1、Designation: D3682 01 (Reapproved 2006)D3682 13Standard Test Method forMajor and Minor Elements in Combustion Residues fromCoal Utilization Processes1This standard is issued under the fixed designation D3682; the number immediately following the designation indicates the year oforiginal adoption or,
2、 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 the commonly determined major and minor
3、elements in combustion residues fromcoal utilization processes.NOTE 1Test MethodsMethod D1757 or D5016 shall be used for determination of sulfur.1.2 The values stated in SI units (are IEEE/ASTM SI 10 ) shall to be regarded as the standard. No other units of measurementare included in this standard.1
4、.3 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 regulatorylimitations prior to use.2. Referenced Docu
5、ments2.1 ASTM Standards:2D121 Terminology of Coal and CokeD346 Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisD1193 Specification for Reagent WaterD1757 Test Method for Sulfate Sulfur in Ash from Coal and Coke (Withdrawn 2009)3D2013 Practice for Preparing Coal Samples
6、 for AnalysisD3173 Test Method for Moisture in the Analysis Sample of Coal and CokeD3174 Test Method for Ash in the Analysis Sample of Coal and Coke from CoalD3180 Practice for Calculating Coal and Coke Analyses from As-Determined to Different BasesD5016 Test Method for Total Sulfur in Coal and Coke
7、 Combustion Residues Using a High-Temperature Tube FurnaceCombustion Method with Infrared AbsorptionD7348 Test Methods for Loss on Ignition (LOI) of Solid Combustion ResiduesD5142D7582 Test Methods for ProximateAnalysis of theAnalysis Sample of Coal and Coke by Instrumental ProceduresMacroThermograv
8、imetric Analysis (Withdrawn 2010)E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodIEEE/ASTM SI 10 Standard for Use of the International System of Units (SI): The Modern Metric System3. Terminology3.1 For definitions of terms used in this test method, r
9、efer to Terminology D121.4. Summary of Test Method4.1 The combustion residue to be analyzed is ignited in air at 750C to a constant weight. The ash is fused within lithiumtetraborate (Li2B4O7) followed by a final dissolution of the melt in either dilute hydrochloric acid (HCl) or dilute nitric acid(
10、HNO3). The solution is analyzed by atomic absorption/emission for applicable elements.1 This test method is under the jurisdiction of ASTM Committee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.29 on Major Elements inAsh and Trace Elements of Coal.Current edition approve
11、d April 1, 2006Oct. 15, 2013. Published April 2006November 2013. Originally approved in 1978. Last previous edition approved in 20012006as D3682 01 1.(2006). DOI: 10.1520/D3682-01R06.10.1520/D3682-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service
12、 at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.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 v
13、ersion. Becauseit may 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 Internat
14、ional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Significance and Use5.1 A compositional analysis of the ash in coal is often useful in the total description of the quality of the coal. Knowledge ofash composition is also useful in predicting the behavior
15、 of ashes and slags in combustion chambers. Utilization of the ashby-products of coal combustion sometimes depends on the chemical composition of the ash.5.2 Note that the chemical composition of laboratory-prepared coal ash may not exactly represent the composition of mineralmatter in the coal or t
16、he composition of fly ash and slag resulting from commercial-scale burning of the coal.6. Apparatus6.1 Ashing Furnace, with an adequate air circulation and capable of having its temperature regulated between 700at 500C and750C.6.2 Fusion Furnace, with an operating temperature of 1000C.6.3 Platinum D
17、ish, 35- to 85-mL 85 mL capacity.6.4 Stirring Hotplate and Bars, operating temperature of 200C.6.5 Atomic Absorption SpectrometerAny dual-channel instrument using a deuterium (D2) arc background corrector or othercomparable simultaneous background correction system.7. Reagents7.1 Purity of ReagentsR
18、eagent grade chemicals shall be used in all tests. It is intended that all reagents shall conform to thespecifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications areavailable.3 Other grades may be used, provided it is first ascertained that th
19、e reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determination. The lithium tetraborate and lanthanum chloride reagents in particular shouldbe examined for alkali and alkaline earth contamination.7.2 Purity of WaterUnless otherwise indicated, references
