Designation:C837−09(Reapproved2014)StandardTestMethodforMethyleneBlueIndexofClay1ThisstandardisissuedunderthefixeddesignationC837;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthemeasurementoftheadsorp-tionofmethylenebluedyebyaclay,whichiscalculatedasamethyleneblueindexforaclay.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2C324TestMethodforFreeMoistureinCeramicWhitewareClays3.SignificanceandUse3.1Testsrunonmanyclaysgenerallyindicatethatastraight-linerelationshipexistsbetweenthemethyleneblueindex(MBI)andsuchfundamentalclaypropertiesascationexchangecapacity,drybondstrength,andcastingrate.Wherethecolloidalportionoftheclayiskaolinite,thereisalsoadirectcorrelationwithspecificsurface(asdeterminedbynitrogenadsorption).Wherethecolloidalportioncontainssignificantamountsofilliteormontmorillonite,thesameclosecorrelationdoesnotexist.TheMBIbettercorrelateswiththeceramic-formingpropertiesthandoesthespecificsurface.3.2Thatportionofaclaylyingwithinthecolloidalrange(generallydefinedasthe0.5-to0.001-µmrange),determinesthestrictlycolloidalpropertiesoftheclayand,togetherwiththeamountandtypeoforganicmaterialassociatedwiththeclayandthe2-to0.2-µmfraction,largelydeterminesthepropertiesoftheclaywhenusedinceramic-formingprocesses.Whilethespecificsurfaceofaclayisafunctionoftheparticlesizeandmorphologyandarelationshipexistsbetweendyeadsorptionandspecificsurface,theMBIshouldnotbecon-sideredtobeaparticlesizeanalysissinc...
