ASTM_D_441_-_07_2012.pdf

Designation:D44107(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 parentheses 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 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 emphasize 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 service 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 this 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 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.Apparatus4.1 Porcelain Jar Tumbler,consisting of a cylindrical por-celain jar of uniform dimensions,714in.(184 mm)in diameterand 714in.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 as shownin Fig.1.The two rings,a,shall be 718in.(181 mm)in outsidediameter and shall be made of34-by18-in.(19-by 3-mm)iron.The three ledges or shelves,b,612by34by18in.(165 by 19by 3 mm),shall be attached radially to the rings by means ofsmall brackets,c,the ends of the shelves being 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,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 with 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 strip 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 for the porcelain jar specified in 4.1,provided it hasapproximately the same internal dimensions,namely,714in.indiameter by 714in.in depth.A jar constructed of cast iron isrecommended,and the interior machined to the requiredinternal dimensions.For making it sufficiently light for lifting,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 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 International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 the jar may have a wall thickness of not less than14in.(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