1、Designation:D241620Standard 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 revision.A number
2、 in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 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 D24
3、15.1.2 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 the gas flame.1.3 The values stated in SI units are to be regarded asstandard.No o
4、ther 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,health,and environmental practices and deter-mine the ap
5、plicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by
6、 the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D140 Practice for Sampling Asphalt MaterialsD189 Test Method for Conradson Carbon Residue of Petro-leum ProductsD370 Practice for Dehydration of Oil-Type PreservativesD2415 Test Method fo
7、r 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 equipment that limits the available oxygen sup-ply.The
8、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 as oneelement in establishing the uniformity of sh
9、ipments 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 capacity,53 mm to 57 mm inside and60 mm to 67 mm outside
10、 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 Metal CrucibleSpun sheet-iron or nickel crucible
11、,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 crucible,with cover on,nearly to the top of theshee
12、t-iron crucible.The sand shall be dry and screened to passthrough a 70 mesh(212 m)screen and to be retained on a 200mesh(75 m)screen.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 the bottom of the metal crucible(see 5.3
13、).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 side to befrom 50 mm to 53 mm;provided at
14、 the top with a chimney1This 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 June 1,2020.Published Ju
15、ne 2020.Originallyapproved in 1965.Last previous edition approved in 2015 as D2416 84(2015)1.DOI:10.1520/D2416-20.2For 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 sta
16、ndards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technic
