1、Designation: C1720 171Standard Test Method forDetermining Liquidus Temperature of Waste Glasses andSimulated 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 revision, t
2、he 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.1NOTEEditorially corrected Fig. 9 title and 15.1.5 in January 2018.1. Scope1.1 These practices cover procedures for det
3、ermining 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 opera
4、tion, 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 waste and
5、 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 precis
6、ion 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 follo
7、wing: (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 manager or
8、 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 under
9、way.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 establish
10、appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of
11、 International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C162 Terminology of Glass and Glass ProductsC829 Practices for Measurement of Liquidus Temperature ofGlass by the Gradien
12、t Furnace MethodC859 Terminology Relating to Nuclear MaterialsD1129 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 Met
13、hodE2282 Guide for Defining the Test Result of a Test Method2.2 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
14、 Response Standard for X-RayPowder Diffraction1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.13 on Spent Fueland High Level Waste.Current edition approved Nov. 1, 2017. Published December 2017. Originallyappr
15、oved in 2011. Last previous edition approved in 2011 as C1720 111. DOI:10.1520/C1720-17E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Su
16、mmary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principl
17、es for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1Z540.3 American National Standards Institute/NationalConference of Standards Laboratories (ANSI/NCSL) Re-quirements for the Calibration of
18、Measuring and TestEquipment3. Terminology3.1 Definitions: (refer to Terminology C859)3.1.1 air quenchingto pour or place a molten glass speci-men on a surface, for example, a steel plate, and cool it to thesolid state.3.1.2 annealto prevent or remove processing stresses inglass by controlled cooling
19、 from a suitable temperature, forexample, the glass transition temperature (Tg) (modified fromTerminology C162).3.1.3 annealinga controlled cooling process for glassdesigned to reduce thermal residual stress to an acceptablelevel and, in some cases, modify structure (modified fromTerminology C162).3
20、.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 electrical resistivity of 18 M cm at 25C (seeSpecification D1193 and Terminology D1129).3.1.5 cleaning glassglass or flux use
21、d to remove highviscosity glass, melt insolubles, or other contamination fromplatinum-ware.3.1.6 crystallizeto form and/or grow crystals from a glassmelt during heat-treatment or cooling.3.1.7 crystallizationthe progression in which crystals arefirst nucleated and then grown within a host medium.Gen
22、erally, 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 boundary between the crys-talline and crystal-free regions in a test specimen that wassubjected to a temperature gradient heat-trea
23、tment.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 furnaces.3.1.10 glassan inorganic product of fusion that has cooledto a rigid condition without crystallizing (see Terminolog
24、yC162); a noncrystalline solid or an amorphous solid (2).33.1.11 glass samplethe material to be heat-treated ortested by other means.3.1.12 glass specimenthe material resulting from a spe-cific heat treatment.3.1.13 glass transition temperature (Tg)on heating, thetemperature at which a glass transfo
25、rms from a solid to a liquidmaterial, characterized by the onset of a rapid change in severalproperties, such as thermal expansivity.3.1.14 gradient furnacea furnace in which a known tem-perature gradient is maintained between the two ends.3.1.15 inhomogeneous glassa glass that is not a singleamorph
26、ous phase; a glass that is either phase separated intomultiple amorphous phases or is crystallized.3.1.16 liquidus temperaturethe maximum temperature atwhich thermodynamic equilibrium exists between the moltenglass and its primary crystalline phase.3.1.17 melt insolublea crystalline, amorphous, or m
27、ixedphase material that is not appreciably soluble in molten glass,for example, noble metals, noble metal oxides.3.1.18 mixed wastewaste containing both radioactive andhazardous components regulated by the Atomic Energy Act(AEA) (3) and the Resource Conservation and Recovery Act(RCRA) (4), respectiv
28、ely; the term “radioactive component”refers to the actual radionuclides dispersed or suspended in thewaste substance (5).3.1.19 molda pattern, hollow form, or matrix for giving acertain shape or form to something in a plastic or molten state.Websters43.1.20 nuclear waste glassa glass composed of gla
29、ss-forming additives and radioactive waste.3.1.21 observationthe process of obtaining informationregarding the presence or absence of an attribute of a testspecimen or of making a reading on a characteristic ordimension of a test specimen (see Terminology E2282).3.1.22 preferred orientationwhen ther
