ASTM D4749/D4749M-87(2019)e1

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.
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Designation: D4749/D4749M − 87 (Reapproved 2019)
Standard Test Method for
Performing the Sieve Analysis of Coal and Designating Coal
Size
This standard is issued under the fixed designation D4749/D4749M; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—The designation was editorially updated to dual and other editorial changes were made throughout in December
2019.
1. Scope 1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This test method covers procedures for determining the
ization established in the Decision on Principles for the
sieve analysis of coal and designating the size of coal from
Development of International Standards, Guides and Recom-
sieve analysis data. Raw as well as prepared (crushed, cleaned
mendations issued by the World Trade Organization Technical
or screened) coals can be tested by this test method.
Barriers to Trade (TBT) Committee.
1.2 This test method explains how to designate coal sizes
from the results of sieve analysis data in order to represent the
2. Referenced Documents
condition of the coal as sold. In the case of special mixtures or
2.1 ASTM Standards:
coals with noncontinuous ranges of sizes, a sufficiently com-
D197Test Method for Sampling and Fineness Test of
plete sieve analysis must be made to properly describe the size
Pulverized Coal
distribution.
D346 Practice for Collection and Preparation of Coke
1.3 This test method is not applicable for determining the
Samples for Laboratory Analysis
sieve analysis nor for designating the size of pulverized coal.
D388Classification of Coals by Rank
(See Note 1.) Size fractions down to and including 38 µm [No.
D2013Practice for Preparing Coal Samples for Analysis
400 U.S.A. Standard Series] can be treated by the methods
D2234/D2234MPractice for Collection of a Gross Sample
discussed in this test method. Methods for handling size
of Coal
fractions below 38 µm [No. 400] will be developed by this
D3302Test Method for Total Moisture in Coal
committee.
D4371Test Method for Determining the Washability Char-
acteristics of Coal
NOTE1—Forpowderedorpulverizedcoalasisfiredintosteamboilers,
refer to Test Method D197. E11Specification forWovenWireTest Sieve Cloth andTest
Sieves
1.4 The values stated in either SI units or inch-pound units
E323Specification for Perforated-Plate Sieves for Testing
are to be regarded separately as standard. The values stated in
Purposes
each system are not necessarily exact equivalents; therefore, to
ensure conformance with the standard, each system shall be 2.2 Other Document:
used independently of the other, and values from the two
SpecificationC-80CommonwealthofPennsylvania,Depart-
systems shall not be combined. ment of General Services, Bureau of Purchases, Specifi-
cation for Coal:Anthracite
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Descriptions of Terms Specific to this Standard
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3.1 as-mined coal—same as ROM coal (3.8).
mine the applicability of regulatory limitations prior to use.
1 2
This test method is under the jurisdiction of ASTM Committee D05 on Coal For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Coke and is the direct responsibility of Subcommittee D05.07 on Physical contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Characteristics of Coal. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2019. Published December 2019. Originally the ASTM website.
approved in 1987. Last previous edition approved in 2012 as D4749–87(2012). Available from Commonwealth of Pennsylvania, Dept. of General Services,
DOI: 10.1520/D4749_D4749M-87R19E01. Bureau of Purchases, 414 N. Office Building, Harrisburg, PA 17125.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D4749/D4749M − 87 (2019)
3.2 as-shipped or produced coal—raw or prepared coal in 3.10 wet sieving—for the purposes of this test method, the
any state or condition at which it leaves the mine property or testmethodforthesievingofcoalthatuseswaterasamedium
loading facility. forfacilitatingthesegregationofthesampleintoparticlesizes;
this is generally used when testing coal particles 600 µm [No.
