ASTM D 291D 291M:2020 Standard Test Method for Bulk Density of Crushed Bituminous Coal

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Designation: D291/D291M − 20

Standard Test Method for
Bulk Density of Crushed Bituminous Coal1

This standard is issued under the fixed designation D291/D291M; 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 (´) indicates an editorial change since the last revision or reapproval.

1. Scope 2. Referenced Documents
2.1 ASTM Standards:2
1.1 This test method covers two procedures for determining D440 Test Method of Drop Shatter Test for Coal
the bulk density of crushed coal less than 37.5 mm [1.5 in.] in D2234/D2234M Practice for Collection of a Gross Sample
size, such as is charged into coke ovens, as follows: of Coal
D3038 Test Method for Drop Shatter Test for Coke
1.1.1 Procedure A—The cone procedure for determining an D3302/D3302M Test Method for Total Moisture in Coal
uncompacted bulk density. D4749 Test Method for Performing the Sieve Analysis of
Coal and Designating Coal Size
1.1.1.1 Standard Method—Procedure employs the use of a
115 mm [4.5 in.] chute opening and a measuring box having 3. Significance and Use
dimensions of 305 mm x 305 mm x 305 mm [12.0 in. x 12.0 in.
x 12.0 in.]. 3.1 This test method concerns the compaction of crushed
coal to determine either its compacted or uncompacted bulk
1.1.1.2 Alternate Method—Procedure employs the use of a density, for purposes such as charging coke ovens.
203 mm [8.0 in.] chute opening and a measuring box having
dimensions of 203 mm x 203 mm x 305 mm [8.0 in. x 8.0 in. x PROCEDURE A—CONE PROCEDURE FOR
12.0 in.] for coals with a total moisture greater than 7 %. UNCOMPACTED BULK DENSITY

1.1.2 Procedure B—The dropped-coal procedure for deter- 4. Apparatus
mining a compacted bulk density, comparable to actual bulk
densities attained in coke ovens. 4.1 Measuring Box:
4.1.1 Standard Method, of rigid construction, having inside
1.2 This test method is not applicable to the testing of dimensions of 305 mm x 305 mm x 305 mm [12.0 in. x 12.0 in.
powdered coal as used in boiler plants, nor to the determination x 12.0 in.], and a volume of 0.02873 m3 6 0.00008 m3
of the bulk density of coal in storage piles. [1.000 ft3 6 .003 ft3]. The exact volume of the box shall be
determined by water calibration.
1.3 Units—The values stated in either SI units or inch- 4.1.2 Alternate Method, of rigid construction, having the
pound units are to be regarded separately as standard. The inside dimensions of 203 mm x 203 mm x 305 mm [8.0 in. x
values stated in each system are not necessarily exact equiva- 8.0 in. x 12.0 in.], and a volume of 0.01257 m3 6 .00003 m3
lents; therefore, to ensure conformance with the standard, each [0.4444 ft 3 6 0.0012 ft3]. The exact volume of the box shall be
system shall be used independently of the other, and values determined by water calibration.
from the two systems shall not be combined.
4.2 Cone:
1.4 This standard does not purport to address all of the 4.2.1 Standard Method, conforming to Fig. 1 for filling the
safety concerns, if any, associated with its use. It is the measuring box. This cone shall be 610 mm [24.0 in.] high and
responsibility of the user of this standard to establish appro- 510 mm [20.0 in.] in inside diameter at the top, with a circular
priate safety, health, and environmental practices and deter- opening 115 mm [4.5 in.] in diameter at the bottom. A slide
mine the applicability of regulatory limitations prior to use. valve consisting of a sliding-plate shutter and its supports shall
be welded to the bottom of the cone in such a manner that the
1.5 This international standard was developed in accor- valve may be opened and closed with ease by removing or
dance with internationally recognized principles on standard- inserting the shutter in its supporting slides. The cone shall be
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
mendations issued by the World Trade Organization Technical contact ASTM Customer Service at For Annual Book of ASTM
Barriers to Trade (TBT) Committee. Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
1 This test method is under the jurisdiction of ASTM Committee D05 on Coal
and Coke and is the direct responsibility of Subcommittee D05.15 on Metallurgical

Properties of Coal and Coke.

