1、Designation:D420818Standard Test Method forTotal Chlorine in Coal by the Oxygen Vessel Combustion/Ion Selective Electrode Method1This standard is issued under the fixed designation D4208;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revisio
2、n,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the analysis of total chlorine incoal.1.2 UnitsThe values stated in SI units are to
3、be regardedas standard.No other units of measurement are included in thisstandard.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 prac
4、tices 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
5、 Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D121 Terminology of Coal and CokeD1193 Specification for Reagent WaterD3173 Test Method for Moisture in the Analysis Sample ofCoal and CokeD3180 Practice for Ca
6、lculating Coal and Coke Analysesfrom As-Determined to Different BasesE144 Practice for Safe Use of Oxygen Combustion VesselsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 For definitions of terms used in this test method,refer toTermi
7、nology D121.4.Summary of Test Method4.1 Total chlorine is determined in this method by combus-ting a weighed sample in an oxygen combustion vessel withdilute base adsorbing the chlorine vapors.The vessel is rinsedinto a beaker with water and following the addition of an ionicstrength adjuster,the ch
8、loride is determined by ion-selectiveelectrode.5.Significance and Use5.1 The purpose of this test method is to measure the totalchlorine content of coal.The chlorine content of coals may beuseful in the evaluation of slagging problems,corrosion inengineering processes,and in the total analysis of co
9、al andcoke.When coal samples are combusted in accordance withthis method,the chlorine is quantitatively retained and isrepresentative of the total chlorine content of the whole coal.6.Apparatus6.1 Combustion Vessel,constructed of materials that are notaffected by the combustion process or products.T
10、he vesselmust be designed so that all liquid combustion products can bequantitatively recovered by washing the inner surfaces.Theremust be no gas leakage during the test.The vessel must becapable of withstanding a hydrostatic-pressure test to approxi-mately 20 MPa at room temperature without stressi
11、ng any partbeyond its elastic limit.6.2 Water BathA container large enough to hold thecombustion vessel and enough cooling water to dissipate theheat generated during the combustion process.The containershall be designed to allow a constant flow of water around thecombustion vessel.6.3 Combustion Cr
12、uciblesSamples shall be burned in anopen crucible of platinum,quartz,or acceptable base-metalalloy.6.4 Firing Wire,100 mm,nickel-chromium alloy,No.34B&S gauge,or platinum,No.34 or No.38 B&S gauge.6.5 Firing CircuitA 6 V to 16 V alternating or directcurrent is required for ignition purposes with an a
13、mmeter orpilot light in the circuit to indicate when current is flowing.Astep-down transformer connected to an alternating-currentlighting circuit or batteries can be used.(WarningThe1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of
14、 Subcommittee D05.21 on Methods ofAnalysis.Current edition approved Dec.15,2018.Published February 2019.Originallyapproved in 1982.Last previous edition approved in 2013 as D4208 13.DOI:10.1520/D4208-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Servic
15、e at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.Uni
16、ted 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.1 ignition circuit switch shall be of the momentary double-contact type,normally open,except when held closed by theoperator.The switch should be depressed only long enough tof
