ASTM_D_3761_-_10.pdf

Designation:D376110Standard Test Method forTotal Fluorine in Coal by the Oxygen Bomb Combustion/IonSelective Electrode Method1This standard is issued under the fixed designation D3761;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()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This test method covers the analysis of total fluorine incoal.1.2 This test method was successfully tested on coalscontaining 25%ash or less.21.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 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.For specific hazardstatements,see Section 7.1.5 All accountability and quality control aspects of GuideD4621 apply to this test method.2.Referenced Documents2.1 ASTM Standards:3D1193 Specification for Reagent WaterD2013 Practice for Preparing Coal Samples for AnalysisD3173 Test Method for Moisture in the Analysis Sample ofCoal and CokeD3180 Practice for Calculating Coal and Coke Analysesfrom As-Determined to Different BasesD4621 Guide for Quality Management in an OrganizationThat Samples or Tests Coal and Coke(Withdrawn 2010)4D5142 Test Methods for Proximate Analysis of the AnalysisSample of Coal and Coke by Instrumental Procedures(Withdrawn 2010)4E144 Practice for Safe Use of Oxygen Combustion Bombs3.Summary of Test Method3.1 Total fluorine is determined in this test method bycombusting a weighed sample in an oxygen bomb with a dilutebase absorbing the fluorine vapors.The bomb is rinsed into abeaker with water and following the addition of a citrate buffer,the fluorine is determined by ion-selective electrode.4.Significance and Use4.1 This test method permits measurement of the fluorinecontent of coal for the evaluation of potential fluorine emissionfrom coal combustion or conversion processes.When coalsamples are combusted in accordance with this test method,thefluorine is quantitatively retained and is representative of thetotal fluorine concentration in whole coal.5.Apparatus5.1 Combustion Bomb,constructed of materials that are notaffected by the combustion process or products.The bombmust 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 bomb must becapable of withstanding a hydrostatic-pressure test to 20 MPa(approximately 3000 psig)at room temperature without stress-ing any part beyond its elastic limit.5.2 Water BathA container large enough to hold thecombustion bomb 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 bomb.5.3 Sample HolderSamples shall be burned in an opencrucible of platinum,quartz,or acceptable base metal alloy.1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.29 on MajorElements in Ash and Trace Elements of Coal.Current edition approved Dec.1,2010.Published January 2010.Originallypublished as D3761 79.Last previous edition D3761 96(2002).DOI:10.1520/D376110.2This standard is based on a published report by Thomas,J.,Jr.,and Gluskoter,H.J.,“Determination of Fluoride in Coal with the Fluoride Ion-Specific Electrode,”Analytical Chemistry,Vol 46,1974,pp.132123.3For 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.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Base-metal alloy crucibles are acceptable if after a fewpreliminary firings the weight does not change significantlybetween tests.5.4 Ignition Wire,100-mm,nickel-chromium alloy,No.34B&S gage,or platinum,No.34 or No.38 B&S gage.5.5 Ignition CircuitA6 to 16-V alternating or direct cur-rent is required for ignition purposes with an ammeter or pilotlight in the circuit to indicate when current is flowing.Astep-down transformer connected to an alternating-currentlighting circuit or batteries may be used.5.6 Balance,analytical,with a sensitivity of 0.1 mg.Thebalance shall be checked periodically to determine its accuracy.5.7 Specific-Ion MeterA pH meter with an expandablemillivolt scale,specific-ion meter,sens