ASTM D6393-99

Standard Test Method for Bulk Solids Characterization by Carr Indices

SCOPE
1.1 This test method covers the apparatus and procedures for measuring properties of bulk solids, henceforth referred to as Carr Indices.
1.2 This test method is suitable for free flowing and moderately cohesive powders and granular materials up to 2.0 mm in size. Materials must be able to pour through a 7.0 + or - 1.0 mm diameter funnel outlet when in an aerated state.
1.3 This method consists of eight measurements and two calculations to provide ten tests for Carr Indices. Each individual test or a combination of several tests can be used to characterize the properties of bulk solids. These ten tests are as follows:
1.3.1 Test A-Measurement of Carr Angle of Repose
1.3.2 Test B-Measurement of Carr Angle of Fall
1.3.3 Test C-Calculation of Carr Angle of Difference
1.3.4 Test D-Measurement of Carr Loose Bulk Density
1.3.5 Test E-Measurement of Carr Packed Bulk Density
1.3.6 Test F-Calculation of Carr Compressibility
1.3.7 Test G-Measurement of Carr Cohesion
1.3.8 Test H-Measurement of Carr Uniformity
1.3.9 Test I-Measurement of Carr Angle of Spatula
1.3.10 Test J-Measurement of Carr Dispersibility
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Apr-1999
• ICS: 19.120 - Particle size analysis. Sieving
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.24 - Characterization and Handling of Powders and Bulk Solids

Relations

• Replaced By: ASTM D6393-99(2006) - Standard Test Method for Bulk Solids Characterization by Carr Indices
• Effective Date: 15-Oct-2006
• Referred By: ASTM C1770-21 - Standard Test Method for Determination of Loose and Tapped Bulk Densities of Small Quantities of Plutonium Oxide
• Effective Date: 10-Apr-1999
• Referred By: ASTM D8135-17(2023) - Standard Guide for Selection of Substitute, Non-hazardous, Particulate Solid Filling Substances for Packagings Subjected to the United Nations Performance Tests
• Effective Date: 10-Apr-1999

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D6393–99
Standard Test Method for
Bulk Solids Characterization by Carr Indices
This standard is issued under the fixed designation D 6393; 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 2.1.2 Carr angle of fall, n—an angle of repose measured
from a powder heap to which a defined vibration has been
1.1 This test method covers the apparatus and procedures
given.
for measuring properties of bulk solids, henceforth referred to
2 2.1.3 Carr angle of repose, n—a measurement from the
as Carr Indices.
powder heap built up by dropping the material through a
1.2 This test method is suitable for free flowing and mod-
vibrating sieve and funnel above a horizontal plate.
erately cohesive powders and granular materials up to 2.0 mm
2.1.4 Carr angle of spatula, n—a measurement by which a
in size. Materials must be able to pour through a 7.0 6 1.0-mm
spatula is inserted into a powder heap parallel to the bottom
diameter funnel outlet when in an aerated state.
and then lifting it up and out of the material.
1.3 This method consists of eight measurements and two
2.1.5 Carr cohesion, n—a descriptive measure of interpar-
calculations to provide ten tests for Carr Indices. Each indi-
ticle forces based on the behavior of the material during
vidual test or a combination of several tests can be used to
sieving.
characterize the properties of bulk solids. These ten tests are as
2.1.6 Carr compressibility, n—a calculation made by using
follows:
Carr loose bulk density and Carr packed bulk density as
1.3.1 Test A—Measurement of Carr Angle of Repose
determined in 5.8.
1.3.2 Test B—Measurement of Carr Angle of Fall
2.1.7 Carr dispersibility, n—a measurement by which a
1.3.3 Test C—Calculation of Carr Angle of Difference
powder sample is dropped through a hollow cylinder above a
1.3.4 Test D—Measurement of Carr Loose Bulk Density
watch glass and then the amount of powder collected by the
1.3.5 Test E—Measurement of Carr Packed Bulk Density
watch glass is measured.
1.3.6 Test F—Calculation of Carr Compressibility
2.1.8 Carr dynamic bulk density, n—a calculated bulk
1.3.7 Test G—Measurement of Carr Cohesion
density of a material. It is used to compute vibration time for
1.3.8 Test H—Measurement of Carr Uniformity
the Carr cohesion measurement.
