1、Designation: C560 88 (Reapproved 2010)1An American National StandardStandard Test Methods forChemical Analysis of Graphite1This standard is issued under the fixed designation C560; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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.1NOTEUpdated 57.1 editorially in May 2010.1. Scope1.1 These test methods cover the chemical analysis ofgraphite.1.2 The
3、analytical procedures appear in the following order:SectionsSilicon by the Molybdenum Blue (Colorimetric) Test Method 8 to 14Ironbytheo-Phenanthroline (Colorimetric) Test Method 15 to 21Calcium by the Permanganate (Colorimetric) Test Method 22 to 28Aluminum by the 2-Quinizarin Sulfonic Acid Test Met
4、hod 29 to 35Titanium by the Peroxide (Colorimetric) Test Method 36 to 43Vanadium by the 3,38-Dimethylnaphthidine (Colorimetric) TestMethod 44 to 51Boron by the Curcumin-Oxalic Acid (Colorimetric) Test Method 52 to 591.3 The preferred concentration of sought element in thefinal solution, the limits o
5、f sensitivity, and the precision of theresults are given in Table 1.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It
6、 is 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. See 56.1 forspecific caution statement.2. Referenced Documents2.1 ASTM Standards:2C561 Test Method for Ash in a Graphite S
7、ampleD1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications3. Significance and Use3.1 These test methods provide a practical way to measurethe concentration of certain trace elements in graphite. Manyend uses of graphit
8、e require that it be free of elements whichmay be incompatible with certain nuclear applications. Otherelemental contamination can affect the rate of oxidative deg-radation.3.2 These test methods allow measurement of trace amountsof contaminants with a minimal amount of costly equipment.The colorime
9、tric procedures used are accessible to mostlaboratories.4. Reagents4.1 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 Chemica
10、l Society,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.1These test methods are under the jurisdiction of ASTM Committee D02 onPetr
11、oleum Products and Lubricants and are the direct responsibility of Subcommit-tee D02.F0 on Petroleum Products and LubricantsCurrent edition approved May 1, 2010. Published May 2010. Originallyapproved in 1965. Last previous edition approved in 2005 as C560 88 (2005)e1.DOI: 10.1520/C0560-88R10E01.2Fo
12、r referenced ASTM standards, visit the ASTM website, 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.3Reagent Chemicals, American Chemical Society Specifications, Am
13、ericanChemical 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. Pharmaceutical Convention, Inc. (
14、USPC), Rockville,MD.TABLE 1 Concentration of Elements, Limits of Sensitivity, andReproducibilityElementConcentrationRange, g/mLSolutionSensitivity Limit,g/mL SolutionReproducibility,Relative, %(s/x 3 100)Silicon 10 to 100 g/100 mL 1 g/100 mL 64Iron 100 to 600 g/100 mL 40 g/100 mL 65Calcium 600 to 30
15、00 g/100 mL 50 g/100 mL 65Aluminum 10 to 100 g/100 mL 2 g/100 mL 60.1Titanium 600 to 3000 g/100 mL 200 g/100 mL 62Vanadium 10 to 130 g/50 mL 5 g/50 mL 65Boron 0.5 to 1.4 g/50 mL 0.1 g/50 mL 6201Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United
16、 States.4.2 When available, National Institute of Standards andTechnology (NIST) certified reagents should be used as stan-dards in preparing calibration curves.4.3 Unless otherwise indicated, references to water shall beunderstood to mean reagent water conforming to SpecificationD1193.4.4 National
17、Institute of Standards and Technology certifiedreagents specified in certain steps of this procedure may nolonger be available. If NIST reagents are not available, then thehighest purity reagent grade shall be substituted.5. Sampling5.1 The entire sample of graphite should be crushed andground to pa
18、ss a No. 60 (250-m) sieve in a roll crusher. Thesample may have been reduced in size initially by drilling thetest bar with silicon carbide-tipped drills.6. Rounding Calculated Values6.1 Calculated values shall be rounded to the desired num-ber of places in accordance with Practice E29.7. Precision
19、and Bias7.1 No statement is being made about either the precision orbias of these test methods. At this time Committee C05 isinvestigating new standard methods of chemical analysis ofgraphite that will eventually replace these test methods. Forthis reason, no statistical study of these test methods
