ASTM D8339-20

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: D8339 − 20
Standard Test Method for
The Analysis of Flue Gas Desulfurization Solids by Macro
Thermogravimetric Analysis
This standard is issued under the fixed designation D8339; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E691Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This instrumental test method covers the determination
E1601Practice for Conducting an Interlaboratory Study to
of free moisture, gypsum (CaSO •2H O), calcium sulfite
4 2
Evaluate the Performance of an Analytical Method
hemihydrate (CaSO •½H2O), calcium hydroxide (Ca(OH) ),
3 2
calciumcarbonate(CaCO ),andashinfluegasdesulfurization
3 3. Terminology
solids using a macro thermogravimetric analyzer.
3.1 Definitions of Terms Specific to This Standard:
1.2 This instrumental test method is not applicable to
3.1.1 flue-gas desulfurization solids, n—generally are finely
thermogravimetric analyzers using microgram size samples.
divided materials containing various amounts of free moisture.
3.1.1.1 Discussion—The origin of the materials is dewa-
1.3 Units—The values stated in SI units are to be regarded
teredslurriesresultingfromtheabsorptionofsulfurdioxideby
as standard. The values given in parentheses after SI units are
slurries of lime or limestone fines in a flue gas desulfurization
provided for information only and are not considered standard.
process.
1.4 This standard does not purport to address all of the
3.1.2 free moisture, n—the moisture that evolves from
safety concerns, if any, associated with its use. It is the
flue-gas desulfurization solids, clay materials, hydrated lime,
responsibility of the user of this standard to establish appro-
and similar materials, when they are heated at temperatures
priate safety, health, and environmental practices and deter-
ranging from 45°C to 60°C until a constant mass is reached.
mine the applicability of regulatory limitations prior to use.
3.1.2.1 Discussion—Free moisture in these materials is not
1.5 This international standard was developed in accor-
thesameasthefreemoistureincoal,asdefinedinTerminology
dance with internationally recognized principles on standard-
D121.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
3.2 For definitions of other terms used in this test method,
mendations issued by the World Trade Organization Technical
refer to Terminology D121.
Barriers to Trade (TBT) Committee.
4. Summary of Test Method
2. Referenced Documents
4.1 In thermogravimetric analysis, the mass of a sample in
a controlled atmosphere is recorded repeatedly as a function of
2.1 ASTM Standards:
temperature or time, or both. Macro thermogravimetric analy-
D121Terminology of Coal and Coke
sis (macro TGA) of flue gas desulfurization solids (FGD-
D3180Practice for Calculating Coal and Coke Analyses
Solids) uses a sample mass of approximately 1 g. In a typical
from As-Determined to Different Bases
analysis, the temperature is normally ramped from ambient to
D8146Guide for Evaluating Test Method Capability and
a specific temperature and held at that temperature for a
Fitness for Use
prescribed length of time, and the correspondent specimen
E177Practice for Use of the Terms Precision and Bias in
mass is repeatedly recorded by the instrument.
ASTM Test Methods
4.2 FGD-Solids components: free moisture, gypsum, cal-
cium sulfite hemihydrate, calcium hydroxide, calcium
This test method is under the jurisdiction of ASTM Committee D05 on Coal carbonate, and ash are sequentially determined in a single
and Coke and is the direct responsibility of Subcommittee D05.29 on Major
multi-step heating program. The analysis of a particular com-
Elements in Ash and Trace Elements of Coal.
ponentiscompletewhenthespecimenreachesaconstantmass
Current edition approved July 1, 2020. Published September 2020. DOI:
or at the end of the step.
10.1520/D8339-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.3 Free Moisture is determined by measuring the mass
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
loss, caused by evaporating free water from the analysis
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. specimen when heated to 50°C.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8339 − 20
4.4 Gypsum, CaSO •2H O, is determined by measuring the 7. Reagents and Materials
4 2
mass loss, caused by removal of gypsum hydrate water from
7.1 Drying Gases—Nitrogen (99.5 % purity) or Argon
the analysis specimen when further heated to 240 °C.
(99.5% purity).
4.5 Calcium Sulfite Hemihydrate, CaSO •½H O, is deter-
3 2
7.2 Oxidizing Gas—Oxygen (99.5% purity).
mined by measuring the mass loss, caused by removal of
calcium sulfite hydrate water from the analysis specimen when
8. Hazards
further heated to 400°C. CaSO is subsequently oxidized to
8.1 The user shall ensure acceptable documented safety
CaSO prior to the next step.
procedures are in place for the handling of all reagents and test
materials and for the operation of laboratory equipment speci-
4.6 Calcium Hydroxide,Ca(OH) ,isdeterminedbymeasur-
ing the mass loss, caused by removal of hydroxide water from fied for these test methods.
the analysis specimen when further heated to 550 °C.