20、 to water shall be understood to mean Type II reagent water asdefined in Specification D1193.7.3 Aluminum Stock Solution (1000-ppm aluminum).7.4 Calcium Stock Solution (1000-ppm calcium).7.5 Iron Stock Solution (1000-ppm iron).7.6 Lanthanum Chloride Solution (175-g/L lanthanum chloride (LaCl3) or eq
21、uivalent 10 % lanthanum).7.7 Lithium Tetraborate(Li2 B4O7), powder.7.8 Magnesium Stock Solution (1000-ppm magnesium).7.9 Potassium Stock Solution (1000-ppm potassium).7.10 Silicon Stock Solution (200-ppm silicon) (Note 2).7.11 Sodium Stock Solution (1000-ppm sodium).7.12 Solvent AcidDilute 50 mLof c
22、oncentrated hydrochloric acid (sp gr 1.19) or 50 mLof concentrated nitric acid (sp gr 1.42)to 1000 mL. Either acid solution may be used, but whichever is chosen should be used throughout the subsequent solutionpreparations.7.13 Titanium Stock Solution (1000-ppm titanium).NOTE 2Commercial silicon sta
23、ndards prepared from sodium silicate have not proved satisfactory.Astandard stock solution can be prepared by fusing0.1070 g of reignited spectrographic grade silica (SiO2) with 1 g of lithium tetraborate, dissolving in solvent acid, and diluting to 250 mL as describedfor sample preparation in 8.3.1
24、9.3.1 and 8.3.29.3.2. This solution is 200-ppm silicon. Preferable standard preparations for silica are made by fusion anddilution of ash sample(s) of known composition in accordance with 8.3.19.3.1 and 8.3.29.3.2.The standard sample(s) should have a composition(s) similarto the unknown.8. Sample Pr
25、eparation8.1 Coal and CokeThe combustion residue to be analyzed must first be ignited in air at 750C to a constant weight beforeanalysis. Allow the ash to cool, transfer to an agatePrepare the analysis sample in accordance with Practice D2013 mortar, andgrind to passfor coal or Practice D346 a 74-m
26、(No. 200) sieve. Reignite the ash at 750C for 1 h, cool rapidly, and immediatelyweigh portions for analysis. If samples are stored, reignite the ash before weighing or determine the loss on ignition at 750C on3 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, W
27、ashington, 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.D368
28、2 132a separate sample weighted out at the same time as the analysis sample and make the necessary corrections. Thoroughly mix eachsample before weighing.for coke by pulverizing the material to pass a 250 m (No. 60) U.S.A. standard sieve.8.1.1 Analyze separate test portions for moisture and ash cont
29、ents in accordance with Test Methods D3173, D3174, or D7582,so that calculations to other bases can be made.8.2 Laboratory Ashing of Coal and Coke Analysis SamplePrepare the ash from a thoroughly mixed analysis sample of coalor coke (8.1). Spread the coal and coke in a layer not over 6 mm in depth i
30、n a porcelain, quartz, or fused silica roasting dish. Placethe dish in a cold muffle furnace and heat gradually so that the temperature reaches 500 6 10C at the end of 1 h. Continue thegradual heating until the temperature rises from 500 6 10C to 750 6 15C at the end of 1 h. Maintain the 750C temper
31、atureuntil the test specimen reaches a constant mass or for an additional two hours. Allow the dish to cool, transfer to an agate mortar,and grind to pass a 75 m (No. 200) U.S.A. standard sieve. Reignite the ash at 750C for 1 h, cool rapidly, and weigh portionsfor analysis.8.3 Solid Combustion Resid
32、ueDry a representative portion of the solid residue to constant mass at 107 6 3C. Determine themoisture loss during this drying step if it is desirable to calculate results to an as-received basis. Crush the dried portion of thesample to pass a 75 m (No. 200) U.S.A. standard sieve. Use a mill that m
33、inimizes metal contamination.8.4 Ashing Solid Combustion ResidueSpread an appropriate amount of the prepared sample in a layer not over 2 mm in aporcelain, quartz, or fused silica roasting dish. Place the dish in a cold muffle furnace and heat gradually so that the temperaturereaches 500 6 10C at th
34、e end of 1 h. Continue the gradual heating until the temperature rises from 500 6 10C to 750 6 15Cat the end of 1 h. Maintain the 750C temperature until the combustion residue reaches a constant mass or for an additional twohours. Cool the test specimen, grind to pass a 75 m (No. 200) U.S.A standard
35、 sieve, and reignite at 750C for 1 h.8.5 If the ash previously ignited samples are stored and the absorption of moisture or CO2is to be prepared from a coal, preparethe coal analysis sample in accordance with Practice , or both, is in question, reignite the ash at 750C before use. Alternatively,dete
