Designation:D5263−15StandardTestMethodforDeterminingtheRelativeDegreeofOxidationinBituminousCoalbyAlkaliExtraction1ThisstandardisissuedunderthefixeddesignationD5263;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thiscolorimetrictestmethoddescribesthedetermina-tionoftherelativedegreeofoxidationbyalkaliextractionofcoalsthatarehighvolatileAbituminoustolowvolatilebituminousinrank.1.2Thistestcannotbesensitivetothermallyoxidizedcoal.Itisintendedforcoalsthatmaybeoxidizedasaresultofweathering.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterD7448PracticeforEstablishingtheCompetenceofLabora-toriesUsingASTMProceduresintheSamplingandAnalysisofCoalandCoke3.Terminology3.1Therearenotermsinthisstandardthatrequireneworotherthandictionarydefinitions.4.SummaryofTestMethod4.1Humicacids,whicharepresentinoxidizedcoals,areextractedfromthecoalwithsodiumhydroxidesolution.Thedegreeofoxidationisdeterminedbycolorimetricallymeasur-ingthetransmittanceofthealkaliextractsolutionat520nm.Theintensityofthecolorproducedbythehumicacidsisafunctionofthedegreeofoxidation.5.SignificanceandUse5.1Thistestmethodisarelativemeasureofthedegreeofoxidationpresentincoal.Itdoesnotdeterminethequantitativeamountofoxidizedcoalpresent.Itisonlyintendedtoserveasaguidetothesupplier,buyer,anduserforselectingcoalsformetallurgicaluse.NOTE1—Lowerrankbituminouscoalsaremoreeasilyextractedthanhigherrankcoal.6.Apparatus6.1TransmissionSpectrophotom...