3.3 bottomsize, nominal—the sieve designating the lower
30 U.S.A. Standard Series] or smaller.
limit or bottomsize shall be that sieve of the series given in
Section 6 with the largest openings through which passes a
4. Significance and Use
total of less than 15% of the sample. This defined bottomsize
is not to be confused with the size of the smallest particles in 4.1 This test method concerns the sieving of coal into
the lot. (Warning—In the case of a commercial, double- designated size fractions for the purpose of characterizing the
screenedproduct,forexample,37.5mmby9.5mm[1 ⁄2in.by materialastoitsparticlesizedistributionforfurtherprocessing
⁄8 in.], this designation may not be valid. In such commercial or for commercial purposes. This is covered in Part A of this
or contractual situations, the amount of allowable material standard. Raw, as well as prepared (crushed, cleaned, or
smaller than the bottomsize (for example, 9.5 mm) must be screened), coals can be tested by this test method.
specified by the contract under which the coal is bought and
4.2 This test method is applicable for all types of coals,
sold.)
exceptforpulverizedcoals(seeMethodD197)suchasfedinto
steam boilers. Low rank coals, that is, lignites, subbituminous,
3.4 dry sieving—forthepurposesofthistestmethod,thetest
method for the sieving of coal after the sample has been andhighvolatilebituminousC,mustbedriedwithcautionand
handledwithcaretominimizedeteriorationorsizedegradation
air-dried under prescribed conditions; this is generally used
when testing with coal particles larger than 600 µm [No. 30 during sieving.
U.S.A. Standard Sieve Series].
4.3 This test method is applicable for the wet or dry-sieving
of coal at sizes from 200 mm [8 in.] to 38 µm [No. 400 U.S.A.
3.5 opening—for the purpose of this test method, openings
Standard]. Methods for sizing materials below 38 µm are
and apertures shall be regarded as synonomous terms. Dimen-
outside the scope of this test method.
sions for round and square openings shall be determined as
follows: for round holes, dimensions shall refer to the opening
NOTE2—Thesizingofmaterialthatpassesthe38µmsieveisnormally
diameter; for square holes, dimensions shall refer to the
performed by optical microscopy, sedimentation, centrifugation, light
distance between parallel wires. scattering or obfuscation, surface area measurement, or other such
methods. Subsieve techniques are also used sometimes.
3.6 prepared coal—any coal, regardless of its topsize, that
4.4 This test method also concerns the designation of a coal
hasbeenmanuallyormechanicallycleaned.Thisincludescoal
sample as to its upper (nominal top-size) and lower (nominal
that has been processed over a picking table or air tables,
bottom-size)limitingsizesforthepurposeofcharacterizingthe
through a breaker, jig, or other device which segregates
material for further processing or for commercial purposes.
according to size or density (specific gravity).
This is covered in Part B of this test method.Anthracite coal is
3.7 raw coal—any coal, regardless of its topsize, that has
further designated by a one word descriptive term (see 14.4).
not been manually or mechanically cleaned. Crushed coal that
4.5 Enough material may not be collected by this test
has not been mechanically cleaned (including coal that has not
method to meet subsequent test procedures, such as washabil-
been through a breaker which normally rejects oversize) is
ity analyses (Test Method D4371).
considered to be raw coal. Coal delivered to the surface from
an underground mine is considered to be raw coal even when
PART A. SIEVE ANALYSIS OF COAL
crushing and grinding is done underground. Coal removed
fromthepitofasurfacemineisconsideredtoberawcoaleven
5. Apparatus
when breaking and crushing facilities are provided in the pit.
5.1 Sieves:
3.8 run-of-mine (ROM) coal—inthecaseofanunderground
5.1.1 Wire Cloth Sieves:
mine, it is that coal delivered to the surface by a slope belt,
5.1.1.1 Standard test sieves that conform to Specification
hoist,etc.Inthecaseofasurfacemine,itisthatcoalasitexists
E11 shall always be used.
afterithasbeenremovedfromthepitandplacedintotheinitial
5.1.1.2 Formostsievetests,wherethelargestparticleinthe
means of transportation whether it be an on-the-road or
sampledoesnotexceed25mm[1in.],standard203mm[8in.]
off-the-roadhaultruck,dumphopperwhichfeedsapit-to-plant
diameter, 50mm [2in.] deep sieves or sieves with larger
conveyor, etc. For both underground and surface mines, ROM
diameters (for example 300 mm [12 in.] or 450 mm [18in.])
coal is as-mined and has not been exposed to any treatment
are recommended. For special cases, and with small samples,
such as breaking, crushing, or cleaning except for that done by
75mm [3in.] and 150mm [6in.] diameter sieves are avail-
thenormaloperationsusedtoextractthecoalfromtheground,
able.
that is, blasting, ripping, loading, cutting, etc.
