1、Designation: D5987 96 (Reapproved 2015)Standard Test Method forTotal Fluorine in Coal and Coke by PyrohydrolyticExtraction and Ion Selective Electrode or IonChromatograph Methods1This standard is issued under the fixed designation D5987; the number immediately following the designation indicates the
2、 year oforiginal adoption 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.1. Scope1.1 This test method covers the analysis of total fluor
3、ine incoal and coke.1.2 This analysis was successfully tested on coals contain-ing 37 % ash or less (see AS 1038.10.4 and Conrad2).1.3 The values stated in SI units shall be regarded asstandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all
4、 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 practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements see Note 4.1.5 All accountability
5、 and quality control aspects of GuideD4621 apply to this test method.2. Referenced Documents2.1 ASTM Standards:3D346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisD1193 Specification for Reagent WaterD2013 Practice for Preparing Coal Samples for AnalysisD2234/D2234M P
6、ractice for Collection of a Gross Sampleof CoalD3174 Test Method for Ash in the Analysis Sample of Coaland Coke from CoalD3180 Practice for Calculating Coal and Coke Analysesfrom As-Determined to Different BasesD4621 Guide for Quality Management in an OrganizationThat Samples or Tests Coal and Coke
7、(Withdrawn 2010)4D5142 Test Methods for Proximate Analysis of the AnalysisSample of Coal and Coke by Instrumental Procedures(Withdrawn 2010)42.2 Australian Standard:5AS 1038.10.4 Determination of Trace ElementsCoal,Coke and Fly-Ash-Determination of Fluorine ContentPyrohydrolysis Method3. Summary of
8、Test Method3.1 Total fluorine is determined in this test method by firstsubjecting the weighed test portion to pyrohydrolytic condi-tions which separate fluorine from the coal/coke matrix. Thepyrohydrolysate is then gravimetrically processed and finaldeterminations are made by either ion-selective e
9、lectrode orion chromatographic techniques.4. Significance and Use4.1 This test method permits measurement of the fluorinecontent of coal and coke for the evaluation of potential fluorineemission from coal combustion or conversion processes. Whencoal samples are combusted in accordance with this test
10、method, the fluorine is quantitatively released from the coaland retained in the pyrohydrolysate so that it is representativeof the total fluorine concentration in coal.5. Apparatus5.1 Laboratory WareExcept as noted, all laboratory ware,for example, volumetric flasks, beakers, bottles, etc., used fo
11、rsolutions containing fluoride ions must be made ofpolyethylene, polystyrene, or a heat-resistant polymer such aspolypropylene.5.2 VialsGlass or polystyrene, 10 to 30-mL capacity withtightly fitting snap-on plastic lids.1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Cok
12、e and is the direct responsibility of Subcommittee D05.29 on MajorElements in Ash and Trace Elements of Coal.Current edition approved Nov. 1, 2015. Published December 2015. Originallypublished approved in 1996. Last previous edition approved in 2007 asD598796(2007). DOI: 10.1520/D5987-96R15.2Conrad,
13、 V. B., and Brownlee, W. D., “HydropyrolyticIon ChromatographicDetermination of Fluoride in Coal and Geological Materials,” Analytical Chemistry,Vol 60, No. 4, 1988, pp. 365369.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. F
14、or Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY
15、 10036.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.3 BottlesPolypropylene, 125-mL capacity, wide-mouth,with liner-less leakproof polyethylene screw cap, for tube-furnace pyrohydrolysate processing.5.4 VialsPolystyrene, 70-mL cap
16、acity, with liner-lessleakproof polyethylene screw cap.5.5 Dispensing BottlesPolyethylene, 250-mL capacity, forthe standard fluorine solution (6.3.1) and of 600-mL capacityfor the absorption solution (6.3.3) and buffer (6.3.5).5.6 MicropipettesPolypropylene or other suitablepolymer, variable volumes
17、 ranging from 0.1 mL to at least 2.0mL. This is a satisfactory alternative to the 250-mL dispensingbottle (5.5), for the delivery of small volumes of the standardfluorine solution.5.7 Glass Dropper Bottle30-mL capacity for dispensingglacial acetic acid.5.8 BalanceAnalytical, with a sensitivity of 0.
