ASTM D4239-2018 Standard Test Method for Sulfur in the Analysis Sample of Coal and Coke Using High-Temperature Tube Furnace Combustion.pdf

1、Designation: D4239 17D4239 18Standard 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

2、 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*

3、1.1 This test method covers the determination of sulfur in samples of coal or coke by high-temperature tube furnace combustion.1.1.1 Two analysis methods are described.1.2 When automated equipment is used, either method can be classified as an instrumental method.1.3 The values stated in SI units ar

4、e to be regarded as standard. No other units of measurement are included in this The valuesgiven in parentheses after SI units are provided for information only and are not considered standard.1.4 All percentages are percent mass fractions unless otherwise noted.1.5 This standard does not purport to

5、 address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.6 This international st

6、andard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Re

7、ferenced Documents2.1 ASTM Standards:2D346D346/D346M Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisD2013D2013/D2013M Practice for Preparing Coal Samples for AnalysisD3173D3173/D3173M Test Method for Moisture in the Analysis Sample of Coal and CokeD3176 Practice for U

8、ltimate Analysis of Coal and CokeD3180 Practice for Calculating Coal and Coke Analyses from As-Determined to Different BasesD7448 Practice for Establishing the Competence of Laboratories UsingASTM Procedures in the Sampling andAnalysis of Coaland CokeD7582 Test Methods for Proximate Analysis of Coal

9、 and Coke by Macro Thermogravimetric AnalysisE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2.2 ISO Standard:3ISO 5725-6 Accuracy (trueness and precision) of measurement methods and resultsPart 6: Use in practice of accuracy valuesISO 11722 Solid Min

10、eral Fuels-Hard Coal Determination of Moisturemineral fuelsHard coalDetermination of moisturein the general analysis test sample by drying in nitrogen3. Summary of Test Method3.1 Combustion Method A (1350C)(1350 C)A weighed test portion of sample is burned in a tube furnace at a minimumcombustion tu

11、be operating temperature of 1350C1350 C in a stream of oxygen. During combustion at temperatures above 1350C, 1350 C, the sulfur and sulfur compounds contained in the sample are decomposed and oxidized almost exclusively to gaseous1 This test method is under the jurisdiction of ASTM Committee D05 on

12、 Coal and Coke and is the direct responsibility of Subcommittee D05.21 on Methods of Analysis.Current edition approved May 15, 2017Sept. 1, 2018. Published May 2017October 2018. Originally approved in 1983. Last previous edition approved in 20132017 asD4239 14D4239 17.2. DOI: 10.1520/D4239-17.10.152

13、0/D4239-18.2 For 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 St

14、andardization (ISO), 1, ch. de la Voie-Creuse, 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

15、 be technically possible 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.*A Summary of Changes section appears at the end

16、 of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1sulfur dioxide, SO2. Moisture and particulates are removed from the gas by filters. The gas stream is passed through a cell in whichsulfur dioxide is measured by an infr

17、ared (IR) absorption detector. Sulfur dioxide absorbs IR energy at a precise wavelength withinthe IR spectrum. Energy is absorbed as the gas passes through the cell body in which the IR energy is being transmitted: thus, atthe detector, less energy is received. All other IR energy is eliminated from

18、 reaching the detector by a precise wavelength filter.Thus, the absorption of IR energy can be attributed only to sulfur dioxide whose concentration is proportional to the change inenergy at the detector. One cell is used as both a reference and a measurement chamber. Total sulfur as sulfur dioxide

19、is detectedon a continuous basis.3.1.1 One procedure for Method A uses coal or coke reference materials to calibrate the sulfur analyzer. A second procedurefor Method A uses a pure substance, BBOT, to calibrate the sulfur analyzer.3.2 Combustion Method B (1150C)(1150 C)A weighed test portion of samp

20、le is burned in a quartz combustion tube in astream of oxygen with an equal or excess weight of tungsten trioxide (WO3). Sulfur is oxidized during the reaction of the sampleand WO3. The tube furnace is operated at a minimum combustion tube operating temperature of 1150C1150 C and tin (Sn)sample boat

