1、Designation: D7582 12Standard Test Methods forProximate Analysis of Coal and Coke by MacroThermogravimetric Analysis1This standard is issued under the fixed designation D7582; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 These instrumental test methods cover the determinationof moisture, volatile matter, and ash, and the calculation
3、 offixed carbon in the analysis of coal and coke samples preparedin accordance with Practice D2013 and Practice D346.1.2 These instrumental test methods are not applicable tothermogravimetric analyzers using microgram size samples.1.3 Test Methods D3173, D3174, and D3175 shall beconsidered the refer
4、ee test methods.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 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 t
5、o establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisD2013 Practice f
6、or Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the Analysis Sample ofCoal and CokeD3174 Test Method for Ash in the Analysis Sample of Coaland Coke from CoalD3175 Test Method for Volatile Matter in the AnalysisSample of Coal and CokeD3176 Practice for Ultimate Analysis of Coa
7、l and CokeD3180 Practice for Calculating Coal and Coke Analysesfrom As-Determined to Different BasesD3302 Test Method for Total Moisture in CoalD5016 Test Method for Total Sulfur in Coal and CokeCombustion Residues Using a High-Temperature TubeFurnace Combustion Method with Infrared AbsorptionE691 P
8、ractice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 For definitions of terms used in this test method, refer toTerminology D121.4. Summary of Test Method4.1 In thermogravimetric analysis the mass of a sample in acontrolled atmosphere is recorde
9、d repeatedly as a function oftemperature or time, or both. In macro thermogravimetricanalysis a sample size of approximately 1 g is used. All massmeasurements are conducted by the system. In a typicalanalysis, the temperature is normally ramped from ambient toa specific temperature and held at that
10、temperature for aprescribed length of time. The mass change is recordedrepeatedly during the entire procedure. For the thermogravi-metric analysis of coal and coke samples the moisture and ashanalyses are complete when the sample reaches a constantmass as defined in the instrumental operating parame
11、ters.Alternatively, the measurement of moisture and ash can beconsidered complete after heating the sample for a fixed periodof time. In the volatile matter analysis, the samples are weighedafter heating to 950C and held at this temperature for 7 min.4.2 Moisture is determined by measuring the loss
12、in mass ofthe analysis specimen of coal or coke when heated underspecified conditions of temperature, time, atmosphere, speci-men mass, and equipment specifications.4.3 Volatile matter is determined by measuring the loss inmass of the analysis specimen of coal or coke when heatedunder rigidly contro
13、lled conditions. The measured mass loss isused to calculate the volatile matter after correcting for themoisture content.4.4 Ash is determined by measuring the mass of the residueremaining after burning the coal or coke specimen under1This test method is under the jurisdiction of ASTM Committee D05
14、on Coaland Coke and is the direct responsibility of Subcommittee D05.21 on Methods ofAnalysis.Current edition approved Nov. 1, 2012. Published December 2012. Originallyapproved in 2009. Last previous edition approved in 2010 as D7582-101. DOI:10.1520/D758212.2For referenced ASTM standards, visit the
15、 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Un
16、ited States1specified conditions of specimen mass, temperature, time,atmosphere, and equipment specifications.4.5 In these test methods, moisture, volatile matter, and ashcan be determined sequentially in a single instrumental proce-dure. Another procedure allows the moisture and ash to bedetermined
17、 sequentially. Moisture and ash can also be deter-mined in separate determinations. Ruggedness testing and pastexperiences have shown the volatile matter values determinedon samples without first determining the moisture (drying thesample) are always higher than those of the dried samples.34.6 Good
18、laboratory practice requires checking for biasesbetween analytical methods for contractual compliance. Whenonly a few coal types will be routinely tested, the instrumentused in these test methods must be shown to yield results, forthe coal(s) to be tested, that are equivalent to those obtainedusing
19、Test Methods D3173, D3174, and D3175. If they arefound to be not equivalent, either the instrument used iscalibrated or the instrumental results are adjusted to establishand maintain equivalence. Alternatively, when a broad spec-trum of coal types will be tested, the instrument used in thesetest met