Current edition approved Nov. 1, 2020. Published January 2021. Originally
approved in 1927. Last previous edition approved in 2012 as D291 – 07(2012).
DOI: 10.1520/D0291_D0291M-20.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States

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D291/D291M − 20

FIG. 1 Example of Apparatus for Cone Procedure: Standard Method

supported in a tripod frame having a circular opening at the top 4.2.2 Alternate Method, 3 conforming to Fig. 2 for filling the
of 457 mm [18.0 in.] in diameter. This frame shall support the measuring box. This cone shall be 470 mm [18.5 in.] high and
cone so that the top-side of the shutter shall be 560 mm
[22.0 in.] from the inside bottom surface of the box. An 3 Supporting data have been filed at ASTM International Headquarters and may
example of the apparatus for the standard cone procedure is be obtained by requesting Research Report RR:D05-2001. Contact ASTM Customer
shown in Fig. 1. Service at

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D291/D291M − 20

FIG. 2 Example of Apparatus for Cone Procedure: Alternate Method

510 mm [20.0 in.] in inside diameter at the top, with a circular supported in a tripod frame having a circular opening at the top
opening of 203 mm [8.0 in.] in diameter at the bottom. A slide of 457 mm [18.0 in.] in diameter. This frame shall support the
valve consisting of a sliding-plate shutter and its supports shall cone so that the top-side of the shutter shall be 560 mm

be welded to the bottom of the cone in such a manner that the [22.0 in.] from the inside bottom surface of the box. An
valve may be opened and closed with ease by removing or example of the apparatus for the alternate cone procedure is
inserting the shutter in its supporting slides. The cone shall be shown in Fig. 2.

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D291/D291M − 20

4.3 Leveling Bar, a steel strip 760 mm [30 in.] long by the determination of the bulk density (see Section 5). The
37.5 mm [1.5 in.] wide and approximately 5 mm [3⁄16 in.] thick. minimum gross sample masses required by Test Methods
D3302/D3302M and D4749 will not apply.
4.4 Scales, platform, capable of weighing up to 100 kg
[220 lb] and sensitive to 0.05 kg [0.1 lb]. 6.5 For the purpose of simplifying communication between
concerned parties in the reporting of the size distribution of the
5. Sampling actual bulk density sample, it is recommended to employ the
standard series of sieves identified in 6.1.2 of Test Method
5.1 Gross Sample—For collecting gross samples of crushed D4749 covering from within the actual topsize of the coal
bituminous coal, the procedures described in Practice D2234/ down to 6.3 mm (1⁄4 in.). Other sieve sizes may be used.
D2234M shall apply. During the period of collecting the gross
sample, the increments of the sample shall be stored in a 7. Calculation
waterproof container with a tightly fitting cover in order to
prevent the loss of moisture. The minimum number and mass 7.1 Calculate the uncompacted bulk density, BDuncomp, to
of increments collected shall be in accordance with Table 2 of the nearest 0.05 kg/m3 [0.1 lb/ft3] as follows:
Practice D2234/D2234M. The minimum gross mass of the
sample shall be 140 kg [300 lb]. BDuncomp,kg⁄m3@lb ⁄ ft3# 5 ~W2 2 W1!⁄V1 (1)

5.2 Laboratory Sample—The gross sample of coal shall be where: the mass of the empty measuring box, kg [lb];
thoroughly mixed and subdivided, without crushing, into four W1 = the mass of the filled measuring box after leveling as
34 kg [75 lb] portions. This operation shall be done as quickly W2 =
as possible to avoid loss of moisture, and the bulk density shall described in 6.3, kg [lb]; and

be determined immediately. If this determination cannot be V1 = the measured volume of the measuring box as deter-
made immediately, the samples shall be kept in waterproof mined by water calibration as described in 4.1, m3
containers with tightly fitting covers until the time for making [ft3].
the determination.
8. Report
6. Procedure
8.1 Report the uncompacted bulk density, BDuncomp, as
6.1 Before filling the cone hopper, level it in its tripod on a calculated in Section 7 to the nearest 0.05 kg/m3 [0.1 lb/ft3].
solid floor. Pour the prepared sample into a pile on the floor and
carefully flatten it to about 100 mm [4 in.] in thickness using a 8.2 Report the method, either the Standard Method or
rake or shovel. Avoid pounding of the pile with the back of the Alternate Method, used to determine the BDuncomp.
shovel. Take successive shovelfuls from uniformly distributed
points in the pile and allow them to slide gently from the shovel 9. Precision and Bias
into the hopper at different peripheral points. This will prevent
segregation and packing while the hopper is being filled. Place 9.1 Repeatability:
about 34 kg [75 lb] of coal in the hopper. 9.1.1 Duplicate results by the same operator in a given
laboratory on consecutive tests determined within a minimum
6.2 Weigh the empty measuring box to the nearest 0.05 kg interval of time shall be considered suspect if they differ by
[0.1 lb]. Center the previously weighed measuring box under more than 9.6 kg/m3 [0.6 lb/ft3].
the valve of the cone. Remove the valve shutter completely, 9.1.2 When two results are obtained that differ by more than
allowing all of the coal to flow into the box and overflow the this value, two additional tests shall be made. If the second pair
edges. Loosen wet coal, not flowing freely from the hopper, by of results differs by less than the repeatability, the first pair
gently thrusting downward (or poke) through the coal to the shall be discarded and the mean of the second pair shall be
valve with the leveling bar. reported as the result of the test.
9.1.3 When both pairs of results exceed the repeatability, the
6.3 After filling the box, carefully level off the excess coal mean of the four results shall be reported, provided that the two
above the box edge by means of the leveling bar, and place the most divergent results differ by less than 13 kg/m3 [0.8 lb/ft3].
box on the platform scale and weigh it to the nearest 0.05 kg Otherwise, all results shall be discarded and the apparatus,
[0.1 lb]. Avoid jarring or shifting of the filled box until all procedure, and sample shall be examined for noncompliance
excess coal is leveled off. Record the mass of the filled causes, which should be corrected before redetermining new

