ASTM D4208-88(1997)

Standard Test Method for Total Chlorine in Coal by the Oxygen Bomb Combustion/Ion Selective Electrode Method

SCOPE
1.1 This test method covers the analysis of total chlorine in coal.
1.2 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-Dec-1987
• Technical Committee: D05 - Coal and Coke
• Drafting Committee: D05.21 - Methods of Analysis

Relations

• Replaced By: ASTM D4208-88(2002) - Standard Test Method for Total Chlorine in Coal by the Oxygen Bomb Combustion/Ion Selective Electrode Method
• Effective Date: 30-Sep-1988

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
Designation: D 4208 – 88 (Reapproved 1997)
Standard Test Method for
Total Chlorine in Coal by the Oxygen Bomb Combustion/Ion
Selective Electrode Method
This standard is issued under the fixed designation D4208; 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 5. Apparatus
1.1 This test method covers the analysis of total chlorine in 5.1 Combustion Bomb, constructed of materials that are not
coal. affected by the combustion process or products. The bomb
1.2 This standard does not purport to address all of the must be designed so that all liquid combustion products can be
safety concerns, if any, associated with its use. It is the quantitatively recovered by washing the inner surfaces. There
responsibility of the user of this standard to establish appro- must be no gas leakage during the test. The bomb must be
priate safety and health practices and determine the applica- capableofwithstandingahydrostatic-pressuretestto3000psig
bility of regulatory limitations prior to use. (approximately20MPa)atroomtemperaturewithoutstressing
any part beyond its elastic limit.
2. Referenced Documents
5.2 Water Bath—A container large enough to hold the
2.1 ASTM Standards:
combustion bomb and enough cooling water to dissipate the
D1193 Specification for Reagent Water heat generated during the combustion process. The container
D3173 TestMethodforMoistureintheAnalysisSampleof
shall be designed to allow a constant flow of water around the
Coal and Coke combustion bomb.
D3180 Practice for Calculating Coal and Coke Analysis
5.3 Combustion Crucibles—Samples shall be burned in an
from As-Determined to Different Bases open crucible of platinum, quartz, or acceptable base-metal
E 144 Practice for Safe Use of Oxygen Combustion
alloy.
Bombs 5.4 Firing Wire, 100-mm, nickel-chromium alloy, No. 34B
&S gage, or platinum, No. 34 or No. 38B& S gage.
3. Summary of Test Method
5.5 Firing Circuit—A6to16-Valternatingordirectcurrent
3.1 Total chlorine is determined in this method by combus-
is required for ignition purposes with an ammeter or pilot light
ting a weighed sample in an oxygen bomb with dilute base
in the circuit to indicate when current is flowing.Astep-down
adsorbingthechlorinevapors.Thebombisrinsedintoabeaker
transformer connected to an alternating-current lighting circuit
with water and following the addition of an ionic strength
or batteries can be used. Caution—The ignition circuit switch
adjuster, the chloride is determined by ion-selective electrode.
shallbeofthemomentarydouble-contacttype,normallyopen,
except when held closed by the operator.The switch should be
4. Significance and Use
depressed only long enough to fire the charge.
4.1 The purpose of this test method is to measure the total
5.6 Balance, analytical, with a sensitivity of 0.1 mg.
chlorine content of coal. The chlorine content of coals may be
5.7 Specific-Ion Meter—A pH meter with an expandable
useful in the evaluation of slagging problems, corrosion in
millivolt scale, specific-ion meter, sensitive to 0.1 mV, suitable
engineering processes, and in the total analysis of coal and
for method of standard addition determinations.
coke. When coal samples are combusted in accordance with
5.8 Electrodes, chloride-sensing, with the appropriate
this method, the chlorine is quantitatively retained and is
reference-typeelectrodeasrecommendedbythemanufacturer.
representative of the total chlorine content of the whole coal.
6. Reagents
6.1 Purity of Reagents—Reagent grade chemicals shall be
ThistestmethodisunderthejurisdictionofASTMCommitteeD-5onCoaland
used in all tests. Unless otherwise indicated, it is intended that
