ASTM D6722-01(2006)

Standard Test Method for Total Mercury in Coal and Coal Combustion Residues by Direct Combustion Analysis

SIGNIFICANCE AND USE
The emission of mercury during coal combustion can be an environmental concern.
When representative test portions are analyzed according to this procedure, the total mercury is representative of concentrations in the sample.
SCOPE
1.1 These test methods cover procedures to determine the total mercury content in a sample of coal or coal combustion residue.
1.2 The values stated in SI units are regarded as the standard.
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: 31-Mar-2006
• ICS: 71.060.10 - Chemical elements
• Technical Committee: D05 - Coal and Coke
• Drafting Committee: D05.29 - Major Elements in Ash and Trace Elements of Coal

Relations

• Replaces: ASTM D6722-01 - Standard Test Method for Total Mercury in Coal and Coal Combustion Residues by Direct Combustion Analysis
• Effective Date: 01-Apr-2006
• Replaced By: ASTM D6722-11 - Standard Test Method for Total Mercury in Coal and Coal Combustion Residues by Direct Combustion Analysis
• Effective Date: 01-Jun-2011

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D6722 – 01 (Reapproved 2006)
Standard Test Method for
Total Mercury in Coal and Coal Combustion Residues by
Direct Combustion Analysis
This standard is issued under the fixed designation D6722; 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 instrument and then thermally and chemically decomposed.
The decomposition products are carried by flowing oxygen to
1.1 These test methods cover procedures to determine the
the catalytic section of the furnace, where oxidation is com-
total mercury content in a sample of coal or coal combustion
pleted and halogens as well as nitrogen and sulfur oxides are
residue.
trapped. The remaining decomposition products are carried to
1.2 The values stated in SI units are regarded as the
a gold amalgamator that selectively traps mercury. After the
standard.
system is flushed with oxygen to remove any remaining
1.3 This standard does not purport to address all of the
decomposition products, the amalgamator is rapidly heated,
safety concerns, if any, associated with its use. It is the
releasing mercury vapor. Flowing oxygen carries the mercury
responsibility of the user of this standard to establish appro-
vapor through absorbance cells positioned in the light path of
priate safety and health practices and determine the applica-
single wavelength atomic absorption spectrophotometer. Ab-
bility of regulatory limitations prior to use.
sorbance peak height or peak area, as a function of mercury
2. Referenced Documents
concentration, is measured at 253.7 nm.
2.1 ASTM Standards:
NOTE 1—Mercury and mercury salts can be volatized at low tempera-
D121 Terminology of Coal and Coke
tures. Precautions against inadvertent mercury loss should be taken when
using this method.
D2013 Practice for Preparing Coal Samples for Analysis
D3173 Test Method for Moisture in theAnalysis Sample of
5. Significance and Use
Coal and Coke
5.1 The emission of mercury during coal combustion can be
D3180 Practice for Calculating Coal and Coke Analyses
an environmental concern.
from As-Determined to Different Bases
5.2 When representative test portions are analyzed accord-
D4621 Guide for Quality Management in an Organization
ing to this procedure, the total mercury is representative of
That Samples or Tests Coal and Coke
concentrations in the sample.
D5142 TestMethodsforProximateAnalysisoftheAnalysis
Sample of Coal and Coke by Instrumental Procedures
6. Apparatus
IEEE/ASTM SI 10 Standard for Use of the International
6.1 There are several configurations of the instrumental
System of Units (SI): The Modern Metric System
components that can be used satisfactorily for this test method.
3. Terminology
Functionally, the instrument shall have the following compo-
nents: drying compartment, decomposition tube, catalyst tube,
3.1 For definitions of terms used in this standard, refer to
gold amalgamator, amalgamator furnace, measuring cuvettes,
Terminology D121.
mercury lamp, and detector. The following requirements are
4. Summary of Test Method
specified for all approved instruments. (Note 2).
4.1 Controlled heating of the analysis sample in oxygen is
NOTE 2—The approval of an instrument with respect to these functions
