1、Designation: D6349 09D6349 13Standard Test Method forDetermination of Major and Minor Elements in Coal, Coke,and Solid Residues from Combustion of Coal and Coke byInductively Coupled PlasmaAtomic EmissionSpectrometry1This standard is issued under the fixed designation D6349; the number immediately f
2、ollowing the designation indicates the year oforiginal adoption or, in the case of revision, 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 This test met
3、hod covers a procedure for the analysis of the commonly determined major and minor elements in coal, coke,and solid residues from combustion of coal and coke. These residues may be laboratory ash, bottom ash, fly ash, flue gasdesulfurization sludge, and other combustion process residues.1.2 The valu
4、es stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate s
5、afety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD346 Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisD1193 Specification for Reagent WaterD2013
6、Practice for Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the Analysis Sample of Coal and CokeD3174 Test Method for Ash in the Analysis Sample of Coal and Coke from CoalD3180 Practice for Calculating Coal and Coke Analyses from As-Determined to Different BasesD7348 Test Metho
7、ds for Loss on Ignition (LOI) of Solid Combustion ResiduesD5142D7582 Test Methods for ProximateAnalysis of theAnalysis Sample of Coal and Coke by Instrumental ProceduresMacroThermogravimetric Analysis (Withdrawn 2010)E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of
8、 a Test Method2.2 ISO Standard:3ISO/IEC Guide 99:2007 International vocabulary of metrology - Basic and general concepts and associated terms (VIM)3. Terminology3.1 For definitions of terms used in this test method, refer to Terminology D121.4. Summary of Test Method4.1 The sample to be analyzed is
9、ashed under standard conditions and ignited to constant weight. The ash is fused with a fluxingagent followed by dissolution of the melt in dilute acid solution. Alternatively, the ash is digested in a mixture of hydrofluoric,nitric, and hydrochloric acids. The solution is analyzed by inductively co
10、upled plasma-atomic emission spectrometry (ICP) for theelements. The basis of the method is the measurement of atomic emissions. Aqueous solutions of the samples are nebulized, and1 This test method is under the jurisdiction of ASTM Committee D05 on Coal and Coke and is the direct responsibility of
11、Subcommittee D05.29 on Major Elements inAsh and Trace Elements of Coal.Current edition approved Nov. 1, 2009Oct. 1, 2013. Published December 2009October 2013. Originally approved in 1998. Last previous edition approved in 20082009as D6349 - 08D6349 - 09.1. DOI: 10.1520/D6349-09.10.1520/D6349-13.2 Fo
12、r referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from International Organization for Standardization (
13、ISO), 1 rue de Varemb, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible
14、 to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West C
15、onshohocken, PA 19428-2959. United States1a portion of the aerosol that is produced is transported to the plasma torch where excitation and emission occurs. Characteristicline emission spectra are produced by a radio-frequency inductively coupled plasma. A grating monochromator system is used tosepa
16、rate the emission lines, and the intensities of the lines are monitored by photomutilplier tube or photodiode array detection.The photocurrents from the detector are processed and controlled by a computer system. A background correction technique isrequired to compensate for variable background cont
17、ribution to the determination of elements. Background must be measuredadjacent to analyte lines of samples during analysis. The position selected for the background intensity measurement, on either orboth sides of the analytical line, will be determined by the complexity of the spectrum adjacent to
18、the analyte line. The positionused must be free of spectral interference and reflect the same change in background intensity as occurs at the analyte wavelengthmeasured.5. Significance and Use5.1 A compositional analysis of coal and coke and their associated combustion residues are often useful in a
19、ssessing theirquality. Knowledge of the elemental composition of the associated residues is also useful in predicting the elementalenrichment/depletion compositional behavior of ashes and slags in comparison to the concentration levels in the parent coal.Utilization of the ash by-products and hazard
