1、Designation: D 3175 07Standard Test Method forVolatile Matter in the Analysis Sample of Coal and Coke1This standard is issued under the fixed designation D 3175; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method determines the percentage of
3、 gaseousproducts, exclusive of moisture vapor, in the analysis samplewhich are released under the specific conditions of the test.1.2 This test method for determination of volatile matter isempirical; because of its empirical nature, strict adherence tobasic principals and permissible procedures is
4、required toobtain valid results.1.3 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 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitati
5、ons prior to use.1.4 The values stated in SI units are to be regarded as thestandard.2. Referenced Documents2.1 ASTM Standards:2D 346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisD 2013 Practice for Preparing Coal Samples for AnalysisD 3173 Test Method for Moisture i
6、n theAnalysis Sample ofCoal and Coke3. Terminology3.1 Definition:3.1.1 sparking fuelswithin the context of this test method,fuels that do not yield a coherent cake as residue in the volatilematter determination but do evolve gaseous products at a ratesufficient to mechanically carry solid particles
7、out of thecrucible when heated at the standard rate. Such coals normallyinclude all low-rank noncaking coals and lignites but can alsoinclude those anthracites, semianthracites, bituminous, andcokes that lose solid particles as described above. These aredefined as sparking fuels because particles es
8、caping at thehigher temperatures can become incandescent and spark asthey are emitted.4. Summary of Test Method4.1 Volatile matter is determined by establishing the loss inweight resulting from heating a coal or coke under rigidlycontrolled conditions. The measured weight loss, corrected formoisture
9、 as determined in Test Method D 3173 establishes thevolatile matter content. Two procedures are described to permitconformity with differences in sample behavior.4.2 In this empirical test method, the use of platinumcrucibles shall be considered the standard reference method forvolatile matter. Plat
10、inum crucibles shall be used in determiningthe volatile matter of coke and volatile matter determined forclassification of coals by rank. Volatile matter determinationsby some laboratories using alternate nickel-chromium alloycrucibles having the physical dimensions specified in 6.1 havebeen shown t
11、o differ from those obtained using platinumcrucibles. A laboratory utilizing nickel-chromium cruciblesshall first determine if a relative bias exists between the use ofnickel-chromium and platinum crucibles on the coals beingtested using the test method set forth in Annex A. Where arelative bias is
12、shown to exist, the volatile matter determinedusing nickel-chromium crucibles shall be corrected by a factordetermined through comparison of volatile matter results fromboth crucible types on coals being tested or analysis of samplesof known proximate analysis.5. Significance and Use5.1 Volatile mat
13、ter, when determined as herein described,can be used to establish the rank of coals, to indicate coke yieldon carbonization process, to provide the basis for purchasingand selling, or to establish burning characteristics.6. Apparatus6.1 Platinum Crucible, with closely fitting cover, for coal.The cru
14、cible shall be of not less than 10 or more than 20-mLcapacity, not less than 25 or more than 35 mm in diameter, andnot less than 30 or more than 35 mm in height.1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.21 o
15、n Methods ofAnalysis.Current edition approved March 1, 2007. Published April 2007. Originallyapproved in 1973. Last previous edition approved in 2002 as D 3175 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
16、 of ASTMStandards volume 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.6.2 Platinum Crucible, with closely fitting cover, for coke.The crucible shall be o
17、f 10-mL capacity, with capsule coverhaving thin flexible sides fitting down into crucible. Or thedouble-crucible method can be used, in which the sample isplaced in 10-mL platinum crucible, which is then covered withanother crucible of such a size that it will fit closely to the sidesof the outer cr
18、ucible and its bottom will rest 8.5 to 12.7 mm (13to12 in.) above the bottom of the outer crucible.6.3 Alternate Crucible Materials, Nickel-chromium cru-cible with closely fitting cover. The crucible shall not be lessthan 10 or more than 20 mL capacity, not less than 25 or morethan 35 mm in diameter