36、rmine loss on ignition using Test Method D2013D7348 by pulverizing the materials to pass a 250-m (No. 60) sieve.on aseparate sample weighed out at the same time as the test portion and make the necessary corrections. Thoroughly mix each samplebefore weighing.7.2.1 Analyze separate test portions of t
37、he coal for moisture and ash contents in accordance with Test Methods D3173, D3174,or D5142 so that calculations to other bases can be made.7.2.2 Prepare the ash from a thoroughly mixed analysis sample of coal. Spread the coal in a layer not over 6 mm (14 in.) in depthin a fireclay or porcelain roas
38、ting dish. Place the dish in a cold muffle furnace and heat gradually so that the temperature reaches500C in 1 h and 750C in 2 h. Ignite at 750C until all carbonaceous matter is removed. Proceed with the preparation of the ashin accordance with 7.1. If samples are stored and the absorption of moistu
39、re or CO2, or both, is in question, reignite the ash usingthe 500-750C staged combustion before use.Alternatively, determine loss on ignition using the 500-750C staged combustion ona separate sample weighed out at the same time as the test portion and make the necessary corrections. Thoroughly mix e
40、achsample before weighing.9. Procedure9.1 The solutions and proportions described below are for typical ash samples as represented by American coals of bituminousrank. Therefore, stronger or weaker dilutions may be required to establish suitable concentrations for those elements of varyingpercents o
41、utside the range of the typical sample. Each analyst must determine the sensitivity and linear range of calibration of theirequipment and choose concentration ranges for standards compatible with the samples and instrument specific to their own work.9.1.1 Calculations used in subsequent sections are
42、 developed from the following general formula for percent concentration ofelement oxide, E, in moisture-free coal ash:E 5C 2B!/A 2B!# 3N/M! 3F 3100 (1)where:A = absorbance of standard;B = absorbance of blank;C = absorbance of sample solution;N = element in standard, ppm;M = sample of solution, ppm;
43、andF = conversion from element to oxide.NOTE 3Concentrations Percent mass fractions in the ash may be converted to the air-drieddry coal basis using the following expression:C 5AB/100!C 5A 3B /100 %!where:C = oxide in air-dried coal, %;A = oxide in ash, %; andD3682 133B = ash as determined in Test M
44、ethod D3174 or Test Method D5142, %.C = elemental oxide (dry basis) in coal, %;A = elemental oxide in ash, %; andB = ash (dry basis) as determined in Test Method D3174 or Test Method D7582, %, and calculated using Practice D3180.See Practice D3180 for procedures to convert values to other bases.9.2
45、To minimize the potential of contamination, the platinumware must be prepared by boiling in solvent acid and rinsingthoroughly with reagent-grade water. After this initial cleaning, the platinumware must be handled with clean tongs and protectedfrom further contamination from table tops, and so fort
46、h. All glassware used in analyses must be equally clean and equallyprotected.9.3 Sample Fusion and Solution:9.3.1 Weigh 0.1 6 0.0002 g of the sample as prepared in 7.2.28.2 8.5 into a platinum dish (5.36.3) (Note 4) and add 0.5 gof Li2B4O7. Mix the ash and lithium tetraborate well, then add an addit
47、ional 0.5 g of Li2B4O7 to cover the mixture. Place the dishin a clean silica or refractory tray and place in a muffle furnace preheated to 1000C; 15 min at 1000C is sufficient to fuse themixture completely. Remove the tray and dish and cool to room temperature. Carefully rinse the bottom and outside
48、 of the platinumdish to remove possible contamination, then place it in a clean 250-250 or 400-mL 400 mL beaker. Place a cleanTFE-fluorocarbon-coated stirring magnet inside the dish, add 150 mLof solvent acid to the beaker and dish, and place immediatelyon the stirring hotplate. Heat the solution to
49、 just below boiling temperature and maintain for not more than 30 min with constantstirring. This time and temperature are sufficient to completely dissolve the melt. If stirring is not maintained constantly, some ofthe ash constituents are apt to precipitate and the analysis must be repeated.NOTE 4The use of graphite crucibles and subsequent dissolution of fused beads from them was not investigated; however, their successful use insimilar methods has been reported.49.3.2 Remove the beaker from the hotplate and permit to co
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