20、hods shall be calibrated using certified referencematerials of known composition covering the range of param-eters being determined. The certified values shall be estab-lished using Test Methods D3173, D3174, and D3175. Section16.2 lists a number of biases that have been shown to existbetween instru
21、mental results. Other biases, of unknown mag-nitude and sign, may exist for other coals.35. Significance and Use5.1 Moisture, as determined by this instrumental testmethod, is used for calculating other analytical results to a drybasis using procedures in Practice D3180.5.2 Moisture can be used in c
22、onjunction with the air-drymoisture loss determined by Test Method D3302 to determinetotal moisture in coal. Total moisture is used for calculatingother analytical results to an as-received basis using PracticeD3180.5.3 Ash yield is the residue remaining after heating the coaland coke samples (see N
23、ote 1).NOTE 1The ash obtained differs in composition and amount from themineral constituents present in the original coal. Combustion causes anexpulsion of all water, the loss of carbon dioxide from carbonates, theconversion of iron pyrite into iron oxides and sulfur oxides, and otherchemical reacti
24、ons. Ash yield, as determined by this test method, candiffer from the amount of ash produced in furnace operations or othercombustion systems because combustion conditions influence the chem-istry and amount of ash.5.4 Ash yield is used, (1) as a parameter for evaluatingsampling procedures and coal
25、cleaning processes, (2) in theultimate analysis calculation of oxygen by difference usingPractice D3176, (3) in calculations including material balance,reactivity and yields of products relevant to coal conversionprocesses such as gasification and liquefaction, (4) in calcula-tions to estimate the l
26、oading on electrostatic precipitators andon the fly ash and bottom ash disposal systems as well aserosion rates on boiler systems.5.5 Volatile matter yield, when determined as hereindescribed, may be used to (1) indicate coke yield oncarbonization, (2) provide the basis for purchasing and selling,or
27、 (3) establish combustion characteristics.5.6 Fixed carbon is a calculated value. It is the differencebetween 100 and the sum of the percent moisture, ash, andvolatile matter. All percents shall be on the same moisturereference base.5.7 Moisture, ash, and volatile matter are three of theprincipal pa
28、rameters used for assessing the quality of coal.6. Interferences6.1 There are no known interferences for these test methods.7. Apparatus7.1 Macro Thermogravimetric Analyzer (Macro TGA)Acomputer controlled apparatus consisting of a furnace with acavity large enough to accept crucibles containing test
29、 speci-mens that meet the minimum mass requirements of theprocedure. The macro TGA system can accommodate multiplecrucibles, allowing for continuous analysis with one cruciblereserved for the blank or reference crucible. The furnace isconstructed so the cavity is surrounded by a suitable refractorya
30、nd insulated so as to develop a uniform temperature in allparts of the cavity, but with a minimum free space. The furnaceshall be capable of being heated rapidly (30-45C/min fromambient to 950C. The temperature shall be monitored andmaintained at values specified for each determination. Thesystem sh
31、all have an integrated balance capable of weighingthe crucibles and test specimens repeatedly throughout theanalysis. All mass measurements are conducted and recordedby the system. The sensitivity of the balance shall be at least0.1 mg. Provision shall be made to introduce gases specifiedfor this st
32、andard and to remove products of drying,devolatilization, and combustion. The macro TGAsystem shallhave a venting fan, tolerant of hot product gases, to efficientlyremove the exhaust gases.7.2 Crucibleswith covers of composition and dimensionsspecified for the instrument by the instrument manufactur
33、er.The covers shall fit closely enough so that the carbon depositfrom bituminous, subbituminous, and lignitic coals does notburn away from the underside of the cover during the deter-mination of the volatile matter8. Reagents and Materials8.1 Drying GasNitrogen (99.5% purity), Argon (99.5%purity) or
34、 air, dried to a moisture content of 1.9 mg/L or less(dew point 10C or less).8.2 Inert GasNitrogen (99.5% purity) or Argon (99.5%purity).8.3 Oxidizing GasOxygen (99.5% purity) or air.8.4 Certified Reference MaterialsCoal or coke material(s)meeting the requirements of 10.1, with a certificate of anal
