1、Designation: C 1022 05Standard Test Methods forChemical and Atomic Absorption Analysis of Uranium-OreConcentrate1This standard is issued under the fixed designation C 1022; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 tode
3、termine compliance with the requirements prescribed inSpecification C 967.1.2 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 o
4、f 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, Magnesium, Molybdenu
5、m, 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 is theresponsib
6、ility 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:2C 761 Test Methods for Chemical, Mass
7、 Spectrometric,Spectrochemical, Nuclear, and Radiochemical Analysis ofUranium HexafluorideC 859 Terminology Relating to Nuclear MaterialsC 967 Specification for Uranium Ore ConcentrateC 1110 Practice for Sample Preparation for X-Ray Emis-sion Spectrometric Analysis of Uranium in Ores Using theGlass
8、Fusion or Pressed Powder MethodC 1219 Test Methods for Arsenic in Uranium HexafluorideC 1254 Test Method for Uranium in Mineral Acids byX-Ray FluoresenceC 1267 Test Method for Uranium by Iron (II) Reduction inPhosphoricAcid Followeed by Chromium (IV) Titration inthe Presence of VanadiumC 1287 Test M
9、ethod for Determination of Impurities inNuclear Grade Uranium Compounds by InductivelyCoupled Plasma Mass SpectrometryC 1347 Practice for Preparation and Dissolution of UranumMaterials for AnalysisD 1193 Specification for Reagent WaterE60 Practice for Photometric and SpectrophotometricMethods for Ch
10、emical Analysis of Metals3. Terminology3.1 DefinitionsFor definitions of terms used in these testmethods, refer to Terminology C 859.4. Significance and Use4.1 The test methods in this standard are designed to showwhether a given material meets the specifications prescribed inSpecification C 967.4.2
11、 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 statements given for each test metho
12、dare those reported by various laboratories and can be used as aguideline.4.3 Instrumental test methods such as X-ray fluorescenceand emission spectroscopy can be used for the determination ofsome impurities where such equipment is available.1These test methods are under the jurisdiction of ASTM Com
13、mittee C26 onNuclear Fuel Cycle and are the direct responsibility of Subcommittee C26.05 onMethods of Test.Current edition approved Jan. 1, 2005. Published February 2005. Originallyapproved in 1984. Last previous edition approved in 2002 as C 1022 02.2For referenced ASTM standards, visit the ASTM we
14、bsite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, 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 St
15、ates.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 procedure forspecific ore concentrates.6. Re
16、agents6.1 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 specifications are available.3Other grad
17、es 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 reagent water conformingto Specification D
18、 1193.7. 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 C 967.8.2 Special requirements for subsampling are given in theindividua
19、l 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 C 1267.9.2 The uranium content of the sample may
20、 also be deter-mined using Test Method C 1254. The users laboratory mustestablish and document method performance.NOTE 1Dissolution of UOC samples may be achieved using thetechniques or combination of techniques described in C 1347 The labo-ratory must validate the performance of C 1347 using charac
21、terized UOCsamples. If C 1347 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 uranium in uranium-ore concentrate that is nots
22、oluble 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. The washed residue is then dried and ignitedat
23、 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 insignificant.13. Apparatus13.1 Digestion Flask
24、, 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 Paper,4of medium porosity.13.8 Spectrophotometer
25、, 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 Hydroxide (100 g/L)Dissolve 10 g of NaOHin 1
26、00 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 water.15. Procedure15.1 Weigh a 50.0 6 0.1-g sa
27、mple 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 Transfer 95 mL of 10 M nitric acid to a 250-mL be
28、akerand 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 added to preventmaterial from sticking to the flask.3Reagent Chemicals, American Chemical Soc
29、iety 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 Formulary, U.S. Pharmaceut
30、ical Convention, Inc. (USPC), Rockville,MD.4Whatman brand No. 40 or its equivalent has been found suitable.C102205215.5 Align a thermometer in such a manner that the mercurychamber of the thermometer is immersed in the stirring slurry,but adequately clears the turning stirrer blades.15.6 Quickly bri
31、ng 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 Remove the thermometer and carfully rinse with waterall
32、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 continuestirring for about 5 min.15.11 Turn off the stir
33、rer, 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 the Bchnerfunnel.15.14 Filter the slurry through the
34、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 %) have been added as a color developer.15.16 Wash the re
35、sidue 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 slowlychar off the organic material.15.19 Ignite the re
36、sidue 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 residue and determine the total milligrams ofuranium i
37、n 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.16.3 Add 5 mL of HNO3(sp gr 1.42) and boil until fumin
38、gof 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 watchglass and digest for approximately10 min near the boilin
39、g 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.16.8 Measure the absorbance of the solution in a spectr
40、o-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 aliquots of a standard uraniumsolution. Proceed as in 16.
41、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 with the reference-blank solution and read again.17. Ca
42、lculation17.1 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 acid-insoluble uranium, UN, and present asfollows:UN
43、5USw3 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 present (see 17.2), %,andUs= uranium in sample, %.18. Pre
44、cision 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 t
45、he extractableorganic material in uranium-ore concentrates. It is recognizedC1022053that 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 method consists of a dual extraction usingn-hexane on the soli
46、d 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 extractable organic mate-rial established for uranium-ore co
47、ncentrations, 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):22.1.1 Modify a medium Soxhlet extraction tube so that thesidearm
48、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 Connect a 250-mL Florence flask, that has a 24/40ground-glass joint
49、 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 Friedrichs condenser. Unless the relative humidity is low,insulate the
