ASTM_D_3516_-_89_2019e1.pdf

Designation:D351689(Reapproved 2019)1Standard Test Methods forAshing Cellulose1This standard is issued under the fixed designation D3516;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.1NOTEEditorial updates made to Section 2 and Footnote 4 in December 2019.1.Scope1.1 These test methods cover four ashing methods forcellulose.These are intended for use on unbleached andbleached cellulose in sheeted or bulk fiber form.Each one ofthe test methods has advantages,so that preference applica-tions exist for all four.1.2 The test methods appear as follows:SectionsTest Method AAsh in Cellulose at 575C6 to 11Test Method BSulfated Ash in Cellulose at 575C12 to 17Test Method CAshing Cellulose by Schoniger Oxidation18 to 22Test Method DWet Ashing of Cellulose for Inorganics23 to 291.3 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For a specific hazard statement,see 20.6.1.1.5 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:2D1193 Specification for Reagent WaterD1348 Test Methods for Moisture in Cellulose(Withdrawn2017)33.Summary of Test Methods3.1 Test Method A,Ash in Cellulose at 575CThis testmethod measures the ash content of cellulose,which is definedfor this test as the residue remaining after ignition at 575 625C until all carbon has been burned off.It is the simplest ofthe four test methods for the determination of ash content only,and it should not be considered as a standard preparativeprocedure for elemental analysis.NOTE1The ash content at this ignition temperature is a reasonablemeasure of the mineral salts and inorganic foreign matter in the cellulose.The weight of ash obtained varies with the temperature of ignition.Highertemperatures(850C)will convert calcium carbonate and other carbonatesto the oxides and thus give lower values for ash.The composition of ashmay vary with the pulping process employed for manufacture,whichlimits the significance of the ash determination in absolute terms.3.2 Test Method B,Sulfated Ash in Cellulose at 575CInthis ashing procedure the metal salts are converted to sulfatesby treatment with sulfuric acid and ignition at 575 6 25C toovercome limitations of Test Method A.It should not beconsidered as a standard preparative test method for elementalanalysis.NOTE2Conventional dry ashing at high temperature(over 850C)results in loss of carbon dioxide from metal carbonates,decomposition ofmagnesium sulfate,and loss of sodium salts.Ashing at lower temperatures(575C)gives a better estimate of the inorganic impurities,but has thedisadvantage of requiring a long ignition time and also the heat producedby the burning pulp can raise the temperature far above 575C for a shortperiod of time,converting calcium carbonate to the oxide in varyingamounts.The sulfated ash method overcomes these objectionable featuresand has additional advantages.It is relatively insensitive to ignition time.Ash weight remains constant during weighing,and because the ash doesnot melt it will not attack the crucible.3.3 Test Method C,Ashing Cellulose by SchonigerOxidationThis test method is generally applicable to ashingcellulose for subsequent analysis of inorganic constituents.Theprocedure utilizes the Schoniger technique in which the cellu-lose is burned in a combustion flask and all combustion1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.36 on Cellulose and Cellulose Derivatives.Current edition approved Dec.1,2019.Published December 2019.Originallyapproved in 1976.Last previous edition approved in 2011 as D3516 89(2011).DOI:10.1520/D3516-89R19E01.2For 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.3The 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 StatesThis internat