30、e is a stronger ten-dency for the crystallites in a powder or a texture to be orientedmore one way, or one set of ways, than all others. This istypically due to the crystal structure. IUCr53.1.23 primary phasethe crystalline phase at equilibriumwith a glass melt at its liquidus temperature.3.1.24 ra
31、dioactiveof or exhibiting radioactivity; a mate-rial giving or capable of giving off radiant energy in 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. AmericanHeritage6Webs
32、ters73.1.25 Round-Robinan interlaboratory and intralaboratorytesting process to develop the precision and bias of a proce-dure.3.1.26 sectiona part separated or removed by cutting; aslice, for example, representative thin section of the glassspecimen. Websters43.1.27 set of samplessamples tested sim
33、ultaneously in thesame oven.3.1.28 simulated nuclear waste glassa glass composed ofglass forming additives with simulants of, or actual chemicalspecies, or both, in radioactive wastes or in mixed nuclearwastes, or both.3.1.29 standardto have the quality of a model, gage,pattern, or type. Websters73T
34、he boldface numbers in parentheses refer to a list of references at the 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 17123.1.30 stand
35、ardizeto make, cause, adjust, or adapt to fit astandard (5); to cause to conform to a given standard, forexample, to make standard or uniform. Websters73.1.31 surface tensiona property, due to molecular forces,by which the surface film of all liquids tends to bring thecontained volume into a form ha
36、ving the least possible area.3.1.32 test determinationthe value of a characteristic ordimension of a single test specimen derived from one or moreobserved values (see Terminology E2282).3.1.33 test methoda definitive procedure that produces atest result (see Terminology E2282).3.1.34 test observatio
37、nsee observation.3.1.35 uniform temperature furnacea furnace in which thetemperature is invariant over some defined volume and withinsome defined variance.3.1.36 vitrificationthe process of fusing waste with glassmaking chemicals at elevated temperatures to form a wasteglass (see Terminology C162).3
38、.1.37 volatilitythe act of one or more constituents of asolid or liquid mixture to pass into the vapor state.3.1.38 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 Standards Institu
39、te3.2.3 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 GTgradient temper
40、ature3.2.11 HFhydrofluoric acid3.2.12 HLWhigh-level waste3.2.13 IDidentification3.2.14 MSEmean squared error3.2.15 NBSNational Bureau of Standards3.2.16 NCSLNational Conference of Standards Laborato-ries3.2.17 NISTNational Institute for Standards and Technol-ogy (formerly NBS)3.2.18 OMoptical micros
41、cope or optical microscopy3.2.19 PDFpowder diffraction file3.2.20 RCRAResource Conservation and Recovery Act3.2.21 RIRrelative intensity ratio3.2.22 RLMreflected light microscopy3.2.23 SDstandard deviation3.2.24 SEMscanning electron microscope or scanningelectron microscopy3.2.25 SRMStandard Referen
42、ce Material3.2.26 SSEsum of squared errors3.2.27 T1%temperature where glass contains 1 volume %of a crystalline phase3.2.28 Taprimary UT measurement above TL3.2.29 Tcprimary UT measurement below TL3.2.30 Tgglass transition temperature3.2.31 TLliquidus temperature3.2.32 TLMtransmitted light microscop
43、y3.2.33 TMmelting temperature for glass preparations3.2.34 UFuniform temperature furnace3.2.35 UTuniform temperature3.2.36 WCtungsten carbide3.2.37 XRDX-ray diffraction4. Summary of Test Method4.1 This procedure describes methods for determining theTLof waste or simulated waste glasses. Temperature
44、is definedas the maximum temperature at which equilibrium existsbetween 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 an arbitrary binary phase dia
45、gram.FIG. 1 Binary Phase Diagram of Components A and B with TLof Composition C HighlightedC1720 17134.1.1 (A) Gradient Temperature Furnace Method (GT)This method is similar to Practice C829, “Standard Practicesfor Measurement of Liquidus Temperature of Glass by theGradient Furnace Method,” although
46、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 method” are the samplepreparation and examination procedures.4.1.1.1 Samples are loaded into a boat, for example, plati-num al
47、loy (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 distance,d, along the sample, is determined by the location within theGF, and the TLis then related to the location of the cry
48、stalli-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 (thisshould be previously measured or estimated) to reduce speci-men cracking during cutting and polishing.4.1.1.3 The sp
49、ecimen 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 temperatures.4.1.1.4 If the specimen is optically transparent, it can beobserved with transmitted light microscopy (TLM) or reflectedlight microscopy (RLM) to look for bulk or surfacecrystallization, respectively. If the specimen is not opticallytransparent or is barely optically transparent (for example, in