5.1.1.3 Standard test sieves shall be made from either brass
3.9 topsize, nominal—the sieve designating the upper limit or stainless steel frames and either brass, phosphor bronze, or
stainless steel cloth.
or topsize shall be that sieve of the series given in Section 6
withthesmallestopeningsuponwhichiscumulativelyretained 5.1.1.4 In general, these square mesh sieves are used when
a total of less than 5% of the sample. This defined topsize is sizing with sieves with openings smaller than 6.3 mm [ ⁄4 in.].
nottobeconfusedwiththesizeofthelargestparticleinthelot. U.S.A. Standard Sieve Designations shall be used.
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D4749/D4749M − 87 (2019)
5.1.1.5 For more complete details of standard test sieves, 5.2.4 Mechanical sieve shakers can generally be classified
including methods of checking and calibrating the sieves, see into two types: batch (acceptable) and continuous (unaccept-
Specification E11. able).
5.1.2 Perforated Plate Sieves: 5.2.4.1 Batch—Batch mechanical sieve shakers are those in
5.1.2.1 Perforated plate sieves, made to conform to Speci- which a controlled quantity of coal is placed into the apparatus
fication E323, are available with square apertures and mechanical action is initiated. After a controlled time
from125mm[5in.]to3.36mm[0.132in.]andwithstaggered period, mechanical action is completed and the size fractions
round apertures from 125mm [5 in.] to 1 mm [0.038 in.]. The are removed from the horizontal sieves. These types of
sizesofsuccessiveaperturesintheseriesfollowthesameratio mechanical sieve shakers are acceptable.
as in Specification E11 for sieves.
5.2.4.2 Continuous—Continuous mechanical sieve shakers
5.1.2.2 Standard frames for perforated plate sieves with are unacceptable for the purpose of this test method. Continu-
apertures4.00mmandlargeraremadeofhardwoodorsteelto ous mechanical sieve shakers are those in which a continuous
hold 300mm [12in.], 400mm [16in.], or 450mm [18in.] stream of coal is fed into the apparatus and over a set of
square sieve plates. For apertures smaller than 4.00 mm, inclined sieves. The retention time on these sieves depends
203mm [8in.] circular frames as well as the above larger upon the degree of inclination, the throw of the sieves, and the
square frames may be used. frequency of mechanical action. The various size fractions are
collected in individual containers in a continuous stream.
5.1.2.3 In general, round hole sieves with staggered open-
ings are used when sizing with sieves with opening diameters
of 6.3 mm [ ⁄4 in.] or larger. 6. Standard Series of Sieves
5.1.2.4 Where perforated sieves and wire cloth sieves are
6.1 Crushed Bituminous, Subbituminous, and Lignitic
usedinthesametest(forexample,inananalysisfrom125mm
Coals:
[5 in.] to 250 µm [No. 60]) or where results with perforated
6.1.1 For crushed bituminous, subbituminous, and lignitic
sieves are to be compared with results with wire cloth sieves,
coals, the standard series of sieves shall utilize round-hole
it is better to use only square aperture sieves.
perforated plate sieves for sieves with opening diameters of
NOTE 3—This action should be taken primarily while performing 6.3 mm [ ⁄4 in.] or larger and wire-cloth (U.S.A. Standard)
sieving analyses on noncommercial samples, as, for instance, in prepara-
sieves with square openings for sieves with openings smaller
tion plant component studies (see 6.5.1). In commerce, mixed series are
than 6.3 mm [ ⁄4 in.].
still customary (see 6.1.1 and 6.3.1).
