1、Designation: C1662 17C1662 18Standard Practice forMeasurement of the Glass Dissolution Rate Using theSingle-Pass Flow-Through Test Method1This standard is issued under the fixed designation C1662; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 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. Scope1.1 This practice describes a single-pass flow-through (SPFT) test method that can be used to me
3、asure the dissolution rate ofa homogeneous silicate glass, including nuclear waste glasses, in various test solutions at temperatures less than 100C. Tests maybe conducted under conditions in which the effects from dissolved species on the dissolution rate are minimized to measure theforward dissolu
4、tion rate at specific values of temperature and pH, or to measure the dependence of the dissolution rate on theconcentrations of various solute species.1.2 Tests are conducted by pumping solutions in either a continuous or pulsed flow mode through a reaction cell that containsthe test specimen. Test
5、s must be conducted at several solution flow rates to evaluate the effect of the flow rate on the glassdissolution rate.1.3 This practice excludes static test methods in which flow is simulated by manually removing solution from the reaction celland replacing it with fresh solution.1.4 Tests may be
6、conducted with demineralized water, chemical solutions (such as pH buffer solutions, simulated groundwatersolutions, and brines), or actual groundwater.1.5 Tests may be conducted with crushed glass of a known size fraction or monolithic specimens having known geometricsurface area. The reacted solid
7、s may be examined to provide additional information regarding the behavior of the material in thetest and the reaction mechanism.1.6 Tests may be conducted with glasses containing radionuclides. However, this test method does not address safety issues forradioactive samples.1.7 Data from these tests
8、 can be used to determine the values of kinetic model parameters needed to calculate the glass corrosionbehavior in a disposal system over long periods (for example, see Practice C1174).1.8 This practice must be performed in accordance with all quality assurance requirements for acceptance of the da
9、ta.1.9 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.10 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establ
10、ish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use.1.11 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for th
11、e Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C92 Test Methods for Sieve Analysis and Water Content of Refractory MaterialsC162 Terminology of Glass and
12、 Glass ProductsC429 Test Method for Sieve Analysis of Raw Materials for Glass Manufacture1 This practice is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.13 on Spent Fuel and HighLevel Waste.Current edition approved Nov. 15, 2
13、017Sept. 1, 2018. Published December 2017October 2018. Originally approved in 2007. Last previous edition approved in 20102017as C1662 10.C1662 17. DOI: 10.1520/C1662-17.10.1520/C1662-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceas
14、tm.org. For 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. Becau
15、seit may not 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 Ba
16、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1C693 Test Method for Density of Glass by BuoyancyC859 Terminology Relating to Nuclear MaterialsC1109 Practice for Analysis of Aqueous Leachates from Nuclear Waste Materials Using Inductively Coupled Plasma-AtomicEmission S
17、pectroscopyC1174 Practice for Evaluation of the Long-Term Behavior of Materials Used in Engineered Barrier Systems (EBS) forGeological Disposal of High-Level Radioactive WasteC1220 Test Method for Static Leaching of Monolithic Waste Forms for Disposal of Radioactive WasteC1285 Test Methods for Deter
18、mining Chemical Durability of Nuclear, Hazardous, and Mixed Waste Glasses and MultiphaseGlass Ceramics: The Product Consistency Test (PCT)C1463 Practices for Dissolving Glass Containing Radioactive and Mixed Waste for Chemical and Radiochemical AnalysisD1129 Terminology Relating to WaterD1193 Specif
19、ication for Reagent WaterD1293 Test Methods for pH of WaterE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 Please refer to Terminologies C162 and C859 for additional terminology which may not be listed below.3.2 Definitions:3.2.1 eff
20、luent solution, nthe solution exiting the reaction cell.3.2.2 fines, nsmall pieces of glass that adhere to the glass particles prepared for use in the test that are not removed by sieving.3.2.3 high-purity water, nASTM Type I or Type II water with a maximum total matter content including soluble sil
21、ica of 0.1g/m3 and a minimal electrical resistivity of 16.67 Mcm at 25C (see Specification D1193 and Terminology D1129).3.2.4 influent solution, nthe solution entering the reaction cell.3.2.5 leaching, nthe preferential loss of soluble components from a material.3.2.6 mesh size fraction, na designat
22、ion of the size range of crushed glass given by the combination of the smallest mesh sizethat the glass is passed through (prefixed by a negative sign) and the largest mesh size that it does not pass through (prefixed bya positive sign). For example, the 40 +60 mesh size fraction will pass through a
23、 40 mesh sieve but will not pass through a 60mesh sieve.3.2.7 reaction cell, nthe container in which the sample remains during the test.3.2.8 secondary phase, nany phase that is not present in the glass being tested that is formed in solution or on the surface ofthe sample or apparatus by combinatio
24、n of components released from the glass as it dissolved or present in the test solution.3.2.9 steady-state, adjin this standard, the condition in which the concentration of a dissolved glass component remainsconstant due to the opposing effects of solution flow to remove the components from the vici
25、nity of the sample and glassdissolution to add components to solution. In the present context, dissolution of the glass may proceed at a steady-state rate thatis fixed by the solution flow rate, temperature, solution pH, and other rate-affecting processes.3.2.10 test solution, nthe solution entering
26、 the reaction cell.4. Summary of Practice4.1 Crushed or monolithic glass specimens having a known surface area are contacted by a solution that continuously flows ata known flow rate and at a constant temperature through a reaction cell that contains the glass sample. The concentration of asoluble g
27、lass component (i) in the effluent solution exiting the sample cell is used to calculate the amount of glass that hasdissolved. The flow rate is determined by dividing the mass of solution that is collected for analysis by the duration over whichit was collected. The dissolution rate of the glass is
