ASTM_D_4438_-_13.pdf

Designation:D443813Standard Test Method forParticle Size Distribution of Catalysts and Catalyst Carriersby Electronic Counting1This standard is issued under the fixed designation D4438;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 particlesize distribution of catalyst and catalyst carrier particles usingan electroconductive sensing method and is one of severalvaluable methods for the measurement of particle size.1.2 The range of particle sizes investigated was 20 to 150m(see IEEE/ASTM SI 10)equivalent spherical diameter.Thetechnique is capable of measuring particles above and belowthis range.The instrument used for this method is an electriccurrent path of small dimensions that is modulated by indi-vidual particle passage through an aperture,and producesindividual pulses of amplitude proportional to the particlevolume.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:2D1193 Specification for Reagent WaterE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodIEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units(SI):The Modern Metric System3.Summary of Test Method3.1 Acarefully dispersed,dilute suspension of the sample ina beaker filled with an electrolyte is placed in the countingposition on the instrument sample stand.The suspension isforced through a restricting aperture.Each passing particle isrecorded on an electronic counter,and the data are accumulatedaccording to selected particle size intervals for subsequentprocessing.3.2 The instrument response is proportional to liquid dis-placement by the particle volume.Equivalent spherical diam-eter is commonly used to express the particle size.4.Significance and Use4.1 This test method can be used to determine particle sizedistributions for material specifications,manufacturing control,and research and development work in the particle size rangeusually encountered in fluidizable cracking catalysts.5.Apparatus35.1 Electronic Particle Counter,with sample stand andstirring motor.5.2 Aperture Tubes,with varying diameters.The diameterrequired is dependent upon the particle size distribution of thesample.Generally,any given tube will cover a particle sizerange from 2 to 40%of its aperture diameter.5.3 Ultrasonic Tank,100 W.5.4 Beaker,100-mL.5.5 Graduated Glass Pipet,5-mL.5.6 Wash Bottles.5.7 Membrane Filtering Device with 0.22-m filters.5.8 Round-Bottom Sample Beakers,250-mL.5.9 Micro-Riffler or Chute Riffler.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibility of Subcommittee D32.02 on Physical-Mechanical Properties.Current edition approved Dec.1,2013.Published December 2013.Originallyapproved in 1985.Last previous edition approved in 2007 as D4438 85(2007).DOI:10.1520/D4438-13.2For 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.3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D32-1011.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 where such specifications are available.4Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Specification D1193,Type II.6.3 ElectrolyteDissolve 10.0 g of reagent grade sodiumchloride(NaCl)in 1 L of distilled or deionized water and filtertwice through a 0.22-m filter.NOTE1Commercially available Electrolyte solution of the sameconcentration can also be used,but should be filtered for apertures smallerthan 100 m.6.4 Wash WaterDistilled or deionized water,twice filteredthrough a 0.22-m filter.Electrolyte may also be used as washwater.6.5 Calibration Spheres5,Near monosized,having a relativestandard