6.1.2 For the purpose of simplifying communication be-
5.1.2.5 Results with a given square aperture and with the
tweenconcernedparties,thefollowingseriesofsievesshallbe
same diameter round aperture are not compatible. Therefore,
considered as the standard series for crushed bituminous,
all reports of sieve analysis data are incomplete without
subbituminous and lignitic coals:
designation as to the type of sieves employed (round or square
Round Hole Perforated Plate Sieves
openings).
200 mm [8 in.] 37.5 mm [1 ⁄2 in.]
5.1.2.6 Aperture sizes of some sieves for anthracitic coal
150 mm [6 in.] 31.5 mm [1 ⁄4 in.]
(6.3.2.1) do not conform to Specification E323.
125 mm [5 in.] 25.0 mm [1 in.]
100 mm [4 in.] 19.0 mm [ ⁄4 in.]
5.2 Mechanical Sieve Shaker:
75 mm [3 in.] 12.5 mm [ ⁄2 in.]
1 3
5.2.1 Mechanical sieve shakers are used in practically all
63 mm [2 ⁄2 in.] 9.5 mm [ ⁄8 in.]
50 mm [2 in.] 6.3 mm [ ⁄4 in.]
laboratories where frequent tests are made. They not only
eliminate tedious hand labor, but, when properly used, will
Wire Cloth (U.S.A. Standard) Sieves with Square Openings
produce more consistent results than hand sieving. They can,
4.75 mm [No. 4] 300 µm [No. 50]
however, result in excessive sample degradation when proper
2.36 mm [No. 8] 150 µm [No. 100]
precautions are not taken.Therefore it is important to establish
1.18 mm [No. 16] 75 µm [No. 200]
and to monitor the sieving amplitude and the sieving time.
600 µm [No. 30] 38 µm [No. 400]
5.2.2 There are several general types of mechanical sieve
6.1.3 For crushed bituminous, subbituminous, and lignitic
shakers. One type is designed to simulate hand sieving by
coals, an alternate standard series of sieves can utilize square-
using a circular motion combined with a tapping action. This
hole perforated plate or steel-wire sieves for sieves with
type of mechanical sieve shaker is acceptable.
openings of 6.3 mm [ ⁄4 in.] or larger and wire cloth (U.S.A.
5.2.3 A type of sieve shaker which will handle a stack of
Standard) sieves for sieves with openings smaller than 6.3 mm
either round or rectangularly framed sieves and produces a 1
[ ⁄4 in.]. This alternate series shall use sieves with openings of
vigorous agitation is especially suitable for handling large
the same dimensions as those given in 6.1.2. When this
samples of coarse material. This type of mechanical sieve
alternate series of square openings is used, the report must
shaker is acceptable for handling large samples provided it is
include this information.
not overloaded and provided agitation time is limited so that
6.1.3.1 Since round hole 6.3mm [ ⁄4in.] perforated plate
degradation of the coal being sieved does not occur (see
sievesproduceundersizeofapproximatelythesameamountas
11.3.5).
4.75mm [No. 4 U.S.A. Standard] wire cloth sieves, that is,
these sieves are nearly equivalent, it is not necessary to utilize
NOTE 4—Some manufacturers can supply machines with reduced
amplitude of vibration or variable speeds, or both, for soft materials. both 6.3mm [ ⁄4 in. round] perforated plate and 4.75mm
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TABLE 2 Comparison Table of U.S.A. Standard with Tyler Sieve
[No.4 U.S.A. Standard] wire cloth sieves simultaneously. The
Series
selection of either will be sufficient.
