1、Designation: D4239 101Standard 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 ca
2、se 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.1NOTEThe title of Tab
3、le 1 was editorially corrected in August 2010.1. Scope1.1 This test method covers the determination of sulfur insamples of coal or coke by high-temperature tube furnacecombustion.1.2 When automated equipment is used the procedure canbe classified as an instrumental method.1.3 The values stated in SI
4、 units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 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 standard to establish appro-priate safety and health
5、practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisD2013 Practice for Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the
6、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 Labo-ratories Using ASTM Procedures in the Sampling andAnalysis of Coal and
7、CokeD7582 Test Methods for Proximate Analysis of Coal andCoke by Macro Thermogravimetric Analysis2.2 ISO Standard:3ISO 11722 Solid Mineral Fuels-Hard Coal Determinationof Moisture in the general analysis test sample by dryingin nitrogen3. Summary of Test Method3.1 Combustion Method with Infrared Abs
8、orptionDetectionA weighed test portion of sample is burned in atube furnace at a minimum operating temperature of 1350C ina stream of oxygen. During combustion at temperatures above1350 C, the sulfur and sulfur compounds contained in thesample are decomposed and oxidized almost exclusively togaseous
9、 sulfur dioxide, SO2. Moisture and particulates areremoved from the gas by filters. The gas stream is passedthrough a cell in which sulfur dioxide is measured by aninfrared (IR) absorption detector. Sulfur dioxide absorbs IRenergy at a precise wavelength within the IR spectrum. Energyis absorbed as
10、the gas passes through the cell body in which theIR energy is being transmitted: thus, at the detector, less energyis received.All other IR energy is eliminated from reaching thedetector by a precise wavelength filter. Thus, the absorption ofIR energy can be attributed only to sulfur dioxide whoseco
11、ncentration is proportional to the change in energy at thedetector. One cell is used as both a reference and a measure-ment chamber. Total sulfur as sulfur dioxide is detected on acontinuous basis.4. Significance and Use4.1 Sulfur is part of the ultimate analysis of coal and coke.4.2 Results of the
12、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 for scientific purposes.1This test method i
13、s under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.21 on Methods ofAnalysis.Current edition approved May 1, 2010. Published July 2010. Originally approvedin 1983. Last previous edition approved in 2008 as D4239 08. DOI: 10.1520/D4239-1
14、0.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact 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 Standardizat
15、ion (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3 The competency of laboratories with respect to use ofthis standard can be esta
16、blished 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 separate portion of the analysis sample formoisture content in accordance with Test Method D3173,orD7582 or ISO
17、11722 for calculations to other than the as-determined basis.5.3 Procedures for calculating as-determined sulfur valuesobtained from the analysis sample to other bases are describedin Practices D3176 and D3180.6. Apparatus6.1 Measurement ApparatusEquipped to combust thesample as described in 3.1 (Se
18、e Fig. 1).6.2 Tube FurnaceCapable of heating the hot zone of thecombustion tube (6.3) to at least 1350C. It is normally heatedelectrically using resistance rods, a resistance wire, or molyb-denum disilicide elements. Specific dimensions can vary withmanufacturers design.6.3 Combustion TubeMade of mu
19、llite, porcelain, or zir-con with provisions for routing the gasses produced bycombustion through the infrared cell.6.4 Sample Combustion Boats, made of iron-free materialand of a convenient size suitable for the dimensions of thecombustion tube.6.5 Boat PullerWhere required, a rod of a heat-resista
20、ntmaterial with a bent or disk end to insert and remove boatsfrom the 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 Ameri
21、can Chemical Society, where suchspecifications are available.4Other 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(WarningMagnesiumperchlorate is a strong o
22、xidizing agent. Do not regenerate theabsorbent. Do not allow 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 com
23、bustion. Verify all regulators, lines,and valves are free of 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
24、 coke(s)prepared by a national metrology body can also be used. 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 Precisi
25、on and Bias ofthis test method.4Reagent 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, Dorset, U.K.,
26、and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Apparatus for the Determination of Sulfur by the Infrared Detection MethodD4239 10127.4.1 To minimize problems with instrument calibration orcalibration verification mix all refe
