1、Designation:D423911 Designation: D4239 12Standard 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 ado
2、ption 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.This standard has been approved for use by agencies of the Department of Defense.1.
3、 Scope1.1 This test method covers the determination of sulfur in samples of coal or coke by high-temperature tube furnace combustion.1.2When automated equipment is used the procedure can be classified as an instrumental method.1.1.1 Two analysis methods are described.1.2 When automated equipment is
4、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 This standard does not purport to address all of the safety concerns, if any, associated with its use. It
5、is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D346 Practice for Collection and Preparation of Coke Samples for Laboratory Analysis
6、D2013 Practice for Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the Analysis Sample of Coal and CokeD3176 Practice for Ultimate Analysis of Coal and CokeD3180 Practice for Calculating Coal and Coke Analyses from As-Determined to Different BasesD7448 Practice for Establishing
7、the Competence of Laboratories UsingASTM Procedures in the Sampling andAnalysis of Coaland CokeD7582 Test Methods for Proximate 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 Standa
8、rd:3ISO 11722 Solid Mineral Fuels-Hard Coal Determination of Moisture in the general analysis test sample by drying in nitrogen3. Summary of Test Method3.1 Combustion Method with Infrared Absorption DetectionA (1350C)A weighed test portion of sample is burned in a tubefurnace at a minimum combustion
9、 tube operating temperature of 1350C in a stream of oxygen. During combustion at temperaturesabove 1350 C, the sulfur and sulfur compounds contained in the sample are decomposed and oxidized almost exclusively togaseous sulfur dioxide, SO2. Moisture and particulates are removed from the gas by filte
10、rs. The gas stream is passed through a cellin which sulfur dioxide is measured by an infrared (IR) 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 beingtransmitte
11、d: thus, at the detector, less energy is received. All other IR energy is eliminated from reaching 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 ce
12、ll is used as both a reference and a measurement chamber. Total sulfur as sulfurdioxide is detected on a continuous basis.1This test method is under the jurisdiction of ASTM Committee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.21 on Methods of Analysis.Current edition
13、approved April 1, 2011. Published April 2011. Originally approved in 1983. Last previous edition approved in 2010 as D4239101. DOI:10.1520/D4239-11.Current edition approved Feb. 1, 2012. Published February 2012. Originally approved in 1983. Last previous edition approved in 2011 as D4239 11. DOI:10.
14、1520/D4239-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Available from International Organization fo
15、r Standardization (ISO), 1, ch. de la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.1This 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 ma
16、y not 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.Copyright ASTM International, 100 Barr Harb
17、or Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 s
18、ample and WO3.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 a
19、n infrared (IR) 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 eliminate
20、d from reaching 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 sulfurdio
21、xide is detected 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
22、processes, and 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
23、 (250-m) sieve 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 calculat
24、ing as-determined 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 o
25、f the combustion tube (Capable of heating the hot zone or outer surfaceof 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 dimensions can vary with manufacturers design.6.3 Co
26、mbustion TubeMade of mullite, porcelain, or zircon with provisions for routing the gasses produced by combustionthrough the infrared cell. Made of mullite, porcelain, or zircon with provisions for routing the gases produced by combustionFIG. 1 Apparatus for the Determination of Sulfur by the Infrare
27、d Detection, Method AD4239 122through 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 suitable for the d
28、imensions 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.Combustion Method B (1150C)6.6 Measurement ApparatusEquipped to combust the sample as described in 3.2 (See Fig. 2)6.7 Tube Fur
29、naceCapable of heating the hot zone or outer surface of the combustion tube, or both (6.8) to at least 1150C.It is normally heated electrically using resistance wire. Specific dimensions can vary with manufacturers design.6.8 Combustion TubeMade of quartz with provisions for routing the gases produc
30、ed by combustion through the infrared cell.6.9 Sample Combustion BoatMade of an iron-free tin material and of 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