U.S.A. Standard Series
6.2 Coal Used as Coke Oven Charge: Tyler
Standard Alternate
6.2.1 For coal that will be used as a coke oven charge, the
1 1
5.60 mm No. 3 ⁄2 3 ⁄2 mesh
standard series of sieves shall utilize square-hole perforated
4.75 mm No. 4 4 mesh
plate or steel-wire sieves with openings of 6.3 mm [ ⁄4 in.] or 4.00 mm No. 5 5 mesh
3.35 mm No. 6 6 mesh
larger and wire cloth (U.S.A. Standard) sieves for sieves with
2.80 mm No. 7 7 mesh
openings smaller than 6.3 mm [ ⁄4 in.].
2.36 mm No. 8 8 mesh
6.2.1.1 Typical coke oven charge is 80% minus 3.2 mm 2.00 mm No. 10 9 mesh
1.70 mm No. 12 10 mesh
[ ⁄8in. round]. For the purpose of identifying compliance with
1.40 mm No. 14 12 mesh
this criteria of 80% passing ⁄8in. round, it should not be
1.18 mm No. 16 14 mesh
1.00 mm No. 18 16 mesh
necessary to use sieves larger than 4.75 mm [No. 4 U.S.A.
850 µm No. 20 20 mesh
Standard]. To designate the topsize of this charge according to
710 µm No. 25 24 mesh
Part B of this test method (Section 14), it may be necessary to
600 µm No. 30 28 mesh
500 µm No. 35 32 mesh
use larger sieves. It is recommended that sieving be done
425 µm No. 40 35 mesh
initially at 4.75 mm [No. 4 U.S.A. Standard], then progres-
355 µm No. 45 42 mesh
sively sieve the oversize through the next larger sieve until the
300 µm No. 50 48 mesh
250 µm No. 60 60 mesh
5% criteria of 4.8 is met.
212 µm No. 70 65 mesh
6.2.2 For the purpose of simplifying communication be-
180 µm No. 80 80 mesh
tweenconcernedparties,thefollowingseriesofsievesshallbe
150 µm No. 100 100 mesh
125 µm No. 120 115 mesh
considered as the standard series for coal that will be used as
106 µm No. 140 150 mesh
a coke oven charge:
90 µm No. 170 170 mesh
75 µm No. 200 200 mesh
Square Hole Perforated Plate Sieves
63 µm No. 230 250 mesh
50.0mm[2in.] 53 µm No. 270 270 mesh
37.5mm[1 ⁄2 in.] 45 µm No. 325 325 mesh
25.0mm[1in.] 38 µm No. 400 400 mesh
19.0mm[ ⁄4 in.]
12.5mm[ ⁄2 in.]
9.5mm[ ⁄8 in.]
6.3mm[ ⁄4 in.]
Round Hole Perforated Plate Sieves
6.2.2.1 Smaller sizes shall conform to specifications for
83 mm [3 ⁄4 in.]
wire-cloth sieves (U.S.A. Standard) with square openings, and
A
76 mm [3 in.]
are the same as those in 6.1.2. 62 mm [2 ⁄16 in.]
41 mm [1 ⁄8 in.]
6.3 Anthracitic Coal:
21 mm [ ⁄16 in.]
14 mm [ ⁄16 in.]
6.3.1 For anthracitic coal, the standard series of sieves shall
A
8mm[ ⁄16 in.]
utilize round-hole perforated plate sieves.
A
4.8mm[ ⁄16 in.]
6.3.1.1 Sieve plates mounted in hardwood or steel box 3
2.4mm[ ⁄32 in.]
1.2mm[ ⁄64 in.]
frames 40.6cm to 50.8 cm [16in. to 20 in.] square are
satisfactory for testing chestnut, pea, and buckwheat sizes of
A
Listed in Specification E323.
anthracitic coal. For egg and stove sizes (see Table 1), it is
more convenient to use sieves with frames that are square or
6.3.2.1 These standard anthracitic coal sieve sizes are those
2 2 2
rectangularinshapehavinganareaof0.37m to0.56m [4ft
specified by Commonwealth of Pennsylvania Specification
to 6ft ].
C-80.
