ASTM C1022-17 Standard Test Methods for Chemical and Atomic Absorption Analysis of Uranium-Ore Concentrate.pdf

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1、Designation: C1022 17Standard Test Methods forChemical and Atomic Absorption Analysis of Uranium-OreConcentrate1This standard is issued under the fixed designation C1022; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of

2、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 These test methods cover procedures for the chemicaland atomic absorption analysis of uranium-ore concentrates todeter

3、mine compliance with the requirements prescribed inSpecification C967.1.2 The analytical procedures appear in the following order:SectionsUranium by Ferrous Sulfate ReductionPotassium DichromateTitrimetry 9Nitric Acid-Insoluble Uranium 10 to 18Extractable Organic Material 19 to 26Determination of Ar

4、senic 27Carbonate by CO2Gravimetry 28 to 34Fluoride by Ion-Selective Electrode 35 to 42Halides by Volhard Titration 43 to 50Phosphorus by Spectrophotometry 52 to 60Determination of Silicon 61Determination of Thorium 62Calcium, Iron, Magnesium, Molybdenum, Titanium, and Vana-dium by Atomic Absorption

5、 Spectrophotometry 63 to 72Potassium and Sodium by Atomic AbsorptionSpectrophotometry 73 to 82Boron by Spectrophotometry 83 to 921.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all

6、of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use. Aspecific precautionary statement is given in Se

7、ction 7.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBar

8、riers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C761 Test Methods for Chemical, Mass Spectrometric,Spectrochemical, Nuclear, and Radiochemical Analysis ofUranium HexafluorideC859 Terminology Relating to Nuclear MaterialsC967 Specification for Uranium Ore ConcentrateC1110 Te

9、st Method for Determining Elements in WasteStreams by Inductively Coupled Plasma-Atomic EmissionSpectroscopy (Withdrawn 2014)3C1219 Test Methods for Arsenic in Uranium Hexafluoride(Withdrawn 2015)3C1254 Test Method for Determination of Uranium in Min-eral Acids by X-Ray FluorescenceC1267 Test Method

10、 for Uranium by Iron (II) Reduction inPhosphoric Acid Followed by Chromium (VI) Titration inthe Presence of VanadiumC1287 Test Method for Determination of Impurities inNuclear Grade Uranium Compounds by InductivelyCoupled Plasma Mass SpectrometryC1347 Practice for Preparation and Dissolution of Uran

11、iumMaterials for AnalysisC1843 Test Method for Determining Moisture Content inUranium-Ore ConcentrateD1193 Specification for Reagent WaterE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Spectrophotometry3. Terminology3.1 DefinitionsFor definitions of terms used in these testmethod

12、s, refer to Terminology C859.4. Significance and Use4.1 The test methods in this standard are designed to showwhether a given material meets the specifications prescribed inSpecification C967.1These test methods are under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and are the direct

13、 responsibility of Subcommittee C26.05 onMethods of Test.Current edition approved Nov. 1, 2017. Published November 2017. Originallyapproved in 1984. Last previous edition approved in 2010 as C1022 05 (2010)1.DOI: 10.1520/C1022-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org,

14、orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor D

15、rive, 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 Principles for theDevelopment of International Standards, Guides and Recommendations

16、issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.14.2 Because of the variability of matrices of uranium-oreconcentrate and the limited availability of suitable reference orcalibration materials, the precision and bias of these testmethods should be established by ea

17、ch individual laboratorythat will use them. The precision and bias statements given foreach test method are those reported by various laboratories andcan be used as a guideline.4.3 Instrumental test methods such as X-ray fluorescenceand emission spectroscopy can be used for the determination ofsome

18、impurities where such equipment is available.5. Interferences5.1 Interferences are identified in the individual test meth-ods.5.2 Ore concentrates are of a very variable nature; therefore,all interferences are very difficult to predict. The individualuser should verify the applicability of each proc

19、edure forspecific ore concentrates.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such

20、specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean re

21、agent water conformingto type I water in Specification D1193.7. Precautions7.1 Proper precautions should be taken to prevent inhalationor ingestion of uranium during sample preparation and anysubsequent sample analysis.7.2 Hydrofluoric acid is a highly corrosive acid that canseverely burn skin, eyes

22、, and mucous membranes. Hydroflu-oric acid differs from other acids because the fluoride ionreadily penetrates the skin, causing destruction of deep tissuelayers. Unlike other acids that are rapidly neutralized, hydro-fluoric acid reactions with tissue may continue for days if leftuntreated. Familia

