ASTM_D_720_-_D_720M_-_22.pdf

Designation:D720/D720M22Standard Test Method forFree-Swelling Index of Coal1This standard is issued under the fixed designation D720/D720M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method2is a small-scale,empirical test forobtaining information regarding the free-swelling properties ofa coal.The results may be used as an indication of the cakingcharacteristic of the coal when burned as a fuel.This test is notrecommended as a method for the determination of expansionof coals in coke ovens.1.2 UnitsThe values stated in either SI units or non-SIunits are to be regarded separately as standard.The valuesstated in each system are not necessarily exact equivalents;therefore,to ensure conformance with the standard,eachsystem shall be used independently of the other,and valuesfrom the two systems shall not be combined.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D2013/D2013M Practice for Preparing Coal Samples forAnalysisE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Significance and Use3.1 This test method,in addition to indicating the cakingproperties of a coal when burned as a fuel,can be used to givea broad indication of the degree of oxidation of a coal.4.Apparatus4.1 This test method can be performed using either electricor gas heating.When using electric heating,the results ob-tained must be the same as those obtained when using the gasheating method.The apparatus common to both electric andgas methods shall consist of the following:4.1.1 Crucible,translucent silica,low-form,with a flat,close-fitting silica ring-handle lid and an extra pierced lid foruse in determining the crucible temperature,conforming to thefollowing requirements:Mass,g11.0 to 12.75External height,mm26 0.5External diameter at top,mm41 0.75Internal diameter at base,min,mm11Capacity(approximate),cm3174.1.2 Sight Tube,as shown in Fig.1,for viewing the cokebuttons so that the effect of parallax will be eliminated.Makethe tube of any rigid and preferably opaque material andsupport vertically on a ring stand.The sight tube shall be38 mm 1.5 in.in diameter and 250 mm 10 in.in length andsupported on the ring stand at a height of 76 mm 3.0 in.abovethe base of the stand.4.1.3 Thermocouple and Potentiometer.1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.15 on MetallurgicalProperties of Coal and Coke.Current edition approved Sept.1,2022.Published October 2022.Originallyapproved in 1943.Last previous edition approved in 2015 as D720/D720M 151.DOI:10.1520/D0720_D0720M-22.2This test method is an adaptation of the Crucible Swelling Test for Coal of theBritish Standards Institution.For information concerning the experimental work onwhich this adaptation is based,see paper by Ostborg,H.N.,Limbacker,H.R.,andSherman,R.A.,“An Experimental Investigation of the British Standard Method forthe Crucible Swelling Test for Coal,”Proceedings,Am.Soc.Testing Mats.,Vol 42,1042,p.851.See also a paper by Selvig,W.A.,and Ode,W.H.,“An Investigationof a Laboratory Test for Determination of the Free-Swelling Index of Coal,”U.S.Bureau of Mines Report of Investigation 4238,Revision of R.I.3989,1948.3For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.14.1.4 Mass,500 g 6 10 g,having a flat bottom surface.Employed to assign the index of a non-swollen button.4.2 The electric apparatus shall consist of