1.3.9 Test I—Measurement of Carr Angle of Spatula
2.1.9 Carr loose bulk density, n—a measurement obtained
1.3.10 Test J—Measurement of Carr Dispersibility
by sieving the sample through a vibrating chute to fill a
1.4 This standard does not purport to address all of the
measuring cup.
safety concerns, if any, associated with its use. It is the
2.1.10 Carr packed bulk density, n—a measurement ob-
responsibility of the user of this standard to establish appro-
tained by dropping a measuring cup, which is filled with the
priate safety and health practices and determine the applica-
sample, a specific number of times from the same height.
bility of regulatory limitations prior to use.
Sometimes known as a tapped density.
2. Terminology
2.1.11 Carr uniformity, n—a measurement calculated from
the particle size distribution of the powder as measured by
2.1 Definitions of Terms Specific to This Standard:
sieving.
2.1.1 Carr angle of difference, n—the difference between
the Carr angle of repose and Carr angle of fall.
3. Significance and Use
3.1 This test method provides measurements that can be
This test method is under the jurisdiction of ASTM Committee D-18 on Soil used to describe the bulk properties of a powder or granular
and Rock and is the direct responsibility of Subcommittee D18.24 on Character-
material.
ization and Handling of Powders and Bulk Solids.
Current edition approved April 10, 1999. Published July 1999.
Carr, R.L., “Evaluating Flow Properties of Solids,” Chemical Engineering,
January 18, 1965, pp. 163–168.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6393
3.2 The measurements can be combined with practical
experience to provide relative rankings of various forms of
bulk handling behavior of powders and granular materials for
a specific application.
4. Apparatus
4.1 The main instrument includes a timer/counter (A), a
vibrating mechanism (B), an amplitude gage (C), a rheostat
(D), and a tapping device (E) (see Fig. 1).
4.1.1 Timer/Counter—The timer is used to control the
durationofvibrationandthenumberoftaps.Aminimum180-s
timer for 60 Hz power supply is required. Alternatively, a
counter can be used to control the number of taps.
4.1.2 Vibrating Mechanism, to deliver vibration at 50 to 60
Hz to the vibration plate at an amplitude of 0.0 to 3.0 mm.
4.1.3 Amplitude Gage, mounted on the vibration plate to
measure the amplitude of the vibration from 0.0 to 4.0 mm.
4.1.4 Rheostat—A dial used to adjust the vibration ampli-
tude of vibration plate from 0.0 to 3.0 mm.
4.1.5 Tapping Device, consists of tap holder and tapping lift
FIG. 2 Carr Spatula Assembly
bar (tapping pin), which lifts and free-fall drops a measuring
cup a stroke of 18.0 6 0.1 mm and a rate of 1.0 6 0.2 taps/s.
assembly including the sliding bushing, pole, spatula blade,
4.2 The spatula assembly consists of a spatula blade (A), a
and blade receiver is 0.65 6 0.35 kg.
pan base/elevator stand (B), and a shocker (C) (see Fig. 2).
4.3 A dispersibility measuring unit consists of a container
4.2.1 Spatula Blade—Achrome-plated brass plate mounted
(A) with shutter cover (B), a cylindrical glass tube (C), and a
on the blade receiver to retain powder while elevator stand
watch glass (D), (see Fig. 3).
lowers the powder-filled pan. The dimensions of the spatula
4.3.1 Container—A hopper unit with a shutter cover at the
blade are 80 to 130 mm length, 22.0 6 0.3-mm width and 3.0
bottom to support a powder sample. The shutter cover opens
6 0.3-mm thick.
horizontally to release the powder sample which then falls
4.2.2 Shocker—A sliding bushing with a mass of 110.0 6
through the glass tube onto the watch glass.
1.0 g at a drop height of 150.0 6 10.0 mm, measured from the
4.3.2 Cylindrical Glass Tube, located vertically 170.0 6
lower edge of the bushing to the shocker base for the
10.0 mm under the shutter cover to confine the scattering/
measurement of angle of spatula.The total mass of the shocker
dispersed powder. The dimension of the tube is 100.06
5.0-mm diameter and 330.0 6 10.0-mm length.