18、1 mg. Thebalance shall be checked periodically to determine its accuracy.5.9 Apparatus for Tube-Furnace Pyrohydrolysis (see Fig.1):5.9.1 Silica Tube-Furnace and Accessories:5.9.1.1 Quartz Combustion TubeTranslucent, pure silica(25-mm outside diameter, 20-mm inside diameter) of lengthappropriate to t
19、he particular furnace used. Preferably, the gasoutlet end should be narrowed to a tubulure of approximately7 mm in diameter.NOTE 1Combustion tubes of alternative refractory compositions donot have adequate thermal stress characteristics for operation with this testmethod.5.9.1.2 Silicone Stoppers20
20、mm in diameter, positioned atinlet end and outlet, if applicable, of silica combustion tube(5.9.1.1).FIG. 1 Pyrohydrolysis Furnace and Fluorine Absorption AssemblyD5987 96 (2015)25.9.1.3 Combustion BoatsUnglazed porcelain, high alu-mina content, approximately 97 mm by 16 mm by 12 mm,preheated at 100
21、0C for 1 h.5.9.1.4 Silica Pusher and T-TubeA silica push rod ofdimensions 5 mm in diameter by 50 cm long, fused at one endto provide a flat disk surface of 10 to 12 mm in diameter andhaving a piece of magnetic steel affixed to the other end byepoxy resin. The T-tube, 50 cm long, is composed of boros
22、ili-cate glass and protrudes 10 mm into the silica tube (5.9.1.1)through a stopper (5.9.1.2). A magnet is used to move thepusher inside the T-tube.5.9.1.5 Combustion FurnaceCapable of reaching a maxi-mum temperature of at least 1100C.5.9.1.6 Heating Tape and Power RegulatorTo preventcondensation fro
23、m forming in the outlet end of the combustiontrain.5.9.2 Steam Generator (Fig. 1):5.9.2.1 Round Bottom FlaskGlass, 2-L capacity.5.9.2.2 Heating MantleOf size sufficient to heat the roundbottom flask (5.9.1.1).5.9.2.3 Y-pieceGlass, 10 mm in diameter.5.9.2.4 Gas Distribution TubeZero porosity.5.9.2.5
24、StopcocksOne three-way and one two-way.5.9.2.6 FlowmeterCapable of regulating and delivering atleast 1000 mL/min of the oxygen.5.9.3 Absorption Vessel Components:5.9.3.1 Separatory FunnelGlass, 125-mL capacity forrinsing Graham Condenser into receiving flask, with stopcockand 24/40 joint with drip t
25、ip.5.9.3.2 Graham CondenserFor condensinghydropyrolysate, with 24/40 outer joint at top. Water jacketlength should be 300 mm.5.9.3.3 Receiving Flask250-mL capacity, flat bottom,wide neck, and tooled mouth, for collection of pyrohydroly-sate.5.10 Ion-specific Electrode (ISE) Measurement Apparatus:5.1
26、0.1 Specific Ion MeterA pH meter with an expandablemillivolt scale sensitive to 0.1 mV, specific-ion meter orequivalent, suitable for method of standard addition determi-nations.65.10.2 ElectrodesSolid-state fluoride sensing, with theappropriate reference-type electrode as recommended by themanufact
27、urer.NOTE 2The fluoride sensing element should be polished frequentlyand in accordance with the manufacturers suggestions to prolong itsoptimal performance.5.10.3 Magnetic StirrerComplete with polytetrafluoroeth-ylene (PTFE) stirring bars and magnet for convenient removalof bars from vials.5.11 Ion-
28、Chromatograph (IC)Equipped with three, 3 by250-mmAS-3 anion separator columns and a fiber suppressor.76. Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall chemicals shall conform to the specifications of the com-mittee
29、 on Analytical Reagents of the American ChemicalSociety, where such specifications are available.8Other gradesmay be used, provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination.6.2 Reagent WaterReagent wat
30、er conforming to type IVof Specification D1193, shall be used in all cases unlessotherwise indicated. (Warning Some reagents used in thistest method are hazardous. Follow the precautions listed in theMaterial Safety Data Sheets of the manufacturer for eachreagent. )6.3 Solutions for ISE Test Method:
31、6.3.1 Standard Fluoride Solution (1 g = 200 g fluoride)The following standard fluoride solutions are required:6.3.1.1 For Direct Comparison MethodDissolve 0.22106 0.0002 g of dry (110C for 1 h) sodium fluoride inapproximately 400 mL of water in a 500-mL polypropylenebeaker. Transfer by thorough rins
32、ing with water to a 500-mLpolypropylene volumetric flask. Dilute to mark with water andmix. Discard after one month.NOTE 3There will not be a classic meniscus in polypropylenevolumetrics. The solution will correctly appear to have a flat surface.6.3.1.2 For Analyte-Addition Test MethodDissolve 0.221
33、06 0.0002 g of dry (110C for 1 h) sodium fluoride in a 500-mLpolypropylene beaker containing 150 mL of water and 250 mLof an unspiked buffered absorption solution (see 6.3.3).Transfer, by thorough rinsing with water, to a 500-mL poly-propylene volumetric flask. Dilute with water to the mark andmix.