8.2 Venting Equipment—Install equipment in the vicinity of
the apparatus to vent combustion and volatile gases evolved
4.7 Calcium Carbonate,CaCO isdeterminedbymeasuring
during the test procedures from the laboratory.
the mass loss caused by removal of carbon dioxide from the
analysis specimen when further heated to 950 °C.
9. Sampling, Test Specimens, and Test Units
4.8 Ash is determined as the residue from the sequential
9.1 FGD-Solids are generally finely divided materials con-
determination of previously analyzed components.
taining various amounts of free moisture. Since the origin of
the materials is slurries, the particle sizes of the solids are
5. Significance and Use
generally less than the 250µm (No. 60 U.S. Standard sieve)
5.1 Free Moisture, as determined by this instrumental test
material required for the analysis for coal. For some FGD-
method, is used for calculating other analytical results to a dry
Solids samples, it may be necessary to pre-dry the samples
basis using procedures in Practice D3180.
before analysis to remove excessive free moisture. One should
be careful to not over dry the sample, which may affect the
5.2 Gypsumistheprimaryproductusedtoassessthequality
sulfite content. (See Note 1.)
of the FGD-Solids for industrial purposes, especially construc-
NOTE 1—During the ruggedness testing in the development of this test
tion wallboard. FGD solids are also used in mining
method,itwasdeterminedthatdryingsomeFGD-Solidsinairat77°Cfor
applications, cement manufacturing, and for agricultural pur-
3h reduced the amount of calcium sulfite hemihydrate (CaSO •½H O) in
3 2
poses.
the wet sample by as much as 20% (relative). Changes to the other
components determined in the method were insignificant.
5.3 Calcium Sulfite Hemihydrate is used to assess the
suitability of some FGD-Solids for industrial uses.
10. Preparation of Apparatus
10.1 Verify the instrument can meet all specifications in the
6. Apparatus
standard with respect to gas flows, heating rates, and balance
6.1 Macro Thermogravimetric Analyzer (Macro TGA)—A sensitivity prior to use. Condition the instrument after initial
computer-controlled apparatus consisting of a furnace with a setup,orrepairs,byconductingarunthroughacompletecycle
cavity large enough to accept crucibles containing test speci- without samples.
mens that meet the minimum mass requirements of the
10.2 Condition new crucibles for use in these test methods
procedure.The macroTGAsystem can accommodate multiple
by heating under the same conditions of the test and cooling
crucibles, allowing for continuous analysis with one crucible
before use.
reserved for the blank or reference crucible. The furnace is
constructed so the cavity is surrounded by a suitable refractory
11. Procedure
and insulated so as to develop a uniform temperature in all
11.1 The determination of free moisture, followed by the
partsofthecavity,butwithaminimumfreespace.Thefurnace
determinationofgypsum,calciumsulfitehemihydrate,calcium
shall be capable of being heated rapidly (25°C⁄min or higher)
hydroxide, calcium carbonate, and ash, is carried out in
from ambient temperature to 950°C. The temperature shall be
multi-step sequence using the same FGD-Solids test specimen.
monitored and maintained at values specified for each deter-
11.2 Each macro TGA step is complete when the test
mination. The system shall have an integrated balance capable
specimen either reaches constant mass or is held at a fixed
of sequentially weighing the crucibles and test specimens
temperature for a fixed time. Constant mass is defined as a
repeatedly throughout the analysis.All mass measurements are
point where the fractional mass change is less than or equal to
conducted and recorded by the system. The sensitivity of the
0.05% over a 9min period, either confirmed by using not less
balance shall be 0.1 mg or lower. Provision shall be made to
than three successive weighings, or a fixed 9 min period of
introduce gases specified for this standard and to remove
successive weighings.
products of drying, devolatilization, and combustion. The
macro TGA system shall have a venting fan, tolerant of hot
11.3 The heating program for determination of FGD-Solids
product gases, to efficiently remove the exhaust gases.
components is given in Table 1.
