Designation:D3943−10(Reapproved2015)StandardTestMethodforTotalMolybdenuminFreshAlumina-BaseCatalysts1ThisstandardisissuedunderthefixeddesignationD3943;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofmolybde-numinalumina-basecatalystsandhasbeencooperativelytestedatmolybdenumconcentrationsfrom8to18weight%,expressedasMoO3.Anycomponentofthecatalystotherthanmolybdenumsuchasiron,tungsten,etc.,whichiscapableofbeingoxidizedbyeitherferricorcericionsafterbeingpassedthroughazinc-amalgamreductorcolumn(Jonesreductor)willinterfere.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterD7442PracticeforSamplePreparationofFluidCatalyticCrackingCatalystsandZeolitesforElementalAnalysisbyInductivelyCoupledPlasmaAtomicEmissionSpectros-copyE173PracticeforConductingInterlaboratoryStudiesofMethodsforChemicalAnalysisofMetals(Withdrawn1998)3E507TestMethodforDeterminationofAluminuminIronOresbyFlameAtomicAbsorptionSpectrometry3.SummaryofTestMethod3.1Thecatalystisdigestedinhotsulfuricacidtodissolvemolybdenum,destroyorganicmatter,andtoexpelnitratesifpresent.Theacidsolutionisdilutedandpassedthroughanamalgamatedzinccolumn(Jonesreductor)intoareceivingflaskcontaininganexcessofferricammoniumsulfate.Thecolumnquantitativelyreducesthemolybdenum(Mo+6toMo+3)whichinturnisreoxidizedinthereceivingflaskaccordingtothereaction:Mo1313Fe13→Mo1613Fe12(1)3.2Theferrousionproduced(threeperMo+3oxidized)is...