28、 calculated by using Eq 1Eq 1:rate5Cii! 2Ci#SFSDfi (1)where Ci(i) is the steady-state concentration of component i measured in the effluent solution, Ci is the backgroundconcentration of component i in the influent solution measured in a blank test, F is the solution flow rate, S is the initial surf
29、acearea of the glass sample that is exposed to solution, and fi is the mass fraction of component i in the glass. Several samples of theeffluent solution are collected during the test to determine the steady-state concentrations of dissolved glass components at aparticular solution flow rate. Becaus
30、e the glass dissolution rate will likely be affected by the steady-state concentrations ofdissolved silica and other solutes, tests must be conducted at several solution flow rates to provide data that can be extrapolatedto zero concentration to determine the forward glass dissolution rate at infini
31、te dilutions.C1662 1825. Significance and Use5.1 This practice provides a prescriptive description of the design of a SPFT test apparatus and identifies aspects of theperformance of SPFT tests and interpretation of test results that must be addressed by the experimenter to provide confidence inthe m
32、easured dissolution rate.5.2 The SPFT test method described in this practice can be used to characterize various aspects of glass corrosion behavior thatcan be utilized in a mechanistic model for calculating long-term behavior of a nuclear waste glass.5.3 Depending on the values of test parameters t
33、hat are used, the results of SPFT tests can be used to measure the intrinsicdissolution rate of a glass, the temperature and pH dependencies of the rate, and the effects of various dissolved species on thedissolution rate.5.4 The reacted sample recovered from a test may be examined with surface anal
34、ytical techniques, such as scanning electronmicroscopy, to further characterize the corrosion behavior. Such examinations may provide evidence regarding whether the glassis dissolving stoichiometrically, if particular leached layers and secondary phases were formed on the specimen surface, and sofor
35、th. These occurrences may impact the accuracy of the glass dissolution rate that is measured using this method. This practicedoes not address the analysis of solid reaction materials.6. Procedure6.1 Fig. 1a shows a block diagram for a generic SPFT test assembly. The components of the system include
36、a solution reservoir,transport lines, a pump, a reaction cell, and a collection bottle. The test solution is pumped from a reservoir through a reaction cellthat contains the sample by a peristaltic pump or similar device. Depending on the temperature of interest, the reaction cell maybe located in a
37、 constant temperature oven or water bath. The leachant in the reservoir can be heated to the test temperature in thesame oven. As influent solution is pumped into the reaction cell, an equal volume of effluent solution will be displaced from thereaction cell. The effluent solution is sampled several
38、 times during the test for analysis. The mass of effluent that is collected foranalysis and the collection time are used to calculate the solution flow rate for that aliquot. Chemical analysis of the effluentsolution is performed to measure the concentration of the components used to calculate the d
39、issolution rate. The concentrationsof several glass components can be tracked to determine whether the glass is dissolving stoichiometrically. Separate tests areconducted at several flow rates and with several sample surface areas to measure the effect of the solution composition on themeasured glas
40、s dissolution rate.6.2 Either column-type or bottle-type reaction cells can be used; these are shown schematically in Fig. 1. In the column celldesign, the influent solution is pumped (usually upwards) through the crushed glass (or around a monolithic sample). In the bottledesign, the influent solut
41、ion is pumped into a cell filled with solution and displaces an equal volume of effluent solution.Polyethylene wool or an equivalent material can be used to prevent crushed glass particles from being flushed from the reactioncell during the test, or the effluent solution can be filtered after it is
42、collected.6.3 Crushed glass can be used to provide high surface area samples. Crushed glass is to be prepared following the procedurefor crushed sample preparation in Test Method C1285 (see Section 19 in C1285; see also Test Methods C92 and C429 for sievingmethods). The surface area of crushed and s
43、ieved glass is estimated based on the size fraction that is used in the test. The particlesize of crushed samples must be large enough that the decrease in surface area during the test is less than 30 percent. The initialsurface area can be calculated from the specific surface area and using the ari
44、thmetic average of the sizes of the sieve mesh andthe density of the glass (see Appendix X1 in C1285). The final surface area can be calculated based on the amount of glass thatdissolved during the test, if the particles can be modeled to have geometric shapes. The crushed glass used in a series of
45、SPFTtests must be from the same source to represent the homogeneity of the glass on the scale of the test sample size. (Aseries of SPFTtests refers to tests conducted with the same glass and test solution but with different masses of glass or at different flow rates.)It is recommended that a small a
46、mount of the crushed glass be examined with a scanning electron microscope prior to testing todocument the size of the particles and the absence of fines.6.4 Monolithic samples can be used to provide samples with low surface areas. Samples can be prepared with any shape forwhich the geometric surfac
47、e area can be measured directly. Monolithic samples are to be prepared following the sample preparationprocedure in Test Method C1220 (see Section 8 in C1220). Enough monolithic glass samples shall be prepared for use in a seriesof SPFT tests. The surface finishes of the monoliths to be used in the
48、series of tests shall be consistent and shall be reported withthe test results. For example, if the faces of the samples are polished with silica carbide paper, the grit and lubricating fluid shallbe reported.6.5 The mass fractions of elemental silicon in the glass must be known to determine the gla
49、ss dissolution rate (see also 9.4.5).This may be determined by direct analysis of the glass (see Test Method C1463) or based on the as-batched composition of theglass.6.6 The flow rate of the solution through the reaction cell is calculated by dividing the mass of test solution collected by theduration over which it was collected. Although the flow rate is set before the sample is placed in the reaction cell, the flow ratemeasured with the sample in place is used for the calculations. The flow rate is likely to vary slightly with each aliquot that is taken
