Standard Test Method for Determination of the Swelling Properties of Bituminous Coal Using a Dilatometer

SCOPE
1.1 This test method specifies a procedure for the measurement of the swelling of bituminous coal using a dilatometer.
1.2 The test method is limited in applicability to those coals which have a free swelling index 1 as determined in accordance with Test Method D 720.
1.3 The values stated in SI units (IEEE/ASTM SI-10) are to be regarded as standard.
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.

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31-Mar-2004
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ASTM D5515-97(2004)e2 - Standard Test Method for Determination of the Swelling Properties of Bituminous Coal Using a Dilatometer
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Designation:D5515–97 (Reapproved 2004)
Standard Test Method for
Determination of the Swelling Properties of Bituminous Coal
Using a Dilatometer
This standard is issued under the fixed designation D5515; 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.
´ NOTE—Editorial changes were made throughout in May 2004.
´ NOTE—Equation 1 was editorially corrected in April 2006.
INTRODUCTION
The principle of this test method is that the final volume of char obtained at the conclusion of a
standard dilatation test is dependent on the mass of coal in the coal pencil and on the radius of the
retort tube. This test method incorporates a procedure which: determines the mass of air-dried coal in
the coal pencil; provides a means to measure the average retort tube radii; and employs a means to
report coal expansion on an air dried coal weight basis.
Other test methods used to determine the swelling properties of bituminous coals include the Ruhr
(ISO 8264) and Audibert-Arnu (ISO 349) International Standard Organization (ISO) test methods.
However these two ISO test methods provide consistently different values for percent dilatation and
percent contraction. Percent contraction and dilatation values obtained using the Audibert-Arnu test
method are higher and lower respectively than those obtained using the Ruhr test method. These
differences have been attributed to trimming the length of the coal pencil from different ends. The
Audibert-Arnu test method specifies that the wider end of the coal pencil be trimmed while the Ruhr
test method specifies that the narrower end of the coal pencil be trimmed.
1. Scope 2. Referenced Documents
1.1 This test method specifies a procedure for the measure- 2.1 ASTM Standards:
ment of the swelling of bituminous coal using a dilatometer. D720 Test Method for Free-Swelling Index of Coal
1.2 The test method is limited in applicability to those coals D2013 Practice for Preparing Coal Samples for Analysis
which have a free swelling index $1 as determined in D2234/D2234M Practice for Collection of a Gross Sample
accordance with Test Method D720. of Coal
1.3 The values stated in SI units (IEEE/ASTM SI-10) are to IEEE/ASTM SI-10 Standard for Use of the International
be regarded as standard. System of Units (SI): The Modern Metric System
1.4 This standard does not purport to address all of the 2.2 International Standardization Organization (ISO) Stan-
safety concerns, if any, associated with its use. It is the dards:
responsibility of the user of this standard to establish appro- ISO 349 Hard Coal-Audibert-Arnu Dilatometer Test
priate safety and health practices and determine the applica- ISO 8264 Hard Coal—Determination of the Swelling Prop-
bility of regulatory limitations prior to use. erties Using a Dilatometer
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 D05.15 on Metalurgical contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Properties of Coal and Coke. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved April 1, 2004. Published May 2004. Originally the ASTM website.
approved in 1994. Last previous edition approved in 1997 as D5515 – 97. DOI: Available from International Organization for Standardization (ISO), 1 rue de
10.1520/D5515-97R04E02. Varembé, Case postale 56, CH-1211, Geneva 20, Switzerland.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D5515–97 (2004)
3. Terminology 3.9 softening temperature, T1, the temperature at which the
height of the coal pencil contracts 1.0 % (0.6 mm) from the
3.1 Abbreviations:basement level reference mark height,
highest recorded initial pencil height, expressed in degrees
BLRM , the char height as measured using the BLRM, after
ht
Celsius (see Fig. 1).
removing the piston/retort assembly as a unit after completion
3.10 wet coal pencil mass, M , the measured mass of a
wet
of the test, expressed in millimetres.
trimmed 60-mm-long coal pencil weight, expressed in grams.
3.2 coal pencil, a 60-mm-long test specimen formed by
compression in a mold from coal which has been pulverized to
4. Summary of Test Method
pass a 250-µm (No. 60) sieve.
4.1 The test involves preparing a coal pencil and determin-
3.3 dry coal pencil mass,M , the calculated mass of the
dry
ing the changes of the coal pencil height in a retort tube during
trimmed 60-mm-long coal pencil corrected for added water,
a prescribed heating cycle.
expressed in grams.