measuring box to the nearest 0.05 kg [0.1 lb]. pairs of values.

6.4 Moisture and size distribution of the coal are the two 9.2 Reproducibility—It is not possible to specify the preci-
main factors which affect the bulk density. It is recommended sion (reproducibility) of the procedure in Test Method D291/
for proper interpretation that a moisture determination and D291M for measuring the uncompacted bulk density because
sieve analysis of the coal be reported along with the bulk of the impracticality of obtaining, transporting, and handling
density result. For directions for determination of the total representative splits of the materials in the quantities that
moisture, see Test Method D3302/D3302M. For directions for would be needed to establish the precision statement.
the determination of size distribution, see Test Method D4749.
For the purposes of reporting both total moisture and size 9.3 Bias—No information can be presented on the bias of
distribution associated with the bulk density results, the repre- the procedure in Test Method D291/D291M for measuring the
sentative sample is taken to be the actual sample employed for uncompacted bulk density because the method is empirical and
no material having an accepted reference value is available.

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D291/D291M − 20

FIG. 3 Example of Apparatus for Dropped Coal Procedure

The use of the 203 mm x 203 mm x 305 mm [8.0 in. x 8.0 in. been shown to produce results 1 kg ⁄m3 [0.06 lb ⁄ft3] higher
x 12.0 in.] measuring box specified in the Alternate Method has

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D291/D291M − 20

than when using the 305 mm x 305 mm x 305 mm [12.0 in. x floor of the dropping apparatus and center it directly under the
12.0 in. x 12.0 in.] measuring box of the standard method. hopper with the long axis of the box parallel to the long axis of
the hopper. Mark the floor of the dropping apparatus so that the

PROCEDURE B—DROPPED-COAL PROCEDURE measuring box will always be positioned exactly the same each
FOR COMPACTED BULK DENSITY4 time.

10. Apparatus 12.2 Pour the prepared coal sample into a pile on the floor
and carefully flatten it to about 100 mm [4 in.] in thickness
10.1 Measuring Box, specially constructed, externally using a rake or shovel. Avoid pounding of the pile with the
braced to ensure rigidity, having inside dimensions of 457 mm back of the shovel. Take successive shovelfuls from uniformly
x 610 mm x 203 mm [18.0 in. x 24.0 in. x 8.0 in.] and a volume distributed points in the pile and carefully place them into the
of 0.05659 m3 6 0.00016 m3 [2.000 ft3 6 0.006 ft3]. The exact hopper to avoid segregation. Place each shovelful to one side
volume of the box shall be determined by water calibration. of the preceding one until 82 kg to 90 kg [180 lb to 200 lb] are
contained in the hopper, avoiding any heaping up of the coal at
10.2 Dropping Apparatus, consisting of the shatter test any one point as well as any compacting of the coal with the
machine described and illustrated in Test Method D3038 and shovel.
Test Method D440. It shall consist of a box 457 mm [18.0 in.]
in width, 710 mm [28 in.] in length, and approximately 12.3 Raise the hopper containing the coal and allow the coal
380 mm [15 in.] in depth, supported above a rigidly mounted to drop into the measuring box from the 1.8 m [6 ft] height.
cast iron or steel plate, not less than 13 mm [0.5 in.] in Carefully level the excess coal even with the top edge of the
thickness, 970 mm [38 in.] in width, and 1220 mm [48 in.] in box by means of the leveling bar. Avoid jarring or shifting of
length. The inside of the bottom of the box shall be 1800 mm the filled box until all excess coal is leveled. Fill any voids left
[72 in.] above the plate. The bottom of the box shall consist of in the corners of the box below the top edge by gently raking
two doors hinged lengthwise and latched so that they will the excess coal across the corner. Place the box, or its contents,
swing open freely and not impede the fall of the coal. In order on the platform scale and weigh it to the nearest 0.05 kg
to facilitate filling the box with coal, the box shall be [0.1 lb].
constructed so that it can be lowered to a convenient level. An
example of the dropping apparatus is shown in Fig. 3. 12.4 Moisture and size distribution of the coal are the two
main factors which affect the bulk density. It is recommended
10.3 Leveling Bar, a steel strip 760 mm [30 in.] long by for proper interpretation that a moisture determination and
37.5 mm [1.5 in.] wide and approximately 5 mm [3⁄16 in.] thick. sieve analysis of the coal be reported along with the bulk
density result. For directions for determination of the total
10.4 Scales, platform, capable of weighing up to 100 kg moisture, see Test Method D3302/D3302M. For directions for

