1、Designation: C1720 111Standard Test Method forDetermining Liquidus Temperature of Immobilized WasteGlasses and Simulated Waste Glasses1This standard is issued under the fixed designation C1720; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEUnits statement was editorially corrected in April 2015.1. Scope1.1 These practices cover procedures f
3、or determining theliquidus temperature (TL) of nuclear waste, mixed nuclearwaste, simulated nuclear waste, or hazardous waste glass in thetemperature range from 600C to 1600C. This method differsfrom Practice C829 in that it employs additional methods todetermine TL. TLis useful in waste glass plant
4、 operation, glassformulation, and melter design to determine the minimumtemperature that must be maintained in a waste glass melt tomake sure that crystallization does not occur or is below aparticular constraint, for example, 1 volume % crystallinity orT1%. As of now, many institutions studying was
5、te and simu-lated waste vitrification are not in agreement regarding thisconstraint (1).1.2 Three methods are included, differing in (1) the type ofequipment available to the analyst (that is, type of furnace andcharacterization equipment), (2) the quantity of glass availableto the analyst, (3) the
6、precision and accuracy desired for themeasurement, and (4) candidate glass properties. The glassproperties, for example, glass volatility and estimated TL, willdictate the required method for making the most precisemeasurement. The three different approaches to measuring TLdescribed here include the
7、 following: (A) Gradient Tempera-ture Furnace Method (GT),(B) Uniform Temperature FurnaceMethod (UT), and (C) Crystal Fraction Extrapolation Method(CF). This procedure is intended to provide specific workprocesses, but may be supplemented by test instructions asdeemed appropriate by the project mana
8、ger or principle inves-tigator. The methods defined here are not applicable to glassesthat form multiple immiscible liquid phases. Immiscibility maybe detected in the initial examination of glass during samplepreparation (see 9.3). However, immiscibility may not becomeapparent until after testing is
9、 underway.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to esta
10、blish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C162 Terminology of Glass and Glass ProductsC829 Practices for Measurement of Liquidus Temperature ofGlass by the Gradient Furnace MethodD
11、1129 Terminology Relating to WaterD1193 Specification for Reagent WaterE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2282 Guide for Defining the Test Result of a Test Method2.2
12、 Other Documents:SRM-773 National Institute for Standards and Technology(NIST) Liquidus Temperature StandardSRM-674b NIST X-Ray Powder Diffraction Intensity Setfor Quantitative Analysis by X-Ray Diffraction (XRD)SRM-1976a NIST Instrument Response Standard for X-RayPowder DiffractionZ540.3 American N
13、ational Standards Institute/NationalConference of Standards Laboratories (ANSI/NCSL) Re-quirements for the Calibration of Measuring and TestEquipment3. Terminology3.1 Definitions:1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of
14、 Subcommittee C26.13 on Spent Fueland High Level Waste.Current edition approved Feb. 1, 2011. Published April 2011. DOI: 10.1520/C172011E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volum
15、e information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.1 air quenchingto pour or place a molten glass speci-men on a surface, for example, a steel plate, and
16、cool it to thesolid state.3.1.2 annealto prevent or remove materials processingstresses in glass by controlled cooling from a suitabletemperature, for example, the glass transition temperature (Tg)(modified from Terminology C162).3.1.3 annealinga controlled cooling process for glassdesigned to reduc
17、e thermal residual stress to an acceptablelevel and, in some cases, modify structure (modified fromTerminology C162).3.1.4 ASTM Type I waterpurified water with a maximumtotal matter content including soluble silica of 0.1 g/m3,amaximum electrical conductivity of 0.056 /cm at 25C anda minimum electri
18、cal resistivity of 18 M cm at 25C (seeSpecification D1193 and Terminology D1129).3.1.5 cleaning glassglass or flux used to remove highviscosity glass, melt insolubles, or other contamination fromplatinum-ware.3.1.6 crystallizeto form or grow, or both, crystals from aglass melt during heat-treatment
19、or cooling.3.1.7 crystallizationthe progression in which crystals arefirst nucleated and then grown within a host medium.Generally, the host may be a gas, liquid, or another crystallineform. However, in this context, it is assumed that the mediumis a glass melt.3.1.8 crystallization frontthe boundar