19、, and not less than 30 or more than 35mm in height. Nickel-chromium crucibles shall be heat-treatedfor4hat500C to ensure that they are completely oxidizedprior to use.6.4 Vertical Electric Tube Furnace, for coal or coke. Theelectric furnace shall be a vertical tube furnace. The furnacecan be of the
20、form shown in Fig. 1. It shall be regulated tomaintain a temperature of 950 6 20C in the crucible, asmeasured by a thermocouple positioned in the furnace. Thefurnace shall accommodate sparking coals and meet thespecifications set forth in 7.3.2.FIG. 1 Electric Furnace for Determining Volatile Matter
21、D31750726.5 Balance, sensitive to 0.1 mg.7. Procedure7.1 The sample shall be the material pulverized to No. 60(250-m) sieve in accordance with Practice D 2013 or PracticeD 346.7.2 Procedure for Nonsparking Coals and Cokes:7.2.1 Weigh1gofthesample in a weighed platinumcrucible, close with a cover whi
22、ch fits closely enough so thatthe carbon deposit from bituminous, subbituminous, and lig-nite coals does not burn away from the underside, place onplatinum or Nichrome-wire supports and insert directly into thefurnace chamber, which shall be maintained at a temperature of950 6 20C, and lower immedia
23、tely to the 950C zone.Regulation of the temperature to within the prescribed limits iscritical. After the more rapid discharge of volatile matter hassubsided, as shown by the disappearance of the luminousflame, or in the case of coke, after 2 or 3 min, inspect thecrucible (see Note 1) to verify that
24、 the lid is still properlysealed. If necessary, reseat the lid to guard against the admis-sion of air into the crucible. Do this as rapidly as possible byraising the crucible to the top of the furnace chamber, reposi-tion the lid to more perfectly seal the crucible, then lower thecrucible immediatel
25、y back to the 950C zone. After heating fora total of exactly 7 min, remove the crucible from the furnaceand without disturbing the cover, allow it to cool. Coke shouldbe cooled in a desiccator. Weigh as soon as cold. Thepercentage loss of weight minus the percentage moistureequals the volatile matte
26、r. With some strongly caking low-volatile and medium-volatile bituminous coals, the coke buttoncan be broken with explosive violence due to the liberation ofvolatile matter within the button. This is usually designated aspopping. Such popping can blow the lid off the crucible andcause mechanical los
27、ses of the coked material. When suchpopping is observed, the determination shall be rejected andthe test repeated until popping does not occur.NOTE 1Inspection of the crucible can be aided by the use of a mirrorheld above the furnace well.7.3 Modified Procedure for All Sparking Fuels:7.3.1 Fuels tha
28、t do not cake or cake weakly when volatilematter is determined shall be watched closely for sparkingduring the heating period (see Note 2); also, at the end of thetest the crucible cover shall be inspected for ash deposits, andthe presence of such deposits shall be considered as evidenceof sparking.
29、7.3.2 All fuels that spark when the volatile matter isdetermined by the methods described in 7.1 shall be treated asfollows: The sample shall be given a preliminary gradualheating such that a temperature of 600 6 50C is reached in 6min (Note 2).After this preliminary heating the sample shall beheate
30、d for exactly 6 min at 950 6 20C. If sparking is thenobserved, the determination shall be rejected and the testrepeated until no sparking occurs either during the preliminaryheating or during the 6-min period at 950C. Remove thecrucible from the furnace, cool on a metal cooling block, andweigh. To e
31、nsure uniformity of results, keep the cooling periodconstant and do not prolong beyond 15 min. The percentageloss in weight minus the percent moisture in accordance withTest Method D 3173, is the volatile matter. All analyses by thistest method shall be so marked when reported to indicate thatthe mo
32、dified procedure was used.NOTE 2If a tubular furnace of the Fieldner type (Fig. 1) is used for thedetermination of volatile matter, the preliminary gradual heating can beaccomplished by moving the crucible to predetermined positions in thecooler top zone of the furnace. Due to variations in the heat
33、ing charac-teristics of the furnace, the operator shall predetermine by thermocouplethe proper positions to meet a preliminary heating rate as specified in7.3.2. A mechanical device to lower the crucible into the furnace can beused to facilitate control of the lowering operation.8. Calculation8.1 Ca
34、lculate the weight loss percent as follows:Weight loss, % 5 A 2 B!/A 3 100 (1)where:A = weight of sample used, g, andB = weight of sample after heating, g.8.2 Calculate the volatile matter percent in the analysissamples as follows:Volatile matter in analysis sample , % 5 C 2 D (2)where:C = weight lo