[220 lb] and sensitive to 0.05 kg [0.1 lb]. the determination of size distribution, see Test Method D4749.
For the purposes of reporting both total moisture and size
11. Sampling distribution associated with the bulk density results, the repre-
sentative sample is taken to be the actual sample employed for
11.1 Gross Sample—For collecting gross samples of the determination of the bulk density (see Section 5). The
crushed bituminous coal, the procedures described in Practice minimum gross sample masses required by Test Methods
D2234/D2234M shall apply. During the period of collecting D3302/D3302M and D4749 will not apply.
the gross sample, the increments of the sample shall be stored
in a waterproof container with a tightly fitting cover in order to 12.5 For the purpose of simplifying communication be-
prevent the loss of moisture. The minimum number and mass tween concerned parties in the reporting of the size distribution
of increments collected shall be in accordance with Table 2 of of the actual bulk density sample, it is recommended to employ
Practice D2234/D2234M. The minimum gross mass of the the standard series of sieves identified in 6.1.2 of Test Method
sample shall be 360 kg [800 lb]. D4749 covering from within the actual topsize of the coal
down to 6.3 mm (1⁄4 in.). Other sieve sizes may be used.
11.2 Laboratory Sample—The gross sample of coal shall be
thoroughly mixed and subdivided, without crushing, into four 13. Calculation
90 kg [200 lb] portions. This operation shall be done as quickly
as possible to avoid loss of moisture, and the bulk density shall 13.1 Calculate the compacted bulk density, BDcomp, to the
be determined immediately. If this determination cannot be nearest 0.05 kg ⁄m3 [0.1 lb ⁄ft3] as follows:
made immediately, the samples shall be kept in waterproof
containers with tightly fitting covers until the time for making BDcomp,kg⁄m3@lb ⁄ ft3# 5 ~W4 2 W3!⁄V2 (2)
the determination.
where: the mass of the empty measuring box, kg [lb];
12. Procedure W3 = the mass of the filled measuring box after leveling as
W4 =
12.1 Weigh the empty measuring box to the nearest 0.05 kg described in 12.3, kg [lb];
[0.1 lb]. Place the previously weighed measuring box on the V2 = the measured volume of the measuring box as deter-
mined by water calibration as described in 10.1, m3
4 Auvi, H. S., Schmidt, L. D., and Graham, H. G., “Control of Bulk Densities in [ft3].
Coke Ovens: Studies on Precision and Application of Various Testing Methods,” U.

S. Bureau of Mines R.I. 3935, 1946.

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D291/D291M − 20

14. Report [1.3 lb ⁄ft3]. Otherwise, all results shall be discarded and the
apparatus, procedure, and sample shall be examined for non-
14.1 Report the compacted bulk density, BDcomp, as calcu- compliance causes, which should be corrected before redeter-
lated in Section 13 to the nearest 0.05 kg ⁄m3 [0.1 lb ⁄ft3]. mining new pairs of values.

15. Precision and Bias 15.2 Reproducibility—It is not possible to specify the pre-
cision (reproducibility) of the procedure in Test Method
15.1 Repeatability: D291/D291M for measuring the compacted bulk density be-
15.1.1 Duplicate results by the same operator in a given cause of the impracticality of obtaining, transporting, and
laboratory on consecutive tests determined within a minimum handling representative splits of the materials in the quantities
interval of time shall be considered suspect if they differ by that would be needed to establish the precision statement.
more than 16 kg ⁄m3 [1.0 lb ⁄ft3].
15.1.2 When two results are obtained that differ by more 15.3 Bias—No information can be presented on the bias of
than this value, two additional tests shall be made. If the second the procedure in Test Method D291/D291M for measuring the
pair of results differs by less than the repeatability, the first pair compacted bulk density because the method is empirical and
shall be discarded and the mean of the second pair shall be no material having an accepted reference value is available.
reported as the result of the test.
15.1.3 When both pairs of results exceed the repeatability, 16. Keywords
the mean of the four results shall be reported, provided that the
two most divergent results differ by less than 21 kg ⁄m3 16.1 compacted bulk density; crushed coal; uncompacted
bulk density

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