20、has beenplanned.7.2 The relative reproducibility data in Table 1 has nosupportive research report on file and does not conform toASTM precision and bias standards.SILICON BY THE MOLYBDENUM BLUE TESTMETHOD8. Summary of Test Method8.1 Silicomolybdic acid is formed by adding ammoniummolybdate to solubl
21、e silicates in acid solution. The heteropolyacid is reduced with stannous chloride to form a deep bluecolloidal solution. Photometric measurement is made at 765nm. Regular classical gravimetric methods for silica usingsodium carbonate fusion followed by hydrofluoric acid vola-tilization may be suita
22、ble for use.9. Stability of Color9.1 The blue colored solution should be disposed of and thedetermination repeated if a period of 12 h has elapsed betweencolor development and measurements.10. Interferences10.1 There is no interference from the ions usually presentin graphite.11. Reagents11.1 Ammoni
23、um Molybdate (50 g/L)Dissolve 50 g ofammonium molybdate (NH4)6-Mo7O244H2O) in water anddilute to 1 L.11.2 Hydrochloric Acid (HCl) (1+1)Mix equal volumesof concentrated HCl, sp gr 1.19 and water.11.3 Silicon, Standard Solution (1 mL = 1 mg Si)Dissolve10.1 g of sodium silicate (Na2SiO39H2O) in water a
24、nd diluteto 1 L in a volumetric flask. Store in a polyethylene bottle.Determine exact concentration by the standard gravimetricprocedure.11.4 Silicon, Working Solution (1 mL = 0.01 mg Si)Dilute10 mL of standard silicon solution (1 mL = mg Si) to 1 L in avolumetric flask. Transfer to a polyethylene b
25、ottle.11.5 Sodium Carbonate Solution (100 g/L)Dissolve 100 gof sodium carbonate (Na2CO3) in water and dilute to 1 L. Storein a polyethylene bottle.11.6 Stannous Chloride SolutionDissolve 2.5 g of stan-nous chloride (SnCl22H2O) in 5 mL of hot concentrated HCl(sp gr 1.19) and dilute to 250 mL with wat
26、er. Prepare a freshsolution every 2 weeks.11.7 Sulfuric Acid (H2SO4) (1+3)Carefully mix 1 volumeof concentrated H2SO4, sp gr 1.84 with 3 volumes of water.12. Preparation of Calibration Curve12.1 Calibration SolutionsTransfer 0, 1.0, 3.0, 5.0, 7.0,and 10 mL of silicon working solution (1 mL = 0.01 mg
27、 Si) to100-mL volumetric flasks. Add 5 drops of H2SO4(1+3) anddilute to approximately 10 mL.12.2 Color DevelopmentAdd 2.5 mL of (NH4)6Mo7O24solution to each flask and let stand 5 min. Then add 5.0 mL ofH2SO4(1+3), mix well, and add 5 drops of SnCl2solution.Dilute to volume and let stand 5 min.12.3 P
28、hotometryTransfer a suitable portion of the reagentblank solution to a 1-cm absorption cell and adjust thephotometer to the initial setting, using a wavelength of 765 nm.While maintaining this photometer adjustment, take the pho-tometric readings of the calibration solutions.12.4 Calibration CurvePl
29、ot the photometric readings (ab-sorbance) of the calibration solution against micrograms ofsilicon per 100 mL of solution.13. Procedure for Carbonate Fusion13.1 Sample SolutionRinse the ash (from a 50 to 75-g ashsample) from the platinum dish into a mullite mortar with three0.5-g portions of Na2CO3p
30、assing a No. 100 (150-m) sieve(see Test Method C561). Grind the resulting mixture to pass aNo. 200 (75-m) sieve to ensure intimate contact of the ashwith the flux. Then transfer the mixture to a platinum crucible(containing 0.5 g of Na2CO3) with three 0.5-g rinses ofNa2CO3. Add sufficient Na2CO3to b
31、ring the total Na2CO3content to 6 g. Cover the crucible, and fuse gently over abunsen burner.13.1.1 When fusion is complete (usually 30 min to 1 h),remove the crucible from the burner, swirl to distribute the melton the sides of the crucible, and allow to cool. Then place thecrucible and contents in
32、 a 200-mL high-form beaker and add25 mL of water. Cover the beaker with a watch glass, andcautiously add HCl (1+1) to decompose the melt. Whensolution of the melt is complete, boil for several minutes on ahot plate and cool.13.1.2 Transfer to a 100-mL volumetric flask, dilute tovolume, and mix. Tran
33、sfer a suitable aliquot of this solution toa 100-mL volumetric flask.C560 88 (2010)1213.2 Color DevelopmentAdjust the pH of the aliquot to 6to 8 with Na2CO3solution, then proceed in accordance with13.2.13.3 PhotometryProceed in accordance with 12.3.13.4 CalibrationConvert the photometric reading of
34、thesample solution to micrograms of silicon by means of thecalibration curve.14. Calculation14.1 Calculate the parts per million (ppm) of silicon in theoriginal sample as follows:Silicon, ppm A 3 B!/Wwhere:A = silicon per 100 mL of solution found in the aliquotused, g,B = aliquot factor = original v
35、olume divided by aliquottaken for analysis, andW = original sample weight, g.IRON BY THE ORTHO-PHENANTHROLINE(PHOTOMETRIC) TEST METHOD15. Summary of Test Method15.1 After suitable dilution of an aliquot from the carbonatefusion is adjusted to a pH of 3.0, the iron is reduced withhydroxylamine hydroc