6.2 Crucibles, of composition and dimensions specified for
theinstrumentbytheinstrumentmanufacturer.Nocruciblelids
Riley, J. T., Marsh, M., and Lawrenz, D., “Analysis of FGD Solids With a
are required for this method. Macro TGASystem,” J. Testing and Evaluation, Vol 45, No. 3, 2017, pp. 904–910
D8339 − 20
TABLE 1 Temperature Program and Conditions for the Macro TGA Analysis of FGD-Solids
A
Step Component T , T , Ramp rate, Hold time, min Gas and flow rate, Final mass
start end
B
°C °C °C/min FV/min
1 free moisture ambient 50 1 NA N ,0.4 m
2 1
2 CaSO 2H O 50 240 17 15 N ,1.0 m
4 2 2 2
3 CaSO  ⁄2 H O 240 400 17 5 N ,1.0 m
3 2 2 3
4 CaSO  ⁄2 H O 400 400 0 15 O ,1.0 m
3 2 2 4
5 Ca(OH) 400 550 10 25 N ,1.0 m
2 2 5
6 CaCO and Ash 550 950 25 15 N ,1.0 m
3 2 6
A
NA = Not applicable
B
FV = furnace volume change
11.4 Sequential Determination of Free Moisture, Gypsum, 12. Calculation or Interpretation of Results
Calcium Sulfite Hemihydrate, Calcium Hydroxide, Calcium
12.1 With a computer-controlled macro thermogravimetric
Carbonate, and Ash:
analyzer, the computer is normally programmed to perform
11.4.1 AfterverifyinginstrumentsetupaccordingtoSection
calculations automatically.
10 on the preparation of apparatus, load and tare the crucibles.
12.2 The following formulae are used to calculate the
Add 1g of the test specimen to the crucible in the balance
as-determined component mass fractions for the various com-
positionandweighitimmediatelybeforeadvancingtothenext
ponents in the analyzed FGD-Solids specimen:
crucible. Transfer the test specimen from the sample bottle to
12.2.1 Free moisture (as-determined):
the crucible quickly to minimize the exposure of the test
specimen to the atmosphere during the initial weighing pro-
m 2 m
0 1
w 5 (1)
H O,ad
cess. The initial mass of the test specimen is recorded as m . 2
m
11.4.2 Step 1—To determine free moisture, use an inert gas
12.2.2 Gypsum (CaSO •2H O) (as-determined):
4 2
with a flow rate of 0.4 furnace volume changes per minute and
m 2 m
heat the weighed test specimen at a rate of 1°C⁄min. Program
1 2
w 5 4.779· (2)
CaSO ·2H O,ad
4 2
m
the instrument to terminate the test when the specimen has
reached a constant mass, m (see 11.2 and Table 1).
12.2.3 Calcium sulfite hemihydrate (CaSO •½H O) (as-
3 2
11.4.3 Step 2—Forgypsumdeterminationfollowingthefree
determined):
moisture analysis, maintain an inert gas atmosphere and
m 2 m
2 3
increasetheflowrateto1.0furnacevolumechangeperminute,
w 1 5 14.338· (3)
CaSO · H O,ad
3 2
m
raise the furnace temperature at a rate of 17°C⁄min to 240°C,
andholdthefinaltemperaturefor15min.Recordthespecimen
12.2.4 Lime (Ca(OH) ) (as-determined):
mass, m , at the end of the hold period.
m 2 m
4 5
11.4.4 Step 3—For calcium sulfite hemihydrate determina- w 5 4.113· (4)
CaOH ! ,ad
~ 2
m
tionfollowingthegypsumanalysis,maintaintheinertgasflow
rate, raise the furnace temperature at a rate of 17°C⁄min to
12.2.5 Calcium carbonate (CaCO ) (as-determined):
400°C, and hold the final temperature for 5min. Record the
m 2 m
5 6
specimen mass, m , at the end of the hold period. w 5 2.274· (5)
CaCO ,ad
3 3
m
11.4.5 Step 4—For the second part of the calcium sulfite
12.2.6 Ash (as-determined):
hemihydrate determination, change the atmosphere to oxygen
with the same flow rate, and hold the furnace temperature at
m
w 5 (6)
ash,ad
400°C for 15 min. Any calcium sulfite in the test specimen
m
will be oxidized and the mass will increase until it becomes
12.2.7 Ash (calculated, as-determined):
stable. Record the specimen mass, m , at the end of the hold
period. w 5 0.7907·w 11.0541·w 1
calcd.ash,ad CaSO ·2H O,ad CaSO · H O,ad
4 2 3 2
11.4.6 Step 5—For calcium hydroxide determination fol-
10.7569·w 10.5603·w (7)
Ca~OH ! ,ad CaCO ,ad
2 3
lowing the calcium sulfite hemihydrate analysis, change the
where:
atmosphere to an inert gas, maintain the same flow rate, raise
the furnace temperature at a rate of 10°C⁄min to 550°C, and
m = the correspondent mass at the end of the step (see
i
hold the final temperature for 25min. Record the specimen
Table 1 and 11.4)
mass, m , at the end of the hold period
...