1、Designation:D241684(Reapproved 2015)1Standard Test Method forCoking Value of Tar and Pitch(Modified Conradson)1This standard is issued under the fixed designation D2416;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last
2、 revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTESI units formatting was corrected editorially in May 2015.1.Scope1.1 This test method covers the determination of the cokingvalue of
3、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 practically thesame as those obtained by Test Method D189,but results aremore reproducible.The apparatus used is identical,except thatan electric furnace is substituted for th
4、e gas flame.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 establ
5、ish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D140 Practice for Sampling Bituminous MaterialsD189 Test Method for Conradson Carbon Residue of Petro-leum ProductsD370 Practice for Dehydrat
6、ion of Oil-Type PreservativesD2415 Test Method for Ash in Coal Tar and PitchE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Summary of Test Method3.1 A sample of the tar or pitch is vaporized and pyrolizedfor a specified time at a specified temperature in specialstandardized equipm
7、ent that limits the available oxygen sup-ply.The percentage of residue 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.This test method can also be used a
8、s oneelement in establishing the uniformity of shipments or sourcesof supply.5.Apparatus(see Fig.1)5.1 CrucibleWide-form,a,either porcelain,glazedthroughout,or silica,a;29 mL to 31 mL capacity,46 mm to49 mm in rim diameter.5.2 Skidmore CrucibleIron crucible,b,flanged andringed,65 mL to 82 mL capacit
9、y,53 mm to 57 mm inside and60 mm to 67 mm outside diameter of flange,37 mm to 39 mmin height,supplied with a cover without delivery tubes andhaving the vertical opening closed.The horizontal opening ofabout 6.5 mm shall be kept clean.The outside diameter of theflat bottom shall be 30 mm to 32 mm.5.3
10、 Metal CrucibleSpun sheet-iron or nickel crucible,c,with cover;78 mm to 82 mm in outside diameter at the top,58 mm to 60 mm in height,and approximately 0.8 mm inthickness.At the bottom of this crucible,and level before eachtest,shall be a layer of about 25 mLof sand,or enough to bringthe Skidmore cr
11、ucible,with cover on,nearly to the top of thesheet-iron crucible.The sand shall be dry and screened to passthrough a 65-mesh screen and to be retained on a 200-meshscreen.5.4 Wire SupportTriangle(65 mm)of bare Nichrome wire1.5 mm to 2.0 mm in cross section,having an opening smallenough to support th
12、e bottom of the metal crucible(see 5.3).The triangle,d,shall have its arms bent to form a cradle thatwill support the metal crucible with its bottom level with thebottom of the insulator(see 5.6).5.5 HoodCircular,sheet-iron,e,from 120 mm to 130 mmin diameter,the height of the lower perpendicular sid
13、e to befrom 50 mm to 53 mm;provided at the top with a chimney50 mm to 60 mm in height and 50 mm to 56 mm in insidediameter,which is attached to the lower part having theperpendicular sides by a cone-shaped member,bringing thetotal height of the complete hood to 125 mm to 130 mm.The1This test method
14、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 April 1,2015.Published May 2015.Originallyapproved in 1965.Last p
15、revious edition approved in 2009 as D2416 84(2009).DOI:10.1520/D2416-84R15E01.2For 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 A
16、STM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 hood may be made from a single piece of metal,providing itconforms to foregoing dimensions.A bridge,g,made ofapproximately 3 mm iron or nichrome wire,and having aheight of 50 mm above the top of the chimney,shall beattached to handle the chimney when positioning.5.6 InsulatorCeramic block or refractory ring,f,150 mmto 175 mm in diameter if round,or on a side if square,32 mmto