34、Discard after one month (see Note 3).6.3.2 Absorption Solution (0.025 M NaOH)Dissolve 2.0 gof sodium hydroxide in about 500 mL of water. Transfer to a2.0-L polypropylene flask, dilute to mark with water, and mix.6.3.3 Unspiked Buffered Absorption (pH 6.5)Dissolve10.0 g of potassium nitrate, 2.0 g of
35、 sodium hydroxide, and 115g of ammonium acetate in 1700 mL of water. Adjust pH to 6.5with a small amount of glacial acetic acid. Transfer to a 2.0-Lpolypropylene flask, dilute to mark with water, and mix.6.3.4 Buffer Added After Tube-Furnace Hydrolysis (pH6.5)Dissolve 10.0 g of potassium nitrate and
36、 115 g ofammonium acetate in 350 mL of water. Adjust pH to 6.5 witha small amount of glacial acetic acid. Transfer to a 500-mLpolypropylene volumetric flask, dilute to mark with water, andmix.6.3.5 Solution for Conditioning Fluoride ISEUsing apipette, transfer 20.0 mL of water, 20.0 mL of absorbing6
37、Midgley, D., and Torrance, K., “Potentiometric Water Analysis,” John Wileyand Sons, 1978.7Rice, T. D., Analytica Chimica Acta, 1983, 151, pp. 383389.8Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents not
38、listed by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D5987 96 (2015)3solution (6.3.2), and 10.0 mL of buffer (6.3.4) int
39、o a polysty-rene vial (5.2). Add 200 L of standard fluoride solution(6.3.1.1) and mix.6.4 Solutions for Ion-Chromatographic Measurement:6.4.1 Standard Fluoride Solution (1000 g/mL fluoride)Dissolve 2.2110 6 0.0002 g of dry (105C for 1 h) sodiumfluoride in a 250-mLpolypropylene beaker containing appr
40、oxi-mately 150 mLof water.Transfer with thorough rinses of waterto a 1.0-L polypropylene volumetric flask. Dilute with water tothe mark and mix (see Note 3).6.4.2 Standard Fluoride Solution (1.0 g/mL fluoride)Transfer, by means of polypropylene pipette, 1.0 mL ofstandard fluoride solution (6.4.1) to
41、 a 1.0-L polypropylenevolumetric flask; dilute to mark with water and mix (see Note3). Prepare fresh solution daily.6.4.3 Sulfuric Acid, Standard (2.5 N)Cautiously dilute 71mL of sulfuric acid (H2SO4, sp gr 1.834 to 1.836) to 1 L withwater. Mix well.6.4.4 Sulfuric Acid, Standard (0.025 N)For use as
42、sup-pressor regenerator. Using a pipette, cautiously dilute 10.0 mLof 2.5 N H2SO4(6.4.3) to 1 L with water. Mix well.6.4.5 Sodium Bicarbonate Solution (0.0015 M)Weakeluent, for use as the absorbing solution and the Grahamcondenser rinsing solution. Dissolve 0.2520 g of dry (105Cfor 1 h) NaHCO3in wat
43、er and dilute to 2.0 L. Mix well.6.4.6 Sodium Bicarbonate Solution (0.02 M)Strong elu-ent. Dissolve 1.6801 g of dry (105C for 1 h) NaHCO3in waterand dilute to 1.0-L. Mix well.6.5 OxygenFree of combustible matter and guaranteed tobe 99.5 % pure.6.6 HeliumRefer to ion chromatograph manufacturersrecomm
44、endations for gas specifications.7. Sample7.1 Prepare the analysis sample in accordance with MethodD2013 or Practice D346 to pass a 250-m (60-mesh) sieve.Pulverize the analysis sample to pass a 75-m (200-mesh)sieve.7.2 Analyze a separate portion of the analysis sample formoisture content in accordan
45、ce with Test Method D3174 orTest Methods D5142 if calculation to other than as-determinedbasis is desired. As an alternative, dry the analysis sample at105 to 110C for 2 h prior to weighing. Transfer the driedsample to a desiccator, and weigh for analysis promptly uponcooling, which will be approxim
46、ately 10 min.8. Procedure for Pyrohydrolysis8.1 Test Preparation:8.1.1 Thoroughly mix the analysis sample of coal or coke.Carefully weigh 1 g 6 0.1 mg into the combustion boat(5.9.1.1).8.1.2 Program the reagent and apparatus blank tests (induplicate) for the beginning, middle, and completion of thep
47、rocessing of the test samples.8.2 Tube-Furnace Pyrohydrolysis:8.2.1 Apparatus ConditioningAdd a few boiling chips andfour sodium hydroxide pellets to the round-bottom flask(5.9.2.1) containing 1600 mL of water. Allow the steamgenerator to achieve a gentle boil. Place an empty receivingflask (5.9.3.3
48、) under the Graham condenser. With the furnaceset at an operational temperature of 1100C, pass oxygenthrough the steam generator into the furnace at approximately1000 mL/min for 15 min.8.2.2 Pyrohydrolysis:8.2.2.1 Add 50 6 1 mL of the appropriate absorptionsolution (6.3.2) for ISE finish or 65 6 1 m
49、L of the absorptionsolution (6.4.5) for the IC finish to a clean receiving flask(5.9.3). Place the flask underneath the condenser. Ensure thatcooling water is passing through the condenser.8.2.2.2 Allow oxygen to flow, bypassing the steamgenerator, at 750 mL/min into the furnace. Place the analysissample boat into a zone at which the temperature of the samplewill not exceed 300C. Redirect the oxygen flow through thesteam generator and into the furnace. At subsequent intervalsof approximately 30 s, push the anal
