1、Designation: C1271 99 (Reapproved 2012)Standard Test Method forX-ray Spectrometric Analysis of Lime and Limestone1This standard is issued under the fixed designation C1271; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the X-ray emission spectromet-ric analysis of limestone, quicklime, hydrated lime, and hy-dr
3、aulic lime using wavelength dispersive instruments.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-pri
4、ate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 10.2. Referenced Documents2.1 ASTM Standards:2C25 Test Methods for Chemical Analysis of Limestone,Quicklime, and Hydrated LimeC50 Practice
5、for Sampling, Sample Preparation, Packaging,and Marking of Lime and Limestone ProductsC51 Terminology Relating to Lime and Limestone (as usedby the Industry)E50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE135 Terminology R
6、elating to Analytical Chemistry forMetals, Ores, and Related MaterialsE305 Practice for Establishing and Controlling AtomicEmission Spectrochemical Analytical CurvesE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a
7、 Test MethodE1060 Practice for Interlaboratory Testing of Spectrochemi-cal Methods of Analysis (Withdrawn 1997)3E1361 Guide for Correction of Interelement Effects inX-Ray Spectrometric Analysis2.2 NIST Documents:4ANSI-NIST Handbook 114NIST Standards Catalog3. Terminology3.1 Definitions:3.1.1 emissio
8、n spectroscopyunless otherwise specified,for definitions of terms used in this test method pertaining toemission spectroscopy, refer to Terminology E135.3.1.2 limeunless otherwise specified, for definitions ofterms used in this test method pertaining to lime, refer toTerminology C51.3.1.3 statistica
9、lunless otherwise specified, for definitionsof terms used in this test method pertaining to statistics, referto Terminology E456.4. Summary of Test Method4.1 A briquetted powder specimen or a fused-glass diskspecimen is irradiated by a high-energy X-ray beam. Thesecondary X rays produced are dispers
10、ed by means of crystals,and the intensities are measured by suitable detectors atselected wavelengths. Data are collected based on the timerequired to reach a fixed number of counts, total count for afixed time, or integration of voltage for a fixed time. Concen-trations of the elements are determin
11、ed by relating the mea-sured radiation of unknown specimens to analytical curvesprepared from reference materials of known composition.5. Significance and Use5.1 This procedure is suitable for manufacturing control andverifying that the product meets specifications. It providesrapid, multi-element d
12、eterminations with sufficient accuracy toensure product quality and minimize production delays. Theanalytical performance data included may be used as a bench-mark to determine whether similar X-ray spectrometers pro-vide equivalent precision and accuracy, or whether the perfor-mance of a particular
13、 X-ray spectrometer has changed.1This test method is under the jurisdiction of ASTM Committee C07 on Limeand is the direct responsibility of Subcommittee C07.05 on Chemical Tests.Current edition approved Dec. 1, 2012. Published December 2012. Originallyapproved in 1994. Last previous edition approve
14、d in 2006 as C1271 99 (2006).DOI: 10.1520/C1271-99R12.2For 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.3The la
15、st approved version of this historical standard is referenced onwww.astm.org.4Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
16、ocken, PA 19428-2959. United States16. Interferences6.1 Interelement effects or matrix effects may exist for someof the elements listed. One way to compensate for these effectsis to prepare a series of calibration curves to cover thedesignated concentration ranges. The composition of the speci-men b
17、eing analyzed must match closely the composition of thereference materials used to prepare the calibration curve.Mathematical corrections, derived from empirical relationshipsor fundamental parameter calculations, may be used alterna-tively.Any of these are acceptable, providing that the analyticala
18、ccuracy required by this test method is achieved.6.2 Calcium is the primary component of the matrix ana-lyzed by this test method. The analyst must be aware of allpossible interferences and matrix effects of this element.Orders of all wavelengths may cause interference, for example,the effect of CaK
19、1 (2nd order) on PK1.6.3 Contamination from the grinding apparatus is an ever-present source of interference of which the analyst must alwaysbe cognizant. For example, stainless steel will impart iron,chrome, and nickel to the prepared sample.6.4 Spectral interferences from the X-ray tube may alsooc