usedtoliberatemercury.Thesampleisheatedtodrynessinthe
is paramount to this test method, since such approval tacitly provides
approval of both the materials and the procedures used with the system to
provide these functions.
This test method is under the jurisdiction of ASTM Committee D05 on Coal
and Coke and is the direct responsibility of Subcommittee D05.29 on Major
6.1.1 The instrument shall be capable of drying the sample
Elements in Ash and Trace Elements of Coal.
once it is weighed and introduced.
Current edition approved April 1, 2006. Published April 2006. Originally
6.1.2 Theinstrumentshallhaveadecompositiontubewhich
approved in 2001. Last previous edition approved in 2001 as D6722–01. DOI:
shall be operated at a temperature high enough to completely
10.1520/D6722-01R06.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
decompose the sample.The suggested operating temperature is
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
800°C.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6722 – 01 (2006)
6.1.3 The catalyst in the catalytic tube shall be capable of rial (CRM), calibrating agent, or reference coal. Analyze the
completing the oxidation of the sample and trapping halogens test portion (see 9.1). Repeat this procedure.Adjust instrument
as well as nitrogen and sulfur oxides. The suggested operating response, as recommended by the manufacturer, until the
temperature of the catalytic tube is 550°C. absence of drift is indicated.
6.1.4 Theinstrumentshallcontainagoldamalgamatorfixed 9.3 Calibration—Select coal CRMs or other calibrating
to an inert material and shall be capable of trapping all agents and materials specified by the manufacturer that have
mercury. certifiedmercuryvaluesintherangeofsamplestobeanalyzed.
6.1.5 The amalgamator shall contain a furnace capable of Three such CRMs or calibrating agents are recommended for
rapidlyheatingtheamalgamatortoreleasealltrappedmercury. each range of mercury values to be tested. When possible, two
6.1.6 The instrument shall have a absorption cell with of the CRMs or calibrating agents shall bracket the range of
measuring cuvettes through which the elemental mercury mercury to be tested, with the third falling within the range.
released from the gold amalgamator flows. The cell shall be 9.3.1 All coal CRMs should be in accordance with 8.2 and
heated to avoid any condensation of water or other decompo- shall be supplied by or have traceability to an internationally
sition products. recognized certifying organization.Warning—An indicated
6.1.7 The light source for the atomic absorption process problem with linearity of the instrument during calibration can
shall be a low pressure mercury lamp.
result from contamination of the CRM or calibrating agent as
6.1.8 Anarrow bandpass interference filter or monochroma- the container becomes depleted. It is therefore recommended
tor, capable of isolating the 253.65 nm mercury line, shall be
that the CRM or calibrating agent be discarded when less than
used. five grams remain in the container.
6.1.9 The system may contain a computer for controlling
9.3.2 Calibration Procedure—Analyze, as samples, por-
the various operations of the apparatus, for recording data, and tions of a CRM, reference coal, or calibrating agent chosen to
for reporting results.
represent the level of mercury in the samples to be tested. Use
6.2 Analytical Balance, with a sensitivity of 0.1 mg. the “as-determined” mercury values for calibration. These
6.3 Sample Combustion Boats, made of nickel and conve-
values must have been calculated previously from the certified
nient size suitable for use in the instrument being used. “dry basis” mercury values and residual moisture determined
using either Test Methods D3173 or D5142. Continue analyz-
7. Sample ing until the results from five consecutive determinations fall
withintherepeatabilityintervalofthesetestmethods.Calibrate
7.1 Prepare the analysis sample of coal in accordance with
the instrument according to the manufacturer’s instructions
Method D2013 by pulverizing the material to pass a 250-mm
using these values. Analyze, as samples, two CRM reference
(No. 60) sieve.
coalsorcalibratingagentsthatbrackettherangeofvaluestobe
7.2 Analyze separate test portions for moisture content in
tested. The results obta
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