31、 all reagentsconform to the specifications of the Committee onAvailable Reagents of theAmerican Chemical Society, where such specificationsare available.4Other grades can be used, provided it is first ascertained the reagent is of sufficiently high purity to permit its usewithout lessening the accur
32、acy of the determination.7.2 Magnesium Perchlorate(WarningMagnesium perchlorate is a strong oxidizing agent. Do not regenerate theabsorbent. 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
33、 regulator and a needlevalve to control gas flow. (WarningPure oxygen vigorously accelerates combustion. Verify all regulators, lines, and valves arefree of grease and oil.)7.4 Reference Materials, Reference Material (RM)that are coal(s) or coke(s) prepared by a national metrology body. Othermateria
34、ls 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. Only use material(s) with an assigned value and assigned uncertainty for sulfur. Theuncertainty expressed as the confidence interval of th
35、e 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 instrument calibration or calibration verification mix all reference material before removingthe test portion from the container. Do not
36、 use the reference material for calibration or calibration verification when less than 2g remain in the container. The remaining material can be used for instrument conditioning.7.5 Tungsten Oxide (WO3)A combustion promoter and a fluxing agent. (WarningTungsten Oxide is a strong oxidizingagent.)8. P
37、rocedure8.1 Instrument 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 SystemCIfIf the instrument has been
38、 previously calibrated in accordance with thesection on instrument calibration proceed to the Analysis Procedure, otherwise carry out a calibration as specified in the sectionon instrument calibration.4Reagent Chemicals, American Chemical Society Specifications , American Chemical Society, Washingto
39、n, 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.FIG. 2 Appar
40、atus for the Determination of Sulfur by the Infrared Detection, Method BD4239 1238.2.1 Select reference materials (7.4), in the range of the samples to be analyzed. Use at least three such reference materials,for each range of sulfur values to be tested. Select one reference material containing at l
41、east as much sulfur as the highest levelof sulfur expected. Select two additional reference materials, one approximately at the mid-point of the range and one below thelowest level of sulfur expected.8.2.1.1 Use a mass of material recommended by the apparatus manufacturer to carry out a minimum of t
42、hree determinationsto condition the equipment before calibration. Use a material with a sulfur value near the mid point of the expected calibrationrange.8.2.1.2 For each reference material employed for calibration, use the as-determined sulfur value previously calculated from thecertified dry-basis
43、sulfur value and residual moisture determined using either Test Methods D3173 or D7582 or ISO 11722. Usea mass of material and the calibration procedure recommended by the apparatus manufacturer. Weigh to at least the nearest 1 mgand evenly spread the test portion of the reference material into the
44、sample combustion boat (6.4). Position the sample in the hotzone of the furnace until the instrument returns to baseline as indicated according to settings recommended by the manufacturer.If the analysis time exceeds the maximum analysis time recommended by the manufacturer take corrective action as
45、 recommendedby the manufacturer.8.2.2 Calibration VerificationCarry out a minimum of three determinations to condition the equipment before calibrationverification (see 8.2.1.1). Verify the instrument calibration prior to analyzing test samples, upon completion of all test samples andas needed to me
46、et quality control requirements. Analyze a test portion of reference material(s) (7.4) using the apparatus conditionsemployed for instrument calibration (8.2.1). Use a mass that does not exceed the maximum mass used for instrument calibrationand with a sulfur value within the range of the instrument
47、 calibration. If the value determined for each reference material employedfor verification is not within the specified uncertainty for the assigned sulfur value repeat the instrument calibration in accordancewith 8.2.1. Repeat all samples analyzed since the last successful calibration verification.8
48、.3 Analysis ProcedureCombustion Method A (1350C)Set up the apparatus (see 8.1) and verify the calibration (see 8.2.2).8.3.1 1Raise the furnace temperature as recommended by the manufacturer to at least 1350C. Weigh a mass of the sample toat least the nearest 1 mg and not exceeding the maximum mass o
49、f reference material(s) used for calibration. Analyze the testsamples using the apparatus conditions employed for calibration (8.2.1).8.3.2 When the analysis is complete, the instrument indicates the sulfur value.8.4 Combustion Method B (1150C)Set up the apparatus (see 8.1) and verify the calibration (see 8.2.2)8.4.1 Raise the furnace temperature as recommended by the manufacturer to at least 1150C.8.4.2 Weigh to the nearest 1 mg and evenly spread into a combustion boat (6.9) a portion of tungsten oxide equal to the targetweig