36、hloride. The ferrous ortho-phenanthroline complex is formed, and its absorption is mea-sured at a wavelength of 490 nm.16. Stability of Color16.1 The color becomes stable within 15 min and does notchange for at least 48 h.17. Interferences17.1 No interfering elements are normally present in graph-it
37、e.18. Reagents18.1 Ammonium Hydroxide (NH4OH) (1+1)Mix equalvolumes of concentrated NH4OH, sp gr 0.90 and water.18.2 Bromine WaterAdd 10 mL of bromine to 1 L ofwater. Allow to stand for 24 h.18.3 Hydrochloric Acid (HCl) (1+1)Mix equal volumesof concentrated HCl, sp gr 1.19 and water.18.4 Hydroxylami
38、ne Hydrochloride SolutionDissolve 10g of hydroxylamine hydrochloride (NH2OHHCl) in water anddilute to 100 mL. Discard the solution if color develops onstanding for long periods of time.18.5 Iron, Standard Solution (1 mL = 0.1 mg Fe)Into a100-mL beaker, weigh 0.1000 g of iron wire. Dissolve the wirei
39、n 50 mL of HCl (1+1). Add 1 mL of bromine water to oxidizethe iron to the ferric state. Boil the solution to expel the excessbromine and dilute to 1 L in a volumetric flask.18.6 Iron Wire, primary standard, over 99.9 % pure.18.7 o-PhenanthrolineDissolve2gof1,10-phenanthroline in ethyl alcohol and di
40、lute to 250 mL with ethylalcohol in a volumetric flask. Discard this solution if colordevelops upon long standing.19. Preparation of Calibration Curve19.1 Calibration SolutionsTransfer 0.0, 1.0, 2.0, 3.0, 4.0,5.0, and 6.0 mL of iron solution (1 mL = 0.1 mg Fe) to 100-mLvolumetric flasks. Add NH4OH (
41、1+1) until the brown hydrousprecipitate of ferric hydroxide (Fe(OH)3) is just visible. Thenadd HCl (1+1) drop-wise, while stirring, until the precipitatejust dissolves. Bring the pH of the solution to 3.0 by adding 2additional drops of HCl (1+1). Then add 2 mL of NH2OHHClsolution.19.2 Color Developm
42、entHeat the solutions in the flasksalmost to boiling. Add 1 mL of o-phenanthroline solution andallow the solutions to cool. Then dilute to the mark with water.19.3 PhotometryTransfer a suitable portion of the reagentblank solution to a 1-cm absorption cell, and adjust thespectrophotometer to the ini
43、tial setting using a wavelength of490 nm. While maintaining this photometer adjustment, takethe photometric readings of the calibration solutions.19.4 Calibration CurvePlot the absorbance of the calibra-tion solution against micrograms of iron per 100 mL ofsolution.20. Procedure20.1 Sample SolutionP
44、roceed in accordance with 13.1.20.2 Color DevelopmentProceed in accordance with 19.2.20.3 PhotometryProceed in accordance with 19.2.20.4 CalibrationConvert the photometric reading of thesample solution to micrograms of iron by means of thecalibration curve.21. Calculation21.1 Calculate the ppm of ir
45、on in the original sample asfollows:Fe, ppm A 3 B!/Wwhere:A = iron per 100 mL of solution in the aliquot used, g,B = aliquot factor = original volume divided by aliquottaken for analysis, andW = original sample weight, g.CALCIUM BY THE PERMANGANATE(COLORIMETRIC) TEST METHOD22. Summary of Test Method
46、22.1 Calcium is precipitated as the oxalate, filtered off, anddissolved in sulfuric acid. The acid solution is added to a dilutepotassium permanganate solution, and the decrease in absorp-tion is measured at a wavelength of 528 nm.23. Stability of Color23.1 Potassium permanganate solution is decompo
47、sed rap-idly by exposure to air or light. Photometric readings should bemade at once.24. Interferences24.1 Ashed graphite samples are normally free of significantconcentrations of possible interfering ions.C560 88 (2010)1325. Reagents25.1 Ammonium Hydroxide (NH4OH2) (1+6)Mix 1 vol-ume of concentrate
48、d NH4OH2, sp gr 0.90 with 6 volumes ofwater.25.2 Ammonium Oxalate SolutionPrepare a saturated so-lution of ammonium oxalate (NH4)2C2O42H2O).25.3 Bromocresol Green Indicator SolutionUse the watersoluble sodium salt. Dissolve 0.040 g in water and dilute to 100mL. Store in a glass-stoppered brown bottl
49、e.25.4 Formate Buffer Solution (pH 3.7)Dissolve 31.5 g ofammonium formate in about 200 mL of water and transfer to a1-L volumetric flask. Add 20.8 mL of formic acid, dilute tovolume, and mix well.25.5 Hydrochloric Acid (HCl) (1+1)Mix equal volumesof concentrated HCl, sp gr 1.19 and water.25.6 Oxalate, Standard Solution (1 mL = 0.125 mg Ca)Dry approximately2gofsodium oxalate (Na2C2O4) at 105Cfor 1 h, and cool in a desiccator. Weigh accurately 0.2090 g intoa 250-mL beaker, dissolve in boiled water, and dilute t
