1、Designation: D441 07 (Reapproved 2012)Standard Test Method ofTumbler Test for Coal1This standard is issued under the fixed designation D441; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in par
2、entheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the relativefriability of a particular size of sized coal. It affords a means ofmeasuring the liability
3、 of coal to break into smaller pieceswhen subjected to repeated handling at the mine orsubsequently, by the distributor or by the consumer. This testmethod is serviceable for ascertaining the similarity of coals inrespect to friability rather than for determining values withinnarrow limits to emphas
4、ize their dissimilarity. This test methodalso may serve to indicate the relative extent to which sizedcoals will suffer size degradation in certain mechanical feeddevices. This test method may be used for differentiatingbetween certain ranks and grades of coal, and therefore the testmethod is of ser
5、vice for coal classification purposes.1.2 The values stated in inch-pound units shall be regardedas the standard. Mass may be expressed in metric values.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of th
6、is standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2234/D2234M Practice for Collection of a Gross Sampleof CoalD4749 Test Method for Performing the Sieve Analysis ofCoal
7、 and Designating Coal SizeE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Significance and Use3.1 This test method is a measure of the resistance of thecoal to breakage upon impact and abrasion as the coal rubstogether and against the walls of the transportation vehicle.4. Apparat
8、us4.1 Porcelain Jar Tumbler, consisting of a cylindrical por-celain jar of uniform dimensions, 714 in. (184 mm) in diameterand 714 in. in depth, inside measurements, such as is used forpulverizing coal samples for analysis. The jar shall be fittedinside an iron frame with lifting shelves constructed
9、 as shownin Fig. 1. The two rings, a, shall be 718 in. (181 mm) in outsidediameter and shall be made of34-by18-in. (19- by 3-mm) iron.The three ledges or shelves, b,612 by34 by18 in. (165 by 19by 3 mm), shall be attached radially to the rings by means ofsmall brackets, c, the ends of the shelves bei
10、ng flush with theouter edges of the rings. The shelves shall be attached so thatthere will be58-in. (15.9-mm) clearance between their outeredge and the outside of the ring. Rivets, not bolts, shall be usedin constructing the frame. As the jars available commerciallyare not of absolutely uniform size
11、, the measurements of theframe may be slightly varied to suit individual cases.The frameshall be fixed inside the jar by means of wedges between therings and the inside wall of the jar so that its axis shall coincideas nearly as possible with the axis of the jar, and so that theframe will rotate wit
12、h the jar. The jar shall be closed by a set-inporcelain lid resting upon a heavy rubber gasket and sealedtightly according to the customary procedure with such jars,that is, by means of a bolt working against the lid. The boltshall be set in a crossbar, the ends of which shall be held by ametal stri
13、p which fits around the body of the jar. For tumbling,the jar shall be laid in a horizontal position in a suitable supportor rack and rotated about its cylindrical axis at the rate of 40rpm. The assembled apparatus is illustrated in Fig. 2.4.2 Optional Iron Jar TumblerAn iron jar may be substi-tuted
14、 for the porcelain jar specified in 4.1, provided it hasapproximately the same internal dimensions, namely, 714 in. indiameter by 714 in. in depth. A jar constructed of cast iron isrecommended, and the interior machined to the requiredinternal dimensions. For making it sufficiently light for lifting
15、,1This method is under the jurisdiction of ASTM Committee D05 on Coal andCoke and is the direct responsibility of Subcommittee D05.07 on PhysicalCharacteristics of Coal.Current edition approved Sept. 1, 2012. Published November 2012. Originallyapproved in 1937. Last previous edition approved in 2007
16、 as D441 86 (2002).DOI: 10.1520/D0441-07R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM In
17、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1the jar may have a wall thickness of not less than14 in. (6.35mm), except at each end. It is recommended that the lid, rubbergasket, and the metal strip that passes from the bottom up theoutside of the j