35、ss, %, andD = moisture, %.9. Precision and Bias9.1 The precision of this test method for the determniationof Volatile Matter in Coal are shown in Table 1. Repeatabilityand Reproducibility limits for this test method were determinedusing only platinum crucibles. Repeatability and Reproducibil-ity lim
36、its for nickel-chromium crucibles have not been deter-mined.9.1.1 Repeatability Limit (r)The value below which theabsolute difference between two test results of separate andconsecutive test determinations, carried out on the samesample, in the same laboratory, by the same operator, using thesame ap
37、paratus on samples taken at random from a singlequantity of homogeneous material, can be expected to occurwith a probability of approximately 95 %.9.1.2 Reproducibility Limit (R)The value below which theabsolute difference between two test results carried out indifferent laboratories, using samples
38、taken at random from asingle quantity of material that is as homogeneous as possible,can be expected to occur with a probability of approximately95 %.TABLE 1 Concentrations Range and Limits for Repeatability andReproducibility of Volatile Matter in CoalRank, % RepeatabilityLimit,rReproducibilityLimi
39、t,RHigh-temperature coke 0.2 0.4Anthracite 0.3 0.6Semianthracite, bituminous,low-temperature coke 0.5 1.0Subbituminous 0.7 1.4Lignite 1.0 2.0D31750739.2 BiasSince this is an empirical test method whenutilizing platinum crucibles, the degree of absolute bias can notbe determined. Bias between the use
40、 of platinum and nickel-chromium crucibles shall be determined in the laboratory oncoal being tested using the test method set forth in Annex A.ANNEXA1. METHOD FOR DETERMINING RELATIVE BIAS BETWEEN PLATINUM AND NICKEL-CHROMIUM ALLOYCRUCIBLESA1.1 ScopeA1.1.1 This method describes the procedure for de
41、termin-ing the component of relative bias between platinum andalternate nickel-chromium alloy crucibles.A1.2 ApparatusA1.2.1 All Apparatus and equipment shall conform to theapparatus and equipment specifications given in the “Appara-tus” Section of Test Method D 3175 with the additionalrequirement t
42、hat temperatures shall be measured with a Type Kor N thermocouple with a standard tolerance of 6 2.2 C.A1.3 ProcedureA1.3.1 Apply one of the two alternate methods given in the“Procedure” section of ASTM D3175 to a minimum of twentypairs of the materials being tested, one member of each pairconsistin
43、g of a one-gram analysis sample in a platinumcrucible, and the other member of each pair consisting of aone-gram analysis sample of the same material in a nickel-chromium alloy crucible.A1.3.2 The following additional limitations apply:A1.3.2.1 The materials in the study group shall all be of thesam
44、e groupings listed in Table 1:1. Anthracite2. Semianthracite, Bituminous3. Subbituminous4. LigniteA1.3.2.2 The range of volatile matter contents within thestudy group shall not exceed 10% absolute. If the range ofvolatile matter routinely analyzed and within the same Table 1grouping exceeds 10% abso
45、lute, analyze multiple groups toaccommodate the expected range of volatile matter. Apply theappropriate relative bias to samples within the same volatilematter range. The relative bias shall be applicable only toanalyses performed in the laboratory in which it is originallydetermined.A1.3.2.3 All va
46、lues determined in any experiment uponmembers of the study group shall be used in the statisticalanalysis (unless there is undeniable evidence that the data to berejected is technically invalid).A1.3.2.4 All materials within the study group shall beanalyzed the same number of times.A1.3.2.5 Confirma
47、tory analyses for each study group (re-determination of relative bias) shall be conducted at least onceper year to ascertain that normal wear of equipment (crucibles,thermocouples, furnace, etc.) does not result in changes to theconclusions of the experiment. See Table A1.2 as an example.A1.4 Assess
48、ment and Uses of Relative Bias Test ResultsA1.4.1 Compute the differences between the matched pairs,subtracting the result obtained with the platinum crucible fromthe result obtained with the nickel-chromium alloy crucibleresults. Calculate the mean and the standard deviation of thedifferences. Mult
49、iply the standard deviation of the differencesby the value of y corresponding to the number of pairs (0.85 for20 pairs) from Table A1.1 This is the limit of bias at the 95%confidence level that could accidentally pass undetected byreason of statistical error. If this limit exceeds one-half therepeatability limits in Table 1, do not use nickel-chromiumalloy crucibles for volatile determinations. If this limit is lessthan one-half the repeatability limits in Table 1, nickel-chromium alloy crucibles can be used provided the resultsobtained with nickel-chromium alloy
