1、Designation: D 2961 02 (Reapproved 2007)Standard 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 D 2961; the number immediately following the designation indicates the year oforiginal adopti
2、on or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a single-stage procedure for thedetermination of
3、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 th
4、e 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 refer
5、eepurposes, users of this test method are referred to Test MethodD 3302 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
6、 between the mean value of the resultsobtained by D 2961 and D 3302 (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 anthracit
7、e. (See 9.2.)1.3 The values stated in SI units are to be regarded as thestandard.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 de
8、termine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 2013 Practice for Preparing Coal Samples for AnalysisD 3302 Test Method for Total Moisture in Coal3. Summary of Test Method3.1 Moisture is determined by establishing the weight lossof the c
9、oal sample by drying in an oven with forced-aircirculation.4. Significance and Use4.1 The measurement of total moisture is required to deter-mine whether coal meets commercial or environmental speci-fications, or both. Within the limitations prescribed in thescope, this test method describes a proce
10、dure for determinationof total moisture that requires less time than the proceduresdescribed in Test Method D 3302.5. Apparatus5.1 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.).5.1.1 The pan size may
11、 be varied to suit the size of thesample and the oven. The height of the sides shall be no morethan 40 mm (112 in.) so that air is not restricted in passing overthe coal.5.2 Drying Oven, forced air-type capable of maintaining atemperature of 107 6 3C and constructed to provide for acontinuous air fl
12、ow to all parts of the oven.6. Sampling6.1 The sample shall be prepared according to Test MethodD 2013 except that the 500 g portion can be further subdividedto 125 g.6.2 That portion of the sample used for the moisturedetermination shall have a minimum weight of 125 g.7. Procedure7.1 Weigh the empt
13、y 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 cont
14、ainer. Record the mass in grams as W3.1This 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 May 1, 2007. Published May 2007. Originallyapproved in 1971. Last previous ed
15、ition approved in 2002 as D 2961 02e1.2For 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.1Copyright ASTM Interna
16、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 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 thatfine particles are not elutriat
17、ed. Dry for 112 h, remove from theoven, and weigh immediately. Record the mass.7.3 Return to the oven for an additional12 h, remove, andweigh. Record the mass. Repeat the drying at12-h intervalsuntil the change in mass for the12-h period is less than 0.05 %of the original mass of the coal sample. Re
18、cord the minimummass of the dried pan, sample, and container as W4.7.4 Remove any residual coal from the dried sample con-tainer and weigh the empty container. Record the mass as W2.NOTE 1If the moisture determination is to be made in the immediatevicinity of sample preparation, the sample need not
19、be placed in acontainer, but can be weighed directly in a tared drying pan.8. Calculation8.1 Calculate the moisture content of the sample as follows:M 5 W32 W4!/W32 W12 W2!# 3 100 (1)where:M = total moisture in the coal as analyzed, %,W1= weight of empty pan,W2= weight of empty sample container,W3=
20、weight of coal plus pan plus sample container wet,andW4= weight of coal plus pan plus sample container afterdrying.9. Precision and Bias9.1 The precision of this test method for the determinationof Single-Stage Total Moisture in coal are shown in Table 1.9.1.1 Repeatability Limit (r)the value below
21、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 apparatus on samples taken at random from a singlequantity of homogeneous material, may be expected to occurwi
22、th 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 taken at random from asingle quantity of material that is as homogeneous as possible,may be expected to occur
23、with a probability of approximately95%.9.2 BiasBias of this test method has not beendetermined.3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determin
24、ation of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or wit
25、hdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that yo
26、ur comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (sin
27、gle or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D05-1024.TABLE 1 Concentrations Range and Limits for Repeatability andReproducibility for Single-Stage Total MoistureRepeatability Limit Reproducibility LimitrR0.30% 0.50%D 2961 02 (2007)2