20、cur, for example, line overlap from CrK1onMnK1caused by a chrome target tube.7. Apparatus7.1 Specimen Preparation Equipment:7.1.1 Jaw Crusher, for initial crushing of lumps.7.1.2 Plate Grinder or Pulverizer, with one static and onerotating disk for further grinding.7.1.3 Rotary Disk Mill or Shatter
21、Box, with hardenedgrinding containers and timer control for final grinding.7.2 Briquetting Equipment:7.2.1 Briquetting Press, capable of providing pressures upto 550 MPa (80 000 psi). The press shall be equipped with amold assembly that provides a briquet compatible with theX-ray specimen holder.7.3
22、 Fusion Equipment:7.3.1 Furnace or Gas Burners, with a timer, capable ofheating the sample and flux to at least 1000 C and homog-enizing the melt.7.3.2 Fusion Crucibles:7.3.2.1 Vitreous Carbon or Graphite, 20 to 30-mL capacity,with a flat bottom 30 to 35 mm in diameter.7.3.2.2 Platinum/Gold, 95 % pl
23、atinum/5 % gold alloy, 30 to35-mL capacity.7.3.2.3 Platinum/Gold Casting Dish, 95 % platinum/5 %gold alloy, 30 to 35-mL capacity, with a flat bottom 30 to 35mm in diameter.7.3.3 Polishing Wheel, suitable for polishing the fusion diskto obtain a uniform surface for irradiation. The analyst shouldbe a
24、ware at all times of possible contamination from thepolishing media used for surfacing the disk (6.3).7.4 Excitation Source:7.4.1 X-Ray Tube Power Supply, providing constant poten-tial or rectified power of sufficient energy to produce secondaryradiation of the specimen for the elements specified. T
25、hegenerator may be equipped with a line voltage regulator andcurrent stabilizer.7.4.2 X-Ray Tubes, with targets of various high-purityelements, capable of continuous operation at required poten-tials and currents, and that will excite the elements to bedetermined.7.5 Spectrometer, designed for X-ray
26、 emission analysis andequipped with specimen holders and a specimen chamber. Thechamber may contain a specimen spinner, and it must beequipped for vacuum operation.7.5.1 Analyzing CrystalsFlat or curved crystals with op-timized capability for diffraction of the wavelengths of interest.7.5.2 Collimat
27、or, for limiting the characteristic X rays to aparallel bundle when flat crystals are used in the instrument. Acollimator is not necessary for curved crystal optics.7.5.3 Detectors, sealed or gas flow, proportional type, Gei-ger counters, scintillation counters or equivalent.7.5.4 Vacuum System, pro
28、viding for the determination ofelements whose radiation is absorbed by air (atomic numberbelow 20). The system shall consist of at least one vacuumpump, gage, and electrical controls to provide automaticpumpdown of the optical path and maintain a controlledpressure, usually 13 Pa or less.7.6 Measuri
29、ng System, consisting of electronic circuits ca-pable of counting or integrating pulses received from thedetectors. The counts, count rate, or integrated voltages may bedisplayed on meters, recorders, digital counters, or voltmeters.The counts, count rates, or integrated voltages can also bepresente
30、d to a computer or programmable calculator forconversion to percent concentration. Pulse height analyzersmay be required to provide more accurate measurements forsome measurements.8. Reagents and Materials8.1 Purity and Concentration of ReagentsThe purity andconcentration of chemical reagents shall
31、conform to the re-quirements prescribed in Practices E50.8.2 BindersVarious binders have been used successfullyto prepare briquettes suitable for presentation to the instrument.As a general rule, the binder should not contain an element thatwill be determined. In addition, the sample to binder ratio
32、 mustbe present in the analytical sample as in the reference materialsthat were used to establish the calibration.8.3 FluxesVarious fluxes have been used successfully toprepare fusion disks. The flux must be capable of dissolving ordispersing the analyzed elements in an homogeneous andreproducible f
33、ashion in the melt. The prepared disks must thenbe suitable for presentation to the instrument.8.4 Detector Gas (P-10), consisting of a mixture of 90 %argon and 10 % methane for use with gas flow proportionalcounters only.9. Reference Materials9.1 Certified reference materials are available from the
34、National Institute for Standards and Technology (NIST) andC1271 99 (2012)2other international certification agencies. Refer to Test Meth-ods C25 for a current listing.9.2 Reference materials with matrixes similar to that of thetest specimen and containing varying amounts of the elementsto be determi
