1、Designation: D4239 142D4239 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, i
2、n 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 NOTESu
3、mmary of Changes added and Tables 3 and A1.4 corrected editorially in November 2014.2 NOTEAdded research report footnotes to Tables A1.2, A1.3, and A1.4 editorially in March 2015.1. Scope*1.1 This test method covers the determination of sulfur in samples of coal or coke by high-temperature tube furn
4、ace 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 are to be regarded as standard. No other units of measurement are included in this standard.1.4 All percentages ar
5、e percent mass fractions unless otherwise noted.1.5 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 safety and health practices and determine the applicability of regu
6、latorylimitations prior to use.1.6 This international standard 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 Organi
7、zation Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D346 Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisD2013 Practice for Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the Analysis Sample of Coal and Co
8、keD3176 Practice for Ultimate 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 Prox
9、imate Analysis of Coal and Coke by Macro Thermogravimetric AnalysisE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2.2 ISO Standard:3ISO 11722 Solid Mineral Fuels-Hard Coal Determination of Moisture in the general analysis test sample by drying in nit
10、rogen3. Summary of Test Method3.1 Combustion Method A (1350C)A weighed test portion of sample is burned in a tube furnace at a minimum combustiontube operating temperature of 1350C in a stream of oxygen. During combustion at temperatures above 1350 C, the sulfur andsulfur compounds contained in the
11、sample are decomposed and oxidized almost exclusively to gaseous sulfur dioxide, SO2.Moisture and particulates are removed from the gas by filters. The gas stream is passed through a cell in which sulfur dioxide is1 This test method is under the jurisdiction of ASTM Committee D05 on Coal and Coke an
12、d is the direct responsibility of Subcommittee D05.21 on Methods of Analysis.Current edition approved March 1, 2014May 15, 2017. Published March 2014May 2017. Originally approved in 1983. Last previous edition approved in 2013 asD4239 13D4239 1412. DOI: 10.1520/D4239-14.10.1520/D4239-17.2 For refere
13、ncedASTM 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 (ISO), 1,
14、 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 be technically possibl
15、e 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 of this standardCopyri
16、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1measured by an infrared (IR) absorption detector. Sulfur dioxide absorbs IR energy at a precise wavelength within the IR spectrum.Energy is absorbed as the gas passes through the cell body in
17、which the IR energy is being transmitted: thus, at the detector, lessenergy is received.All other IR energy is eliminated from reaching the detector by a precise wavelength filter. Thus, the absorptionof IR energy can be attributed only to sulfur dioxide whose concentration is proportional to the ch
18、ange in energy at the detector.One cell is used as both a reference and a measurement chamber. Total sulfur as sulfur dioxide is detected on 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
19、 a pure substance, BBOT, to calibrate the sulfur analyzer.3.2 Combustion Method B (1150C)A weighed test portion of sample is burned in a quartz combustion tube in a stream ofoxygen with an equal or excess weight of tungsten trioxide (WO3). Sulfur is oxidized during the reaction of the sample and WO3
20、.The tube furnace is operated at a minimum combustion tube operating temperature of 1150C and tin (Sn) sample boats areutilized. Moisture and particulates are removed from the combustion gas by filters. The gas stream is then passed through a cellin which sulfur dioxide is measured by an infrared (I
21、R) absorption detector. Sulfur dioxide absorbs IR energy at a precisewavelength within the IR spectrum. Energy is absorbed as the gas passes through the cell body in which the IR energy is beingtransmitted: thus, at the detector, less energy is received. All other IR energy is eliminated from reachi
22、ng the detector by a precisewavelength filter. Thus, the absorption of IR energy can be attributed only to sulfur dioxide whose concentration is proportionalto the change in energy at the detector. One cell is used as both a reference and a measurement chamber. Total sulfur as sulfurdioxide is detec
23、ted on a continuous basis.4. Significance and Use4.1 Sulfur is part of the ultimate analysis of coal and coke.4.2 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, an
24、d evaluation of coal and coke quality in relation to contractspecifications, as well as for scientific purposes.4.3 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) siev
25、e and mix thoroughly in accordance with Practice D2013 or PracticeD346.5.2 Analyze a separate portion of the analysis sample for moisture content in accordance with Test Method D3173, or D7582or ISO 11722 for calculations to other than the as-determined basis.5.3 Procedures for calculating as-determ