6.3.2 For the purpose of simplifying communication be-
6.4 Additional Sieves—Additional sieves are required if a
tweenconcernedparties,thefollowingseriesofsievesshallbe
discontinuity(ies) or deviation(s), or both, from a normal
considered as the standard series for anthracitic coal:
gradation of sizes is (are) found. For sieves below 6.3 mm
[ ⁄4in.],additionalwire-clothsievescanbeselectedfromTable
TABLE 1 Size Designation, Anthracitic Coal
1 of Specification E11. For sieves above 6.3 mm [ ⁄4in.],
Size of Round-Hole Openings in Testing
additional round or square hole perforated plate sieves may be
Sieves, mm [in.]
Size
selected from Table 1 of Specification E323.
Passing Retained On
A
1 7
Egg 83 [3 ⁄4 ] 62 [2 ⁄16 ]
6.5 Other Shapes—Other opening shapes can more fully
7 5
Stove 62 [2 ⁄16]41[1 ⁄8 ]
characterize the coal (oval, rectangular, etc.). They shall only
5 13
Chestnut 41 [1 ⁄8]21[ ⁄16 ]
13 9 be used by agreement between the concerned parties.
Pea 21 [ ⁄16]14[ ⁄16 ]
A
9 5
Buckwheat #1 14 [ ⁄16]8[ ⁄16 ]
6.5.1 Theuseofroundholesievesinplantsizingoperations
A A
5 3
Buckwheat #2 (Rice) 8 [ ⁄16 ] 4.8 [ ⁄16 ]
has been a common practice and much data has been estab-
3 A 3
Buckwheat #3 (Barley) 4.8 [ ⁄16 ] 2.4 [ ⁄32 ]
3 3 lished. However, newer plants, most coking operations, and
Buckwheat #4 2.4 [ ⁄32 ] 1.2 [ ⁄64 ]
A mathematical treatment of comminution studies use the square
Listed in Specification E323, Table 1.
hole sieves. For comparison purposes, round hole openings
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D4749/D4749M − 87 (2019)
maybecalculatedtoanapproximationofthesquareopeningin and removing all coal from a transverse section of it, or by
accordance with the following formula: momentarily inserting a suitable container into the stream and
withdrawing the sample. When it is impracticable to collect
roundopening, mm
5 squareopening, mm (1)
increments the full width and thickness of the coal stream,
1.25
collect the increments systematically from all portions of the
6.5.1.1 Due to differences in particle shape peculiar to
stream.
individual coal types, 1.25 is not always the best factor to use
7.6 The method of collection of the gross sample shall be
when converting between round hole and square hole open-
such as to produce a minimum of degradation.
ings.The normal range for this factor varies from 1.17 to 1.26.
7.7 The probability of collecting representative portions
It is best to determine this conversion factor for any coal in
(samples) for sieve analysis is less from the surface of coal in
question by determining the sieve analysis alternatively using
piles or from loaded cars or bins than from a moving stream of
first round and then square openings.
coal. Where possible, sample such that the full volume of coal
6.5.1.2 When specifying preparation plant components that
in the lot being sampled is represented in the final sample.
utilize wire mesh, Tyler mesh designations are often used
rather than U.S.A. Standard. Table 2 shows the comparison of
8. Weight of Gross Sample
Tyler mesh designations with the U.S.A. Standard designation
based on the aperture sizes of each type. U.S.A. Standard
8.1 The weight of the gross sample collected shall conform
Series designations shall always be used. Tyler mesh designa-
to the general principles of Practice D2234/D2234M. Usually
tions are also to be given where necessary for clarity.
theminimummassestobecollectedarethosegiveninTable3.
For lots of coal greater than 10000 tons, the interested parties
6.6 Frames conforming to criteria in Specification E11 or
shallagreeonthemethodtobeusedforcollectionanddivision
Specification E323 shall be used with applicable sieves.
of the gross sample prior to sieve analysis. In such cases, the
6.7 Suitable pans and covers as applicable to fit specific
following information shall be included on the analysis report:
sieves shall be used as required by Specification E11 or
8.1.1 Total weight of lot sampled.
Specification E323.