4.3.3 Watch Glass, centered 101.0 6 1.0 mm under the
Available from Hosokawa Micron International Inc., New York, NY.
cylindrical glass tube to collect undispersed powder. The
FIG. 1 Powder Characteristics Tester for Carr Indices FIG. 3 Carr Dispersibility Measuring Unit
D6393
dimension of watch glass is 100.0 6 5.0-mm diameter and 2.0 measurement of Carr angle of fall. The total mass of the
6 0.1-mm thickness with the radius of curvature of 96.3 mm, shocker, platform, and pan for the measurement of angle of fall
concave upwards. is 1.35 6 0.25 kg.
4.4 Accessories:
NOTE 1—The pan has molded-in feet so it is slightly raised from the
4.4.1 Spatula Pan—A stainless steel pan with at least a
table top. This helps make vibration more consistent.
100.0-mm width, a 125.0-mm length, a 25.0 mm height, and a
4.4.16 Brush, a laboratory brush for dust removal.
1.0-mm thickness, used to retain powder for the preparation of
4.4.17 Cover, for measuring dispersibility. A removable
the measurement of Carr angle of spatula.
enclosure to confine the dust of sample powder when it falls
4.4.2 Scoop—A stainless steel container used to transport
ontothewatchglassforthemeasurementofCarrdispersibility.
powder.
4.5 Balance, capable of measuring sample mass to an
4.4.3 Scraper—A chrome plated brass or stainless steel
accuracy of 6 0.01 g with a max of 2.0 kg.
plate used to scrape off excess powder in the cup.
3 4.6 Data Acquisition Equipment—A microprocessor or
4.4.4 Cup—A 100-cm stainless steel cylindrical container
computer may be used to guide the measuring operation,
with the inside dimensions of 50.5 6 0.1-mm diameter and
collect data, calculate data, and print test results.
49.9 6 0.1-mm height used for Carr bulk density measure-
ment. The wall thickness of the cup is 1.75 6 0.25 mm. The
5. Procedure
interior walls of the cup are sufficiently smooth that machining
5.1 A representative powder sample from process stream
marks are not evident.
should be riffled carefully into portions for each individual
4.4.5 Cup Extension—A white Delriny extension sleeve
measurement.
for the 100 cm measuring cup, 55.0 6 0.1 mm in diameter by
5.2 All the measurements should be performed on a strong,
48.0 6 1.0 mm in height.
horizontally-leveled bench or work table. If possible, use a
4.4.6 Funnel for Angle of Repose—A glass funnel with 55°
concrete or stone-topped table.
angle bowls as measured from the horizontal, 7.0 6 1.0-mm
bottom outlet diameter and outlet stem length 33.5 mm for the
Test A—Measurement of Carr Angle of Repose
measurement of Carr angle of repose.
5.3 Placement of Parts:
4.4.7 Stationary Chute—Astainless steel conical chute with
5.3.1 Placethepartsontothevibrationplateinthefollowing
the dimensions of 75.0-mm top diameter, 55.0-mm height, and
order starting at the bottom:
50.0-mm bottom diameter to guide the powder flow into the
5.3.1.1 Glass funnel;
measuring cup (see 4.4.4).
5.3.1.2 Spacer ring;
4.4.8 Vibration Chute—A stainless steel conical chute with
5.3.1.3 Sieve with opening of 710 µm;
the dimensions of 75.0-mm top diameter, 55.0-mm height, and
5.3.1.4 Sieve extension; and,
50.0-mm bottom diameter installed on the vibration plate to
5.3.1.5 Sieve holding bar.
guide the powder flow to the stationary chute or cup extension.
5.3.2 Fasten the vibration assembly with knob nuts located
4.4.9 Sieves, certified 76.0-mm diameter stainless steel
on both sides of sieve holding bar.
sieves with the opening of 710 µm, 355 µm, 250 µm, 150 µm,
5.3.3 Center the platform under the glass funnel.
75 µm, and 45 µm.
5.3.4 Position the stem end of the glass funnel 76.06 1.0
4.4.10 Sieve Extension—A stainless steel extension piece
mm above the platform.
used as a spacer in the vibration unit when only one sieve is
5.3.5 Set desired vibration time on timer (usually 180 s on
used.
60 Hz vibrating frequency is selected).
4.4.11 Spacer Ring—A white Delriny spacer inserted be- 3
5.3.6 Pour 200 to 300 cm of powder over the sieve using
tween sieve and vibration chute or glass funnel to protect them
the scoop.
from damage.