21、s are utilized. Moisture and particulates are removed from the combustion gas by filters. The gas stream is then passedthrough a cell in which sulfur dioxide is measured by an infrared (IR) absorption detector. Sulfur dioxide absorbs IR energy at aprecise wavelength within the IR spectrum. Energy is

22、 absorbed as the gas passes through the cell body in which the IR energy isbeing transmitted: thus, at the detector, less energy is received. All other IR energy is eliminated from reaching the detector by aprecise wavelength filter. Thus, the absorption of IR energy can be attributed only to sulfur

23、 dioxide whose concentration isproportional to the change in energy at the detector. One cell is used as both a reference and a measurement chamber. Total sulfuras sulfur dioxide is detected on a continuous basis.4. Significance and Use4.1 Sulfur is part of the ultimate analysis of coal and coke.4.2

24、 Results of the sulfur analysis are used for evaluation of coal preparation and cleaning, evaluation of potential sulfuremissions from coal and coke combustion or conversion processes, and evaluation of coal and coke quality in relation to contractspecifications, as well as for scientific purposes.4

25、3 The competency of laboratories with respect to use of this standard can be established through reference to Practice D7448.5. Sample5.1 Pulverize the sample to pass No. 60 (250-m)250 m (No. 60) sieve and mix thoroughly in accordance with PracticeD2013D2013/D2013M or Practice D346D346/D346M.5.2 An

26、alyze a separate portion of the analysis sample for moisture content in accordance with Test Method D3173D3173/D3173M, or Test Methods D7582 or ISO 11722 for calculations to other than the as-determined basis.5.3 Procedures for calculating as-determined sulfur values obtained from the analysis sampl

27、e to other bases are described inPractices D3176 and D3180.6. ApparatusCombustion Method A (1350C)(1350 C)6.1 Measurement ApparatusEquipped to combust the sample as described in 3.1 (See(see Fig. 1).6.2 Tube FurnaceCapable of heating the hot zone or outer surface of the combustion tube, or both (6.3

28、) to at least1350C.1350 C. It is normally heated electrically using resistance rods, a resistance wire, or molybdenum disilicide elements.Specific dimensions can vary with manufacturersmanufacturers design.6.3 Combustion TubeMade of mullite, porcelain, or zircon with provisions for routing the gases

29、 produced by combustionthrough the infrared cell. The tube may have a boat stop made of reticulated ceramics heated to 1350C1350 C that serves tocomplete the combustion of sulfur containing materials.6.4 Sample Combustion Boats, made of iron-free material and of a convenient size suitable for the di

30、mensions of the combustiontube.6.5 Boat PullerWhere required, a rod of a heat-resistant material with a bent or disk end to insert and remove boats from thecombustion tube.6.6 BalanceAstand-alone balance or a balance integrated with the instrument, with a resolution of at least 0.3%0.3 % relativeof

31、the test portion mass.Combustion Method B (1150C)(1150 C)6.7 Measurement ApparatusEquipped to combust the sample as described in 3.2 (See(see Fig. 2).D4239 1826.8 Tube FurnaceCapable of heating the hot zone or outer surface of the combustion tube, or both (6.9) to at least1150C.1150 C. It is normall

32、y heated electrically using resistance wire. Specific dimensions can vary withmanufacturersmanufacturers design.6.9 Combustion TubeMade of quartz with provisions for routing the gases produced by combustion through the infrared cell.6.10 Sample Combustion BoatMade of an iron-free tin material and of

33、 a convenient size suitable for the dimensions of thecombustion tube.7. Reagents7.1 Purity of ReagentsUse reagent grade chemicals in all tests. Unless otherwise indicated, it is intended that all reagentsconform to the specifications of the Committee onAvailable Reagents of theAmerican Chemical Soci

34、ety, where such specificationsare available.4 Other grades can be used, provided it is first ascertained the reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determination.7.2 Magnesium Perchlorate(WarningMagnesium perchlorate is a strong oxidizing agent.

