1、Designation: D7582 101Standard 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 ye
2、ar 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.1NOTE13.2.3 was editorially corrected in December 2011.1. Scope1.1 These instrumental test methods cover the determinationof
3、 moisture, volatile matter, and ash, and the calculation 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 Meth
4、ods D3173, D3174, and D3175 shall beconsidered the referee 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
5、. 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.2. Referenced Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD346 Practice for Collection and Preparatio
6、n of CokeSamples for Laboratory AnalysisD2013 Practice for 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
7、Coal and CokeD3176 Practice for Ultimate Analysis of Coal 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 Tube
8、Furnace Combustion Method with Infrared AbsorptionE691 Practice 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 t
9、he mass of a sample in acontrolled atmosphere is recorded 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
10、 from ambient toa specific temperature and held at that 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 cons
11、tantmass as defined in the instrumental operating parameters.Alternatively, the measurement of moisture and ash can be1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.21 on Methods ofAnalysis.Current edition approv
12、ed June 1, 2010. Published July 2010. Originally approvedin 2009. Last previous edition approved in 2009 as D7582-09. DOI: 10.1520/D758210E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vol
13、ume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.considered complete after heating the sample for a fixed periodof time. In the volatile matter analysis,
14、 the samples are weighedafter heating to 950C and held at this temperature for 7 min.4.2 Moisture is determined by measuring the loss in mass ofthe analysis specimen of coal or coke when heated underspecified conditions of temperature, time, atmosphere, speci-men mass, and equipment specifications.4
15、.3 Volatile matter is determined by measuring the loss inmass of the analysis specimen of coal or coke when heatedunder rigidly controlled 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 o
16、f the residueremaining after burning the coal or coke specimen underspecified 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. Anoth
17、er procedure allows the moisture and ash to bedetermined 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
18、always higher than those of the dried samples.4.6 Good 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
19、 be tested, that are equivalent to those obtainedusing 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 typ
20、es will be tested, the instrument used in thesetest methods 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 numbe
21、r of biases that have been shown to existbetween instrumental results. Other biases, of unknown mag-nitude and sign, may exist for other coals.5. Significance and Use5.1 Moisture, as determined by this instrumental testmethod, is used for calculating other analytical results to a drybasis using proc
22、edures in Practice D3180.5.2 Moisture can be used in conjunction 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 r
23、emaining after heating the coaland coke samples (see Note 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 i
24、ron oxides and sulfur oxides, and otherchemical reactions. 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
25、 parameter for evaluatingsampling procedures and coal 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 an
26、d liquefaction, (4) in calcula-tions to estimate the loading 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 herein de-scribed, may be used to (1) indicate coke yield on carboniza
27、-tion, (2) provide the basis for purchasing and selling, or (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 Moist
28、ure, ash, and volatile matter are three of theprincipal parameters 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 wit
29、h acavity large enough to accept crucibles containing test 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 isconstru
30、cted so the cavity is surrounded by a suitable refractoryand 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 andmaintaine
31、d at values specified for each determination. Thesystem shall 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. Provi
32、sion shall be made to introduce gases specifiedfor this standard and to remove products of drying, devolatil-ization, and combustion. The macro TGA system shall have aventing fan, tolerant of hot product gases, to efficiently removethe exhaust gases.7.2 Crucibleswith covers of composition and dimens
33、ionsspecified for the instrument by the instrument manufacturer.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 Materials
34、8.1 Drying GasNitrogen (99.5% purity), Argon (99.5%purity) or air, dried to a moisture content of 1.9 mg/L or less(dew point 10C or less).D7582 10128.2 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
35、material(s)meeting the requirements of 10.1, with a certificate of analysisspecifying the reference value and the uncertainty of thereference value. Reference material(s) can be employed tocalibrate the instrument for the determination of volatilematter. Certified reference values shall have been es
36、tablishedusing Test Methods D3173, D3174, and D3175. Referencematerials used for the calibration of volatile matter shallinclude information 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 acce
37、ptable documented safetyprocedures are in place for the handling of all reagents and testmaterials and for the operation of laboratory equipment speci-fied for these test methods.9.2 Venting EquipmentInstall equipment in the vicinity ofthe apparatus to vent combustion and volatile gases evolveddurin
38、g the test procedures from the laboratory.10. Analysis Sample10.1 The analysis sample shall be the material pulverized topass a 250-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 wit
39、h respect to gas flows, heating rates, and balancesensitivity prior to use. Condition the instrument after initialsetup, or repairs, 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 o
40、f the test andcool before use.11.3 The macro TGA system can be programmed to termi-nate the measurement process when the test specimens andcrucibles have reached a constant mass. Crucibles are weighedby the instrument at specified intervals. The analysis iscomplete when the sample reaches constant m
41、ass. Constantmass is defined as a point where the mass change is or = to0.05% over a nine-minute period, either by using not less 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
42、, the instrumentcan be programmed to allow for moisture and ash determina-tion by heating the test specimens for the time periods, 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
43、Standardization12.1 The instrument shall be calibrated for the determina-tion of volatile matter employing certified reference materials.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 matte
44、r calibration. Donot use coke reference material(s) for coal volatile mattercalibration. Use coal reference material(s) with a certifiedreference value and uncertainty based on measurements madeemploying Test Methods D3173, D3174, and D3175 to cali-brate this test method.13. Procedure13.1 The determ
45、ination of moisture, followed by volatilematter followed by ash can be carried out in sequence using thesame test specimen. Alternatively, the determination of mois-ture, volatile matter, or ash can be carried out separately on testspecimens of coal or coke.13.2 Sequential Determination of Moisture,
46、 Volatile Matterand Ash:13.2.1 After verifying instrument setup according to Section11 on the preparation of apparatus, load and tare 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
47、from the sample bottle tothe crucible quickly to minimize the exposure of the testspecimen to the atmosphere during the initial weighing 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 f
48、urnace volume changes perminute (see 8.1). Program the instrument to terminate the testwhen the test specimens and crucibles have reached 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 matte
49、r 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 to 1.4 furnace volume changes perminute to sweep away the volatile components. Raise thefurnace temperature at a rate such that the temperature is raisedfrom 107C