3.4 equivalentpercentdilatationfor2.50gofairdriedcoal,
5. Significance and Use
%D ,thecalculatedpercentexpansionfora2.50-g,unmoist-
2.50
5.1 Values of the dilatation properties of coals may be used
ened, 60-mm-long, coal pencil corrected for average tube radii,
to predict or explain the behavior of a coal or blends during
expressed as a percentage.
carbonization or in other processes such as gasification, lique-
3.5 maximum contraction temperature, T2, the temperature
faction, and combustion.
at which the coal pencil starts swelling, expressed in degrees
Celsius. For coals which exhibit contraction only, T2 is the
6. Apparatus
temperature at which the coal pencil reaches its minimum (see
6.1 Dilatometer apparatus, a typical arrangement of the
Fig. 1). For coals that exhibit contraction only and are still
dilatometer apparatus is shown in Fig. 2. The apparatus
contracting at 500°C, T2 will be reported as taken at 500°C
consists of the following:
(see Fig. 1d).
6.1.1 Electric Furnace—The dilatometer furnace has a core
3.6 maximum dilatation temperature, T3, the temperature at
consisting of a 65-mm-diameter cylindrical block of aluminum
which the coal pencil first reaches a maximum height after
bronze, resistant to oxidation, and having a sufficiently high
swelling, expressed in degrees Celsius (see Fig. 1).
meltingpoint.Thelengthofthefurnacecorecanvaryfrom400
3.7 percent contraction, %C, the minimum recorded height
to 460 mm depending on the length of the retort tubes used.
of char expressed as a percentage, based on an initial coal
The block has three symmetrically placed 15-mm-diameter
pencil height of 60 mm (see Fig. 1).
bored holes capable of accepting three retort tubes. The core is
3.8 percent dilatation, %D, the maximum recorded height
of char expressed as a percentage, based on an initial coal
pencil height of 60 mm (see Fig. 1).
FIG. 1 Types of Dilatation Curves FIG. 2 Typical Dilatometer Apparatus
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D5515–97 (2004)
heated electrically by insulated resistance windings capable of 7. Preparation of Sample
being controlled at a temperature ramp rate of 3.0 6 0.1°C per
7.1 Collect a gross sample in accordance with the require-
minute from within 7 min of the time a test is started to a final
ments of Test Method D2234/D2234M.
temperatureof520°C.Thefurnaceshallperforminaccordance
7.2 The analysis sample shall consist of a minimum of 50 g
with the specifications outlined in 8.2. The thermocouple used
ofcoalpulverizedto250-µm(No.60)sieveinaccordancewith
for temperature control is situated in a retort tube placed in the
TestMethodD2013.Performthedilatationanalysisonthecoal
third role of the core.The thermocouple tip is placed in contact sample passing 250-µm (No. 60) sieve within five days after
with the retort tube wall 60 mm above the bottom of the retort
reduction to 250-µm (No. 60) sieve.
tube plug.
8. Calibration
6.1.2 System for Measuring Piston Movement and
Temperature—The system shall be capable of measuring the 8.1 For all systems not using a mechanical pen/chart,
linear displacement of the piston to the nearest 1.0 mm and calibrate the recorder of piston height when there is a differ-
ence of 3.0 mm or more between the final char heights as
providing a correlation of displacement with temperature.
calculated from the chart readout and those directly measured
6.1.3 RetortTubeandPistons—The retort tube consists of a
using the BLRM for two consecutive determinations.
seamlesstubeofsteel,withaninternaldiameterof8.00 60.05
8.2 The furnace, while being ramped at 3°C per minute,
mmandanexternaldiameterof14.50 60.05mm.Itshallhave
must meet the following temperature criteria with the empty
a support collar at the top and be threaded to accept a gastight,
retort tubes placed in Bores 1 and 2 of the furnace and all
threaded plug at its base.The retort tube shall have a minimum
temperature measurements made with the thermocouple(s) in
length of 345 mm and be supported only by its collar when
contact with the retort tube wall(s): temperatures measured in
placed in the furnace. The retort tube shall be discarded when
Bores 1 and 2 must be 63.0°C measured at the same height for
its internal diameter exceeds 8.15 mm.
45-mm intervals encompassing the bottom 180 mm; tempera-
6.1.3.1 The piston shall be machined from a steel rod to a
tures between the control thermocouple placed in its usual
finished diameter of 7.80 6 0.05 mm. The piston shall be of
position and those of Bores 1 and 2 measured at 45-mm
sufficient length to permit the mechanical recording or trans-
intervalsshallbe 63.0°Cforthebottom135mmand 66°Cfor
ducer assembly to record a coal pencil height of 30 mm. The
the next 45 mm. The furnace temperature profile shall be
piston and mechanical recording or transducer assembly shall
calibrated every twelve months.
weigh 150 6 10 g. The piston shall be discarded when its
8.3 The dilatometer temperature readout of the measuring
diameter is less than 7.65 mm.
thermocouple shall be checked every four months by compari-
son with a digital thermometer which is calibrated for the same
6.1.3.2 The piston and retort tube shall be marked and used
type of thermocouple. If the temperature difference is greater
as a matched set and require identification imprinted on both
than 3°C, then the dilatometer furnace temperature readout
the retort tube and its matched piston. A line, called the
requires recalibration using a temperature calibrator.
