1、Designation: D 5987 96 (Reapproved 2007)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 D 5987; the number immediately following the designation indicates t
2、he 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the analysis of total fl
3、uorine 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
4、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 practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements see Note 4.1.5 All accountabil
5、ity and quality control aspects of GuideD 4621 apply to this test method.2. Referenced Documents2.1 ASTM Standards:3D 346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisD 1193 Specification for Reagent WaterD 2013 Practice for Preparing Coal Samples for AnalysisD 2234/
6、D 2234M Practice for Collection of a Gross Sampleof CoalD 3174 Test Method forAsh in theAnalysis Sample of Coaland Coke from CoalD 3180 Practice for Calculating Coal and Coke Analysesfrom As-Determined to Different BasesD 4621 Guide for Quality Management in an OrganizationThat Samples or Tests Coal
7、 and CokeD 5142 Test Methods for Proximate Analysis of the Analy-sis Sample of Coal and Coke by Instrumental Procedures2.2 Australian Standard:4AS 1038.10.4 Determination of Trace ElementsCoal,Coke and Fly-Ash-Determination of Fluorine ContentPyrohydrolysis Method3. Summary of Test Method3.1 Total f
8、luorine 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 electrode orion chromat
9、ographic 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 testmethod, the fluorine i
10、s 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 forsolutions containing
11、fluoride ions must be made of polyethyl-ene, polystyrene, or a heat-resistant polymer such as polypro-pylene.5.2 VialsGlass or polystyrene, 10 to 30-mL capacity withtightly fitting snap-on plastic lids.5.3 BottlesPolypropylene, 125-mL capacity, wide-mouth,with liner-less leakproof polyethylene screw
12、 cap, for tube-furnace pyrohydrolysate processing.5.4 VialsPolystyrene, 70-mL capacity, with liner-lessleakproof polyethylene screw cap.1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.29 on MajorElements in Ash an
13、d Trace Elements of Coal.Current edition approved Oct. 1, 2007. Published October 2007. Originallypublished approved in 1996. Last previous edition approved in 2002 asD 598796(2002).2Conrad, V. B., and Brownlee, W. D., “HydropyrolyticIon ChromatographicDetermination of Fluoride in Coal and Geologica
14、l 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. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM we
15、bsite.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.5 Dispensing BottlesPolyethylene, 250-mLcapacity, forthe standard fluo
16、rine 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 suitable poly-mer, variable volumes ranging from 0.1 mL to at least 2.0 mL.This is a satisfactory alternative to the 250-mL dispensingbottle (5.5), for the deliv
17、ery 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 0.1 mg. Thebalance shall be checked periodically to determine its accuracy.5.9 Apparatus for Tube-Furnace Pyrohydrolysis (see Fi
18、g.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 the particular furnace used. Preferably, the gasoutlet end should be narrowed to a tubulure of approximately7 mm in diameter.NO
19、TE 1Combustion tubes of alternative refractory compositions donot have adequate thermal stress characteristics for operation with this testmethod.5.9.1.2 Silicone Stoppers20 mm in diameter, positioned atinlet end and outlet, if applicable, of silica combustion tube(5.9.1.1).5.9.1.3 Combustion BoatsU
20、nglazed porcelain, high alu-mina content, approximately 97 mm by 16 mm by 12 mm,preheated at 1000C for 1 h.FIG. 1 Pyrohydrolysis Furnace and Fluorine Absorption AssemblyD 5987 96 (2007)25.9.1.4 Silica Pusher and T-TubeA silica push rod ofdimensions 5 mm in diameter by 50 cm long, fused at one endto
21、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 borosili-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 thepus
22、her 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 from forming in the outlet end of the combustiontrain.5.9.2 Steam Generator (Fig. 1):5.9.2.1 Round Bottom FlaskGlass, 2-L capaci
23、ty.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 StopcocksOne three-way and one two-way.5.9.2.6 FlowmeterCapable of regulating and delivering atleast 1000 mL/min of the oxyge
24、n.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 tip.5.9.3.2 Graham CondenserFor condensing hydropyroly-sate, with 24/40 outer joint at top. Water jacket length shouldbe 300 m
25、m.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:5.10.1 Specific Ion MeterA pH meter with an expandablemillivolt scale sensitive to 0.1 mV, specific-ion meter orequivalent, su
26、itable for method of standard addition determi-nations.55.10.2 ElectrodesSolid-state fluoride sensing, with theappropriate reference-type electrode as recommended by themanufacturer.NOTE 2The fluoride sensing element should be polished frequentlyand in accordance with the manufacturers suggestions t
