1、Designation: D8214 18Standard Test Method forForms of Sulfur in Coal by Inductively CoupledPlasma Atomic Emission Spectrometry1This standard is issued under the fixed designation D8214; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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 method applies to the determination of sulfatesulfur and pyritic sulfur in coal and calculate
3、s organic sulfur bydifference. This test method is not applicable to coke or othercarbonaceous materials.1.2 The values stated in SI units are to be regarded asstandard. Non-SI units, if provided, are considered informa-tional and are contained within parentheses1.3 This standard does not purport to
4、 address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was
5、developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced
6、 Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD1193 Specification for Reagent WaterD2013 Practice for Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the Analysis Sample ofCoal and CokeD3180 Practice for Calculating Coal and Coke Analysesfrom As-Determined to Di
7、fferent BasesD4239 Test Method for Sulfur in the Analysis Sample ofCoal and Coke Using High-Temperature Tube FurnaceCombustionD7582 Test Methods for Proximate Analysis of Coal andCoke by Macro Thermogravimetric AnalysisE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision o
8、f a Test MethodE832 Specification for Laboratory Filter Papers2.2 ISO Standards:3ISO 5725-6 Accuracy (Trueness and Precision) of Measure-ment Methods and Results Part 6: Use in Practice ofAccuracy Values3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology D121.4.
9、Summary of Test Method4.1 Sulfate Sulfur:4.1.1 Sulfate sulfur is extracted from the analysis samplewith a dilute hydrochloric acid solution. The sulfate sulfur inthe extract is determined by inductively coupled plasma atomicemission spectrometry (ICP-AES). Sulfates are soluble inhydrochloric acid, p
10、yritic sulfur and organic sulfur are notsoluble in hydrochloric acid.4.2 Pyritic Sulfur:4.2.1 Pyritic sulfur is extracted from the pretreated samplewith a dilute nitric acid solution. The pyritic sulfur in theextract is determined by correlating extracted iron content,measured by ICP-AES, as pyritic
11、 sulfur content.4.2.2 Monosulfides (pyrites and FeS2are disulfides) of ironand elements such as cadmium, lead, vanadium, and zinc canbe present in coal. In mass fractions up to 100 gg, thesemonosulfides do not contribute significantly to the total inor-ganic sulfide content.4-61This test method is u
12、nder the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.21 on Methods ofAnalysis.Current edition approved Nov. 1, 2018. Published January 2019. DOI: 10.1520/D8214-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orconta
13、ct ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from International Organization for Standardization (ISO), ISOCentral Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 121
14、4 Vernier,Geneva, Switzerland, http:/www.iso.org.4Edwards, A. H., Daybell, G. N., and Pringle, W. J. S., “An Investigation intoMethods for the Determination of Forms of Sulfur in Coal,” Fuel, Vol 37,1958, pp. 47-59.5Burns, M. S., “Determination of Pyritic Sulfur in Australian Coals,” Fuel,Vol49, 197
15、0, pp. 126-133.6Shrimp, N. F., Helfinstine, R. J., and Kuhn, J. K.,“Determination of Forms ofSulfur in Coal,” Symposium on Sulfur and Nitrogen in Coal and Oil Shale, 1975,pp. 99-108.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis
16、international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT
17、) Committee.15. Significance and Use5.1 This test method provides for a separation of coal-associated sulfur into two commonly recognized forms: pyriticand sulfate. Organic sulfur is calculated by difference. Resultsobtained by the test method are used to serve a number ofinterests, including the ev
18、aluation of coal preparation andprocessing operations designed to reduce coal sulfur levels.6. Analysis Sample6.1 The analysis sample is that sample which has beenpulverized to pass a 250 m (No. 60) sieve as prepared inaccordance with Practice D2013.6.2 Determine the moisture in the analysis sample
19、in accor-dance with Test Method D3173 or Test Methods D7582 topermit calculation to other bases.7. Apparatus7.1 Balance, sensitive to 0.1 mg.7.2 Hot Plate, electric or gas-heated with capability fortemperature control.7.3 Inductively Coupled Plasma Atomic Emission Spectrom-eter (ICP-AES)Either a seq
