1、Designation: D4239 17Standard Test Method forSulfur in the Analysis Sample of Coal and Coke Using High-Temperature Tube Furnace Combustion1This standard is issued under the fixed designation D4239; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This
3、 test method covers the determination of sulfur insamples of coal or coke by high-temperature tube furnacecombustion.1.1.1 Two analysis methods are described.1.2 When automated equipment is used, either method canbe classified as an instrumental method.1.3 The values stated in SI units are to be reg
4、arded asstandard. No other units of measurement are included in thisstandard.1.4 All percentages are percent mass fractions unless other-wise noted.1.5 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 st
5、andard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles f
6、or theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisD2013 Practice for
7、 Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the Analysis Sample ofCoal and CokeD3176 Practice for Ultimate Analysis of Coal and CokeD3180 Practice for Calculating Coal and Coke Analysesfrom As-Determined to Different BasesD7448 Practice for Establishing the Competence of La
8、bora-tories Using ASTM Procedures in the Sampling andAnalysis of Coal and CokeD7582 Test Methods for Proximate Analysis of Coal andCoke by Macro Thermogravimetric AnalysisE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ISO Standard:3ISO 11722 Solid
9、 Mineral Fuels-Hard Coal Determinationof Moisture in the general analysis test sample by dryingin nitrogen3. Summary of Test Method3.1 Combustion Method A (1350C)A weighed test por-tion of sample is burned in a tube furnace at a minimumcombustion tube operating temperature of 1350C in a streamof oxy
10、gen. During combustion at temperatures above 1350 C,the sulfur and sulfur compounds contained in the sample aredecomposed and oxidized almost exclusively to gaseous sulfurdioxide, SO2. Moisture and particulates are removed from thegas by filters. The gas stream is passed through a cell in whichsulfu
11、r dioxide is measured by an infrared (IR) absorptiondetector. Sulfur dioxide absorbs IR energy at a precise wave-length within the IR spectrum. Energy is absorbed as the gaspasses through the cell body in which the IR energy is beingtransmitted: thus, at the detector, less energy is received. Alloth
12、er IR energy is eliminated from reaching the detector by aprecise wavelength filter. Thus, the absorption of IR energy canbe attributed only to sulfur dioxide whose concentration isproportional to the change in energy at the detector. One cell isused as both a reference and a measurement chamber. To
13、talsulfur as sulfur dioxide is detected on a continuous basis.3.1.1 One procedure for Method A uses coal or cokereference materials to calibrate the sulfur analyzer. A second1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommi
14、ttee D05.21 on Methods ofAnalysis.Current edition approved May 15, 2017. Published May 2017. Originallyapproved in 1983. Last previous edition approved in 2013 as D4239 142. DOI:10.1520/D4239-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
15、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), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.*A S
16、ummary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization establis
17、hed in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1procedure for Method A uses a pure substance, BBOT, tocalibrate the sulfur analyzer.3.2 Combustion Method B
18、(1150C)A weighed test por-tion of sample is burned in a quartz combustion tube in astream of oxygen with an equal or excess weight of tungstentrioxide (WO3). Sulfur is oxidized during the reaction of thesample and WO3. The tube furnace is operated at a minimumcombustion tube operating temperature of
19、 1150C and tin (Sn)sample boats are utilized. Moisture and particulates are re-moved from the combustion gas by filters. The gas stream isthen passed through a cell in which sulfur dioxide is measuredby an infrared (IR) absorption detector. Sulfur dioxide absorbsIR energy at a precise wavelength wit
20、hin the IR spectrum.Energy is absorbed as the gas passes through the cell body inwhich the IR energy is being transmitted: thus, at the detector,less energy is received. All other IR energy is eliminated fromreaching the detector by a precise wavelength filter. Thus, theabsorption of IR energy can b
