1、Designation: D5757 11Standard Test Method forDetermination of Attrition of FCC Catalysts by Air Jets1This standard is issued under the fixed designation D5757; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. 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 relativeattrition characteristics of FCC catalysts by means of air jetattrition.
3、 Other fine powder catalysts can be analyzed by thistest method but the precision of this test method has beendetermined only for FCC catalysts. It is applicable to spheri-cally or irregularly shaped particles which range in sizebetween 10 and 180 m, have skeletal densities between 2.4and 3.0 g/cm3(
4、2400 and 3000 kg/m3) (see IEEE/ASTM SI-10)and are insoluble in water. Particles less than 20 m areconsidered fines.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 thesafet
5、y 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 Term
6、s Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 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 System23. Terminolog
7、y3.1 Definitions of Terms Specific to This Standard:3.1.1 Air Jet Index (AJI)a unitless value numericallyequal to the percent attrition loss at 5 h.4. Summary of Test Method4.1 A sample of dried powder is humidified and attrited bymeans of three high velocity jets of humidified air. The finesare con
8、tinuously removed from the attrition zone by elutriationinto a fines collection assembly.4.2 The AJI is calculated from the elutriated fines to give arelative estimate of the attrition resistance of the powderedcatalyst as may be observed in commercial use.5. Significance and Use5.1 This test method
9、 is intended to provide informationconcerning the ability of a powdered catalyst to resist particlesize reduction during use in a fluidized environment.5.2 This test method is suitable for specification acceptance,manufacturing control, and research and development pur-poses.6. Apparatus6.1 The air
10、jet attrition system consists of the following:6.1.1 Attrition Tube, a stainless steel tube 710-mm long witha 35-mm inside diameter.NOTE 1NPS 114-in. pipe, Schedule 40 has the appropriate insidediameter.6.1.2 Three 2-mm Long Drilled Sapphire Square EdgedNozzles, precision drilled 0.381 6 0.005 mm in
11、 diameter. Theyare mounted equidistant from each other, 10 mm from centerand flush with the top surface in a circular orifice plate 6.4-mmthick. The plate is designed to be attached to the bottom of thevertical attrition tube within an air delivery manifold.6.1.3 Settling Chamber, a 300-mm long cyli
12、nder with a110-mm inside diameter and with conical ends reducing to30-mm inside diameter. The upper cone is approximately100-mm long and the lower cone is approximately 230-mmlong. The chamber is mounted to the top of the attrition tube.6.1.4 Fines Collection Assembly, made up of a 250-mLfiltering f
13、lask, an extraction thimble connected to the side armsof the flask, and a 200 by 13-mm diameter metal tubing bent toan angle of 125 connecting the top of the flask to the top of thesettling chamber.1This test method is under the jurisdiction of ASTM Committee D32 onCatalysts and is the direct respon
14、sibility of Subcommittee D32.02 on Physical-Mechanical Properties.Current edition approved Nov. 15, 2011. Published December 2011. Originallyapproved in 1995. Last previous edition approved in 2006 as D575700(2006).DOI: 10.1520/D5757-11.2For referenced ASTM standards, visit the ASTM website, www.ast
15、m.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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NOTE 2The
16、 flask may be eliminated and the thimble connecteddirectly to the tubing if the attrition is expected to be low enough to avoidclogging the thimble and creating a backpressure in the settling chamber.6.1.5 Rubber Couplers and Seals, appropriately sized toensure tight and leak free connections of the
17、 system.6.2 Air Supply Source, controlled and capable of maintain-ing an air flow rate of 10.00 L/min stable to 0.05 L/min at apressure up to 200 kPa. The air must be at a relative humidityof 30 to 40 % to minimize electrostatic effects.NOTE 3The air may be bubbled through a 0.25-m column ofdeionize
18、d water at ambient temperature to obtain the required humidity.6.3 Diaphragm-Type Test Meter (dry test meter) or Liquid-Sealed Rotating Drum Meter (wet test meter), minimumcapacity of 30 L/min and maximum scale subdivision of 0.1 L.Alternately, an electric mass flow controller may be used.6.4 Balanc
19、e, 400-g capacity open pan with 0.01-g sensitiv-ity.6.5 Desiccator, with a desiccant grade molecular sieve suchas 4A.6.6 Muffle Furnace.6.7 Relative Humidity Gage.7. Sampling7.1 Obtain a representative sample of approximately 65 g ofmaterial from larger composites by riffling or splitting with theai
20、m of obtaining a sample that represents the size distributionof the larger composite.7.2 Gently screen the sample through a No. 80 (180 m)ASTM sieve to remove any particles larger than 180 m.7.3 The step in 7.3.1 is followed for all samples except freshFCC catalysts for proper equilibration at 35 %
21、humidity toavoid absorption of water during the test.7.3.1 Transfer the presieved sample to a shallow wide dishand place in a humidifier over a saturated calcium chloridesolution for 16 h.7.4 The steps in 7.4.1-7.4.4 are followed for fresh FCCcatalysts to ensure a proper moisture level that will not
22、 changeduring the test.7.4.1 Transfer the presieved sample to a shallow dish anddryitfor1hinamufflefurnace preheated to 565C.7.4.2 Cool the sample to room temperature in a desiccator.7.4.3 Mix 45 g of the dried and cooled material thoroughlywith5gofdemineralized water ensuring that the water is well
23、dispersed and that there are no lumps of material present.7.4.4 Allow the sample to stand over a saturated calciumchloride solution in a humidifier for 1 h.8. Preparation of Apparatus8.1 Thoroughly clean any residual material from the appa-ratus by tapping it loose and blowing or vacuuming the dust.