35、ysis3Riley J.T., Yanes E.G, Marsh M., Lawrenz D., and Eichenbaum L., “Coal andCoke Volatile Matter Determination and Reconciliation of Differences in YieldsDetermined by Two ASTM Methods,” J. Testing and Evaluation, 2010, 38(4),458-466.D7582 122specifying the reference value and the uncertainty of t
36、hereference value. Reference material(s) can be employed tocalibrate the instrument for the determination of volatilematter. Certified reference values shall have been establishedusing Test Methods D3173, D3174, and D3175. Referencematerials used for the calibration of volatile matter shallinclude i
37、nformation on the certificate of analysis detailing themethod(s) employed to determine volatile matter of the refer-ence material.9. Hazards9.1 The user shall insure acceptable documented safetyprocedures are in place for the handling of all reagents and testmaterials and for the operation of labora
38、tory equipment speci-fied for these test methods.9.2 Venting EquipmentInstall equipment in the vicinity ofthe apparatus to vent combustion and volatile gases evolvedduring the test procedures from the laboratory.10. Analysis Sample10.1 The analysis sample shall be the material pulverized topass a 25
39、0-m (No. 60) sieve in accordance with PracticeD2013 or Practice D346.11. Preparation of Apparatus11.1 Verify the instrument can meet all specifications in thestandard with respect to gas flows, heating rates, and balancesensitivity prior to use. Condition the instrument after initialsetup, or repair
40、s, by conducting a run through a complete cyclewithout samples.11.2 Condition new crucibles and covers for use in these testmethods by heating under the same conditions of the test andcool before use.11.3 The macro TGA system can be programmed to termi-nate the measurement process when the test spec
41、imens andcrucibles have reached a constant mass. Crucibles are weighedby the instrument at specified intervals. The analysis iscomplete when the sample reaches constant mass. Constantmass is defined as a point where the mass change is or = to0.05% over a nine-minute period, either by using not less
42、thanthree successive weighings or a fixed nine-minute period ofsuccessive weighings. This mass change of 0.05% is equivalentto 0.0005 g for a 1.0000 g sample. Alternately, the instrumentcan be programmed to allow for moisture and ash determina-tion by heating the test specimens for the time periods,
43、 heatingrates and soak temperatures specified in Test Methods D3173and D3174. The mass measured at the end of the time periodis used for calculations.12. Calibration and Standardization12.1 The instrument shall be calibrated for the determina-tion of volatile matter employing certified reference mat
44、erials.The calibration shall be performed at the same furnace ramptemperature as that used for the analysis. Do not use coalreference materials(s) for coke volatile matter calibration. Donot use coke reference material(s) for coal volatile mattercalibration. Use coal reference material(s) with a cer
45、tifiedreference value and uncertainty based on measurements madeemploying Test Methods D3173, D3174, and D3175 to cali-brate this test method.13. Procedure13.1 The determination of moisture, followed by volatilematter followed by ash can be carried out in sequence using thesame test specimen. Altern
46、atively, the determination ofmoisture, volatile matter, or ash can be carried out separatelyon test specimens of coal or coke.13.2 Sequential Determination of Moisture, Volatile Matterand Ash:13.2.1 After verifying instrument setup according to Section11 on the preparation of apparatus, load and tar
47、e the crucibles.Add1g6 0.1 g of coal or coke to the crucible in the balanceposition and weigh immediately before advancing the nextcrucible. Transfer the test specimen from the sample bottle tothe crucible quickly to minimize the exposure of the testspecimen to the atmosphere during the initial weig
48、hing pro-cess.13.2.2 For moisture determinations, heat the weighed testspecimens in crucibles without the covers at 107 6 3 C. Usea drying gas flow rate of 0.4 to 1.4 furnace volume changes perminute (see 8.1). Program the instrument to terminate the testwhen the test specimens and crucibles have re
49、ached a constantmass (see 11.3). Alternatively, program the instrument to allowfor moisture determination by heating the test specimens for 1h.13.2.3 For volatile matter determinations following themoisture analysis, place covers on the crucibles in the TGAcarousel (the covers are placed automatically in some systemsand manually in others). Program the instrument to reweigh thecrucibles, with specimens inside, and covers in place beforeinitiating the volatile matter part of the cycle.13.2.3.1 To provide an inert atmosphere, use nitrogen orargon with a flow rate of 0.7
