1、Designation: D 7481 09Standard Test Methods forDetermining Loose and Tapped Bulk Densities of Powdersusing a Graduated Cylinder1This standard is issued under the fixed designation D 7481; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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 the apparatus and proceduresfor determining the bulk densities of free flowin
3、g and moder-ately cohesive powders and granular materials up to 3.5 mm insize in their loose (Method A) and tapped (Method B) states.1.2 This test method should be performed in a laboratoryunder controlled conditions of temperature and humidity.1.3 This test method is similar to those of Test Method
4、sB 212, D29, and D 2854.1.4 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D 6026.1.4.1 The procedures used to specify how data are collected/recorded or calculated in this standard are regarded as theindustry standard. In
5、 addition they are representative of thesignificant digits that generally should be retained. The proce-dures used do not consider material variations, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; and it is common practice toincrease or red
6、uce significant digits of reported data to becommensurate with these considerations. It is beyond the scopeof this standard to consider significant digits used in analysismethods for engineering design.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are
7、 included in thisstandard.1.6 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 pr
8、ior to use.2. Referenced Documents2.1 ASTM Standards:2B 212 Test Method for Apparent Density of Free-FlowingMetal Powders Using the Hall Flowmeter FunnelB 527 Test Method for Determination of Tap Density ofMetallic Powders and CompoundsC 29/C 29M Test Method for Bulk Density (“Unit Weight”)and Voids
9、 in AggregateD29 Test Methods for Sampling and Testing Lac Resins3D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD 2854 Test Method for Apparent Density of ActivatedCarbonD 3740 Practi
10、ce for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD 4164 Test Method for Mechanically Tapped PackingDensity of Formed Catalyst and Catalyst CarriersD 4753 Guide for Evaluating, Selecting, and SpecifyingBalances
11、and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD 6026 Practice for Using Significant Digits in Geotechni-cal DataD 6683 Test Method for Measuring Bulk Density Values ofPowders and Other Bulk Solids as Function of Compres-sive Stress3. Terminology3.1 Definitions: For comm
12、on definitions of technical termsin this standard, refer to Terminology D 653.3.2 Definitions of Terms Specific to This Standard:3.2.1 loose bulk density, rL, g/cm3, nin powders, the bulkdensity that results from pouring the powder into a heap orcontainer in the absence of any applied compression, g
13、/cm3.3.2.2 tapped bulk density, rT, g/cm3, nin powders, thebulk density resulting from the application of compression, forexample, impact or vibration, g/cm3.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.24 on Ch
14、aracterizationand Handling of Powders and Bulk Solids.Current edition approved Oct. 1, 2009. Published October 2009.2For 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
15、the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Test Method4.1 Loose
16、bulk density (Method A) is determined by mea-suring the volume of a known mass of powder that has beenpassed through a screen or funnel into a graduated cylinder.4.2 Tapped bulk density (Method B) is achieved by me-chanically tapping a measuring cylinder containing a powder.After observing the initi
17、al volume, the cylinder is mechanicallytapped, and volume readings are taken until little furthervolume change is observed.5. Significance and Use5.1 The data from the loose bulk density test can be used toestimate the size of bags, totes, small bins or hoppers for thestorage of a fixed mass of powd
18、er in its loose condition. It canalso be used to estimate the mass of powder that will fit insmall size containers such as drums. It cannot be used toestimate powder quantities of large vessels such as silos.5.2 Values of loose bulk density obtained using this testmethod should be used with caution,
19、 since they can varyconsiderably depending on the inital state of dispersion of thetest specimen, height-to-diameter ratio of specimen in gradu-ated cylinder, dryness of powder, and other factors.5.3 The data from the tapped bulk density test can be usedto estimate the needed volume of small contain
