Designation:C1720−11´1StandardTestMethodforDeterminingLiquidusTemperatureofImmobilizedWasteGlassesandSimulatedWasteGlasses1ThisstandardisissuedunderthefixeddesignationC1720;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ε1NOTE—UnitsstatementwaseditoriallycorrectedinApril2015.1.Scope1.1Thesepracticescoverproceduresfordeterminingtheliquidustemperature(TL)ofnuclearwaste,mixednuclearwaste,simulatednuclearwaste,orhazardouswasteglassinthetemperaturerangefrom600°Cto1600°C.ThismethoddiffersfromPracticeC829inthatitemploysadditionalmethodstodetermineTL.TLisusefulinwasteglassplantoperation,glassformulation,andmelterdesigntodeterminetheminimumtemperaturethatmustbemaintainedinawasteglassmelttomakesurethatcrystallizationdoesnotoccurorisbelowaparticularconstraint,forexample,1volume%crystallinityorT1%.Asofnow,manyinstitutionsstudyingwasteandsimu-latedwastevitrificationarenotinagreementregardingthisconstraint(1).1.2Threemethodsareincluded,differingin(1)thetypeofequipmentavailabletotheanalyst(thatis,typeoffurnaceandcharacterizationequipment),(2)thequantityofglassavailabletotheanalyst,(3)theprecisionandaccuracydesiredforthemeasurement,and(4)candidateglassproperties.Theglassproperties,forexample,glassvolatilityandestimatedTL,willdictatetherequiredmethodformakingthemostprecisemeasurement.ThethreedifferentapproachestomeasuringTLdescribedhereincludethefollowing:(A)GradientTempera-tureFurnaceMethod(GT),(B)UniformTemperatureFurnaceMethod(UT),and(C)CrystalFractionExtrapolationMethod(CF).Thisprocedureisintendedtoprovidespecificworkprocesses,butmaybesupplementedbytestinstructionsasdeemedappropriatebytheprojectmanagerorprincipleinves-tigator.Themethodsdefinedherearenotapplicabletoglassesthatformmultipleimmiscibleliquidphases.Immiscibilitymaybedetectedintheinitialexaminationofglas...