21、e attributed only to sulfur dioxidewhose concentration is proportional to the change in energy atthe detector. One cell is used as both a reference and ameasurement chamber. Total sulfur as sulfur dioxide is de-tected on a continuous basis.4. Significance and Use4.1 Sulfur is part of the ultimate an
22、alysis of coal and coke.4.2 Results of the sulfur analysis are used for evaluation ofcoal preparation and cleaning, evaluation of potential sulfuremissions from coal and coke combustion or conversionprocesses, and evaluation of coal and coke quality in relation tocontract specifications, as well as
23、for scientific purposes.4.3 The competency of laboratories with respect to use ofthis standard can be established through reference to PracticeD7448.5. Sample5.1 Pulverize the sample to pass No. 60 (250-m) sieve andmix thoroughly in accordance with Practice D2013 or PracticeD346.5.2 Analyze a separa
24、te portion of the analysis sample formoisture content in accordance with Test Method D3173,orD7582 or ISO 11722 for calculations to other than theas-determined basis.5.3 Procedures for calculating as-determined sulfur valuesobtained from the analysis sample to other bases are describedin Practices D
25、3176 and D3180.6. ApparatusCombustion Method A (1350C)6.1 Measurement ApparatusEquipped to combust thesample as described in 3.1 (See Fig. 1).6.2 Tube FurnaceCapable of heating the hot zone or outersurface of the combustion tube, or both (6.3) to at least 1350C.It is normally heated electrically usi
26、ng resistance rods, aresistance wire, or molybdenum disilicide elements. Specificdimensions can vary with manufacturers design.6.3 Combustion TubeMade of mullite, porcelain, or zirconwith provisions for routing the gases produced by combustionthrough the infrared cell. The tube may have a boat stop
27、madeof reticulated ceramics heated to 1350C that serves to com-plete the combustion of sulfur containing materials.6.4 Sample Combustion Boats, made of iron-free materialand of a convenient size suitable for the dimensions of thecombustion tube.FIG. 1 Apparatus for the Determination of Sulfur by the
28、 Infrared Detection, Method AD4239 1726.5 Boat PullerWhere required, a rod of a heat-resistantmaterial with a bent or disk end to insert and remove boatsfrom the combustion tube.6.6 BalanceA stand-alone balance or a balance integratedwith the instrument, with a resolution of at least 0.3% relativeof
29、 the test portion mass.Combustion Method B (1150C)6.7 Measurement ApparatusEquipped to combust thesample as described in 3.2 (See Fig. 2)6.8 Tube FurnaceCapable of heating the hot zone or outersurface of the combustion tube, or both (6.9) to at least 1150C.It is normally heated electrically using re
30、sistance wire. Specificdimensions can vary with manufacturers design.6.9 Combustion TubeMade of quartz with provisions forrouting the gases produced by combustion through the infraredcell.6.10 Sample Combustion BoatMade of an iron-free tinmaterial and of a convenient size suitable for the dimensions
31、 ofthe combustion tube.7. Reagents7.1 Purity of ReagentsUse reagent grade chemicals in alltests. Unless otherwise indicated, it is intended that all reagentsconform to the specifications of the Committee on AvailableReagents of the American Chemical Society, where suchspecifications are available.4O
32、ther grades can be used, pro-vided it is first ascertained the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of thedetermination.7.2 Magnesium Perchlorate(WarningMagnesium per-chlorate is a strong oxidizing agent. Do not regenerate theabsorbent. Do not allow
33、contact with organic materials orreducing agents.)7.3 Oxygen, 99.5 % PureCompressed gas contained in acylinder equipped with a suitable pressure regulator and aneedle valve to control gas flow. (WarningPure oxygenvigorously accelerates combustion. Verify all regulators, lines,and valves are free of
34、grease and oil.)7.4 Reference Materials, Reference Material (RM)that arecoal(s) or coke(s) prepared by a national metrology body.Other materials that are coal(s) or coke(s) with documentedtraceability to reference material (CRM) coal(s) or coke(s)prepared by a national metrology body can also be use