20、ous potential may also depend on the chemical composition and leachability of theinorganic constituents of the coal ash.5.2 The chemical composition of laboratory-prepared ash may not exactly represent the composition of mineral matter in coalor the composition of fly ash and slag resulting from com
21、merical-scale burning of the coal.6. Interferences6.1 Several types of interference effects may contribute to inaccuracies in the determination of major and minor elements. Theanalyst should follow the manufacturers operating guide to develop and apply correction factors to compensate for theinterfe
22、rences. The interferences can be classified as spectral, physical, and chemical.6.1.1 Spectral interferences can be categorized as overlap of a spectral line from another element, unresolved overlap ofmolecular band spectra, background contribution from continuous or recombination phenomena, and bac
23、kground contributionfrom stray light from the line emission of high concentration elements. The second effect may require selection of an alternatewavelength. The third and fourth effects can usually be compensated by a background correction adjacent to the analyte line. Inaddition, users of simulta
24、neous multi-element instrumentation must assume the responsibility of verifying the absence of spectralinterference from an element that could occur in a sample but for which there is no channel in the instrument array.6.1.2 Table 1 lists the elements determined by this method and the recommended wa
25、velengths using conventional nebulization.Sulfur may only be determined if the sample is dissolved by the mixed acid dissolution described in 10.3.2.6.1.3 Table 24 lists some interference effects for the recommended wavelengths given in Table 1. The data in Table 2 areintended for use only as a rudi
26、mentary guide for the indication of potential spectral interferences. For this purpose, linear relationsbetween concentration and intensity for the analytes and the interferents can be assumed. The analyst should follow themanufacturers operating guide to develop and apply correction factors to comp
27、ensate for the interferences.6.1.4 Physical interferences are generally considered to be effects associated with the sample nebulization and transportprocesses. Such properties as change in viscosity and surface tension can cause significant inaccuracies, especially in samples thatmay contain high d
28、issolved solids or acid concentrations, or both. The use of a peristaltic pump is recommended to lessen theseinterferences. If these types of interferences are operative, they must be reduced by dilution of the sample or utilization of standardaddition techniques, or both. Another problem that can o
29、ccur from high dissolved solids is salt buildup at the tip of the nebulizer.4 Methods for Chemical Analysis of Water and Wastes , (EPA-600/4-79-020), Metals-4, Method 200.7 CLP-M.TABLE 1 Recommended Wavelengths for Elements Determinedby ICPElement Wavelengths, nmAluminum 396.152, 256.80, 308.215, 30
30、9.271Barium 455.403, 493.41, 233.53Calcium 317.93, 315.887, 364.44, 422.67Iron 259.940, 271.44, 238.204Magnesium 279.553, 279.08, 285.21, 277.983Manganese 257.610, 294.92, 293.31, 293.93Phosphorous 178.287, 214.900Potassium 766.491, 769.896Silicon 212.412, 288.16, 251. 611Sodium 588.995, 589.592Stro
31、ntium 421.55Sulfur 182.04Titanium 337.280, 350.50, 334.941D6349 132This affects aerosol flow rate causing instrumental drift. Wetting the argon before nebulization, the use of a tip washer, or sampledilution have been used to control this problem. Also, it has been reported that better control of th
32、e argon flow rate, particularlynebulizer flow, improves instrument precision. This is accomplished with the use of mass flow controllers.6.1.5 Chemical interferences are characterized by molecular compound formation, ionization effects, and solute vaporizationeffects. Normally these effects are not
33、pronounced with the ICP technique. However, if such effects are observed they can beminimized by careful selection of operating conditions (that is, incident power, observation position, and so forth), by bufferingof the sample, matrix matching, and standard addition procedures. These types of inter
34、ferences can be highly dependent on matrixtype and the specific analyte element.7. Apparatus7.1 Ashing Furnace, with an adequate air circulation (two to four volume changes per minute) and capable of having itstemperature regulated between 700at 500C and 750C.7.2 Fusion Furnace, with an operating te