20、ers holding afixed mass of powder that has been compacted. An examplewould be a packing line where vibration is used to tamppowders into a small container for effective packing purposes.5.4 Bulk density values can vary significantly if the particlesize of the actual material to be handled is differe
21、nt than tested.A bulk solid consisting of large and small particles often hashigher bulk densities than the fine particles by themselves. Forpowders, lower densities are possible if the fine particles arefluidized or aerated.5.5 The results of this test method are most applicable tocontainers with v
22、olumes up to about one cubic meter. Anothermethod (such as D 6683) should be used when consideringlarger silos.NOTE 1The quality of the results produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies th
23、at meet thecriteria of Practice D 3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D 3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D 3
24、740provides a means of evaluating some of those factors. Practice D 3740 wasdeveloped for agencies engaged in the testing or inspection (or both) ofsoil and rock. As such it is not totally applicable to agencies performingthis standard. However, users of this standard should recognize that theframew
25、ork of Practice D 3740 is appropriate for evaluating the quality ofan agency performing this standard. Currently there is no known quali-fying national authority that inspects agencies that perform this standard.6. Apparatus6.1 Balance having a minimum capacity of 400 g andmeeting the requirements o
26、f Guide D 4753 for a balance of 0.1g readability.6.2 250 mL or 100 mL standard glass graduated cylinder.See 7.3.6.3 Two screens: 1.7 mm (No. 12 U.S. sieve), 4.00 mm (No.5 U.S. sieve). Each screen should be full height and 200 mmdiameter.6.4 Suitable mechanical tapped density tester that provides afi
27、xed drop of 14 6 2 mm at a nominal rate of 300 drops perminute or a fixed drop of 3 mm 6 0.3 mm at a nominal rate of250 drops per minute. A typical tester is shown in Fig. 1.7. Preparation of Apparatus7.1 Check that the balance is set on a sturdy table or bench,leveled and zeroed.7.2 Make sure that
28、the graduated cylinder is clean of anyand all foreign material (including water or other liquids) priorto starting each test.7.3 Depending on the untapped apparent volume of the testspecimen and its particle size gradation, choose either a 250mLor 100 mLstandard glass graduated cylinder using the ta
29、blebelow.Graduated cylindersize, mLUntapped apparent volumeof test specimen, mLUpper limit onparticle size, mmMin. Max. d50Absolute max.100 50 100 1.3 2.5250 125 250 1.7 3.58. Procedure8.1 Loose Bulk Density (Method A):8.1.1 Determine and record the mass of the graduatedcylinder to the nearest 0.1 g
30、.8.1.2 Choose an appropriate dispersion method to ensurethat the material hasnt agglomerated from transit. If this test isbeing conducted on a fine powder with particles much smallerthan 1 mm, pass a sufficient quantity though a 1.00 mm (18mesh) screen to break up agglomerates that may have formeddu
31、ring storage. Oversized particles should not be excludedfrom the test. Should any particles not pass through the screen,an alternate dispersion method is required, such as selecting ascreen slightly larger than the largest particle to pass thematerial through, or stirring the material in a mixing bo
32、wl witha spatula. Maximum limits on particle size for this test areprovided in 7.3. Avoid agglomeration and segregation ofmaterial. Describe method used on Test Data Sheet.8.1.3 If necessary, carefully level the powder without com-pacting, and read the unsettled apparent volume to the nearestgraduat
33、ed unit. Determine and record the volume of thepowder in the cylinder to the nearest graduated unit; that is, 1mL for the 100-mL cylinder and 2 mL for the 250-mL cylinder,noting that 1 mL is equal to 1 cm3.8.1.4 An alternate method would be to fill a 250-mL or100-mL cylinder to a measured volume lin
34、e.8.1.5 Determine and record the mass of the specimen plusgraduated cylinder to the nearest 0.1 g.8.2 Tapped Bulk Density (Method B):8.2.1 Repeat steps 8.1.1 through 8.1.5.8.2.2 Mechanically tap the cylinder containing the powderspecimen by raising the cylinder and allowing it to drop underits own m
