ASTM C1022-2005(2010) Standard Test Methods for Chemical and Atomic Absorption Analysis of Uranium-Ore Concentrate.pdf

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1、Designation: C1022 05 (Reapproved 2010)Standard 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 revi

2、sion, 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 These test methods cover procedures for the chemicaland atomic absorption analysis of uranium-ore co

3、ncentrates todetermine 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 26D

4、etermination of Arsenic 27Carbonate by CO2Gravimetry 28 to 34Fluoride by Ion-Selective Electrode 35 to 42Halides by Volhard Titration 43 to 50Moisture by Loss of Weight at 110C 51 to 57Phosphorus by Spectrophotometry 58 to 66Determination of Silicon 67Determination of Thorium 68Calcium, Iron, Magnes

5、ium, Molybdenum, Titanium, and Vana-dium by Atomic Absorption Spectrophotometry 69 to 78Potassium and Sodium by Atomic AbsorptionSpectrophotometry 79 to 88Boron by Spectrophotometry 89 to 981.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It i

6、s theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. A specific precau-tionary statement is given in Section 7.2. Referenced Documents2.1 ASTM Standards:2C761 Test Methods for C

7、hemical, Mass Spectrometric,Spectrochemical, Nuclear, and Radiochemical Analysis ofUranium HexafluorideC859 Terminology Relating to Nuclear MaterialsC967 Specification for Uranium Ore ConcentrateC1110 Practice for Sample Preparation for X-Ray EmissionSpectrometric Analysis of Uranium in Ores Using t

8、heGlass Fusion or Pressed Powder MethodC1219 Test Methods for Arsenic in Uranium HexafluorideC1254 Test Method for Determination of Uranium in Min-eral Acids by X-Ray FluorescenceC1267 Test Method for Uranium by Iron (II) Reduction inPhosphoric Acid Followed by Chromium (VI) Titration inthe Presence

9、 of VanadiumC1287 Test Method for Determination of Impurities inNuclear Grade Uranium Compounds by InductivelyCoupled Plasma Mass SpectrometryC1347 Practice for Preparation and Dissolution of UraniumMaterials for AnalysisD1193 Specification for Reagent WaterE60 Practice for Analysis of Metals, Ores,

10、 and RelatedMaterials by Molecular Absorption Spectrometry3. Terminology3.1 DefinitionsFor definitions of terms used in these testmethods, 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 pres

11、cribed inSpecification C967.4.2 Because of the variability of matrices of uranium-oreconcentrate and the lack of suitable reference or calibrationmaterials, the precision and bias of these test methods shouldbe established by each individual laboratory that will use them.The precision and bias state

12、ments given for each test methodare those reported by various laboratories and can be used as aguideline.1These test methods are under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and are the direct responsibility of Subcommittee C26.05 onMethods of Test.Current edition approved June

13、1, 2010. Published June 2010. Originallyapproved in 1984. Last previous edition approved in 2005 as C1022 05. DOI:10.1520/C1022-05R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume info

14、rmation, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3 Instrumental test methods such as X-ray fluorescenceand emission spectroscopy can be used for the determinat

15、ion ofsome 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 o

16、f each procedure 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,

17、where such specifications are available.3Other 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

18、 to mean reagent water conformingto Specification D1193.7. Precautions7.1 Proper precautions should be taken to prevent inhalationor ingestion of uranium during sample preparation and anysubsequent sample analysis.8. Sampling8.1 Collect samples in accordance with Specification C967.8.2 Special requi

19、rements for subsampling are given in theindividual test methods.URANIUM BY FERROUS SULFATEREDUCTIONPOTASSIUM DICHROMATETITRIMETRY9. Scope9.1 This test method covers the determination of uranium inuranium-ore concentrates. This test method was discontinuedin January 2002 and replaced with Test Method

20、 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.NOTE 1Dissolution of UOC samples may be achieved using thetechniques or combination of techniques described in C1347 The labora-tory must v

21、alidate the performance of C1347 using characterized UOCsamples. If C1347 methods are not suitable for UOC sample dissolution,the user may establish and document applicable dissolution methods.NITRIC ACID-INSOLUBLE URANIUM10. Scope10.1 This test method covers the determination of thatquantity of ura

22、nium in uranium-ore concentrate that is notsoluble in nitric acid.11. Summary of Test Method11.1 A sample of ore concentrate is digested in 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. Th

23、e washed residue is then dried and ignitedat 1000 6 25C for 1 h. The uranium content is determined onthe ignited residue by spectrophotometry.12. Interference12.1 At the specification limit for nitric acid insolubleuranium usually established for uranium-ore concentrates,interference effects are ins

24、ignificant.13. Apparatus13.1 Digestion Flask, 500-mL, with side entry tube andattached reservoir.13.2 Stirring Apparatus, with sleeve-type 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 Pape

25、r,4of medium porosity.13.8 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 gr1.42) to 1 L with distilled water.14.3 Sodium

26、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 constant stirring. Cool and diluteto 1 L with wat