Coke and is the direct responsibility of Subcommittee D05.21 on Methods of
all reagents shall conform to the specifications of the Commit-
Analysis.
Current edition approved Sept. 30, 1988. Published November 1988. Originally
tee onAnalytical Reagents of theAmerican Chemical Society,
published as D4208–82. Last previous edition D4208–83.
Annual Book of ASTM Standards, Vol 11.01.
3 5
Annual Book of ASTM Standards, Vol 05.05. Midgley, D., and Torrance, K., Potentiometric Water Analysis, John Wiley and
Annual Book of ASTM Standards, Vol 14.02. Sons, 1978.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D 4208 – 88 (1997)
where such specifications are available. Other grades may be 8.3.1 The weight of coal sample and the pressure of the
used, provided it is first ascertained that the reagent is of oxygen admitted to the bomb must not exceed the bomb
sufficiently high purity to permit its use without lessening the manufacturer’s recommendation.
accuracy of the determination. 8.3.2 Inspect the bomb parts carefully after each use.
6.2 Purity of Water, deionized, high-purity, low-specific Frequently check the threads on the main closure for wear.
conductivity, Type II reagent water as defined in Specification Replace the cracked or significantly worn parts. Return the
D1193D1193. bomb to the manufacturer occasionally for inspection and
6.3 Ionic Strength Adjuster Solution (5M NaNO )— possibly proof testing.
Dissolve 42.5 g of sodium nitrate in 100 mL water. 8.3.3 The oxygen supply cylinder should be equipped with
6.4 Sodium Carbonate Solution (Na CO )(2%)—Dissolve an approved type of safety device, such as a reducing valve, in
2 3
2.0 g of sodium carbonate in 100 mL water. addition to the needle valve and pressure gage used in
6.5 Chloride, Standard Stock Solution (1000 µg/mL)— regulating the oxygen feed to the bomb. Valves, gages, and
Dissolve 1.6486 g of sodium chloride (NaCl) in water and gaskets must meet industry safety code. Suitable reducing
dilute to 1 L. The NaCl should be dried for1hat 105°C and valves and adaptors for 300 to 500-psi (approximately 3 to
cooled to room temperature in a desiccator before weighing. 5-MPa) discharge pressure are obtainable from commercial
6.6 Chloride, Standard Stock Solution (100 µg/mL)—Dilute sources of compressed-gas equipment. Check the pressure
10.0 mL of chloride stock solution to 100 mL in a volumetric gage periodically for accuracy.
flask with water. 8.3.4 During ignition of a sample, the operator must not
6.7 Oxygen,freeofcombustiblematterandguaranteedtobe permit any portion of his body to extend over the combustion
99.99% pure. bomb or its container.
8.3.5 Exercise extreme caution when combustion aids are
7. Sample
employed so as not to exceed the bomb manufacturer’s
recommendations and to avoid damage to the bomb.
7.1 A convenient sample is the air-dried coal that must be
8.3.6 Admit oxygen slowly into the bomb to avoid blowing
pulverized to pass a No. 60 (250-µm) sieve.
powdered material from the crucible.
7.2 A separate portion of the analysis sample shall be
8.3.7 Donotfirethebombifithasbeenfilledtogreaterthan
analyzed simultaneously for moisture content in accordance
30 atm (3 MPa) pressure with oxygen, if the bomb has been
with Test Method D3173D3173 if calculation to other than
dropped or turned over after loading, or if there is evidence of
the as-determined basis is desired.
a gas leak when the bomb is submerged in the water bath.
8. Procedure for Bomb Combustion 8.4 Place the bomb in a cooling water bath, with water
moving.Attach the ignition wires from the firing circuits, and
8.1 Thoroughly mix the analysis sample of coal. Carefully
ignite the sample. Allow the bomb to remain in the cooling
weigh approximately 1g 6 0.1 mg into a previously ignited
water for 15 min to allow cooling and absorption of soluble
crucible in which it is to be combusted.
vapors within the bomb.
NOTE 1—For samples in excess of 5% sulfur, the weight of coal must
8.5 Remove the bomb and release the pressure at a uniform
be reduced to 0.5 6 0.1 g to ensure that all the acidic vapors produced in
rate, such that the operation will require not less than 2 min.
the combustion process are
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