ASTM D4781-03

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4781–03
Standard Test Method for
Mechanically Tapped Packing Density of Fine Catalyst
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Particles and Catalyst Carrier Particles
This standard is issued under the fixed designation D 4781; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 6. Apparatus
1.1 This test method covers the determination of the me- 6.1 Graduated Cylinder, capacity 100 mL.
chanically tapped packing density of fine catalyst and catalyst 6.2 Holder—A cylinder holder weighing 454 g (1 lb).
carrier particles smaller than 0.8 mm in diameter. 6.3 Tapping Device, consisting of a baseplate with worm
1.2 This standard does not purport to address all of the drive, with specifications of 250 r/min camshaft speed, tapping
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safety concerns, if any associated with its use. It is the stroke travel of 3.2 mm ( ⁄8 in.).
responsibility of the user of this standard to establish appro- 6.4 Counter—Afour-digit adjustable counter, which can be
priate safety and health practices and determine the applica- preset to deliver number of taps between 1 and 9999.
bility of regulatory limitations prior to use. 6.5 Desiccator, with a desiccant grade molecular sieve such
as 4A.
2. Referenced Documents
6.6 Balance having a sensitivity of 0.1 g.
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2.1 ASTM Standards: 6.7 Drying Oven.
D 3766 Terminology Relating to Catalysts and Catalysis
7. Procedure
E 177 Practice for Use of the Terms Precision and Bias in
ASTM Test Methods 7.1 Heatanadequatesampleat400 615°Cfornotlessthan
E 456 Terminology Relating to Quality and Statistics 3 h. Normally, this treatment can take place in air. However, in
E 691 Practice for Conducting an Interlaboratory Study to the case of materials that might react with air at elevated
Determine the Precision of a Test Method temperature (such as prereduced catalysts) the heat treatment
should take place in an inert atmosphere. After heating, cool
3. Terminology
the test sample in a desiccator or other suitable container to
3.1 Definitions—See Terminology D 3766.
eliminate the possibility of moisture adsorption prior to testing.
NOTE 1—These conditions may not be appropriate for all materials.
4. Summary of Test Method
NOTE 2—Since many catalyst formulations are strong adsorbents, the
4.1 A preconditioned sample of dried fine catalyst or cata-
use of 4A indicating (cobalt-treated) molecular sieves as a desiccating
lyst carrier particles is tapped in a graduated cylinder. The
medium is recommended. The desiccant should be regenerated at 220 to
mechanically tapped packing density is determined from the 260°C, as required.
NOTE 3—Multiple samples can be pretreated but must be desiccated
known mass and tapped volume.
prior to analysis.
5. Significance and Use
7.2 Carefully pour between 90 and 100 mL of the test
5.1 This test method is for measuring the mechanically
specimen into the tared-graduated cylinder using a funnel. To
tapped packing density of powders that are smaller than 0.8
ensure proper level, rotate the funnel while pouring the test
mmindiameter,suchasFluidizedCatalyticCrackingCatalysts
specimen. Weigh immediately to the nearest tenth of a gram.
(FCC).
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.
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This test method is under the jurisdiction of ASTM Committee D32 on
7.5 When tapping is
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