1、Designation: C1720 111C1720 17Standard 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
2、 case of 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.1 NOTEUnits statement was editorially corrected in April 2015.1. Scope1.1 These practices cover pro
3、cedures for determining the liquidus temperature (TL) of nuclear waste, mixed nuclear waste,simulated nuclear waste, or hazardous waste glass in the temperature range from 600C to 1600C. This method differs fromPractice C829 in that it employs additional methods to determine TL. TL is useful in wast
4、e glass plant operation, glass formulation,and melter design to determine the minimum temperature that must be maintained in a waste glass melt to make sure thatcrystallization does not occur or is below a particular constraint, for example, 1 volume % crystallinity or T1%. As of now, manyinstitutio
5、ns studying waste and simulated waste vitrification are not in agreement regarding this constraint (1).1.2 Three methods are included, differing in (1) the type of equipment available to the analyst (that is, type of furnace andcharacterization equipment), (2) the quantity of glass available to the
6、analyst, (3) the precision and accuracy desired for themeasurement, and (4) candidate glass properties. The glass properties, for example, glass volatility and estimated TL, will dictatethe required method for making the most precise measurement. The three different approaches to measuring TL descri
7、bed hereinclude the following: (A) Gradient Temperature Furnace Method (GT), (B) Uniform Temperature Furnace Method (UT), and (C)Crystal Fraction Extrapolation Method (CF). This procedure is intended to provide specific work processes, but may besupplemented by test instructions as deemed appropriat
8、e by the project manager or principle investigator.The methods defined hereare not applicable to glasses that form multiple immiscible liquid phases. Immiscibility may be detected in the initial examinationof glass during sample preparation (see 9.3). However, immiscibility may not become apparent u
9、ntil after testing is underway.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user
10、of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principl
11、es for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C162 Terminology of Glass and Glass ProductsC829 Practices for Measurement of Liquidus Temperatur
12、e of Glass by the Gradient Furnace MethodC859 Terminology Relating to Nuclear MaterialsD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study to Determine
13、the Precision of a Test MethodE2282 Guide for Defining the Test Result of a Test Method1 This test method is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.13 on Spent Fuel andHigh Level Waste.Current edition approved Feb. 1, 2
14、011Nov. 1, 2017. Published April 2011December 2017. Originally approved in 2011. Last previous edition approved in 2011 asC1720 111. DOI: 10.1520/C172011E01. 10.1520/C1720-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For
15、Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not
16、 be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Dr
17、ive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 Other Documents:SRM-773 National Institute for Standards and Technology (NIST) Liquidus Temperature StandardSRM-674b NIST X-Ray Powder Diffraction Intensity Set for Quantitative Analysis by X-Ray Diffraction (XRD)SRM-1976a NIST In
18、strument Response Standard for X-Ray Powder DiffractionZ540.3 American National Standards Institute/National Conference of Standards Laboratories (ANSI/NCSL) Requirements forthe Calibration of Measuring and Test Equipment3. Terminology3.1 Definitions: (refer to Terminology C859)3.1.1 air quenchingto
19、 pour or place a molten glass specimen on a surface, for example, a steel plate, and cool it to the solidstate.3.1.2 annealto prevent or remove materials processing stresses in glass by controlled cooling from a suitable temperature, forexample, the glass transition temperature (Tg) (modified from T
20、erminology C162).3.1.3 annealinga controlled cooling process for glass designed to reduce thermal residual stress to an acceptable level and,in some cases, modify structure (modified from Terminology C162).3.1.4 ASTM Type I waterpurified water with a maximum total matter content including soluble si