35、 Do not regenerate the absorbent.Do not allow contact with organic materials or reducing agents.)4 Reagent Chemicals, American Chemical Society Specifications , American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Anala

36、r 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.FIG. 1 Apparatus for the Determination of Sulfur by the Infrared Detection, Method AFIG. 2 Apparatus for the Determ

37、ination of Sulfur by the Infrared Detection, Method BD4239 1837.3 Oxygen, 99.5 % 99.5 % PureCompressed gas contained in a cylinder equipped with a suitable pressure regulator and aneedle valve to control gas flow. (WarningPure oxygen vigorously accelerates combustion. Verify all regulators, lines, a

38、ndvalves are free of grease and oil.)7.4 Reference Materials, Reference Material (RM)that are coal(s) or coke(s) prepared by a national metrology body. Othermaterials that are coal(s) or coke(s) with documented traceability to reference material (CRM) coal(s) or coke(s) prepared by anational metrolo

39、gy body can also be used. Only use material(s) with an assigned value and assigned uncertainty for sulfur. Theuncertainty expressed as the confidence interval of the assigned value shall be less than the repeatability reproducibility standarddeviation SR specified in the appropriate section on Preci

40、sion and Bias of this test method.7.4.1 To minimize problems with instrument calibration or calibration verification mix all reference material before removingthe test portion from the container. Do not use the reference material for calibration or calibration verification when less than 2g 2 g rema

41、in in the container. The remaining material can be used for instrument conditioning.7.5 BBOT (2,5-di(5-tert-butylbenzoxazol-2-yl)thiophene, C26H26N2O2S)A pure substance and certified reference material forsulfur (7.47 % (7.47 % sulfur).7.6 Tungsten Oxide (WO3)A combustion promoter and a fluxing agen

42、t. (WarningTungsten Oxide is a strong oxidizingagent.)8. Procedure8.1 Instrument PreparationPerform apparatus set up system checks in accordance with manufacturersmanufacturersinstructions.8.1.1 Balance CalibrationCalibrate the instrument balance in accordance with manufacturersmanufacturers instruc

43、tions.8.2 Calibration of the Infrared Detection SystemIf the instrument has been previously calibrated in accordance with thesection on instrument calibration, proceed to theAnalysis Procedure, otherwise carry out a calibration as specified in the followingsection.8.2.1 Calibration with Coal and Cok

44、e Certified Reference MaterialsSelect reference materials (7.4), in the range of thesamples to be analyzed. Use at least three such reference materials, for each range of sulfur values to be tested. Select one referencematerial containing at least as much sulfur as the highest level of sulfur expect

45、ed. Select two additional reference materials, oneapproximately at the mid-point of the range and one below the lowest level of sulfur expected.8.2.1.1 Use a mass of material recommended by the apparatus manufacturer to carry out a minimum of three determinationsto condition the equipment before cal

46、ibration. Use a material with a sulfur value near the mid point of the expected calibrationrange.8.2.1.2 For each reference coal or coke employed for calibration, use the as-determined sulfur value previously calculated fromthe certified dry-basis sulfur value and residual moisture determined using

47、either Test Methods D3173D3173/D3173M or , D7582,or ISO 11722. Use a mass of material and the calibration procedure recommended by the apparatus manufacturer. Weigh inaccordance with section 6.6 and evenly spread the test portion of the reference material into the sample combustion boat (6.4).Positi

48、on the sample in the hot zone of the furnace until the instrument returns to baseline as indicated according to settingsrecommended by the manufacturer. If the analysis time exceeds the maximum analysis time recommended by the manufacturertake corrective action as recommended by the manufacturer.8.2

49、2 Calibration with BBOTTo meet the precision requirements of this method, six calibration points are required for a linearfit and eight calibration points are required for a nonlinear fit.Acalibration point consists of a determination on a single test portionof calibration material. Select test portions of the calibrant that have at least as much sulfur as the highest level of sulfur expected,test portions of the calibrant that have as much sulfur as the lowest level of sulfur expected and test portions spread e