27、o prolong itsoptimal performance.5.10.3 Magnetic StirrerComplete with polytetrafluoroet-hylene (PTFE) stirring bars and magnet for convenient removalof bars from vials.5.11 Ion-Chromatograph (IC)Equipped with three, 3 by250-mmAS-3 anion separator columns and a fiber suppressor.66. Reagents6.1 Purity
28、 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 on Analytical Reagents of the American ChemicalSociety, where such specifications are available.7Other gradesmay be used,
29、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 water conforming to type IVof Specification D 1193, shall be used in all cases unlessotherwise indicated. (WarningSome reagent
30、s 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:6.3.1 Standard Fluoride Solution (1 g = 200 g fluoride)The following standard fluoride solutions are required:6.3.1.1 For Di
31、rect 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 rinsing with water to a 500-mLpolypropylene volumetric flask. Dilute to mark with water andmix. Discard after one month.NOTE 3Th
32、ere 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 MethodDissolve0.2210 6 0.0002 g of dry (110C for 1 h) sodium fluoride in a500-mL polypropylene beaker containing 150 mL of water and250 mLof an
33、unspiked buffered absorption solution (see 6.3.3).Transfer, by thorough rinsing with water, to a 500-mLpolypro-pylene volumetric flask. Dilute with water to the mark and mix.Discard after one month (see Note 3).6.3.2 Absorption Solution (0.025 M NaOH)Dissolve 2.0g of sodium hydroxide in about 500 mL
34、 of water. Transfer toa 2.0-L polypropylene flask, dilute to mark with water, andmix.6.3.3 Unspiked Buffered Absorption (pH 6.5)Dissolve10.0 g of potassium nitrate, 2.0 g of sodium hydroxide, and 115g of ammonium acetate in 1700 mL of water. Adjust pH to 6.5with a small amount of glacial acetic acid
35、. 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 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-mLp
36、olypropylene 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 absorbingsolution (6.3.2), and 10.0 mL of buffer (6.3.4) into a polysty-rene vial (5.2). Add 200 L of standard fluoride solution(6.3.1.1)
37、 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) sodium5Midgley, D., and Torrance, K., “Potentiometric Water Analysis,” John Wileyand Sons, 1978.6Rice, T. D., Analytica Chimica Acta, 1983,
38、 151, pp. 383389.7Reagent 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., and the United
39、 States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D 5987 96 (2007)3fluoride in a 250-mLpolypropylene beaker containing approxi-mately 150 mLof water.Transfer with thorough rinses of waterto a 1.0-L polypropylene volumetric flask. Dilute with water t
40、othe 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 a 1.0-L polypropylenevolumetric flask; dilute to mark with water and mix (see Note3). Prepare fresh solution daily.6.4.3 Sulf
41、uric 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 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 Sod
42、ium Bicarbonate Solution (0.0015 M)Weak elu-ent, for use as the absorbing solution and the Graham con-denser rinsing solution. Dissolve 0.2520 g of dry (105C for 1h) NaHCO3in water 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
43、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 manufacturersrecommendations for gas specifications.7. Sample7.1 Prepare the analysis sample in accordance with MethodD 2013 or Practice D 34
44、6 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 accordance with Test Method D 3173 orTest Methods D 5142 if calculation to other than as-determinedbasis is desired. As an alter
45、native, 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 approximately 10 min.8. Procedure for Pyrohydrolysis8.1 Test Preparation:8.1.1 Thoroughly mix the analysis sample of coal or c
46、oke.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 theprocessing of the test samples.8.2 Tube-Furnace Pyrohydrolysis:8.2.1 Apparatus ConditioningAdd a few boiling chipsand f
47、our 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) under the Graham condenser. With the furnaceset at an operational temperature of 1100C, pass oxygenthrough the steam
48、 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 mL of the absorptionsolution (6.4.5) for the IC finish to a clean receiving flask(5.9.3). Place the flask underneath th
49、e condenser. Ensure thatcooling water is passing through the condenser.8.2.2.2 Allow oxygen to flow, bypassing the steam genera-tor, at 750 mL/min into the furnace. Place the analysis sampleboat into a zone at which the temperature of the sample will notexceed 300C. Redirect the oxygen flow through the steamgenerator and into the furnace. At subsequent intervals ofapproximately 30 s, push the analysis sample boat into hotterzones with the temperature not exceeding 400, 500, 750, and1000C, with a final push into
