ASTM_C_1069_-_09_2014.pdf

Designation:C106909(Reapproved 2014)Standard Test Method forSpecific Surface Area of Alumina or Quartz by NitrogenAdsorption1This standard is issued under the fixed designation C1069;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.1.Scope*1.1 This test method covers the determination of the specificsurface area of aluminas and silicas used in the manufacture ofceramics.The test method is a general one,permitting the useof any modern commercial nitrogen adsorption apparatus butstrictly defining the outgassing procedure.Calculations arebased on the Brunauer-Emmett-Teller(BET)equation.1.2 The values stated in SI units are to be regarded asstandard.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E173 Practice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals(Withdrawn1998)33.Summary3.1 An appropriate size sample is degassed for 1 h at 423 Kbefore proceeding with the analysis as prescribed by themanufacturer of the instrument used.The sample is accuratelyweighed after analysis.3.2 Calculations are based on the BET equations,adaptedwhere necessary for the equipment being used.The cross-sectional area of the nitrogen molecule is taken as 0.162 nm2.4.Significance and Use4.1 Both sellers and purchasers of alumina and quartz willfind the test method useful to determine the specific surfacearea and indirectly as a measure of the particle size for materialspecifications,manufacturing control,and research and devel-opment.5.Apparatus5.1 Specific Surface Area Analyzer,recently(after 1970)manufacturedcommercialequipmentemployinglow-temperature(77 K)nitrogen adsorption.This test method maybe dynamic or static.5.2 Degassing Equipment,suitable to the instrument used.5.3 Analytical Balance,having a sensitivity of 1.0 mg.6.Reagents and Materials6.1 Liquid Nitrogen.6.2 Cylinder of compressed nitrogen gas,high purity asspecified by manufacturer,with pressure regulator.6.3 Cylinder of compressed helium gas,high purity asspecified by manufacturer,with pressure regulator,for staticinstruments or for dynamic instruments having gas mixingability and employing the multipoint procedure or,6.4 Cylinder of compressed,approximately 0.30 molfraction,nitrogen in helium with pressure regulator,for otherdynamic instruments employing the single point procedure.7.Procedure7.1 Sample PreparationBlend the gross sample very well.For non-free-flowing materials mechanical agitation is neces-sary(for example,V-type blender with intensifier).If samplesplitting of free-flowing materials is necessary,use a spinningriffler.7.2 Sample Degassing7.2.1 Sample size is related to the equipment being used andshall conform to the equipment manufacturers recommenda-tions for highest precision.7.2.2 The degassing technique(for example,vacuum,no-vacuum)shall conform to the equipment manufacturers rec-ommendations.1This test method is under the jurisdiction ofASTM Committee C21 on CeramicWhitewares and Related Products and is the direct responsibility of SubcommitteeC21.04 on Raw Materials.Current edition approved Dec.1,2014.Published December 2014.Originallyapproved in 1986.Last previous edition approved in 2009 as C1069 09.DOI:10.1520/C1069-09R14.2For 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.*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.United States1 7.2.3 The degassing temperature shall be 1 h at 423 K.7.2.4 Samples must be analyzed immediately after degas-sing.7.3 AnalysisThe analysis procedure recommended by themanufacturer as their most precise shall be followed.8.Calculations8.1 The procedure recommended by the manufacturer asbeing the most complete shall be followed.9.Report9.1 Report the following information:9.1.1 ResultsIn units of m2/g.9.1.2 Specific surface area as the average of twodeterminations,each made on separately degassed samples.Ifthe results do not agree within 5%the procedure should bereviewed,the equipment checked,and the test repeated a thirdtime.9.1.3 From a practical standpoint it is recommended that thefollowing guidelines be used in reporting data:9.1.3.1 Fr