27、rence 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 instrument conditioning.8. Procedure8.1 Instrument PreparationPerform app
28、aratus 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 SystemCIf theinstrument has been previously calibrated in accordance withthe s
29、ection on instrument calibration proceed to the AnalysisProcedure otherwise carry out a calibration as specified in thesection on instrument calibration.8.2.1 Select reference materials (7.4), in the range of thesamples to be analyzed. Use at least three such referencematerials, for each range of su
30、lfur values to be tested. Selectone reference material 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 materia
31、l recommended by the appa-ratus manufacturer to carry 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 material employed for calibra-tion, use the as-
32、determined sulfur value previously calculatedfrom the certified dry-basis sulfur value and residual moisturedetermined using either Test Methods D3173 or D7582 orISO 11722. Use a mass of material and the calibration proce-dure recommended by the apparatus manufacturer. Weigh to atleast the nearest 1
33、 mg and evenly spread the test portion of thereference material into the sample combustion boat (6.4).Position the sample in the hot zone of the furnace until theinstrument returns to baseline as indicated according to settingsrecommended by the manufacturer. If the analysis time ex-ceeds the maximu
34、m analysis time recommended by the manu-facturer take corrective action as recommended by the manu-facturer.8.2.2 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
35、analyzing test samples, upon completion of all testsamples and as needed to meet quality control requirements.Analyze a test portion of reference material(s) (7.4) using theapparatus conditions employed for instrument calibration(8.2.1). Use a mass that does not exceed the maximum massused for instr
36、ument calibration and with a sulfur value withinthe range of the instrument calibration. If the value determinedfor each reference material employed for verification is notwithin the specified uncertainty for the assigned sulfur valuerepeat the instrument calibration in accordance with 8.2.1.Repeat
37、all samples analyzed since the last successful calibra-tion verification.8.3 Analysis ProcedureSet up the apparatus (see 8.1) andverify the calibration (see 8.2.2).8.3.1 1 Raise the furnace temperature as recommended bythe manufacturer to at least 1350C. Weigh a mass of thesample to at least the nea
38、rest 1 mg and not exceeding themaximum mass of reference material(s) used for calibration.Analyze the test samples using the apparatus conditionsemployed for calibration (8.2.1).8.3.2 When the analysis is complete, the instrument indi-cates the sulfur value.9. Calculation to Other Bases9.1 The perce
39、nt sulfur value obtained is on an as-determinedbasis.9.2 Procedures for converting the as-determined value toother bases are described in Practices D3176 and D3180.10. Precision and Bias10.1 Precision-250 m (No. 60) Samples5The precisionof this method for the determination of Sulfur in the 60 meshsa
40、mple of coal and coke is shown in Table 1. The precision ischaracterized by repeatability (Sr, r) and reproducibility (SR,R) is described in Table A1.1 in the Annex A1.10.1.1 Repeatability Limit (r)-the value below which theabsolute difference between two test results calculated to a drybasis (Pract
41、ice D3180) of separate and consecutive test deter-minations, carried out on the same sample in the samelaboratory by the same operator using the same apparatus onsamples taken at random from a single quantity of homoge-neous material, may be expected to occur with a probability ofapproximately 95%.1
42、0.1.2 Reproducibility Limit (R)the value below whichthe absolute difference between two test results calculated to adry basis (Practice D3180) carried out in different laboratoriesusing samples taken at random from a single quantity ofmaterial that is as homogeneous as possible, may be expectedto oc
43、cur with a probability of approximately 95%.10.2 BiasBias is minimized when reference material(s)are employed to calibrate the instrument.5An interlaboratory study, designed consistent with ASTM Practice E691, wasconducted in 1999. Twelve laboratories participated in this study. Supporting datahave
44、been filed at ASTM International Headquarters and may be obtained byrequesting Research Report RR:D05-1020. This report contains information on 60mesh samples from the InfraredAbsorption Detection method, not for theAcid Basemethod.TABLE 1 Repeatability and Reproducibility for Sulfur in 250 m(No.60)
45、 CoalRange Repeatability Limit (r) Reproducibility Limit (R)0.285.61 0.02 + 0.03 XA0.02 + 0.09 XAAwhere X is the average of two single test results.D4239 1013ANNEXA1. Precision StatisticsA1.1 The precision of this test method, characterized byrepeatability (Sr, r) and reproducibility (SR, R) has bee
46、ndetermined for the following materials as listed in Table A1.1.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any suc
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