26、ined sulfur values obtained from the analysis sample to other bases are described inPractices D3176 and D3180.6. ApparatusCombustion Method A (1350C)6.1 Measurement ApparatusEquipped to combust the sample as described in 3.1 (See Fig. 1).6.2 Tube FurnaceCapable of heating the hot zone or outer surfa
27、ce of the combustion tube, or both (6.3) to at least 1350C.It is normally heated electrically using resistance rods, a resistance wire, or molybdenum disilicide elements. Specific dimensionscan vary with manufacturers design.6.3 Combustion TubeMade of mullite, porcelain, or zircon with provisions fo
28、r routing the gases produced by combustionthrough the infrared cell. The tube may have a boat stop made of reticulated ceramics heated to 1350C that serves to completethe combustion of sulfur containing materials.6.4 Sample Combustion Boats, made of iron-free material and of a convenient size suitab
29、le for the dimensions 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 0.1%0.3%
30、 relativeof the test portion mass.Combustion Method B (1150C)6.7 Measurement ApparatusEquipped to combust the sample as described in 3.2 (See Fig. 2)6.8 Tube FurnaceCapable of heating the hot zone or outer surface of the combustion tube, or both (6.9) to at least 1150C.It is normally heated electric
31、ally using resistance wire. Specific dimensions can vary with manufacturers design.6.9 Combustion TubeMade of quartz with provisions for routing the gases produced by combustion through the infrared cell.D4239 1726.10 Sample Combustion BoatMade of an iron-free tin material and of a convenient size s
32、uitable 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 Society, where such spec
33、ificationsare 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. Do not regenerate t
34、he absorbent.Do not allow contact with organic materials or reducing agents.)7.3 Oxygen, 99.5 % PureCompressed gas contained in a cylinder equipped with a suitable pressure regulator and a needlevalve to control gas flow. (WarningPure oxygen vigorously accelerates combustion. Verify all regulators,
35、lines, and valves arefree of grease and oil.)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 Analar Standards for Laboratory Chemicals, BDH Ltd., Pool
36、e, 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 Determination of Sulfur by the Infrared Detection, Method
37、BD4239 1737.4 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 metrology body can also be used. O
38、nly 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 specified in the appropriatesection on Precision and Bias of this test method.7.4.1 To minimize problems with
39、 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 remain in the container. The remaining material can be used for instrumen
40、t conditioning.7.5 BBOT (2,5-di(5-tert-butylbenzoxazol-2-yl)thiophene, C26H26N2O2S)A pure substance and certified reference material forsulfur (7.47 % sulfur).7.6 Tungsten Oxide (WO3)A combustion promoter and a fluxing agent. (WarningTungsten Oxide is a strong oxidizingagent.)8. Procedure8.1 Instrum
41、ent PreparationPerform apparatus set up system checks in accordance with manufacturers instructions.8.1.1 Balance CalibrationCalibrate the instrument balance in accordance with manufacturers instructions.8.2 Calibration of the Infrared Detection SystemIf the instrument has been previously calibrated
42、 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 Coke Certified Reference MaterialsSelect reference materials (7.4), in the range of thesamples to be anal
43、yzed. 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 expected. Select two additional reference materials, oneapproximately at the mid-point of the range and one
44、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 calibration. Use a material with a sulfur value near the mid point of the expected calibrationrange.8.2.1
45、.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 either Test Methods D3173 or D7582 or ISO 11722.Use a mass of material and the calibration procedure r
46、ecommended by the apparatus manufacturer. Weigh to at least the nearestinaccordance with section 6.6 1 mg and evenly spread the test portion of the reference material into the sample combustion boat (6.4).Position the sample in the hot zone of the furnace until the instrument returns to baseline as
47、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.8.2.2 Calibration with BBOTTo meet the precision requirements of this method, six calibratio
48、n 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 e
49、xpected,test portions of the calibrant that have as much sulfur as the lowest level of sulfur expected and test portions spread evenly inbetween the highest and lowest levels of sulfur.8.2.2.1 The mass of the calibrant needed can be calculated using the following equation: (Note 1).MC 5MT 3 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 substance calibrantNOTE 1In the interlaboratory study that yielded the data
