recommended; if a standard wire clo
23、th sieve is used, it may become distorted through use as a protective sieve and should, therefore, be marked as unsuitable for test sieving. 5.6 Mechanical sieving machine, capable of accepting an assembly of vertically nested sieves and a cover and receiver of diameter about 200 mm. The machine sha
24、ll be able to simulate the motions of hand sieving. This may be achieved by imparting a horizontal oscillatory motion of amplitude 25 mm to 30 mm at a frequency of approximately 300 min1, whilst striking the top of the oscillating assembly with a mass of 1,9 kg, moving through a vertical distance of
25、 about 25 mm under the influence of gravity, at a frequency of approximately 150 blows per minute. Alternatively, the nest of sieves, cover and receiver may be vibrated by an electromagnetic device, provided the sieving performance is equivalent to the mechanically vibrated machine described. 1) In
26、this International Standard, the term “hard coal” is used as an indication of maturity or rank in the coalification sequence and is not related to the physical properties of the coal. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:08:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5074:
27、1994(E) 2 BSI 07-1999 5.7 Hardgrove grindability machine, as shown in Figure 1 and with the essential tolerances shown in Figure 2. It includes a stationary grinding bowl, of hardened iron or steel, with a horizontal track in which run eight steel balls, each of diameter 25,4 mm. The balls shall be
28、driven by an upper grinding ring rotated at 20 r/min 1 r/min. The upper grinding ring, which shall be of similar material to the bowl, shall be connected to a spindle and shall be driven by an electric motor through reduction gears. A load shall be added to the spindle so that the total vertical for
29、ce on the balls due to the top ring, gear, load and spindle is 284 N 2 N, i.e. closely equivalent to a total mass of 29 kg 0,2 kg. The machine shall be fitted with a revolution counter and an automatic device for stopping the machine after 60 0,25 revolutions. It shall be calibrated by the method de
30、scribed in clause 8, before use for the determination of Hardgrove indices. NOTE 1The grinding bowl, balls and top grinding ring should be protected from rusting when not in use. 5.8 Soft brush 6 Sampling The gross sample shall be collected and prepared in accordance with the requirements of ISO 198
31、8, except that the initial crushing shall be up to 4,75 mm instead of up to 10 mm. The gross sample shall be reduced to a final sample of about 1 kg by using a sample divider (5.3) of suitable size and capacity. NOTE 2Initial crushing should be performed by a mill that does not produce too much fine
32、 material which could lead to bias. 7 Preparation of test sample 7.1 Air-dry the final sample (see ISO 1988) and determine the mass of the dried sample to the nearest gram. Since the Hardgrove grindability index, especially for coals with a high content of inherent moisture, varies depending on the
33、moisture content of the coal, air-drying should take place at a relative humidity of 30 % to 70 %. If this has not been done, a determination of the moisture content of the air-dried sample shall be made, and the result shall be reported. Sieve the dried sample on a nest of sieves consisting of a 1,
34、18 mm aperture sieve on top of a 600 4m aperture sieve, by sieving batches of about 200 g for 2 min in the sieving machine, followed by gentle brushing of the oversize material with a soft brush (5.8), to assist the passage through the sieve. Crush the material retained on the 1,18 mm sieve with the
35、 crusher (5.4) adjusted so that only the largest particles are crushed; sieve the crushed material for 3 min and return the oversize material to the crusher again, readjust to crush only the largest particles. Continue crushing and sieving until all the material passes through the 1,18 mm sieve. 7.2
36、 Discard that part of the portion passing through the 600 4m sieve and weigh, to the nearest gram, the coal passing through the 1,18 mm sieve and retained on the 600 4m sieve. If the yield in this size range is less than 50 % of the dried sample, the coal thus prepared shall be discarded and another
37、 final sample of about 1 kg shall be taken from the gross sample and the sample preparation repeated. NOTE 3If, after careful crushing of softer coals (those with a Hardgrove grindability index greater than 80), less than 50 % is retained on the 600 4m sieve, proceed with the test and qualify the re
38、sult. 7.3 Thoroughly mix the size fraction passing through the 1,18 mm sieve and retained on the 600 4m sieve, take about 120 g using a sample divider and dedust by sieving for 5 min on a 600 4m sieve using the sieving machine. Reduce the dedusted material, using a sample divider (5.3) to not less t
39、han 50 g. 8 Procedure 8.1 Clean the grindability machine (5.7) thoroughly and space the balls as evenly as possible around the grinding bowl. 8.2 Weigh a test portion of 50 g 0,01 g of the dedusted material, distribute it evenly in the grinding bowl and smooth the surface. Assemble the top grinding
40、ring to the bowl and fasten the bowl in position to the driving spindle, making sure that the load is evenly applied. Preset the counter and adjust the automatic stopping device so that the machine will operate for 60 0,25 revolutions. Start the apparatus. 8.3 When the rotation has stopped, switch o
41、ff the machine and dismantle the bowl assembly. Brush any adherent coal dust onto the protective sieve (see 5.5.2) nested on the 75 4m sieve and receiver. Empty the grinding balls and ground coal onto the protective sieve. Brush any coal from the bowl and the balls into the protective sieve and set
42、them aside. Brush any coal and dust from the inside and underside of the protective sieve into the 75 4m sieve and set it aside. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:08:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5074:1994(E) BSI 07-19993 Figure 1 Hardgrove grindability ma
43、chine Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:08:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5074:1994(E) 4 BSI 07-1999 Figure 2 Sectional view of the grinding elements with an indication of the essential tolerances Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:08
44、:13 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 5074:1994(E) BSI 07-19995 8.4 Replace the cover on the 75 4m sieve and shake the assembled receiver, 75 m sieve and cover for 10 min in the sieving machine. Invert the sieve over a collector and carefully brush along the warp and weft of the cloth s
45、o that all the coal on the sieve enters the collector. Return the cleaned sieve to the nest, add the coal from the collector and sieve for a further 5 min. Repeat this operation. Finally clean the sieve by brushing so that the coal retained on the sieve and in the apertures enters the collector, whi
46、le all the coal that has passed through the apertures enters the undersize receiver. 8.5 Weigh separately, to the nearest 0,01 g, the coal brushed off the 75 4m sieve and the coal passing through the 75 4m sieve. If the sum of these masses differs by more than 0,5 g from the initial mass of the test
47、 portion, the result shall be rejected and the test repeated. 9 Expression of results 9.1 Calculate the mass m, in grams, of the test portion passing through the 75 4m sieve, using the formula m = 50 m1 where m1 is the mass, in grams, of test portion retained on the 75 4m sieve. Record the grindabil
48、ity index from the calibration chart (see Annex A). 9.2 Carry out duplicate determinations on test portions taken from the 1,18 mm to 600 4m fraction. Report the mean of the two determinations, rounded to the nearest whole number, as the Hardgrove grindability index (HGI). 10 Precision 10.1 Repeatab
49、ility limit The results of duplicate determinations carried out at different times in the same laboratory by the same operator with the same apparatus, on test portions taken from the same sample passing through a 1,18 mm sieve and retained by a 600 4m sieve (see clause 7) should not differ by more than 2 units. 10.2 Reproducibility limit The means of the results of duplicate determinations carried out in each of two different laboratories on test portions taken from the same gross sample of 4,75 mm coal should not differ by more th