ASTM_D_2961_-_11.pdf

Designation:D296111Standard Test Method forSingle-Stage Total Moisture Less than 15%in CoalReduced to 2.36-mm(No.8 Sieve)Topsize1This standard is issued under the fixed designation D2961;the number immediately following the designation indicates the 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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers a single-stage procedure for thedetermination of total moisture less than 15%in coal reducedto 2.36-mm(No.8 sieve)topsize.This test method is fordetermination of total moisture only.Materials subjected to thistest shall not be used in the determination of other testparameters.It is recognized that the conditions of the test canincrease the potential for significant oxidation effects on somecoals.If the oxidation potential is of concern,the use of thissingle-stage method shall involve prior agreement between theparties involved.This test method shall not be construed as thereferee standard test method for total moisture.For refereepurposes,users of this test method are referred to Test MethodD3302 for moisture determination methods which are not assusceptible to oxidation effects.1.2 Statistical analysis of data from several sources indi-cates that at a 95%confidence level,there is statistically nosignificant difference between the mean value of the resultsobtained by D2961 and D3302(that is,no bias is detectedbetween the two methods at the 95%confidence level)formoisture levels between 1.4%and 15.8%.These two testmethods were not compared in this study for some ranks ofcoal including lignite and anthracite.(See 10.2.)1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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 limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD2013 Practice for Preparing Coal Samples for AnalysisD3302 Test Method for Total Moisture in Coal3.Terminology3.1 DefinitionsFor additional definitions of terms used inthis test method,refer to Terminology D121.4.Summary of Test Method4.1 Moisture is determined by establishing the weight lossof the coal sample by drying in an oven with forced-aircirculation.5.Significance and Use5.1 The measurement of total moisture is required to deter-mine whether coal meets commercial or environmentalspecifications,or both.Within the limitations prescribed in thescope,this test method describes a procedure for determinationof total moisture that requires less time than the proceduresdescribed in Test Method D3302.6.Apparatus6.1 Drying Pans,noncorrodible,stable at the temperatureused,and of such size that the sample can be spread to a depthof not more than 25 mm(1 in.).6.1.1 The pan size may be varied to suit the size of thesample and the oven.The height of the sides shall be no morethan 40 mm(112in.)so that air is not restricted in passing overthe coal.6.2 Drying Oven,forced air-type capable of maintaining atemperature of 107 6 3C and constructed to provide for a1This 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 approved Nov.1,2011.Published December 2011.Originallyapproved in 1971.Last previous edition approved in 2007 as D2961 02(2007).DOI:10.1520/D2961-11.2For 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 website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 continuous air flow to all parts of the oven.Air changes shallbe at the rate of two to four volumes per minute.7.Sampling7.1 The sample shall be prepared to 2.36 mm(No.8)according to Test Method D2013.Divide from the 2.36-mm(No.8)sieve size subsample(Test Method D2013)a portionnot less than 125 g.7.2 That portion of the sample used for the moisturedetermination shall have a minimum weight of 125 g.8.Procedure8.1 Weigh the empty drying pan.Record the mass in gramsas W1.Transfer the sample from the sample container to thedrying pan.Distribute the sample uniformly over the pan.Donot exceed a depth of 25 mm(1 in.).Place the empty samplecontainer in the drying pan.Weigh the drying pan,coal sample,and empty sample container.Record the mass in grams as W3.8.2 Place the pan,sample,and empty sample container inthe oven at a temperature of 107 6 3C.Maintain the air flowto provide continuous introduction of air while ensuring th