5.3.7 Set vibration adjustment dial (Rheostat) to 0.
4.4.12 Sieve Holding Bar—A chrome-plated brass holding
5.3.8 Turn on the vibrating mechanism and timer.
bar used to hold sieve assembly on the vibration plate.
5.3.9 Gradually increase the amplitude of the vibration, no
4.4.13 Pan, with base for tapping device, measuring cup,
more than 0.2 mm at a time, by incrementally turning the
and shocker. A stainless steel pan, at least 210.0-mm length,
vibration adjustment dial until powder starts to flow out of the
150.0-mm width, 35.0-mm height, and 1.0-mm thickness,
end of the glass funnel and builds up on the circular platform
designed to accept tapping device, measuring cup and plat-
in a conical shape.
form, as well as provide a stand base for shocker.
5.3.10 Turn off the vibration mechanism when the powder
4.4.14 Platform—A chrome-plated brass circular platform
starts to fall from the edge of the platform and the powder pile
with a diameter of 80.0 6 0.3 mm and a height of 59.0 6 2.0
is completely formed.
mm to be used for the measurement of Carr angle of repose.
5.3.11 If a conical shape is not completely formed, remove
4.4.15 Shocker—A sliding bushing with a mass of 110.0 6
the powder pile and repeat steps 5.3.6-5.3.10.
1.0 g at a drop height of 150.0 6 10.0 mm, measured from the
5.3.12 After the cone has been built up, calculate an average
lower edge of the bushing to the shocker base for the
angleofthecone(fromhorizontal)inrelationtotheedgeofthe
platform by the equation below. This average angle is called
the Carr angle of repose.
–1
Delriny Carr Angle of Repose 5 tan @H/R# (1)
D6393
5.8.6 Set vibration time on timer (a normal vibration time is
where:
about 30 s).
H 5 Height of the powder pile, mm, and
5.8.7 Set vibration adjustment dial (rheostat) to 0.
R 5 Radius of the circular platform, mm.
5.8.8 Turn on the vibrating mechanism and timer.
5.3.13 Indicate the shape of the cone either Concave Up
5.8.9 Adjust the amplitude of vibration to control the
(A), Concave Down (B), or Straight (C) (see Fig. 4) in the
report. powder flow rate so that the powder will fill the cup within 20
to 30 s.
5.3.14 If the cone is irregular in shape, repeat the test three
times and obtain an average. 5.8.10 When the cup is filled and overflowing, stop the
vibration.
5.3.15 If the powder has free-flowing characteristics or has
coarse particles larger than 710 µm, the vibration and 710 µm 5.8.11 Using the scraper, lift and scrape excess material
from the top of the cup as shown in Fig. 5. Remove small
sieve are not necessary. In this case, use the scoop to slowly
pour the powder through the funnel.Adjust the pouring rate so quantities at a time, and continue the process until the material
is flush with the top of the cup. Do not exert a downward force
that it takes 15 to 30 s to form the conical pile.
with the scraper.
Test B—Measurement of Carr Angle of Fall
5.8.12 Weigh the cup with powder.
5.8.13 Subtract the empty cup mass from that of cup with
5.4 After determining the Carr Angle of Repose as in 5.3,
powder. The difference divided by 100 is the Carr loose bulk
place the shocker on the shocker base.
density of the powder in g/cm .
5.5 Thenraisetheslidingbushingcarefully(sothatthecone
will not be disturbed) to the upper end of the pole (at a drop 3
NOTE 2—The cup is exactly 100 cm in volume.
height of 150.0 6 10.0 mm) and let it fall to give a shock to the
5.8.14 Repeat steps 5.8.5-5.8.13 three to five times and
pan. Repeat this three times. The powder layer will be
obtain an average value.
collapsed and exhibit a smaller angle of repose.
5.8.15 When the powder is free-flowing and of fairly coarse
5.6 Wait for 30 s after the final shock and then measure the
particle size, it will not be necessary to use the vibrating sieve.
angle as described in 5.3.12-5.3.14. This new, lower angle is
The powder can be poured gently into the cup by the scoop.
called Carr angle of fall.
Test E—Measurement of Carr Packed Bulk Density
Test C—Calculat
...