18、ar to serve in holding in place the crossbar abovethe lid, be similar in design with those for the porcelain jar. Thewall of the iron jar for a distance of approximately 1 in. (25.4mm) from the top shall have a thickness of at least12 in. (12.7mm) to correspond with that of the porcelain jar; and in
19、 orderthat the metal strip may fit evenly, the lower inch of the wallshould also have a thickness of not less than12 in.4.3 SievesFor sizing the sample for test, square-holesieves having 1.50- and 1.06-in. (38.1- and 26.9-mm) actualopenings between the wires shall be used. These sieves may befitted
20、into frames, 12 by 30 in. (305 by 762 mm) or larger. Forsieving the coal after tumbling, square-hole sieves having1.06-, 0.750-, 0.530-, 0.375-, 0.0469-, and 0.0117-in. (26.9-,19.0-, 13.5-, 9.51-, 1.19-, and 0.297-mm) actual openingsbetween the wires shall be used. For this purpose, round,metal-fram
21、ed sieves 8 in. (200 mm) in diameter are suitable.The sieves shall conform to Specification E11.4.4 BalanceThe balance used for weighing the sampleshall be sensitive to 1 g.5. Sampling5.1 Collection of Gross SampleCollect the gross sampleof coal in accordance with Practice D2234/D2234M and TestMetho
22、d D4749.5.2 Preparation of Sample:5.2.1 Make a preliminary sieving of a representativeportion, approximately 100 lbs (45 kg), of the gross sample,using square-hole sieves with 1.06- and 1.50-in. (26.9- and38.1-mm) openings. If this preliminary sieving indicates thatthe pieces of coal are mostly smal
23、ler than 1.50 in., sievesuccessive representative portions of the gross sample until atleast 25 lbs (11 kg) of the 1.06- to 1.50-in. size are obtained. Ifmost of the pieces obtained by the preliminary sieving arelarger than 1.50 in., conduct sieving of representative portionsof the gross sample unti
24、l at least 50 lbs (23 kg) of the sievedmaterial remaining on the 1.06-in. sieve are available. Thenbreak the pieces so obtained that are larger than 1.50 in. witha hammer until they pass the 1.50-in. sieve, avoiding as muchas possible the production of pieces smaller than 1.06 in.Should the combined
25、 weights of the 1.06- to 1.50-in. size,obtained by sieving before and after hammer breakage of thelarger pieces, be less than the required 25 lbs, augment theamount by further sieving and breakage of additional repre-sentative portions, or the remainder of the gross sample, takingcare to discard all
26、 pieces in which noticeable cracks havedeveloped by hammer breakage. Take care also to providepieces covering the whole range of the 1.06- to 1.50-in. size inboth the 25-lbs composite sample, and in each 1000-g sampletaken for test as in Section 5. This may be accomplished by theuse of a 1.25-in. (3
27、1.5-mm) sieve to see that approximately halfof the weight of the pieces comprising these samples will bebetween 1.06 and 1.25 in. and half between 1.25 and 1.50 in.5.2.2 Mix thoroughly the total quantity of the 1.06- to1.50-in. size and then resieve it to pass the 1.50-in. sieve andbe retained on th
28、e 1.06-in. sieve. Place only a thin layer of coalon the sieve so as to allow the pieces to be in direct contactwith the sieve openings. Upend by hand individual pieces ofcoal not passing readily through the sieve to determine whetherin any position they pass the sieve.6. Procedure6.1 Weigh approxima
29、tely 1000 g of the coal sample, pre-pared in accordance with 5.1, and place it in the jar. Rotate thejarfor1hinthetumbler test machine at 40 6 1 rpm. Tostandardize the time of tumbling, use a revolution counter,Metric Equivalentsin.185834 612 718(mm) (3.18) (15.9) (19.0) (165) (181)FIG. 1 Steel Fram
30、e Used in Jar MillNOTE 1On the bench are shown typical jar mills in which thethree-vane iron frames are fitted, together with a set of 8-in. (200 mm)diameter sieves and a 1000-g charge of 1.06- to 1.50-in. (26.5 to 38.1-mm)size coal. The jar to the left is one of the regular porcelain jars, and that
31、to the right an optional iron jar.FIG. 2 Tumbler Test ApparatusD441 07 (2012)2either periodically or as permanent accessory equipment to themachine, to ensure that the total number of revolutions duringa test is approximately 2400. After tumbling, thoroughly gradethe coal as to size upon the sieves
