1、Designation: D 6175 03Standard Test Method forRadial Crush Strength of Extruded Catalyst and CatalystCarrier Particles1This standard is issued under the fixed designation D 6175; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers and is suitable for determiningthe resistance of extruded catalysts and catalyst carr
3、iers tocompressive force from the side.1.2 This test method was developed using extruded catalystand catalyst carriers from116 to18 in. in diameter (0.159 to0.318 cm) and limited to pieces with a length to diameter ratiogreater than or equal to 1:1. This test method may be applicableto other diamete
4、rs.1.3 This test method is suitable for the determination ofmean crush strength per millimetre in the range of 0 to 15lbf/mm (0 to 65 N/mm).1.4 The values stated in pounds lbf/mm units are to beregarded as the standard. The values given in parentheses areprovided for information only.1.5 This standa
5、rd 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 to determine theapplicability of regulatory limitations before use.2. Referenced Documents2.1 ASTM
6、 Standards:2D 3766 Terminology Relating to Catalysts and CatalysisE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 456 Terminology Relating to Quality and StatisticsE 691 Practice for Conducting and Interlaboratory Study toDetermine the Precision of a Test Method3. Termino
7、logy3.1 DefinitionsSee Terminology D 3766.3.2 Definitions of Terms Specific to This Standard:3.2.1 extruded catalyst particlescylindrical particles withuniform cross sections, either solid, hollow core, or multi-lobed, formed by extrusion.4. Summary of Test Method4.1 Individual extrudates taken from
8、 a representativesample are calcined, measured in length, placed between twoflat surfaces, and subjected to a compressive force. The forcerequired to crush the extrudate is measured. The procedure isreplicated, the force per millimetre calculated, and the averageof all quotients determined.5. Signif
9、icance and Use5.1 This test method is intended to provide information onthe ability of an extruded catalyst to retain physical integrityduring use.6. Apparatus6.1 A suitable compression testing device is required, com-posed of the following:6.1.1 Calibrated Pressure or Force Gage, marked for directr
10、eading of the force in pounds force (Newtons) with a rangeabout two times the expected average force reading. A suitablesystem (mechanical, hydraulic, or pneumatic) must be pro-vided so that the rate of force applied is both uniform andcontrollable within specified limits (see 9.4).6.1.2 Tool Steel
11、Anvils, between which the sample will becrushed. The faces of the tool steel anvils shall be smooth andfree from hollows or ridges that would interfere with uniformcontact along the length of the extrudate. The faces shall beparallel to each along their entire length of travel. The faces ofboth anvi
12、ls must be longer in one dimension than the length ofthe sample pieces to be crushed.6.2 A device for determining length, reading in millimetres,and of suitable accuracy to measure to the nearest tenth.1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct re
13、sponsibility of Subcommittee D32.02 on Physical-Mechanical Properties.Current edition approved Oct. 1, 2003. Published October 2003. Originallyapproved in 1998. Last previous edition approved in 1998 as D 617598.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cus
14、tomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Sampling7.1 A test sample of 50
15、 to 200 individual particles shall beobtained from larger composites by riffling or splitting accord-ing to STP 447A,3with the aim of obtaining a representativesample that represents both the shape and size of the largercomposite. The amount of the sample shall depend on theprecision required and th
16、e homogeneity of the material beingtested. All of the individual particles sampled that have a lengthto diameter ratio greater than or equal to one shall be tested.7.2 Heat the test sample(s) at 400 6 15C for not less than3h.NOTE 1Moisture pick-up by extrudates is often rapid and the mea-sured crush
17、 strength may be affected.7.3 After heating, cool the test sample(s) in a desiccator orother suitable container to prevent the adsorption of moisturebefore testing.NOTE 2If the catalyst may be damaged at 400C, a lower temperaturecan be used so long as it is specified with the result. Normally, thist
18、reatment can take place in air. However, for materials that might reactwith air at elevated temperatures (such as prereduced catalysts), the heattreatment should take place in an inert atmosphere.NOTE 3Since many catalyst formulations are strong adsorbents, theuse of 4A indicating (cobalt-treated) m
19、olecular sieves as a desiccatingmedium is suggested. Regenerate the desiccant at 220 to 260C, asrequired.8. Calibration and Standardization8.1 Before use, the test apparatus should be set to zero andcalibrated with any commercially available force gage withmarked graduations of no more than12 lbf (2