Basement Level Reference Mark (BLRM), shall be imprinted
8.4 Calibrate the retort tubes, as described in Annex A1,
on the piston, so when assembled with its matched retort tube,
every four months.
with plug in place, the BLRM is even with the top of the retort
tube. The length from the bottom of the piston to the BLRM is
9. Preparation of the Coal Pencil
the length of the retort tube bore with plug in place.
9.1 All weights shall be recorded to the nearest 0.01 g. Care
6.2 Mold and Accessories—The mold and accessories shall
must be taken to avoid sample loss and the following steps
be capable of producing a 60.0 6 0.5-mm-long coal pencil.
must be performed without a break.
The mold shall have a 70.0 6 0.1-mm inside bore length with
9.1.1 Preparation of Homogeneous Coal Sample and Water
a taper of 1:50. The narrow end of the bore shall have a
Mix—The amount of water in the mix shall be#11 % on a
diameterof6.00 60.01mm.Useatrimmingblocktofacilitate
weight basis.
the trimming of the coal pencil to length and the subsequent
9.1.1.1 Weigh a mixing vessel. Record the mass as M1.
weighingofthetrimmedpencil(seeNote1).Theportionofthe
9.1.1.2 Add approximately2gof coal to the pre-weighed
trimming block holding the pencil shall not weigh more than
mixing vessel; distribute the coal evenly over the bottom of the
155 g.
mixing vessel. Record the mass as M2.
9.1.1.3 Add approximately 1 mL of distilled water to the
NOTE 1—The coal pencil may be trimmed to length from either end.
coal. Record the mass as M3.
6.3 Cleaning Implements (Recommended)—The cleaning
9.1.1.4 Mix the coal and water together using a metal
implements for the retort tube consist of an approximately
spatula to form a homogeneous paste. Care must be taken to
7.95-mm-diameter reamer and a 9-mm bronze wire rifle brush
avoid loss of sample.
with suitable attachments to permit cleaning of the full length
9.1.1.5 Add another increment of approximately8gof coal.
of the retort tube.Acircular wire brush, attached to a bench top
Record the mass as M4. Mix to homogeneity using a metal
mounted grinder, is recommended for the cleaning of the
spatula.
pistons.
9.2 Construction of the Coal Pencil:
6.4 Balance—The balance shall have a weighing range of
9.2.1 If a mold release agent has been applied to the bore of
160.00 g with 0.01-g readability. the pencil mold, then excess release agent must be removed by
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D5515–97 (2004)
forcing a wad of tissue through the bore of the mold before
M2 = mass of the mixing vessel plus first coal incre-
adding the moistened coal.
ment, g;
9.2.2 Addnotlessthantenincrementsofthemoistenedcoal
M1 = mass of the mixing vessel, g; and
to a mold and compact. M4 = mass of the mixing vessel plus first coal incre-
9.2.3 Press the coal pencil out of the mold using equipment
ment plus water plus last coal increment, g.
provided. Gently place the pencil into a trimming block and
12.2 Calculatethemassofthepreparedcoalpencil,M ,as
wet
trim the pencil to a 60-mm length. Discard the trimmed off
follows:
portion of the pencil. Record the mass of the trimmed coal
M 5~M5 2 M6! (2)
wet
pencil and trimming block as M5.
9.3 Transfer the trimmed coal pencil into the top of the
where:
horizontally placed retort tube. The coal pencil is gently
M = mass of the prepared coal pencil, g;
wet
pushedtothebottomoftheretorttubewiththematchedpiston.
M5 = mass of the trimmed coal pencil and trimming
Check that the matched piston slides freely inside the retort
block, g; and
tube.Recordthemassofthetrimmingblockandanyfragments M6 = mass of the trimming block and any untransferred
ofthetrimmedpencilnottransferredintotheretorttubeasM6.
portion of the coal pencil, g.
To determine the accurate mass of coal in the coal pencil, it is
12.3 Calculate the mass of air-dried coal in the coal pencil,
essentialthatanyuntransferredfragmentsofthecoalpencilare
M , as follows:
dry
weighed along with the trimming block.
M 5 M 2~M 3 % 3 0.01! (3)
dry wet wet H O
10. Procedure
where:
10.1 Clean the dilatometer retort and piston assembly.
M = mass of air-dried coal in the coal pencil, g;
dry
Firmly attach the retort tube plugs to the retort tubes. Check
M = mass of the prepared coal pencil calculated in
wet
that the matched piston slides freely in the retort tube. 12.2; and
10.2 Prepare the coal pencils and load them
...

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