23、rization and compliance with the Safety DataSheet is essential.7.3 Chloroform is a dangerous chemical causing acutetoxicity with repeated inhalation, dermal, or oral exposure.Many health hazards are associated with exposure to chloro-form including its potential to cause cancer. Familiarizationand c

24、ompliance with the Safety Data Sheet is essential.8. Sampling8.1 Collect samples in accordance with Specification C967.8.2 Special requirements for subsampling are given in theindividual test methods.URANIUM BY FERROUS SULFATEREDUCTIONPOTASSIUM DICHROMATETITRIMETRY9. Scope9.1 This test method covers

25、 the determination of uranium inuranium-ore concentrates. This test method was discontinuedin January 2002 and replaced with Test Method C1267.9.2 The uranium content of the sample may also be deter-mined using Test Method C1254. The users laboratory mustestablish and document method performance.NOT

26、E 1Dissolution of UOC samples may be achieved using thetechniques or combination of techniques described in Practice C1347. Thelaboratory must validate the performance of Practice C1347 usingcharacterized UOC samples. If Practice C1347 methods are not suitablefor UOC sample dissolution, the user may

27、 establish and documentapplicable dissolution methods.NITRIC ACID-INSOLUBLE URANIUM10. Scope10.1 This test method covers the determination of thatquantity of uranium in uranium-ore concentrate that is notsoluble in nitric acid.11. Summary of Test Method11.1 A sample of ore concentrate is digested in

28、 10 M nitricacid at 95 to 100C for 1 h. The slurry is filtered and the residuewashed with 1 M nitric acid until the filtrate gives a negativetest for uranium. The washed residue is then dried and ignitedat 1000 6 25C for 1 h. The uranium content is determined onthe ignited residue by spectrophotomet

29、ry.12. Interference12.1 At the specification limit for nitric acid insolubleuranium usually established for uranium-ore concentrates,interference effects are insignificant.13. Apparatus13.1 Digestion Flask, 500-mL, with side entry tube andattached reservoir.13.2 Stirring Apparatus, with sleeve-type

30、stirrer.13.3 Heating Mantle, 250-W, controlled by a variable trans-former.13.4 Bchner Funnel.13.5 Porcelain Crucibles, 40-mL.13.6 Muffle Furnace.13.7 Filter Paper, ashless of medium porosity, and a me-dium flow rate with a particle retention of 8 m has been foundto be suitable.4Reagent Chemicals, Am

31、erican Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formula

32、ry, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.C1022 17213.8 Spectrophotometer, with 1-cm cells that are in accor-dance with Practice E60.14. Reagents14.1 Nitric Acid (10 M)Dilute 62.5 mL of HNO3(sp gr1.42) to 100 mL with distilled water.14.2 Nitric Acid (1 M)Dilute 62.5 mL of HNO3(sp

33、gr1.42) to 1 L with distilled water.14.3 Sodium Hydroxide (100 g/L)Dissolve 10 g of NaOHin 100 mL of water.14.4 Hydrogen Peroxide (H2O2, 30 %).14.5 Hydrochloric Acid (HCl, sp gr 1.19).14.6 Hydrofluoric Acid (HF, 48 %).14.7 Sulfuric Acid (9 M)Add 500 mL H2SO4(sp gr 1.84)to 500 mL of iced water with c

34、onstant stirring. Cool and diluteto 1 L with water.15. Procedure15.1 Weigh a 50.0 6 0.1-g sample directly into the diges-tion flask.15.2 Place the flask in the heating mantle and adjust thesupport ring so that the joints of the flask and sleeve stirrer areengaged, and the stirrer blades turn freely

35、but just clear thebottom of the flask.15.3 Transfer 95 mL of 10 M nitric acid to a 250-mL beakerand heat between 95 to 100C.15.4 Slowly transfer the heated nitric acid solution to thedigestion flask through the entry side tube with the stirrerturning.NOTE 2The stirrer is started before the acid is a

36、dded to preventmaterial from sticking to the flask.15.5 Adjust the thermometer so that the bulb of the ther-mometer is immersed in the stirring slurry, but adequatelyclears the turning stirrer blades.15.6 Quickly bring the sample to 97C and digest between95 to 100C for 1 h while stirring. (Measure t