21、lica of 0.1 g/m3, a maximumelectrical conductivity of 0.056 /cm at 25C and a minimum electrical resistivity of 18 M cm at 25C (see SpecificationD1193 and Terminology D1129).3.1.5 cleaning glassglass or flux used to remove high viscosity glass, melt insolubles, or other contamination fromplatinum-war
22、e.3.1.6 crystallizeto form or grow, or both, and/or grow crystals from a glass melt during heat-treatment or cooling.3.1.7 crystallizationthe progression in which crystals are first nucleated and then grown within a host medium. Generally, thehost may be a gas, liquid, or another crystalline form. H
23、owever, in this context, it is assumed that the medium is a glass melt.3.1.8 crystallization frontthe boundary between the crystalline and crystal-free regions in a test specimen that was subjectedto a temperature gradient heat-treatment.3.1.9 furnace profilingthe process of determining the actual t
24、emperature inside of a furnace at a given location; this involvesdifferent processes for different types of furnaces.3.1.10 glassan inorganic product of fusion that has cooled to a rigid condition without crystallizing (see Terminology C162);a noncrystalline solid or an amorphous solid (2).33.1.11 g
25、lass ceramicsolid material, partly crystalline and partly glassy (see Terminology C162).3.1.11 glass samplethe material to be heat-treated or tested by other means.3.1.12 glass specimenthe material resulting from a specific heat treatment.3.1.13 glass transition temperature (Tg)on heating, the tempe
26、rature at which a glass transforms from a solid to a liquidmaterial, characterized by the onset of a rapid change in several properties, such as thermal expansivity.3.1.14 gradient furnacea furnace in which a known temperature gradient is maintained between the two ends.3.1.16 hazardous waste glassa
27、 glass composed of glass forming additives and hazardous waste.3.1.17 homogeneous glassa glass that is a single amorphous phase; a glass that is not separated into multiple amorphousphases.3.1.15 inhomogeneous glassa glass that is not a single amorphous phase; a glass that is either phase separated
28、into multipleamorphous phases or is crystallized.3.1.16 liquidus temperaturethe maximum temperature at which thermodynamic equilibrium exists between the molten glassand its primary crystalline phase.3.1.17 melt insolublea crystalline, amorphous, or mixed phase material that is not appreciably solub
29、le in molten glass, forexample, noble metals, noble metal oxides.3.1.18 mixed wastewaste containing both radioactive and hazardous components regulated by the Atomic Energy Act (AEA)(3) and the Resource Conservation and Recovery Act (RCRA) (4), respectively; the term “radioactive component” refers t
30、o theactual radionuclides dispersed or suspended in the waste substance (5).3.1.19 molda pattern, hollow form, or matrix for giving a certain shape or form to something in a plastic or molten state.Websters43 The boldface numbers in parentheses refer to a list of references at the end of this standa
31、rd.4 Websters New Universal Unabridged Dictionary, 1979.C1720 1723.1.20 nuclear waste glassa glass composed of glass-forming additives and radioactive waste.3.1.21 observationthe process of obtaining information regarding the presence or absence of an attribute of a test specimenor of making a readi
32、ng on a characteristic or dimension of a test specimen (see Terminology E2282).3.1.25 phase separated glassa glass containing more than one amorphous phase.3.1.22 preferred orientationwhen there is a stronger tendency for the crystallites in a powder or a texture to be oriented moreone way, or one s
33、et of ways, than all others. This is typically due to the crystal structure. IUCr53.1.23 primary phasethe crystalline phase at equilibrium with a glass melt at its liquidus temperature.3.1.24 radioactiveof or exhibiting radioactivity; a material giving or capable of giving off radiant energy in the
34、form ofparticles or rays, for example, , , and , by the disintegration of atomic nuclei; said of certain elements, such as radium, thorium,and uranium and their products. American Heritage6 Websters73.1.25 Round-Robinan interlaboratory and intralaboratory testing process to develop the precision and