32、designated in 4.3. Carry outthe sieving in such small increments as to permit satisfactorycontact between the individual pieces of coal and the sieve. Onthe two larger sieves, 1.06- and 0.750-in. (26.9- and 19.0-mm)upend by hand individual pieces of coal not readily passingthrough the sieves to dete
33、rmine whether in any position theypass the sieve.6.2 Sieving may be carried out either by hand ormechanically, though the former method is preferable.6.3 Make at least four single-jar tests, and, provided suffi-cient sample is available, it is recommended that two or morefour-jar tests be made. When
34、 only four single-jar tests aremade, sieve the contents of each jar separately in order to besure that there is satisfactory agreement between the resultsobtained. When two or more four-jar tests are made, thecontents of the four jars from each set may be mixed and sievedtogether. Make the weighings
35、 to the nearest 1 g.7. Calculations7.1 The product of the weight percent of the initial 1.06- by1.50-in. sample and its average sieve opening in inches isnormalized to equal 100 % (see Table 1). This is S.7.2 After testing, the resultant weight percent distribution isdetermined. The products of the
36、various normalized averagesize opening of the size fractions and the respective weightpercent are determined. These products are summed. This sumis s (see Table 1).7.3 Friability is calculated as 100 (S s)/S and is reportedto the nearest 0.5 %.7.4 Dust index is numerically equal to the percent of No
37、.50 (USA Standard) material produced during the tumbler testand is reported as the nearest whole number index (see Table1).8. Report8.1 Report friability in percent to the nearest 0.5 %. This isthe percentage reduction in average size of the coal during thetumbler test.NOTE 1Anumerical example of th
38、e method of calculating friability isgiven in Table 1, where the average of the openings of the retaining andpassing sieves is expressed in inches (millimetres) to the nearest 0.001 in.(0.025 mm). The data shown are for a typical coal of medium friability. Itis from the average of the sieve openings
39、 that the approximate relative sizefactors, shown as column (3) are derived. In the column to the extremeright, S represents the average size of the coal pieces before tumbling, ands the average size of the tumbled coal, the value for S being arbitrarilychosen as 100 times its corresponding size fac
40、tor.9. Precision and Bias9.1 Data for repeatability and reproducibility do not existbut are being determined.9.2 This is an empirical test method and no statement of biasis possible.10. Keywords10.1 breakage; coal; coal handling; friability; size stability;tumblerD441 07 (2012)3ASTM International ta
41、kes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own r
42、esponsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addre
43、ssed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at t
44、he address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (p
45、hone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 1 Sieve Analysis of Coal Using Square-Hole SievesNOTE 1Friability, % = 100(S s)/S =
46、 100(100 68.56)/100 = 31.4. To be reported as: Friability, 31.5 %.Retained On PassingWeight,%(1)Average ofSieve OpeningsProduct of(1)(2)InchesNormalizingFactor(2)SAMPLE1.06 in. (26.5 mm) 1.50 in. (38.1 mm) 100.0 1.280 1 100.00 = STUMBLED COAL1.06 in. (26.5 mm) 1.50 in. (38.1 mm) 46.2 1.280 1 46.20.7
47、50 in. (19.0 mm) 1.06 in. (26.5 mm) 26.9 0.905 0.7 18.830.530 in. (13.2 mm) 0.750 in. (19.0 mm) 4.0 0.640 0.5 2.000.375 in. (9.5 mm) 0.530 in. (13.2 mm) 1.6 0.452 0.35 0.560.0469 in. (No. 16) 0.375 in. (9.5 mm) 5.5 0.211 0.16 0.8800.0117 in. (No. 50) 0.0469 in. (No. 16) 0.5 0.029 0.023 0.0120.0117 i
48、n. (No. 50)A15.3B0.006 0.005 0.077Total (Sum of products (1)(3) for tumbled coal) 68.56=sAIncluding loss, not to exceed 0.5 %.BThe percentage of “fines and dust” passing the 0.0117-in. (No. 50) sieve represents the proportion of the breakage due to attrition or abrasion rather than to shattering,and
49、 may be reported as “dust index” to the nearest whole percent to indicate the relative dust-producing properties of coals when subjected to severe handling. Henceboth the friability in percent and the “dust index” may be reported as follows: Friability, % = 31.5; with dust index of 15.D441 07 (2012)4
