ASTM C1318-95(2001)

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 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-2000
• ICS: 75.180.20 - Processing equipment
• Technical Committee: C07 - Lime and Limestone
• Drafting Committee: C07.05 - Chemical Tests

Relations

• Replaces: ASTM C1318-95 - Standard Test Method for Determination of Total Neutralizing Capability and Dissolved Calcium and Magnesium Oxide in Lime for Flue Gas Desulfurization (FGD)
• Effective Date: 01-Jan-2001
• Replaced By: 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)
• Effective Date: 01-Jun-2009
• Referred By: ASTM C911-19 - Standard Specification for Quicklime, Hydrated Lime, and Limestone for Selected Chemical and Industrial Uses
• Effective Date: 01-Jan-2001

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:C1318–95 (Reapproved 2001)
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 C 1318; 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 4. Summary of Test Method
1.1 This test method covers analysis of magnesian, dolo- 4.1 Lime is slaked by boiling and is reacted with acid at a
mitic and high-calcium limes for total neutralizing capability pH and residence time similar to those found in full-scale FGD
anddissolvedmajoroxides.Dissolvedcalciumandmagnesium reaction tanks.
are the major species that neutralize acid under the conditions 4.2 A sample of lime is titrated with 1N hydrochloric acid,
of the test. maintaining a pH of 6 for 30 min. After 30 min, the acid
1.2 The test conditions are chosen to measure the acid- consumption is recorded. The total neutralizing capacity is
neutralizing capacity of both calcium hydroxide and magne- calculated from the acid consumption and reported as CaO.
sium hydroxide contained in slaked lime. By controlling the Dissolved magnesium is determined by atomic absorption
neutralization pH at 6, magnesium hydroxide and magnesium spectrometry or by EDTA titration and reported as percent
oxide are titrated in addition to calcium hydroxide fraction. dissolved Magnesium Oxide (as MgO).
1.3 ThistestmethodalsodeterminesthefractionofMgions
5. Significance and Use
present in the lime that will dissolve under lime flue gas
++
desulfurization (FGD) conditions. Because the Mg ion alters 5.1 There are existing lime-based flue gas desulfurization
units in operation that require a method to measure the oxides
FGD performance, it is important to know its concentration.
1.4 This standard does not purport to address all of the available for sulfur dioxide absorption. Dissolved magnesium
oxide varies among limes depending on the limestone sources
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- and calcination conditions.
priate safety and health practices and determine the applica-
6. Interferences
bility of regulatory limitations prior to use.
6.1 Any substance reacting with acid under the conditions
2. Referenced Documents
of the test will contribute to the total oxide and dissolved oxide
values.
2.1 ASTM Standards:
C 25 Test Methods for Chemical Analysis of Limestone, 6.2 Magnesium in forms other than MgO, which dissolve
under test conditions, may affect the dissolved MgO and total
Quicklime, and Hydrated Lime
C 50 Practice for Sampling, Sample Preparation, Packing, oxide value.
and Marking of Lime and Limestone Products
7. Apparatus
C 51 Terminology Relating to Lime and Limestone (as
7.1 Digital Readout pH Meter, with combination electrode
Used by the Industry)
readable to 0.01 pH units, or an autotitrator with an automatic
3. Terminology
temperature compensator capable of titrating to a preset
endpoint (Note 1).
3.1 Definitions—Unless otherwise specified, for definitions
of terms used in these test methods refer to Terminology C 51.
NOTE 1—Use of an automatic titrator is recommended.
7.2 Stirrers and Stir Bars.
This test method is under the jurisdiction of ASTM Committee C07 on Lime
7.3 Atomic Absorption Spectrometer, if not using EDTA
and is the direct responsibility of Subcommittee C07.05 on Chemical Uses.
titration.
Current edition approved Nov. 10, 1995. