ASTM_D_4179_-_11.pdf

Designation:D417911Standard Test Method forSingle Pellet Crush Strength of Formed Catalysts andCatalyst Carriers1This standard is issued under the fixed designation D4179;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 determining the resistance offormed catalysts and catalyst carriers to compressive force andis applicable to regular catalyst shapes such as tablets andspheres.Extrudates,granular materials,and other irregularshapes are specifically excluded.1.2 This test method determines the average crush strengthin the range from 0 to 50 lbf(0 to 220 N).Some materials mayhave crush strengths above 50 lbf(220N);the test method isapplicable to these materials,but the precision of the test is notknown.1.3 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 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:2E177 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 Method3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 pelletsany catalyst shapetablets,spheres,or othersimilar configurationthat is not otherwise excluded from thescope of this test method.3.1.2 tabletstableted cylindrical catalyst particles,eithersolid or hollow core,with lengths that do not vary from themean by more than 610%.4.Summary of Test Method4.1 Individual pellets taken from a representative sample areplaced between two flat surfaces,subjected to a compressiveload,and the force required to crush the pellet is measured.Theprocedure is replicated and the average of all measurementstaken is determined.5.Significance and Use5.1 This test method is intended to provide informationconcerning the ability of a catalyst shape to retain physicalintegrity during use.6.Apparatus6.1 A suitable compression testing device is required,con-sisting of the following:6.1.1 Calibrated Gauge,marked for direct reading of theforce in pounds(newtons).Additionally,a suitable system(mechanical,hydraulic,or pneumatic)must be provided so thatthe rate of force application is both uniform and controllablewithin specified limits.6.1.2 Tool Steel Anvils,between which the sample will becrushed.The faces of the tool steel anvils shall be smooth andfree from recesses or ridges that would interfere with uniformcontact along the major axis of the pellet.When testing tabletsor spheres,the anvils may be of any convenient size or shape1This 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 Oct.1,2011.Published November 2011.Originallyapproved in 1982.Last previous edition approved in 2006 as D417901(2006).DOI:10.1520/D4179-11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 as long as their length and width are greater than the corre-sponding dimensions of the tablet or pellet being tested(seeFig.1).7.Sampling7.1 A test sample of 50 to 200 individual pieces shall beobtained from larger composites by riffling or splitting inaccordance with STP 447A,3(paragraph 5.12)with the aim ofobtaining a representative sample that represents shape andsize distribution of the larger composite.The size of the sampleshall depend on the precision required and the homogeneity ofthe material being tested.7.2 Pretreat the test sample(s)at 400 6 15C for not lessthan 3 h.Normally,this treatment can take place in air;however,in the case of materials that might react with air atelevated temperatures(such as prereduced catalysts)the heattreatment should take place in an inert atmosphere.Care shouldbe taken to ensure that the pretreatment does not alter theinherent strength or structure of the sample as evidenced bychanges in surface area or phase.Any modifications to pre-treatment conditions should be noted in the report.7.3 After heating,cool the test sample(s)in a desiccator orother suitable container to elimi