8.1.2 Number of sampling increments taken.
8.1.3 Total weight of sample taken. (Warning—Enough
7. Gross Sample
material may not be collected by this method to meet subse-
7.1 Collect the gross sample in accordance with the prin-
quent test procedures, such as determining the washability
ciples of Practice D2234/D2234M.
characteristics of coal (Test Method D4371). See the weight
required by proposed subsequent test methods prior to sam-
NOTE 5—ASTM methods for collection of gross samples from
stockpiles, cartops, etc. (stationary sampling) are being developed. When
pling for the sieve analysis.)
these methods are available, application of those standards will be
required for stationary sampling.
9. Preparation and Division of Gross Sample into Test
7.2 Accurate sampling is of the greatest importance and is Sample for Sieving
the basic requirement for reliable sieve analyses. Take great
9.1 When necessary for proper handling and division, air-
caretoobtainsamplesthatarerepresentativeofthebatchorlot
dry the gross sample in accordance with Method D2013.
being tested. The greatest cause of inconsistencies in test
9.2 In order to divide the gross sample into test samples, do
results is improper sampling that does not represent the
sample division in accordance with the procedures outlined in
material being tested. Therefore, once a sampling procedure
Method D2013 or Practice D2234/D2234M. Warning—
has been established, this same procedure is followed during
Never reduce the topsize of a sample to be used for size
subsequent sampling.
analysis, that is, decreasing the quantity of a sample is allowed
7.3 The quantity or mass of a gross sample will depend on
as long as the remaining portion is representative of the
the character of the material and the form in which it is
material sampled, but reduction in topsize is never allowed.
available and also on whether the test is to determine the
particle size distribution of a pile, batch, shipment, day’s
production, or a short span of time for production control. The
TABLE 3 Gross Sample Quantity to be Collected for Crushed
range of quantity or mass of a gross sample can be as much as
A
Coals Other than Anthracitic Coal
several thousand kilograms or it may be as little as a fraction
Type of Coal Minimum Mass Required
of a kilogram.
Run-of-mine-coal Not less than 1800 kg [4000 lb]
Screened coal with upper limit larger than Not less than 1800 kg [4000 lb]
7.4 Collect increments regularly and systematically, so that
100 mm [4 in.] round
the entire quantity of coal sampled will be represented propor-
Coal smaller than 100 mm [4 in.] round Not less than 900 kg [2000 lb]
tionately in the gross sample, and with such frequency that a
Coal smaller than 50 mm [2 in.] round Not less than 450 kg [1000 lb]
Coal smaller than 25 mm [1 in.] round Not less than 215 kg [500 lb]
grosssampleoftherequiredamountshallbecollected.Collect
Coal smaller than 12.5 mm [ ⁄2 in.] round Not less than 45 kg [100 lb]
not less than the number of increments specified in Table 2 of
Coal smaller than 2.36 mm [No. 8 mesh, Not less than 4.5 kg [10 lb]
Practice D2234/D2234M. U.S.A. Standard]
Coal smaller than 600 µm [No. 30 mesh, Not less than 0.5 kg [1 lb].
7.5 When the coal is passing over a conveyor or through a
U.S.A. Standard]
chute, take increments which include the full width and A
For anthracitic coal, see 9.4.
thicknessofthestreamofcoal,eitherbystoppingtheconveyor
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D4749/D4749M − 87 (2019)
9.3 Samples may be divided according to the following 10.3 When necessary, do sample division in accordance
schedule: with the procedures outlined in Method D2013 or Practice
9.3.1 Coal Larger than 25 mm [1 in.] Round—Sievewithout D2234/D2234M.
mixing or dividing.
10.4 When subsequent testing or analysis, or both, is
9.3.2 Coal Smaller than 25 mm [1 in.] Round—Divide in
required, use careful judgement to ensure that sufficient mate-
amount to not less than 56.6 kg [125 lb] by riffling or by
rial is present in all fractions.
arranging the sample in a long, flat pile and successively
halving it or quartering
...