ASTM_D_1756_-_02_2007.pdf

Designation:D 1756 02(Reapproved 2007)Standard Test Method forDetermination as Carbon Dioxide of Carbonate Carbon inCoal1This standard is issued under the fixed designation D 1756;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of carbondioxide in coal in any form,such as mineral carbonate,fromwhich carbon dioxide is released by action of mineral acids.Itapplies to high-carbonate and low-carbonate coals.1.2 The values stated in SI units are to be regarded as thestandard.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:2D 1193 Specification for Reagent WaterD 2013 Practice for Preparing Coal Samples for AnalysisD 3180 Practice for Calculating Coal and Coke Analysesfrom As-Determined to Different Bases3.Summary of Test Method3.1 The determination of carbon dioxide is made by decom-posing with acid a weighed quantity of the sample in a closedsystem and absorbing the carbon dioxide in an absorbent.Theincrease in weight of the absorbent is a measure of the carbondioxide in the sample used.4.Significance and Use4.1 Small amounts of mineral carbonates occur in manycoals and comparatively large amounts in some coals.Thedetermination of these carbonates is the purpose of this testmethod.The value found for carbon dioxide is used to estimatethe mineral matter content,particularly CaCO3and MgCO3,ofhigh-carbonate coals.5.Apparatus(see Fig.1)5.1 The use of apparatus modified from that shown in Fig.1 shall be considered permissible so long as results agreewithin the accepted precision.35.2 Air-Purifying Train,consisting of the following unitsarranged in the order of passage of air:Any convenient form offlow meter(1)connected to a carbon dioxide absorber(2)filledwith an acceptable absorbent.The absorber(2)shall beconnected to a trap(3).5.3 Reaction Unit,consisting of a 300-mL wide-mouth flask(5)fitted with a three-hole rubber stopper.One hole is toaccommodate a 60-mL open-end separatory funnel(4)extend-ing almost to the bottom of the flask(5).The second hole in thestopper is used to connect the purifying train through the trap(3);the tip of the glass tubing shall extend almost to the bottomof flask(5).The third hole of the stopper shall be fitted to awater-cooled condenser(6).5.4 Absorption Unit,consisting of a water absorber(7)filledwith an acceptable desiccant connected to the condenser(6)onthe one side and on the other side to absorber(8)containinganhydrous copper sulfate on pumice or granular silver sulfate.The carbon dioxide absorber(9)shall be connected to absorber(8)and to another water absorber(10).The absorber(10)shallbe connected to a T-piece stopcock(11)which in turn shall beattached to a filter-flask(12).The system shall be aspirated bya water pump(13).6.Purity of Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,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 1960.Last previous edition approved in 2002 as D 175602.2For 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.3For further information regarding this determination,see Krumin,P.O.,“TheMeigs Creek No.9 Coal Bed in Ohio,Part IIIFurther Study of the Chemical andPhysical Properties,and Washability Characteristics,with a Brief Review of NewMethods Employed,”Bulletin No.165,Ohio State University,Engineering Experi-ment Station,(1957),pp.3846;and Krumin,P.O.,and Svanks,K.,“Four Methodsof Determination of Carbon Dioxide in Solid Fuels,”ASTM Bulletin,No.227,January 1958,pp.5157.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.where such specifications are available.4Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Unless otherwise indicated,references to water shall beunderstood to mean Type IV reagent water conforming toSpecification D 1193.7.Reagents and Ma