35、ass using a suitable mechanical tapped density testerthat provides a fixed drop of 14 6 2 mm at a nominal rate of300 drops per minute. This is Method B1.D74810928.2.3 An alternate method (Method B2) is to use a fixeddrop of 3 mm 6 0.3 mm at a nominal rate of 250 drops perminute. This may yield lower
36、 values of tapped bulk density.8.2.4 Unless otherwise specified, tap the cylinder 500 timesinitially and measure the tapped volume to the nearest gradu-ated unit. Determine and record the volume of the powder inthe cylinder to the nearest graduated unit; that is, 1 mL for the100-mL cylinder and 2 mL
37、 for the 250-mL cylinder, noting that1 mL is equal to 1 cm3.8.2.5 If necessary, carefully level the powder without com-pacting, and read the settled apparent volume to the nearestgraduated unit.8.2.6 Repeat the tapping an additional 750 times and mea-sure the tapped volume to the nearest graduated u
38、nit.NOTE 2Fewer taps may be appropriate, if validated, for somepowders.8.2.7 If the difference of the two tapped volumes of 8.2.3and 8.2.5 is less than 2 %, use the second measurement for thetapped volume. Otherwise, repeat in increments of 1250 taps,as needed, until the difference between succeedin
39、g measure-ments is less than 2 %.9. Calculations9.1 Loose Bulk Density (Method A):9.1.1 Determine the net mass of the specimen by subtractingthe mass of the graduated cylinder from that of the specimenplus graduated cylinder.9.1.2 Divide the net mass of the specimen by the measuredvolume as noted on
40、 the graduated cylinder. The calculatedvalue is the loose bulk density in g/cm3. Record value to twosignificant digits if 100-mL cylinder is used, and three signifi-cant digits if 250-mL cylinder is used.9.2 Tapped Bulk Density (Method B):9.2.1 Divide the net mass of the specimen by the measuredvolu
41、me as noted on the graduated cylinder after tapping iscomplete. The calculated value is the tapped bulk density ing/cm3. Record value to two significant digits if 100-mLcylinder is used, and three significant digits if 250-mL cylinderis used.10. Test Data Sheet10.1 The methodology used to specify ho
42、w data are re-corded on the test data sheet(s)/form(s), as given below, iscovered in 1.4.10.2 Record as a minimum the following general informa-tion (data):10.2.1 Requesting agency or client and/or identifying num-ber for job or project10.2.2 Technician10.2.3 Date10.3 Record as a minimum the followi
43、ng test specimendata:10.3.1 Generic name of sample10.3.2 Chemical name of sample, if knownFIG. 1 Typical Mechanical Tapped Density TesterD748109310.3.3 Specimen moisture (water) content, if determined.Record value to nearest 0.1 %. Indicate method used todetermine moisture if not Test Method D 2216.
44、10.3.4 Specimen temperature10.3.5 Specimen particle size, if determined. Indicate pro-cedure used, which may have been specified by requestingagency or client.10.3.6 Method used to prepare test specimen in a loose state(Section 8.1.2)10.4 Record as a minimum the following test data:10.4.1 Volume of
45、graduated cylinder10.4.2 Mass of graduated cylinder empty (tare)10.4.3 Mass of graduated cylinder filled with material10.4.4 Volume of loose filled specimen in graduated cylin-der10.4.5 Mass of specimen plus graduated cylinder10.4.6 Calculated net mass of specimen10.4.7 Calculated loose bulk density
46、10.4.8 Fixed drop during tapped bulk density (Method B1or B2)10.4.9 Rate of drops per minute during tapped bulk density10.4.10 Number of taps and corresponding values of cylin-der volume10.4.11 Calculated tapped bulk density10.4.12 Name and model of tapped density tester used11. Precision and Bias11
47、.1 PrecisionTest data on precision is not presented dueto the nature of the powder and other bulk solids tested by thisstandard. It is not feasible or too costly at this time to have tenor more laboratories participate in a round-robin testing pro-gram. In addition, it is either not feasible or too
48、costly toproduce multiple specimens that have uniform physical prop-erties. Any variation observed in the data is just as likely to bedue to specimen variation as to operator or laboratory varia-tion.11.1.1 Subcommittee D18.24 is seeking any data from usersof this standard that might be used to make
49、 a limited statementon precision.11.2 BiasThere is no accepted reference value for thisstandard, therefore, bias cannot be determined.12. Keywords12.1 loose bulk density; tapped bulk densityASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. 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 re
