ASTM D6722-01

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

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.
1.3 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: 09-Oct-2001
• 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

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

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D 6722 – 01
Standard Test Method for
Total Mercury in Coal and Coal Combustion Residues by
Direct Combustion Analysis
This standard is issued under the fixed designation D 6722; 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 (e) 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-
D 121 Terminology of Coal and Coke
tures. Precautions against inadvertent mercury loss should be taken when
using this method.
D 2013 Method of Preparing Coal Samples for Analyses
D 3173 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
D 3180 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-
D 4621 Guide forAccountability and Quality Control in the
ing to this procedure, the total mercury is representative of
Coal Analysis Laboratory
concentrations in the sample.
D 5142 Test Methods for the Proximate Analysis of the
Analysis Sample of Coal and Coke by Instrumental
6. Apparatus
Procedures
6.1 There are several configurations of the instrumental
IEEE/ASTM SI 10 Standard for Use of the International
components that can be used satisfactorily for this test method.
System of Units (SI): The Modern Metric System
Functionally, the instrument shall have the following compo-
3. Terminology
nents: drying compartment, decomposition tube, catalyst tube,
gold amalgamator, amalgamator furnace, measuring cuvettes,
3.1 For definitions of terms used in this standard, refer to
mercury lamp, and detector. The following requirements are
Terminology D 121.
specified for all approved instruments. (Note 2).
4. Summary of Test Method
NOTE 2—The approval of an instrument with respect to these functions
4.1 Controlled heating of the analysis sample in oxygen is
is paramount to this test method, since such approval tacitly provides
usedtoliberatemercury.Thesampleisheatedtodrynessinthe
approval of both the materials and the procedures used with the system to
provide these functions.
6.1.1 The instrument shall be capable of drying the sample
This test method is under the jurisdiction of ASTM Committee D05 on Coal
once it is weighed and introduced.
and Coke and is the direct responsibility of Subcommittee D05.29 on Major
Elements in Ash and Trace Elements of Coal.
Current edition approved October 10, 2001. Published December 2001.
Annual Book of ASTM Standards, Vol 05.06.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 6722
6.1.2 Theinstrumentshallhaveadecompositiontubewhich facturer’s recommended procedure to optimize the perfor-
shall be operated at a temperature high enough to completely mance of the instrument.
decompose the sample.The suggested operating temperature is 9.2 Adjustment of Response of Measurement System—
800°C. Weigh an appropriate test portion of certified reference mate-
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
rapidly heating the amalgamator to release all trapped mercury. 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. CAUTION: 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 D 3173 or D 5142. Continue ana-
7. Sample lyzing until the results from five consecutive determinations
fall within the repeatability interval of these test methods.
7.1 Prepare the analysis sample of coal in accordance with
Calibrate the instrument according to the manufacturer’s in-
Method D 2013 by pulverizing the material to pass a 250-mm
structions using these values. Analyze, as samples, two CRM
(No. 60) sieve.
reference coals or calibrating agents that bracket the range of
7.2 Analyze s
...