ASTM_D_4715_-_98_2012.pdf

Designation:D471598(Reapproved 2012)Standard Test Method forCoking Value of Tar and Pitch(Alcan)1This standard is issued under the fixed designation D4715;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 cokingvalue of tar and pitch having an ash content not over 0.5%,asdetermined by Test Method D2415.1.2 Coking values by this test method are higher than thoseobtained by Test Method D2416.See the bias statement inSection 13.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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:2D850 Test Method for Distillation of Industrial AromaticHydrocarbons and Related MaterialsD2415 Test Method for Ash in Coal Tar and PitchD2416 Test Method for Coking Value of Tar and Pitch(Modified Conradson)D4296 Practice for Sampling PitchE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Summary of Test Method3.1 A test portion of the tar or pitch is heated for a specifiedtime at 550 6 10C in an electric furnace.The percentage ofresidue is reported as the coking value.4.Significance and Use4.1 This test method is useful for indicating the relativecoke-forming propensities and for evaluating and characteriz-ing tars and pitches.The test method can also be used as oneelement in establishing the uniformity of shipments or sourcesof supply.5.Apparatus5.1 Porcelain Crucible,tall form,30 mL capacity,height of37 mm and diameter 43 mm,with lids of the overlapping type.5.2 Nickel Crucible,100 to 130 mL capacity,height of 64mm and diameter of 60 mm,with lids.5.3 Wire SupportStainless steel wire support,fitting intothe nickel crucible,used to keep the porcelain crucible(5.1)inplace within the nickel crucible(5.2).This support shall allowa separation of 10 6 1 mm between the bases of the twocrucibles(see Fig.1).5.4 Crucible TrayA suitable crucible tray to support thenickel crucibles should be made so that there is at least 7 mmof space between the bottom of the crucible and the base of thefurnace.5.5 Electric Furnace,capable of being controlled at 550 610C.5.6 Sieves1 mm(U.S.Standard No.18),300-m(U.S.Standard No.50)and 212m(U.S.Standard No.70),con-forming to Specification E11.6.Reagents and Materials6.1 Calcined Petroleum CokeUse the fraction whichpasses a 1-mm mesh sieve(U.S.Standard No.18)and isretained by a 212m mesh sieve(U.S.Standard No.70).7.Bulk Sampling7.1 Samples from shipments shall be taken in accordancewith Practice D4296,and shall be free of foreign substances.Thoroughly mix the sample immediately before removing arepresentative portion for the determination or for dehydration.8.Dehydration of Sample8.1 Hard PitchIf the solid bulk sample contains freewater,air-dry a representative portion.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.05 on Properties of Fuels,Petroleum Coke and Carbon Material.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 1987.Last previous edition approved in 2008 as D471598(2008)1.DOI:10.1520/D4715-98R12.2For 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 8.2 Soft PitchIf the presence of water is indicated bysurface foam on heating,maintain a representative portion ofthe bulk sample at a temperature between 125 and 150C in anopen container until the surface is free from foam.Take carenot to overheat,and remove heat source immediately whenfoam subsides.8.3 TarDehydrate a representative portion of the bulksample at atmospheric pressure using a simple side-armdistillation apparatus similar to the one in Test Method D850and stop the distillation when the temperature reaches 170C.Separate any oil from the water that has distilled over(ifcrystals are present,warm sufficiently to ensure their solution),and thoroughly mix the oil with the residual tar in the still afterthe latter has cooled to a moderate temperature.9.Preparation of Working Specimen9.1 Hard PitchIf the pitch can be crushed at roomtemperature,prepare a 20 6 1 g working specimen by suitablecrushing,mixing,and quarter