35、ned may be used provided that they have beenanalyzed in accordance with ASTM standard test methods.9.3 Standard additions method or spiked samples may alsobe used to create standards for which appropriate referencematerials are not available for an element desired to beanalyzed. The matrix material
36、must match that of the testspecimen.10. Safety Precautions10.1 Occupational health and safety standards for ionizingradiation shall be observed at all X-ray emission spectrometerinstallations. It is also recommended that operating and main-tenance personnel follow the guidelines of safe operatingpro
37、cedures given in current handbooks and publications fromthe original equipment manufacturer, NIST, U.S. GovernmentPrinting Office, or similar handbooks on radiation safety. SeeNIST Standards Catalog and ANSI-NIST Handbook 114.10.2 PersonnelX-ray equipment shall be used only underthe guidance and sup
38、ervision of a responsible, qualified person.10.3 Monitoring DevicesEither film badges or dosimetersshall be worn by all operating and maintenance personnel.Periodic radiation surveys of the equipment for leaks andexcessive scattered radiation shall be made by a qualifiedperson using an ionization ch
39、amber detector to meet local,state, and federal radiation standards. The personal film badgesurvey record, the radiation survey record, and an equipmentmaintenance record shall be available upon request.10.4 Special precautions for operators and maintenancepersonnel shall be posted at the equipment
40、site.10.5 Radiation caution signs shall be posted near the X-rayequipment and at all entrances to the radiation area.10.6 Fail-Safe “X-ray on” warning lights shall be used onthe equipment.11. Sampling11.1 Gross sample is to be taken in accordance withMethods C50.11.2 Sample preparation is to be perf
41、ormed in accordancewith Methods C50 and Test Methods C25.11.3 Special preparation may be required to grind theanalytical sample finer than is required in 11.2.12. Preparation of Reference Materials and TestSpecimens12.1 Treat reference materials and specimens exactly thesame way throughout the proce
42、dure. Either briquetted powderor fused disk specimens may be used.13. Preparation of Apparatus13.1 Prepare and operate the spectrometer in accordancewith the manufacturers instructions, using the parametersgiven in Table 1. Once established, control all instrumentparameters closely to ensure repeata
43、ble analyses.14. Calibration and Standardization14.1 Calibration (Preparation of Analytical Curves)Select a sufficient number of reference materials to cover theconcentration ranges of the elements sought.Average duplicateintensity measurements of each reference material, and estab-lish a calibratio
44、n curve for each element in accordance withPractice E305. Establish the curve by a least squares ormultiple regression fit of the X-ray intensity measurementsversus the corresponding weight percent concentrations of theelement in the reference materials.14.2 Standardization (Analytical Curve Adjustm
45、ent)Verify that the calibration curve for each element has notdrifted using a control reference material. Drift is indicated bya change in counts that exceeds the normal variation of countsfor that element. A change of 1 % or greater usually signifiesthat the calibration curve for that element has d
46、rifted andshould thus be adjusted. Re-measure the reference materials toverify that acceptable analyses are obtained after the adjust-ments are made.15. Procedure15.1 ExcitationIntroduce the specimen into the specimenchamber, using care not to contaminate the surface to beexcited. Produce the second
47、ary fluorescence using the equip-ment used in 7.4.15.2 Radiation MeasurementsObtain and record thecounting rate measurement for each element. Either fixed countor fixed time modes may be used. A predetermined minimumcount rate is obtainable only after unacceptable long countingtimes for lime materia
48、ls, with the exception of the major oxides(Si, Fe, Al, Ca, and Mg). A minimum counting time of 60 s isacceptable.15.3 Spectral InterferencesSome X-ray spectrometerswill not resolve radiation completely from several line over-laps. Care must therefore be exercised in these cases. Alternatewavelengths
49、 without interference may be used. Otherwise,mathematical calculations must be used to correct for theinterferences.TABLE 1 Analytical Lines and CrystalsElement Wavelength, A CrystalsSodium 11.91 TLAP, multilayerMagnesium 9.889 ADP, TLAP, RAP, multilayerAluminum 8.338 PET, EDdT, RAPSilicon 7.126 PET, EDdT, RAP, InSbPhosphorus 6.155 Ge, PETSulfur 5.373 Ge, PET, NaClChlorine 4.729 PET, GePotassium 3.742 LiF 200, PETCalcium 3.359 LiF 200, PETTitanium 2.750 LiF 200, LiF 220Manganese 2.103 LiF 200, LiF 220Iron 1.937 LiF 200, LiF 220Strontium 0.8766 LiF 200, LiF 220Ba