20、uential or simultaneous spectrom-eter is suitable. Because of differences between various makesand models of satisfactory instruments, no detailed operatinginstructions can be provided. Instead, the analyst should followthe instructions provided by the manufacturer of the particularinstrument. Sensi
21、tivity, instrumental detection limits, precision,linear dynamic range, and interference effects shall be inves-tigated and established for each analyte on that particularinstrument. All measurements shall be within the instrumentslinear range in which correction factors are valid. It is theresponsib
22、ility of the analyst to verify that the instrumentconfiguration and operating conditions used satisfy the analyti-cal requirements of this test method. The analyst shall maintainquality control data confirming the instrument performance andanalytical results.8. Reagents and Materials8.1 Purity of Re
23、agentsReagent 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.7Other grades may beused, provide
24、d that the reagent is of sufficiently high purity topermit its use without lessening the accuracy of the determi-nation.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D1193, Type II.8.3 Ethanol, reagent grade, de
25、natured.8.4 Filter PaperUnless otherwise indicated, references tofilter paper shall be understood to mean filter paper conformingto Specification E832.8.5 Hydrochloric Acid, 4.8N(2+3)Mix two volumes ofconcentrated aqueous hydrochloric acid (HCl, 12 N) with threevolumes of water.8.6 Nitric Acid, 2N(1
26、+7)Mix one volume of concen-trated nitric acid (HNO3, 15.8 N) with seven volumes of water.8.7 Standard Stock SolutionsStock solutions of1000 gmL for sulfur and iron are needed for preparation ofdilute standards. Prepare stock solutions from 99.99 % puritymetals or salts. Alternatively, one can use c
27、ommerciallyavailable stock solutions specifically prepared for ICP-AES8.8 Internal StandardSolution of yttrium, 200 gmL innitric acid or other suitable element not found in significantmass fractions in the test samples.9. Procedure for Sulfate Sulfur9.1 ExtractionWeigh, to the nearest 1 mg, a 1 g te
28、stspecimen and transfer it to a 200 mL beaker (tall-form/Berzelius).Add 50 mLof 4.8 N HCl and a few drops of ethanolto the coal sample. Ethanol facilitates the wetting process.Cover the sample with a watch glass, place it on a hotplate, andheat at 85 C for 30 min while stirring it with a magnetic st
29、irbar or periodically using a glass stir rod.9.2 FilteringCarefully filter the contents of the beaker intoa 250 mL to 500 mL vacuum flask, using a Type II, Class F orG filter paper. Wash the filter paper and contents with sufficientsmall volume water washings to ensure the transfer of all theHCl ext
30、ract to the vacuum flask. Save the filter paper withextracted residue for the subsequent extraction of pyritic sulfurcontent.9.3 Test Solution PreparationTransfer the filtrate to a200 mL volumetric flask with a glass stir rod. Rinse thevacuum flask with small volume water washings and transfer tothe
31、 volumetric flask.Add 10 mLof 200 gmLyttrium solutionor appropriate non-interfering internal standard and fill theflask to volume with water. Stopper the flask and mix well.Store the sample solution in washed plastic sample bottles.9.4 Sulfate BlankPrepare a sulfate blank following thesame procedure
32、 and using the same amounts of all reagents asdescribed above. Save this filter paper for determining thepyritic iron blank.9.5 Preparation of Calibration SolutionsPrepare a set ofsulfur calibration standards (2.5, 5, 10, 25, 50, 100) gmL.9.5.1 Spectrometric ConditionsSuitable ICP-AES condi-tions fo
33、r the determination of sulfur are as follows:Wavelength 180.731 nmWavelength 182.624 nmWavelength 182.034 nmSingle integration of 300 sRF Power: 0.8 kWTorch Gas: Coolant 20 L minAux 0.5 L minNebulizer 200 kPa (30 psi)7Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Soci
34、ety, 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. Pharmacopeia Convention, Inc. (USPC), Rockville,MD.D
35、8214 1829.5.2 Measure the emission intensity of the calibrationsolutions and construct a calibration curve of the emissionintensity against the sulfur mass concentration for the calibra-tion solutions.9.6 Determination of Sulfur in the Test Solution and BlankTestMeasure the emission intensity of the