35、d. Onlyuse material(s) with an assigned value and assigned uncertaintyfor sulfur. The uncertainty expressed as the confidence intervalof the assigned value shall be less than the repeatabilityspecified in the appropriate section on Precision and Bias ofthis test method.7.4.1 To minimize problems wit
36、h instrument calibration orcalibration verification mix all reference material before re-moving the test portion from the container. Do not use thereference material for calibration or calibration verificationwhen less than 2 g remain in the container. The remainingmaterial can be used for instrumen
37、t conditioning.7.5 BBOT (2,5-di(5-tert-butylbenzoxazol-2-yl)thiophene,C26H26N2O2S)A pure substance and certified reference ma-terial for sulfur (7.47 % sulfur).7.6 Tungsten Oxide (WO3)A combustion promoter and afluxing agent. (WarningTungsten Oxide is a strong oxidiz-ing agent.)8. Procedure8.1 Instr
38、ument PreparationPerform apparatus set up sys-tem checks in accordance with manufacturers instructions.8.1.1 Balance CalibrationCalibrate the instrument bal-ance in accordance with manufacturers instructions.8.2 Calibration of the Infrared Detection SystemIf theinstrument has been previously calibra
39、ted in accordance withthe section on instrument calibration, proceed to the AnalysisProcedure, otherwise carry out a calibration as specified in thefollowing section.8.2.1 Calibration with Coal and Coke Certified ReferenceMaterialsSelect reference materials (7.4), in the range of thesamples to be an
40、alyzed. Use at least three such reference4Reagent Chemicals, American Chemical Society 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, Dors
41、et, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 2 Apparatus for the Determination of Sulfur by the Infrared Detection, Method BD4239 173materials, for each range of sulfur values to be tested. Selectone reference mater
42、ial containing at least as much sulfur as thehighest level of sulfur expected. Select two additional refer-ence materials, one approximately at the mid-point of the rangeand one below the lowest level of sulfur expected.8.2.1.1 Use a mass of material recommended by the appa-ratus manufacturer to car
43、ry out a minimum of three determi-nations to condition the equipment before calibration. Use amaterial with a sulfur value near the mid point of the expectedcalibration range.8.2.1.2 For each reference coal or coke employed forcalibration, use the as-determined sulfur value previouslycalculated from
44、 the certified dry-basis sulfur value and residualmoisture determined using either Test Methods D3173 orD7582 or ISO 11722. Use a mass of material and thecalibration procedure recommended by the apparatus manufac-turer. Weigh in accordance with section 6.6 and evenly spreadthe test portion of the re
45、ference material into the samplecombustion boat (6.4). Position the sample in the hot zone ofthe furnace until the instrument returns to baseline as indicatedaccording to settings recommended by the manufacturer. If theanalysis time exceeds the maximum analysis time recom-mended by the manufacturer
46、take corrective action as recom-mended by the manufacturer.8.2.2 Calibration with BBOTTo meet the precision re-quirements of this method, six calibration points are requiredfor a linear fit and eight calibration points are required for anonlinear fit. A calibration point consists of a determination
47、ona single test portion of calibration material. Select test portionsof the calibrant that have at least as much sulfur as the highestlevel of sulfur expected, test portions of the calibrant that haveas much sulfur as the lowest level of sulfur expected and testportions spread evenly in between the
48、highest and lowest levelsof sulfur.8.2.2.1 The mass of the calibrant needed can be calculatedusing the following equation: (Note 1).MC5MT3 SAD!SC(1)WhereMC= Mass of calibrantMT= Mass normally used for test samplesSAD= Percent sulfur (as-determined) in the test sampleSC= Percent sulfur in the pure su
49、bstance calibrantNOTE 1In the interlaboratory study that yielded the data for theprecision statement for this method, the mass of BBOT used forcalibration ranged from about 15 mg to over 80 mg. Some analyzers mayuse larger amounts.8.2.3 Calibration VerificationCarry out a minimum ofthree determinations to condition the equipment before cali-bration verification (see 8.2.1.1). Verify the instrument calibra-tion prior to analyzing test samples, upon completion of all testsamples and as needed to meet quality control requi
