ASTM_D_4607_-_14.pdf

Designation:D460714Standard Test Method forDetermination of Iodine Number of Activated Carbon1This standard is issued under the fixed designation D4607;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.Scope1.1 This test method covers the determination of the relativeactivation level of unused or reactivated carbons by adsorptionof iodine from aqueous solution.The amount of iodineabsorbed(in milligrams)by 1 g of carbon using test conditionslisted herein is called the iodine number.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.Specific hazardstatements are given in Section 7.2.Referenced Documents2.1 ASTM Standards:2C819 Test Method for Specific Surface Area of Carbon orGraphite(Withdrawn 1987)3D1193 Specification for Reagent WaterD2652 Terminology Relating to Activated CarbonD2867 Test Methods for Moisture in Activated CarbonD3860 Practice for Determination ofAdsorptive Capacity ofActivated Carbon by Aqueous Phase Isotherm TechniqueE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE287 Specification for Laboratory Glass Graduated BuretsE288 Specification for Laboratory Glass Volumetric FlasksE300 Practice for Sampling Industrial Chemicals2.2 NIST Publication:Circular 602Testing of Glass Volumetric Apparatus43.Summary of Test Method3.1 This test method is based upon a three-point adsorptionisotherm(see Practices D3860).A standard iodine solution istreated with three different weights of activated carbon underspecified conditions.The carbon treated solutions are filtered toseparate the carbon from the treated iodine solution(filtrate).Iodine remaining in the filtrate is measured by titration.Theamount of iodine removed per gram of carbon is determinedfor each carbon dosage and the resulting data used to plot anadsorption isotherm.The amount of iodine adsorbed(inmilligrams)per gram of carbon at a residual iodine concentra-tion of 0.02 N is reported as the iodine number.3.2 Iodine concentration in the standard solution affects thecapacity of an activated carbon for iodine adsorption.Therefore,the normality of the standard iodine solution mustbe maintained at a constant value(0.100 6 0.001 N)for alliodine number measurements.3.3 The apparatus required consists of various laboratoryglassware used to prepare solutions and contact carbon with thestandard iodine solution.Filtration and titration equipment arealso required.4.Significance and Use4.1 The iodine number is a relative indicator of porosity inan activated carbon.It does not necessarily provide a measureof the carbons ability to absorb other species.Iodine numbermay be used as an approximation of surface area for sometypes of activated carbons(see Test Method C819).However,it must be realized that any relationship between surface areaand iodine number cannot be generalized.It varies withchanges in carbon raw material,processing conditions,andpore volume distribution(see Definitions D2652).4.2 The presence of adsorbed volatiles,sulfur;and waterextractables may affect the measured iodine number of anactivated carbon.1This test method is under the jurisdiction of ASTM Committee D28 onActivated Carbon and is the direct responsibility of Subcommittee D28.02 on LiquidPhase Evaluation.Current edition approved March 1,2014.Published May 2014.Originallyapproved in 1986.Last previous edition approved in 2006 as D4607 94(Reap-proved 2011).DOI:10.1520/D4607-14.2For 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.4Available from National Institute of Standards and Technology(NIST),100Bureau Dr.,Stop 1070,Gaithersburg,MD 20899-1070,http:/www.nist.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.ApparatusNOTE1All volumetric measuring equipment should meet or exceedthe requirements of NIST Circular 602.Volumetric glassware meetingthese specifications is generally designated as“Class A”.See alsoSpecifications E287 and E288.5.1 Analytical Balance,accuracy 60.0001 g.5.2 Buret,10-mL capacity or 5-mL precision buret.5.3 Flasks,Erlenmeyer 250-mL capacity with ground glassstop