35、 bias of a procedure.3.1.26 sectiona part separated or removed by cutting; a slice, for example, representative thin section of the glass specimen.Websters43.1.27 set of samplessamples tested simultaneously in the same oven.3.1.28 simulated nuclear waste glassa glass composed of glass forming additi
36、ves with simulants of, or actual chemicalspecies, or both, in radioactive wastes or in mixed nuclear wastes, or both.3.1.29 standardto have the quality of a model, gage, pattern, or type. Websters73.1.30 standardizeto make, cause, adjust, or adapt to fit a standard (5); to cause to conform to a give
37、n standard, for example,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 the containedvolume into a form having the least possible area.3.1.32 test determinationthe value of a characteristic or di
38、mension of a single test specimen derived from one or moreobserved values (see Terminology E2282).3.1.33 test methoda definitive procedure that produces a test result (see Terminology E2282).3.1.34 test observationsee observation.3.1.39 test resultthe value of a characteristic obtained by carrying o
39、ut a specific test method (see Terminology E2282).3.1.35 uniform temperature furnacea furnace in which the temperature is invariant over some defined volume and withinsome defined variance.3.1.36 vitrificationthe process of fusing waste with glass making chemicals at elevated temperatures to form a
40、waste glass (seeTerminology C162).3.1.37 volatilitythe act of one or more constituents of a solid or liquid mixture to pass into the vapor state.3.1.38 waste glassa glass developed or used for immobilizing radioactive, mixed, or hazardous wastes.3.2 Abbreviations:3.2.1 AEAAtomic Energy Act3.2.2 ANSI
41、American National 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 temperat
42、ure furnace3.2.10 GTgradient temperature3.2.11 HFhydrofluoric acid3.2.12 HLWhigh-level waste3.2.13 IDidentification5 IUCr Online Dictionary of Crystallography, 2011.6 American Heritage Dictionary, 1973.7 Websters New Twentieth Century Dictionary, 1973.C1720 1733.2.14 MSEmean squared error3.2.15 NBSN
43、ational Bureau of Standards3.2.16 NCSLNational Conference of Standards Laboratories3.2.17 NISTNational Institute for Standards and Technology (formerly NBS)3.2.18 OMoptical microscope or optical microscopy3.2.19 PDFpowder diffraction file3.2.20 RCRAResource Conservation and Recovery Act3.2.21 RIRrel
44、ative intensity ratio3.2.22 RLMreflected light microscopy3.2.23 SDstandard deviation3.2.24 SEMscanning electron microscope or scanning electron microscopy3.2.25 SRMStandard Reference Material3.2.26 SSEsum of squared errors3.2.27 T1%temperature where glass contains 1 volume % of a crystalline phase3.
45、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 microscopy3.2.33 TMmelting temperature for glass preparations3.2.34 UFuniform temperature furnace3.2.35 UTuniform temperature3.2
46、.36 WCtungsten carbide3.2.37 XRDX-ray diffraction4. Summary of Test Method4.1 This procedure describes methods for determining the TL of waste or simulated waste glasses. Temperature is defined as themaximum temperature at which equilibrium exists between the molten glass and its primary crystalline
47、 phase. In other words, TLis the maximum temperature at which a glass melt crystallizes. Fig. 1 illustrates an example TL for a simple two-component liquidon a an arbitrary binary phase diagram.4.1.1 (A) Gradient Temperature Furnace Method (GT)This method is similar to Practice C829, “Standard Pract
48、ices forMeasurement of Liquidus Temperature of Glass by the Gradient Furnace Method,” thoughalthough it has been modified to meetthe specific needs of waste and simulated waste glass measurements. The most pronounced differences between this method andthe Practice C829 “boat method” are the sample p
49、reparation and examination procedures.FIG. 1 Binary Phase Diagram of Components A and B with TL of Composition C HighlightedC1720 1744.1.1.1 Samples are loaded into a boat, for example, platinum alloy (Fig. 2) with a tight-fitting lid, and exposed to a lineartemperature gradient in a gradient furnace (Fig. 3) for a fixed period of time. The temperature, as a function of distance, d, alongthe sample, is determined by itsthe location within the GF, and the TL is then related