35、mperature of 1000 to 1200C.7.3 Meeker-TypeMeker-Type Burner, with inlets for fuel gas (propane or natural gas) and compressed air, capable of flametemperatures of 1000 to 1200C.7.4 Platinum Dishes or Crucibles, 35- to 85-mL capacity. Graphite crucibles with 10- to 15-mL capacity may also be used.7.5
36、 Stirring Hotplate and Bars, with operating temperature up to 200C.7.6 Polycarbonate Bottles, 250-mL capacity with an O-ring seal and screw cap, capable of withstanding temperatures of 100to 130C, the pressure that is developed during the digestion, and resistant to oxidation. Other types of bottles
37、 or vials may be usedprovided they are capable of withstanding the temperatures and pressures developed duing the digestion.7.7 Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP), either a sequential or simultaneous spectrometer issuitable. Because of the differences between various makes
38、 and models of satisfactory instruments, no detailed operatinginstructions can be provided. Instead, the analyst should follow the instructions provided by the manufacturer of the particularinstrument. Sensitivity, instrumental detection limit, precision, linear dynamic range, and interference effec
39、ts must be investigatedand established for each individual analyte line on that particular instrument. All measurements must be within the instrumentslinear range in which correction factors are valid. It is the responsibility of the analyst to verify that the instrument configurationand operating c
40、onditions used satisfy the analytical requirements of this method and to maintain quality control data confirminginstrument performance and analytical results.8. Reagents8.1 Purity of ReagentsReagents grade chemicals shall be used in all tests. It is intended that all reagents shall conform to thesp
41、ecifications of the Committee on Analytical Reagents of the American Chemical Society in which such specifications areavailable.5 Other grades may be used provided it is first ascertained that the reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determina
42、tion.8.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean Type II reagent water asdefined by Specification D1193.8.3 Standard Stock SolutionsStock solutions of 1000 ppm (mg/L) for each element are needed for preparation of dilutestandards in the range from 0
43、.1 to 100 ppm. Prepare standard stock solutions from 99.999 % purity metals or salts.Alternatively,one can use commercially available stock solutions specifically prepared for ICP-AES spectroscopy.5 Reagent Chemicals, American Chemical Society Specifications , American Chemical Society, Washington,
44、DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.TABLE 2 Example
45、s of Analyte Concentration Equivalents Arising from Interference at the 100-ppm (mg/L) Level4NOTE 1Dashes indicate that no interference was observed even when interferents were introduced at the following levels:Al, Ca, and Fe = 1000 ppm,Mn = 200 ppm, and Mg = 100 ppm.InterferentsAnalyte Elements Wa
46、velengths, nm Al Ca Fe Mg Mn TiAluminum 308.215 - - - - - - - - - - - - 0.21 - - -Barium 455.103 - - - - - - - - - - - - - - - - - -Calcium 317.933 - - - - - - 0.01 0.01 0.04 0.03Iron 259.940 - - - - - - - - - - - - 0.12 - - -Magnesium 279.079 - - - 0.02 0.13 - - - 0.25 0.07Manganese 257.610 0.005 -
47、 - - 0.002 0.002 - - - - - -Silicon 288.148 - - - - - - - - - - - - - - - - - -Sodium 588.995 - - - - - - - - - - - - - - - 0.08D6349 1338.4 Internal Standard SolutionStock solution of 1000 ppm (mg/L) of yttrium (Y), scandium (Sc), indium (In), or other suitableelement not found in significant conce
48、ntrations in the test samples.8.5 Acids:8.5.1 Hydrochloric AcidConcentrated HCl. sp gr 1.19.8.5.2 Hydrofluoric AcidConcentrated HF, sp gr 1.17.8.5.3 Nitric Acid Concentrated HNO3, sp gr 1.42.8.5.4 Nitric Acid (5 + 95)Dilute 50 mL of concentrated nitric acid to 1000 mL.8.5.5 Mixed Acid Solution, 70/3
49、0 HCl/HFMix seven parts concentrated hydrochloric acid and three parts concentratedhydrofluoric acid.8.6 Fluxing Agents Lithium tetraborate, Li2B4O7, or mixtures of lithium tetraborate (Li2B4O7) and anhydrous lithiummetaborate (LiBO3).8.7 Boric Acids Solution1.5 %.8.8 Hydrogen Peroxide30%8.9 Wetting AgentsApproximately 0.1 g of reagent grade lithium iodide (LiI) or other suitable wetting agent may be addedto the flux to facilitate pooling of the melt and removal of the melt of cooled pellet.8.10 Standard Solution DiluentUse either 7.10.18.10.1 or 7.10.