37、he 1-h digestiontime after the temperature of the slurry has reached 97C.)15.7 Turn off the variable transformer, but allow the stirrerto continue turning.15.8 Remove the thermometer and carefully rinse withwater all slurry that adheres to it.15.9 Wipe the immersed portion of the thermometer withone

38、 fourth of a circle of filter paper and transfer the paper to aprepared Bchner funnel fitted with a filter paper.15.10 Add 10 mL of paper pulp to the slurry and continuestirring for about 5 min.15.11 Turn off the stirrer, then lower the flask and mantle.15.12 Carefully wash the slurry that adheres t

39、o the stirrershaft and blades into the flask with water.15.13 Wipe the shaft and blades with one fourth of a circleof filter paper and transfer the filter paper to the Bchnerfunnel.15.14 Filter the slurry through the Bchner funnel and washcontents of the flask into the funnel.15.15 Wash the residue

40、with 1 M nitric acid until a 10-mLportion of the filtrate shows no detectable yellow color whenmade basic with sodium hydroxide and after a few drops ofH2O2(30 %) have been added as a color developer.15.16 Wash the residue several times with water after anegative test is obtained.15.17 Draw air thro

41、ugh the filter until the residue and filterpad are dry.15.18 Scrape the residue and paper into a preignited(1000C) tared 40-mL crucible, place on a hot plate and slowlychar off the organic material.15.19 Ignite the residue for1hat1000C in a mufflefurnace.15.20 Cool the crucible in a desiccator and w

42、eigh.15.21 Calculate the percentage of solids in accordance with17.1. If the percentage of solids (insoluble residue) is greaterthan 0.1 %, grind and mix the residue and determine the totalmilligrams of uranium in the residue by the photometricprocedure in 16.1 16.10.16. Photometric Procedure for Ur

43、anium16.1 Transfer the ground, blended residue from 15.20 to a100-mL beaker.16.2 Add 10 mL of water and 10 mL of HCl (sp gr 1.19),cover, and boil for 10 min.16.3 Add 5 mL of HNO3(sp gr 1.42) and boil until fumingof NO2ceases. Remove cover glass.16.4 Add 5 mL of 9M H2SO4and 2 mL of HF (48 %), thenhea

44、t to dryness on the hotplate. Bake to fume off remainingH2SO4and cool.16.5 Wash down sides of beaker with water and add 5 mLof HNO3.16.6 Cover with a watchglass and digest for approximately10 min near the boiling point.16.7 Quantitatively transfer the solution to a 250-mL volu-metric flask. Add 25 m

45、L of NaOH solution and a few drops ofH2O2. Make up to mark with water and mix.NOTE 3The solution must be basic for yellow sodium peruranatecolor to develop.16.8 Measure the absorbance of the solution in a spectro-photometer at 425 nm in a 1-cm cell using a blank as reference.The blank is prepared by

46、 diluting 25 mL of a 100 g/L NaOHsolution, plus a few drops of H2O2, to 250 mL with water.16.9 Prepare a calibration curve covering the range from 0to 50 mg of uranium from aliquots of a standard uraniumsolution. Proceed as in 16.5 16.8. Plot the milligrams ofuranium against absorbance readings.16.1

47、0 Determine the total milligrams of uranium in thesample solution from the calibration curve.NOTE 4If the sample solution falls outside the calibration range,C1022 173dilute a portion with the reference-blank solution and read again.17. Calculation17.1 Calculate the percentage of insoluble residue,

48、R, pres-ent as follows:R 5Rw3100Sw(1)where:Rw= weight of residue (see 15.20), g, andSw= weight of samples, g.17.2 If the insoluble residue exceeds 0.1 %, calculate thepercentage of nitric acid-insoluble uranium, UN, and present asfollows:UN5USw310(2)where:U = uranium content calculated in 16.10, mg,

49、 andSw= weight of sample, g.17.3 Calculate the percentage of nitric acid-insolubleuranium, Uu, on a uranium basis as follows:Uu5UN3100Us(3)where:UN= nitric acid-insoluble residue present (see 17.2), %, andUs= uranium in sample, %.18. Precision and Bias18.1 PrecisionA relative standard deviation for this testmethod has been reported as 10 % at the 0.2 % HNO3insolubleuranium level (see 4.2).18.2 BiasFor information on the bias of this test methodsee 4.2.EXTRACTABLE ORGANIC MATERIAL19. Scope19.1 This test method is used to determine th