Standard Test Method for Determination of Total Neutralizing Capability and Dissolved Calcium and Magnesium Oxide in Lime for Flue Gas Desulfurization (FGD)

SIGNIFICANCE AND USE
There are existing lime-based flue gas desulfurization units in operation that require a method to measure the oxides available for sulfur dioxide absorption. Dissolved magnesium oxide varies among limes depending on the limestone sources and calcination conditions.
SCOPE
1.1 This test method covers analysis of magnesian, dolomitic and high-calcium limes for total neutralizing capability and dissolved major oxides. Dissolved calcium and magnesium are the major species that neutralize acid under the conditions of the test.
1.2 The test conditions are chosen to measure the acid-neutralizing capacity of both calcium hydroxide and magnesium hydroxide contained in slaked lime. By controlling the neutralization pH at 6, magnesium hydroxide and magnesium oxide are titrated in addition to calcium hydroxide fraction.
1.3 This test method also determines the fraction of Mg ions present in the lime that will dissolve under lime flue gas desulfurization (FGD) conditions. Because the Mg++ ion alters FGD performance, it is important to know its concentration.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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-May-2009
Technical Committee
Drafting Committee
Current Stage
Ref Project

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ASTM C1318-95(2009)e1 - Standard Test Method for Determination of Total Neutralizing Capability and Dissolved Calcium and Magnesium Oxide in Lime for Flue Gas Desulfurization (FGD)
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
´1
Designation: C1318 − 95(Reapproved 2009)
Standard Test Method for
Determination of Total Neutralizing Capability and Dissolved
Calcium and Magnesium Oxide in Lime for Flue Gas
Desulfurization (FGD)
This standard is issued under the fixed designation C1318; 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—A units statement was added editorially as new paragraph 1.4 and subsequent paragraphs were renumbered in
June 2009.
1. Scope C50 Practice for Sampling, Sample Preparation, Packaging,
and Marking of Lime and Limestone Products
1.1 This test method covers analysis of magnesian, dolo-
C51 Terminology Relating to Lime and Limestone (as used
mitic and high-calcium limes for total neutralizing capability
by the Industry)
anddissolvedmajoroxides.Dissolvedcalciumandmagnesium
are the major species that neutralize acid under the conditions
3. Terminology
of the test.
3.1 Definitions—Unless otherwise specified, for definitions
1.2 The test conditions are chosen to measure the acid-
of terms used in these test methods refer to Terminology C51.
neutralizing capacity of both calcium hydroxide and magne-
sium hydroxide contained in slaked lime. By controlling the
neutralization pH at 6, magnesium hydroxide and magnesium 4. Summary of Test Method
oxide are titrated in addition to calcium hydroxide fraction.
4.1 Lime is slaked by boiling and is reacted with acid at a
1.3 ThistestmethodalsodeterminesthefractionofMgions
pH and residence time similar to those found in full-scale FGD
present in the lime that will dissolve under lime flue gas
reaction tanks.
++
desulfurization (FGD) conditions. Because the Mg ion alters
4.2 A sample of lime is titrated with 1N hydrochloric acid,
FGD performance, it is important to know its concentration.
maintaining a pH of 6 for 30 min. After 30 min, the acid
1.4 The values stated in SI units are to be regarded as
consumption is recorded. The total neutralizing capacity is
standard. No other units of measurement are included in this
calculated from the acid consumption and reported as CaO.
standard.
Dissolved magnesium is determined by atomic absorption
1.5 This standard does not purport to address all of the
spectrometry or by EDTA titration and reported as percent
safety concerns, if any, associated with its use. It is the
dissolved Magnesium Oxide (as MgO).
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5. Significance and Use
bility of regulatory limitations prior to use.
5.1 There are existing lime-based flue gas desulfurization
2. Referenced Documents
units in operation that require a method to measure the oxides
available for sulfur dioxide absorption. Dissolved magnesium
2.1 ASTM Standards:
oxide varies among limes depending on the limestone sources
C25 Test Methods for Chemical Analysis of Limestone,
and calcination conditions.
Quicklime, and Hydrated Lime
6. Interferences
This test method is under the jurisdiction of ASTM Committee C07 on Lime
6.1 Any substance reacting with acid under the conditions
and is the direct responsibility of Subcommittee C07.05 on Chemical Tests.
Current edition approved June 1, 2009. Published September 2009. Originally
of the test will contribute to the total oxide and dissolved oxide
approved in 1995. Last previous edition approved in 2001 as C1318 – 95(2001).
values.
DOI: 10.1520/C1318-95R09E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.2 Magnesium in forms other than MgO, which dissolve
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
under test conditions, may affect the dissolved MgO and total
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. oxide value.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
C1318 − 95 (2009)
7. Apparatus 10.2.3 Record the amount of acid consumed after 30 min.
10.2.4 Filter the solution and rinse the flask thoroughly with
7.1 Digital Readout pH Meter, with combination electrode
CO free distilled water.
readable to 0.01 pH units, or an autotitrator with an automatic 2
10.2.5 Carefully transfer the solution to an appropriately
temperature compensator capable of titrating to a preset
sized volumetric flask, add approximately 10 mL of 1:1
endpoint (Note 1).
hydrochloric acid, and dilute to volume.
NOTE 1—Use of an automatic titrator is recommended.
10.3 Determination of Dissolved Oxides:
7.2 Stirrers and Stir Bars.
10.3.1 Atomic Absorption:
7.3 Atomic Absorption Spectrometer, if not using EDTA
10.3.1.1 From the diluted solution make the required dilu-
titration.
tions and determine the dissolved magnesium by standard
7.4 Filtering Funnel, TypeAE glass fiber paper, volumetric
atomic absorption spectroscopy techniques.
flasks (size as needed), 500 mL volumetric flasks, and various
10.3.1.2 Calculate the dissolved magnesium as MgO ac-
Class A pipettes.
cording to 11.2.
10.3.2 EDTA Titration:
8. Reagents
10.3.2.1 From the diluted solution pipette 20 mL of sample
8.1 1.0 Normal Hydrochloric Acid, standardize using pro-
into a 500 mL Erlenmeyer flask and dilute with CO free
cedures in
...

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