Designation:D5263−21StandardTestMethodforDeterminingtheRelativeDegreeofOxidationinBituminousCoalbyAlkaliExtraction1ThisstandardisissuedunderthefixeddesignationD5263;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thiscolorimetrictestmethoddescribesthedetermina-tionoftherelativedegreeofoxidationbyalkaliextractionofcoalsthatarehighvolatileAbituminoustolowvolatilebituminousinrank.1.2Thistestcannotbesensitivetothermallyoxidizedcoal.Itisintendedforcoalsthatmaybeoxidizedasaresultofweathering.1.3Units—ThevaluesstatedinSIunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesafterSIunitsareprovidedforinformationonlyandarenotconsideredstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterD7448PracticeforEstablishingtheCompetenceofLabora-toriesUsingASTMProceduresintheSamplingandAnalysisofCoalandCoke3.Terminology3.1Therearenotermsinthisstandardthatrequireneworotherthandictionarydefinitions.4.SummaryofTestMethod4.1Humicacids,whicharepresentinoxidizedcoals,areextractedfromthecoalwithsodiumhydroxidesolution.Thedegreeofoxidationisdeterminedbycolorimetricallymeasur-ingthetransmittanceofthealkaliextractsolutionat520nm.Theintensityofthecolorproducedbythehumicacidsisafunctionofthedegreeofoxidation.5.Sign...
