1、Designation: D4781 03 (Reapproved 2018)1Standard Test Method forMechanically Tapped Packing Density of Fine CatalystParticles and Catalyst Carrier Particles1This standard is issued under the fixed designation D4781; the number immediately following the designation indicates the year oforiginal adopt
2、ion 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.1NOTESection 6.2 updated editorially in May 2018.1. Scope1.1 This test method covers
3、the determination of the me-chanically tapped packing density of fine catalyst and catalystcarrier particles smaller than 0.8 mm in diameter.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
4、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.1.4 This international standard was
5、 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. Reference
6、d Documents2.1 ASTM Standards:2D3766 Terminology Relating to Catalysts and CatalysisE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Me
7、thod3. Terminology3.1 DefinitionsSee Terminology D3766.4. Summary of Test Method4.1 A preconditioned sample of dried fine catalyst or cata-lyst carrier particles is tapped in a graduated cylinder. Themechanically tapped packing density is determined from theknown mass and tapped volume.5. Significan
8、ce and Use5.1 This test method is for measuring the mechanicallytapped packing density of powders that are smaller than 0.8mm in diameter, such as Fluidized Catalytic Cracking Catalysts(FCC).6. Apparatus6.1 Graduated Cylinder, capacity 100 mL.6.2 Holder, a cylinder holder weighing 454 g.6.3 Tapping
9、Device, consisting of a baseplate with wormdrive, with specifications of 250 r/min camshaft speed, tappingstroke travel of 3.2 mm.6.4 Counter, a four-digit adjustable counter, which can bepreset to deliver number of taps between 1 and 9999.6.5 Desiccator, with a desiccant grade molecular sieve sucha
10、s 4A.6.6 Balance, having a sensitivity of 0.1 g.6.7 Drying Oven.7. Procedure7.1 Heat an adequate sample at 400 6 15C for not less than3 h. Normally, this treatment can take place in air. However, inthe case of materials that might react with air at elevatedtemperature (such as prereduced catalysts)
11、the heat treatmentshould take place in an inert atmosphere. After heating, coolthe test sample in a desiccator or other suitable container toeliminate the possibility of moisture adsorption prior to testing.NOTE 1These conditions may not be appropriate for all materials.NOTE 2Since many catalyst for
12、mulations are strong adsorbents, theuse of 4A indicating (cobalt-treated) molecular sieves as a desiccatingmedium is recommended. The desiccant should be regenerated at 220 to260C, as required.1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct responsibil
13、ity of Subcommittee D32.02 on Physical-Mechanical Properties.Current edition approved May 1, 2018. Published June 2018. Originallyapproved in 1988. Last previous edition approved in 2013 as D478103(2013).DOI: 10.1520/D4781-03R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, o
14、rcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international
15、standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1N
16、OTE 3Multiple samples can be pretreated but must be desiccatedprior to analysis.7.2 Carefully pour between 90 and 100 mL of the testspecimen into the tared-graduated cylinder using a funnel. Toensure proper level, rotate the funnel while pouring the testspecimen. Weigh immediately to the nearest ten
17、th of a gram.The entire transfer time should be between 35 and 50 s.7.3 Preset the counter to 1000 taps.7.4 Start the tapping device.7.5 When tapping is completed, read the tapped volume, V,to the nearest 1 mL by estimating the average level of thecatalyst surface in the cylinder.8. Calculation8.1 C
18、alculate the mechanically tapped packing density asfollows:MTD 5 W/V (1)where:MTD = mechanically tapped packing density, g/mL,W = mass of catalyst particles, g, andV = volume occupied by particles in measuring cylinder,mL.9. Precision and Bias39.1 Test ProgramAn interlaboratory study was conductedin
19、 which the named property was measured in two separate testmaterials in four separate laboratories. Practice E691, modifiedfor non-uniform data sets, was followed for the data reduction.Analysis details are in the research report.9.2 PrecisionPairs of test results obtained by a proceduresimilar to t
20、hat described in the study are expected to differ inabsolute value by less than 2.772 S, where 2.772 S is the 95 %probability interval limit on the difference between two testresults, and S is the appropriate estimate of standard deviation.Definitions and usage are given in Terminology E456 andPract
21、ice E177, respectively.Test Result(ConsensusMean), g/mL95 % Repeatability Interval(Within Laboratory) g/mL(mean %)95 % Reproducibility Interval(Between Laboratories) g/mL(mean %)0.61950.93550.005 g/mL (0.87)0.010 g/mL (1.07)0.060 (9.74)0.041 (4.41)9.3 BiasThe procedure in this test method has no bia
22、sbecause the value of packing density can be defined only interms of the test method.10. Keywords10.1 catalyst; catalyst carrier; packing densityASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
23、this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five
24、years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical com
25、mittee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
26、9428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D32-1026.D4781 03 (2018)12