20、y between the crys-talline and crystal-free regions in a test specimen that wassubjected to a temperature gradient heat-treatment.3.1.9 furnace profilingthe process of determining theactual temperature inside of a furnace at a given location; thisinvolves different processes for different types of f
21、urnaces.3.1.10 glassan inorganic product of fusion that has cooledto a rigid condition without crystallizing (see TerminologyC162); a noncrystalline solid or an amorphous solid (2).33.1.11 glass ceramicsolid material, partly crystalline andpartly glassy (see Terminology C162).3.1.12 glass samplethe
22、material to be heat-treated ortested by other means.3.1.13 glass specimenthe material resulting from a spe-cific heat treatment.3.1.14 glass transition temperature (Tg)on heating, thetemperature at which a glass transforms from a solid to a liquidmaterial, characterized by the onset of a rapid chang
23、e in severalproperties, such as thermal expansivity.3.1.15 gradient furnacea furnace in which a known tem-perature gradient is maintained between the two ends.3.1.16 hazardous waste glassa glass composed of glassforming additives and hazardous waste.3.1.17 homogeneous glassa glass that is a single a
24、mor-phous phase; a glass that is not separated into multipleamorphous phases.3.1.18 inhomogeneous glassa glass that is not a singleamorphous phase; a glass that is either phase separated intomultiple amorphous phases or is crystallized.3.1.19 liquidus temperaturethe maximum temperature atwhich equil
25、ibrium exists between the molten glass and itsprimary crystalline phase.3.1.20 melt insolublea crystalline, amorphous, or mixedphase material that is not appreciably soluble in molten glass,for example, noble metals, noble metal oxides.3.1.21 mixed wastewaste containing both radioactive andhazardous
26、 components regulated by the Atomic Energy Act(AEA) (3) and the Resource Conservation and Recovery Act(RCRA) (4), respectively; the term “radioactive component”refers to the actual radionuclides dispersed or suspended in thewaste substance (5).3.1.22 molda pattern, hollow form, or matrix for giving
27、acertain shape or form to something in a plastic or molten state.Websters43.1.23 nuclear waste glassa glass composed of glass-forming additives and radioactive waste.3.1.24 observationthe process of obtaining informationregarding the presence or absence of an attribute of a testspecimen or of making
28、 a reading on a characteristic ordimension of a test specimen (see Terminology E2282).3.1.25 phase separated glassa glass containing more thanone amorphous phase.3.1.26 preferred orientationwhen there is a stronger ten-dency for the crystallites in a powder or a texture to be orientedmore one way, o
29、r one set of ways, than all others. This istypically due to the crystal structure. IUCr53.1.27 primary phasethe crystalline phase at equilibriumwith a glass melt at its liquidus temperature.3.1.28 radioactiveof or exhibiting radioactivity; a mate-rial giving or capable of giving off radiant energy i
30、n the formof particles or rays, for example, , , and , by the disinte-gration of atomic nuclei; said of certain elements, such asradium, thorium, and uranium and their products. AmericanHeritage6Websters73.1.29 Round-Robinan interlaboratory and intralaboratorytesting process to develop the precision
31、 and bias of a proce-dure.3.1.30 sectiona part separated or removed by cutting; aslice, for example, representative thin section of the glassspecimen. Websters43.1.31 set of samplessamples tested simultaneously in thesame oven.3The boldface numbers in parentheses refer to a list of references at the
32、 end ofthis standard.4Websters New Universal Unabridged Dictionary, 1979.5IUCr Online Dictionary of Crystallography, 2011.6American Heritage Dictionary, 1973.7Websters New Twentieth Century Dictionary, 1973.C1720 11123.1.32 simulated nuclear waste glassa glass composed ofglass forming additives with
33、 simulants of, or actual chemicalspecies, or both, in radioactive wastes or in mixed nuclearwastes, or both.3.1.33 standardto have the quality of a model, gage,pattern, or type. Websters73.1.34 standardizeto make, cause, adjust, or adapt to fit astandard (5); to cause to conform to a given standard,
34、 forexample, to make standard or uniform. Websters73.1.35 surface tensiona property, due to molecular forces,by which the surface film of all liquids tends to bring thecontained volume into a form having the least possible area.3.1.36 test determinationthe value of a characteristic ordimension of a
