1、Designation: D2961 11D2961/D2961M 17Standard Test Method forSingle-Stage Total Moisture Less than 15 % in CoalReduced to 2.36-mm (No. 8 Sieve) Topsize 1This standard is issued under the fixed designation D2961;D2961/D2961M; the number immediately following the designation indicatesthe year of origin
2、al adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 This test method covers a single-stage procedure for the d
3、etermination of total moisture less than 15 % in coal reduced to2.36- mm 2.36-mm (No. 8 sieve) topsize. This test method is for determination of total moisture only. Materials subjected to thistest shall not be used in the determination of other test parameters. It is recognized that the conditions
4、of the test can increase thepotential for significant oxidation effects on some coals. If the oxidation potential is of concern, the use of this single-stage methodshall involve prior agreement between the parties involved. This test method shall not be construed as the referee standard testmethod f
5、or total moisture. For referee purposes, users of this test method are referred to Test Method D3302 for moisturedetermination methods which are not as susceptible to oxidation effects.1.2 Statistical analysis of data from several sources indicates that at a 95% confidence level, there is statistica
6、lly no significantdifference between the mean value of the results obtained by D2961 and D3302 (that is, no bias is detected between the twomethods at the 95% confidence level) for moisture levels between 1.4% and 15.8%. These two test methods were not comparedin this study for some ranks of coal in
7、cluding lignite and anthracite. (See 10.211.2.)1.3 The values stated in either SI units or inch-pound units are to be regarded as standard. No other units of measurement areincluded in this standard. separately as standard. The values stated in each system may not be exact equivalents; therefore, ea
8、chsystem shall be used independently of the other. Combining values from the two systems may result in non-conformance with thestandard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to e
9、stablish appropriate safety and health practices and determine the applicability of regulatorylimitations 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. Term
10、inology3.1 DefinitionsFor additional definitions of terms used in this test method, refer to Terminology D121.4. Summary of Test Method4.1 Moisture is determined by establishing the weight loss of the coal sample by drying in an oven with forced-air circulation.5. Significance and Use5.1 The measure
11、ment of total moisture is required to determine whether coal meets commercial or environmental specifications,or both. Within the limitations prescribed in the scope, this test method describes a procedure for determination of total moisturethat requires less time than the procedures described in Te
12、st Method D3302.1 This test method is under the jurisdiction of ASTM Committee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.21 on Methods of Analysis.Current edition approved Nov. 1, 2011Feb. 1, 2017. Published December 2011February 2017. Originally approved in 1971. Las
13、t previous edition approved in 20072011as D2961 02D2961 11.(2007). DOI: 10.1520/D2961-11.10.1520/D2961_D2961M-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the
14、standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accu
15、rately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor
16、 Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Apparatus6.1 Drying Pans, noncorrodible, stable at the temperature used, and of such size that the sample can be spread to a depth ofnot more than 25 mm (1 in.).1 in.6.1.1 The pan size may be varied to suit the size of the sampl
17、e and the oven. The height of the sides shall be no more than 40mm (1112 in.)in. so that air is not restricted in passing over the coal.6.2 Drying Oven, forced air-type capable of maintaining a temperature of 107 6 3C and constructed to provide for acontinuous air flow to all parts of the oven. Air
18、changes shall be 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) sievesize subsample (Test Method D2013) a portion not less than 125 g.7.2 That portion of the sample used for
19、the moisture determination shall have a minimum weight of 125 g.8. Procedure8.1 Weigh the empty drying pan. Record the mass in grams as W1. Transfer the sample from the sample container to the dryingpan. Distribute the sample uniformly over the pan. Do not exceed a depth of 25 mm (1 in.).1 in. Place
20、 the empty sample containerin 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 in the oven at a temperature of 107 6 3C. Maintain the air flow toprovide continuous introduction of air w
21、hile ensuring that fine particles are not elutriated. Dry for 112 h, remove from the oven,and weigh immediately. Record the mass.8.3 Return to the oven for an additional 12 h, remove, and weigh. Record the mass. Repeat the drying at 12-h intervals until thechange in mass for the 12-h period is less
22、than 0.05 % of the original mass of the coal sample.Change in mass %5SLoss in mass during the 12 hour intervalD*100Original sample mass! (1)8.4 Remove any residual coal from the dried sample container and weigh the empty container. Record the mass as W2.NOTE 1If the moisture determination is to be m
23、ade in the immediate vicinity of sample preparation, the sample need not be placed in a container,but can be weighed directly in a tared drying pan.9. Calculation9.1 Calculate the moisture content of the sample as follows:M 5W32W4!/W32W12W2!#3100 (2)where:M = total moisture in the coal as analyzed,
24、%,W1 = weight of empty pan,W2 = weight of empty sample container,W3 = weight of coal plus pan plus sample container wet, andW4 = weight of coal plus pan plus sample container after drying.10. Report10.1 Report the following information:10.1.1 M, the total moisture in the coal as analyzed, %, to the
25、nearest 0.01 percentage point.11. Precision and Bias11.1 The precision of this test method for the determination of Single-Stage Total Moisture in coal are shown in Table 1.11.1.1 Repeatability Limit (r)the value below which the absolute difference between two test results of separate andconsecutive
26、 test determinations, carried out on the same sample in the same laboratory by the same operator using the sameapparatus on samples taken at random from a single quantity of homogeneous material, may be expected to occur with a probabilityof approximately 95%.TABLE 1 Concentrations Range and Limits
27、for Repeatability andReproducibility for Single-Stage Total MoistureRepeatability Limit Reproducibility Limitr R0.30% 0.50%D2961/D2961M 17211.1.2 Reproducibility Limit (R)the value below which the absolute difference between two test results carried out in differentlaboratories using samples taken a
28、t random from a single quantity of material that is as homogeneous as possible, may be expectedto occur with a probability of approximately 95%.11.2 BiasBias of this test method has not been determined.3SUMMARY OF CHANGESCommittee D05 has identified the location of selected changes to this standard
29、since the last issue (D296111)that may impact the use of this standard.(1) Report section (10) added.(2) Designation corrected to D2961/D2961M-17.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
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33、9428-2959,United States. Individual reprints (single 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D05-1024.D2961/D2961M 173