20、 N) and havingaccuracy traceable to the National Institute for Standards andTechnology or other similar authority.9. Procedure9.1 Remove from the desiccator only that number of extru-dates that can be tested within a 10-min period. To hold the dryextrudates, the use of an upright fritted disk funnel
21、 equippedwith a dry, upward-flowing, inert gas purge is suggested.NOTE 4Precaution must be taken to ensure that moisture pick-up inthe 10-min period will not significantly affect the extrudate crush strength.9.2 Measure and record the length of an extrudate to thenearest tenth of a millimetre. Use t
22、weezers, forceps, or othersuitable device or procedure to prevent the transfer of moisturefrom the operators hands to the piece being tested.9.3 Then place the measured extrudate that has a length todiameter ratio greater than or equal to one between the anvilsof the compression testing device. The
23、extrudates shall be flatagainst the face of the anvil and be crushed radially (see Fig.1).9.4 Apply increasing force at a uniform rate in the range of1 to 5 lbf/s (4.4 to 22 N/s) until the extrudate crushes orcollapses. Compression of any surface irregularities or limitedfracturing of the extrudate
24、followed by continued resistance toincreasing load are not be used as criteria for determining theendpoint of this test.9.5 Read and record, to the nearest one-half graduation orfirst decimal place, the force indicated on the calibrated meterof the apparatus at the instant of collapse. A pressure ho
25、lding orrecording device coupled to the moving anvil is suggested toindicate the pressure at the time of collapse.9.6 Separate the anvils and remove all residue with a softcloth or brush. Ensure that the faces of the anvils are free fromadhering particles.9.7 Repeat 9.2-9.6 until all extrudates with
26、 a length todiameter ratio greater than or equal to one in the sample havebeen crushed.10. Calculation10.1 Calculate the crush strength per millimetre (x) for eachextrudate, retaining the results to the nearest tenth unit, asfollows:x 5FL(1)where:x = the crush strength for one extrudate per millimet
27、re,lbf/mm (N/mm),F = the force necessary to crush the extrudate, lbf (N), andL = the length of the extrudate along its cylindrical axis,mm.10.2 Calculate the mean crush strength per millimeter (X)asfollows, retaining the results to the nearest tenth unit:X 5 (x / n (2)3STP 447A, Manual on Test Sievi
28、ng Methods, Section 5.12, ASTM Interna-tional, W. Conshohocken, PA. This title is out of print.FIG. 1 Placement of Extrudate Between AnvilsD6175032where:X = mean crush strength millimetre, lbf/mm (N/mm),(x = the sum of the observed crush strengths per millime-tre, andn = the number of extrudates cru
29、shed.10.3 Calculate the standard deviation of the n readings (tothree significant digits):S 5(X X!2n 1lbf N! (3)where:S = standard deviation of the individual strengthin lbf/mm (N/mm).SX X!2= the sum of the squares of the deviations ofeach individual strength per millimetre fromthe average strength
30、per millimetre.NOTE 5Many calculators are programmed to perform these opera-tions and to report average and standard deviation directly. It is importantto verify that the program chosen uses the n-1 denominator rather than nin calculating standard deviation.11. Report11.1 Report the mean crush stren
31、gth per millimetre (X)tothe nearest tenth unit and the standard deviation (S).11.2 Record and report the number of particles measured.11.3 If applicable, report the method used to obtain theanalysis sample from the parent sample.12. Precision and Bias12.1 Test ProgramAn interlaboratory study was con
32、-ducted in which the named property was measured in twoseparate test materials in six and seven laboratories. PracticeE 691, modified for non-uniform data sets, was followed forthe data reduction. See Table 1.12.2 PrecisionPairs of test results obtained by the proce-dure described in the test method
33、 are expected to differ inabsolute value by less than 2.772 S, where 2.772 S is the 95 %probability interval on the difference between two test results,and S is the appropriate estimate of standard deviation.Definitions and usage are given in Terminology E 456 andPractice E 177, respectively.12.3 Bi
34、asThe procedure described is without bias sincethe property is defined in terms of the procedure.13. Keywords13.1 catalyst; crush strength; extrudate; radialASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standar
35、d. Users of 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
36、 every five 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 t
37、echnical committee, 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 Consho
38、hocken, PA 19428-2959,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).TABLE 1 Test Program ResultsTest Results95 % RepeatabilityInterval95 % ReproducibilityInterval(Consensus Means) (Within Laboratory) (Between Laboratories)4.15 lbf/mm 0.16 lbf/mm 0.834 lbf/mm(3.90 % of mean) (20.5 % of mean)3.95 lbf/mm 0.17 lbf/mm 0.641 lbf/mm(4.25 % of mean) (16.8 % of mean)D6175033