35、single test specimen derived from one or moreobserved values (see Terminology E2282).3.1.37 test methoda definitive procedure that produces atest result (see Terminology E2282).3.1.38 test observationsee observation.3.1.39 test resultthe value of a characteristic obtained bycarrying out a specific t
36、est method (see Terminology E2282).3.1.40 uniform temperature furnacea furnace in which thetemperature is invariant over some defined volume and withinsome defined variance.3.1.41 vitrificationthe process of fusing waste with glassmaking chemicals at elevated temperatures to form a wasteglass (see T
37、erminology C162).3.1.42 volatilitythe act of one or more constituents of asolid or liquid mixture to pass into the vapor state.3.1.43 waste glassa glass developed or used for immobi-lizing radioactive, mixed, or hazardous wastes.3.2 Abbreviations:3.2.1 AEAAtomic Energy Act3.2.2 ANSIAmerican National
38、 Standards Institute3.2.3 ASTMAmerican Society for Testing and Materials3.2.4 CFcrystal fraction extrapolation3.2.5 CFcrystal fraction in a sample or specimen3.2.6 EDSenergy dispersive spectrometry3.2.7 viscosity3.2.8 FWHMfull width of a peak at half maximum3.2.9 GFgradient temperature furnace3.2.10
39、 GTgradient temperature3.2.11 HFhydrofluoric acid3.2.12 HLWhigh-level waste3.2.13 IDidentification3.2.14 NBSNational Bureau of Standards3.2.15 NCSLNational Conference of Standards Laborato-ries3.2.16 NISTNational Institute for Standards and Technol-ogy (formerly NBS)3.2.17 OMoptical microscope or op
40、tical microscopy3.2.18 PDFpowder diffraction file3.2.19 RCRAResource Conservation and Recovery Act3.2.20 RIRrelative intensity ratio3.2.21 RLMreflected light microscopy3.2.22 SEMscanning electron microscope or scanningelectron microscopy3.2.23 SRMStandard Reference Material3.2.24 T1%temperature wher
41、e glass contains 1 volume %of a crystalline phase3.2.25 Taprimary UT measurement above TL3.2.26 Tcprimary UT measurement below TL3.2.27 Tgglass transition temperature3.2.28 TLliquidus temperature3.2.29 TLMtransmitted light microscopy3.2.30 TMmelting temperature for glass preparations3.2.31 UFuniform
42、 temperature furnace3.2.32 UTuniform temperature3.2.33 WCtungsten carbide3.2.34 XRDX-ray diffraction4. Summary of Test Method4.1 This procedure describes methods for determining theTLof waste or simulated waste glasses. Temperature is definedas the maximum temperature at which equilibrium existsbetw
43、een the molten glass and its primary crystalline phase. Inother words, TLis the maximum temperature at which a glassmelt crystallizes. Fig. 1 illustrates an example TLfor a simpletwo-component liquid on a binary phase diagram.4.1.1 (A) Gradient Temperature Furnace Method (GT)This method is similar t
44、o Practice C829, “Standard Practicesfor Measurement of Liquidus Temperature of Glass by theGradient Furnace Method,” though it has been modified tomeet the specific needs of waste and simulated waste glassmeasurements. The most pronounced differences between thismethod and the Practice C829 “boat me
45、thod” are the samplepreparation and examination procedures.4.1.1.1 Samples are loaded into a boat, for example, plati-num alloy (Fig. 2) with a tight-fitting lid, and exposed to alinear temperature gradient in a gradient furnace (Fig. 3) for afixed period of time.The temperature, as a function of di
46、stance,d, along the sample, is determined by its location within theGF, and the TLis then related to the location of the crystalli-zation front in the heat-treated specimen (Fig. 4).4.1.1.2 Following the heat-treatment, the specimen shouldbe annealed at or near the glass transition, Tg, of the glass
47、 (thisshould be previously measured or estimated) to reduce speci-men cracking during cutting and polishing.4.1.1.3 The specimen should then be scored or marked tosignify the locations on the specimen located at different depthsinto the gradient furnace, that is, locations heat-treated atspecific te
48、mperatures.4.1.1.4 If the specimen is optically transparent, it can beobserved with transmitted light (that is, transmitted lightmicroscopy or TLM) or reflected light microscopy (RLM) tolook for bulk or surface crystallization, respectively. If thespecimen is not optically transparent or is barely o
49、pticallyC1720 1113transparent (for example, in high iron glasses with highquantities of FeO), a cut or fractured section of the glass can bepolished very thin (that is, a thin section can be made) to allowfor observation. Another option for surface observations isscanning electron microscopy (SEM). This method provides aquick measurement of TLin the absence of convective flow ofglass in the GF, which distorts the crystallization front (that is,the crystallization front shall not b