27、er.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 but just clear thebottom of the flask.15.3 Trans

28、fer 95 mL of 10 M nitric acid to a 250-mL beakerand heat between 95 to 100C.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for Laborato

29、ryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.4Whatman brand No. 40 or its equivalent has been found suitable.C1022 05 (2010)215.4 Slowly transfer the heated nitric acid solution to thed

30、igestion flask through the entry side tube with the stirrerturning.NOTE 2The stirrer is started before the acid is added to preventmaterial from sticking to the flask.15.5 Align a thermometer in such a manner that the mercurychamber of the thermometer is immersed in the stirring slurry,but adequatel

31、y clears the turning stirrer blades.15.6 Quickly bring the sample to 97C and digest between95 to 100C for 1 h while stirring. (Measure the 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 Remo

32、ve the thermometer and carefully rinse withwater all slurry that adheres to it.15.9 Wipe the immersed portion of the thermometer withone 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 con

33、tinuestirring for about 5 min.15.11 Turn off the stirrer, then lower the flask and mantle.15.12 Carefully wash the slurry that adheres to 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

34、the Bchnerfunnel.15.14 Filter the slurry through the Bchner funnel and washcontents of the flask into the funnel.15.15 Wash the residue 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 %) h

35、ave been added as a color developer.15.16 Wash the residue several times with water after anegative test is obtained.15.17 Draw air through 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 sl

36、owlychar off the organic material.15.19 Ignite the residue for1hat1000C in a mufflefurnace.15.20 Cool the crucible in a desiccator and weigh.15.21 Calculate the percentage of solids in accordance with17.1.NOTE 3If the percentage of solids (insoluble residue) is greater than0.1 %, grind and mix the r

37、esidue and determine the total milligrams ofuranium in the residue by the photometric procedure in 16.1-16.10.16. Photometric Procedure for Uranium16.1 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.1

38、6.3 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 %), thenheat 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 watchgla

39、ss and digest for approximately10 min near the boiling point.16.7 Quantitatively transfer the solution to a 250-mL volu-metric flask. Add 25 mL of NaOH solution and a few drops ofH2O2. Make up to mark with water and mix.NOTE 4The solution must be basic for yellow sodium peruranatecolor to develop.16

40、.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 diluting 25 mL of NaOH, plus a fewdrops of H2O2, to 250 mL with water.16.9 Prepare a calibration curve covering the range from 0to 50 mg of uranium from aliq

41、uots of a standard uraniumsolution. Proceed as in 16.5-16.8. Plot the milligrams ofuranium against absorbance readings.16.10 Determine the total milligrams of uranium in thesample solution from the calibration curve.NOTE 5If the sample solution falls outside the calibration range,dilute a portion wi

42、th the reference-blank solution and read again.17. Calculation17.1 Calculate the percentage of insoluble residue, R,present as follows:R 5Rw3 100Sw(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

43、 acid-insoluble uranium, UN, and present asfollows:UN5USw3 10(2)where:U = uranium content calculated in 16.10, mg, andSw= weight of sample, g.17.3 Calculate the percentage of nitric acid-insoluble ura-nium, Uu, on a uranium basis as follows:Uu5UN3 100Us(3)where:UN= nitric acid-insoluble residue pres

44、ent (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.C1022 05 (2010)3EXTRACTABLE

45、ORGANIC MATERIAL19. Scope19.1 This test method is used to determine the extractableorganic material in uranium-ore concentrates. It is recognizedthat certain water-soluble organic materials, such as flocculat-ing agents, are not measured by this test method.20. Summary of Test Method20.1 This test m

46、ethod consists of a dual extraction usingn-hexane on the solid uranium-ore concentrate sample andchloroform on a subsequent nitric acid solution of the sample.Each of the extractants is evaporated to measure the amount oforganic material extracted.21. Interferences21.1 At the specification limit for

47、 extractable organic mate-rial established for uranium-ore concentrations, and within thescope of this test method, interferences are insignificant.22. Apparatus22.1 Soxhlet Extraction ApparatusThe n-hexane extrac-tion is done in a Soxhlet extraction apparatus. Construct asfollows (see Fig. 1):22.1.

48、1 Modify a medium Soxhlet extraction tube so that thesidearm siphon is about 2 cm high, therefore, reducing thevolume of solvent needed. Inserta3to4-cm long, 25-mmoutside diameter glass tube upright into the extraction tube insuch a manner that an extraction thimble may be placed on it.22.1.2 Connec

49、t a 250-mL Florence flask, that has a 24/40ground-glass joint on the lower end to the top of the extractiontube. A250-mL heating mantle connected to a 7.5-A variabletransformer shall be used to heat this.22.1.3 Connect a Friedrichs condenser, that has a 45/50ground-glass joint on the lower end, to the top of the extractiontube. Turn this side of the condenser upward, and fuse the outermember of a 24/40 ground-glass joint to it.22.1.4 Connect a Graham condenser, that has a 24/40ground-glass joint on the lower end, to the modified sidearm ofthe Friedri