36、 test solution andblank test using the same conditions as used for the calibrationsolutions. Determine the mass concentration of the analyte inthe test solution and blank test by reference to the calibrationcurve.9.7 Calculate the mass fraction of sulfate sulfur on a drybasis as follows:SS 5 Ts 2 Bs
37、! 3 V 3 C 3100# W! 3 100 100 2 M!(1)where:SS = mass fraction of sulfate sulfur of the test specimen,dry basis, %,Ts = mass concentration of sulfur in the test solution,g/mL,Bs = mass concentration of sulfur in the blank test, g/mL,V = volume of the test solution from 9.3, mL,C =106, conversion facto
38、r from grams to micrograms,g/g,100 = conversion factor from dimensionless mass fraction topercent, %,W = mass of the test specimen, g, andM = moisture content of sample, %.10. Procedure for Pyritic Sulfur10.1 ExtractionTransfer the filter paper and residue from9.2 to a 200 mLbeaker (tall-form/Berzel
39、ius).Add 50 mLof the2 N HNO3acid solution and a few drops of ethanol to the coalsample. Ethanol facilitates the wetting process. Cover thesample with a watch glass, place it on a hotplate, and heat at85 C for 1 h while stirring with a magnetic stir bar orperiodically using a glass stir rod.10.2 Filt
40、eringCarefully filter the contents into a 250 mLto 500 mL vacuum flask, using a Type II, Class F or G filterpaper. Wash the filter paper and contents with sufficient smallvolume water washings to ensure the transfer of all HNO3extract to the vacuum flask.10.3 HCl WashWash the filter paper and residu
41、e with25 mL of the 4.8 N HCl solution. Wash the filter paper andcontents with sufficient small volume water washings to ensurethe transfer of all the HCl washings into the vacuum flask.10.4 Test Solution PreparationTransfer the filtrate to a200 mL volumetric flask with a glass stir rod. Rinse thevac
42、uum flask with small volume water washings and transfer tothe volumetric flask.Add 10 mLof 200 g/mLyttrium solutionor an appropriate non-interfering internal standard and fill theflask to volume with water. Stopper the flask and mix well.Store the sample solution in washed plastic sample bottles.10.
43、5 Pyritic Sulfur BlankPerform a blank test followingthe same procedure and using the same amounts of all reagentsas described above using the filter paper from 9.4.10.6 Preparation of Calibration SolutionsPrepare a set ofiron mass calibration standards (10, 20, 30) gmL.10.6.1 Spectrometric Condition
44、sSuitable ICP-AES condi-tions for the determination of iron are as follows:Wavelength 234.350 nmWavelength 238.204 nmWavelength 240.489 nmWavelength 259.837 nmWavelength 259.940 nmThree Integrations, 10 s eachRF Power: 0.8 kWTorch Gas: Coolant 19 L minAux 0.7 L minNebulizer 200 kPa (30 psi)10.6.2 Me
45、asure the emission intensity of the calibrationsolutions and construct a calibration curve of the emissionintensity against the iron concentration for the calibrationsolutions.10.7 Determination of Iron in the Test Solution and BlankTestMeasure the emission intensity of the test solution andblank te
46、st using the same conditions as used for the calibrationsolutions. Determine the mass concentration of the analyte inthe test solution and blank test by reference to the calibrationcurve.10.8 Calculate the mass fraction of pyritic sulfur on a drybasis as follows:PS 5 Ti 2 Bi! 3 V 3 C 3100 3 F# W! 3
47、100 100 2 M!(2)where:PS = mass fraction of pyritic sulfur of the test specimen,dry basis, %,F = 1.148, dimensionless stoichiometric ratio for sulfur toiron in iron disulfide (FeS2),V = volume of the test solution from 10.4, mL,C =106, conversion factor from grams to micrograms tograms, g/g,100 = con
48、version factor from dimensionless mass fractionto percent, %,Ti = mass concentration of iron in the test solution,g/mL,Bi = mass concentration of iron in the blank test, g/mL,W = mass of the test specimen, g, andM = moisture content of sample, %.11. Organic Sulfur11.1 When analyses are expressed on
49、a common moisturebasis, the percentage of organic sulfur is obtained by subtract-ing the sum of the percentages of sulfate sulfur and pyriticsulfur from the percentage of total sulfur as determined by TestMethod D4239.12. Report12.1 Report the following information along with the testresults for total, sulfate, pyritic, and organic sulfur:12.1.1 Date of the test,12.1.2 Identification of sample tested,12.1.3 Basis for expression of results,D8214 18312.1.4 The instrumental conditions used for thedetermination,1