24、Reassemble the system except for the fines collection assem-bly.8.2 Turn on the air supply and adjust the relative humidityof the air exiting the settling chamber to a range of 30 to 40 %.8.3 Connect the inlet of the wet test gas meter to the top ofthe settling chamber and adjust the humidified air
25、flow to 10.006 0.05 L/min at standard temperature and pressure (STP)(273.15 K and 101.325 kPa). The back pressure should be inthe range of 130 to 180 kPa; if it is not, check that the air jetnozzles are clean and within specifications and that there are noleaks in the apparatus connections.8.4 Prepa
26、re two fines collection assemblies and conditionthe thimbles by installing them on the apparatus in successionand passing the humidified air through the apparatus for 30 mineach.9. Procedure9.1 Weigh the first conditioned fines collection assembly tothe nearest 0.01 g and record its mass.9.2 With th
27、e air flowing at the prescribed 10.00 L/min andthe fines collection assembly off, charge 50 g of waterequilibrated sample to the apparatus through the top of thesettling chamber, quickly secure the first fines collectionassembly to the apparatus and start the timekeeping.9.3 Weigh the second conditi
28、oned fines collection assemblyto the nearest 0.01 g and record its mass.9.4 After exactly 1 h from the start, replace the first finescollection assembly with the second one. Weigh and record themass of the first fines collection assembly.9.5 After exactly 5 h from the start, remove the finescollecti
29、on assembly, weigh it, and record its mass.9.6 Turn off the apparatus and disassemble.9.7 Recover the sample from the attrition tube and settlingchamber and weigh to the nearest 0.01 g.9.8 Clean the apparatus.10. Calculations10.1 Calculate the percent fines lost in the first hour asfollows:fines los
30、s, % 5 m12 m0!/ms3 100 (1)where:m0= mass of the first empty fines collection assembly atthe start of the test, g,m1= mass of the first fines collection assembly at 1 h, g,andms= mass of the sample charged to apparatus (nominally50 g).10.2 Calculate the percent fines lost from attrition at the fifthh
31、our as follows:attrition loss, % 5 m12 m01 m52 m80!/ms3 100 (2)where:m80= mass of the second empty fines collection assembly,g, andm5= mass of the second fines collection assembly at 5 h,g.10.3 Calculate the percent sample recovery after the test asfollows:recovery, % 5 m11 m51 mr2 m02 m80!/ms3 100
32、(3)where:mr= mass of the sample recovered from the attrition tubeand the settling chamber.11. Report11.1 Report the following information:11.1.1 The AJI.D5757 11211.1.2 The first hour fines loss as percent.11.1.3 The recovery as percent.12. Precision and Bias12.1 Test ProgramAn interlaboratory study
33、 was con-ducted in which the named property was measured in fourseparate test materials in four to seven separate laboratories.Practice E691, modified for nonuniform data sets, was fol-lowed for the data reduction. Analysis details are in theresearch report.12.2 PrecisionPairs of test results obtain
34、ed by a proce-dure similar to that described in the study are expected to differin absolute value by less than 2.772 S, where 2.772 S is the95 % probability interval limit on the difference between twotest results, and S is the appropriate estimate of standarddeviation. Definitions and usage are giv
35、en in Practices E456and E177, respectively. See Table 1.12.3 BiasThe procedure in this test method for measuringattrition has no known bias because the value of the attritionloss is defined only in terms of this test method.13. Keywords13.1 abrasion; air jet; attrition; fines; powdered catalystsASTM
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37、irely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsan
38、d should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical 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 o
39、n Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or a
40、t 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 ASTM website (www.astm.org/COPYRIGHT/).TABLE 1 Repeatability and ReproducibilityTest ResultAJI(consensus mean)9
41、5 % Repeatability Interval(within laboratory)95 % Reproducibility Interval(between laboratories)2.530 0.226 (8.95 % of mean) 0.907 (35.9 % of mean)4.209 0.279 (6.64 % of mean) 1.939 (46.1 % of mean)20.353 1.121 (5.51 % of mean) 11.370 (55.9 % of mean)39.945 1.414 (3.54 % of mean) 12.029 (30.1 % of mean)D5757 113
