ASTM_D_1412_-_D_1412M_-_15.pdf

Designation:D1412/D1412M15Standard Test Method forEquilibrium Moisture of Coal at 96 to 97 Percent RelativeHumidity and 30C1This standard is issued under the fixed designation D1412/D1412M;the number immediately following the designation indicates theyear of original 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.Scope1.1 This test method covers determination of the equilib-rium moisture of coal in an atmosphere over a saturatedsolution of potassium sulfate at 30C.NOTE1For information concerning the experimental work on whichthis test method is based,see(1-5).21.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.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 limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3D121 Terminology of Coal and CokeD388 Classification of Coals by RankD2013 Practice for Preparing Coal Samples for AnalysisD2234/D2234M Practice for Collection of a Gross Sampleof CoalD3172 Practice for Proximate Analysis of Coal and CokeD3173 Test Method for Moisture in the Analysis Sample ofCoal and CokeD3302 Test Method for Total Moisture in CoalD4596 Practice for Collection of Channel Samples of Coalin a Mine3.Significance and Use3.1 This test method affords a means of estimating the bedmoisture of either coal that is wet and shows visible surfacemoisture or coal that may have lost some moisture.It may beused for estimating the surface,or extraneous moisture of wetcoal,such moisture being the difference between the totalmoisture as determined by Test Method D3302 and theequilibrium moisture.3.2 When samples are collected in conformity with Classi-fication D388,the equilibrium moisture is considered to beequal to bed moisture with the exception of some low rankcoals that yield equilibrium moisture values below bed mois-ture.3.3 The results obtained by this test method are sensitive tomany influences,and therefore,raw(uncorrected)equilibriummoisture data may be of limited value in and of themselves.When working with low rank coals,the results yielded by thistest method require critical assessments.It is recommendedthat the procedure outlined in the Appendix X1 be applied,andthe results corrected before use in situations where a morereliable estimation inherent or bed moisture for low rank coalsis required.The Appendix also provides useful quality assur-ance information which is applicable to coals of all ranks.4.Apparatus4.1 Water Bath or Insulated Air CabinetThe bath orcabinet shall be of sufficient size to accommodate severalvacuum-type desiccators,and shall be provided with a tem-perature regulator to maintain a uniform temperature of 30.0 60.2C.4.2 Moisture OvenThe oven shall be so constructed as tohave a uniform temperature in all parts and a minimum of airspace.It may be of the type shown in the Apparatus section ofTest Method D3173.Provision shall be made for renewing theair(or,if desired,dry oxygen-free nitrogen for subbituminousand lignitic coals)in the oven at a rate of two times per minute,with the air dried as defined in 5.1.4.3 Mechanical Vacuum Pump.4.4 Crusher,laboratory,coffee-mill type.4.5 Sieve,203-mm 8-in.diameter,with 1.18-mm(No.16)openings.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 Sept.1,2015.Published September 2015.Originallyapproved in 1956.Last previous edition approved in 2007 as D1412 07.DOI:10.1520/D1412_D1412M-15.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.3For 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 4.6 Shaking Machine.4.7 DesiccatorSmall vacuum-type desiccator,160 mm indiameter(see Fig.1).4.8 WeighingBottles,glass,low-form,flat-bottom,cylindrical,70 mm in diameter,with well-fitting covers.4.9 Filter Pump,aspirator.4.10 Buchner-Type Funnel,approximately 64 mm 212in.in diameter.5.Reagents5.1 Dry airAir used to purge the drying oven should bedried to a moisture content of 1.9 mg/L or less.(Dew point of-10C or less.)Any desiccant or drying method capable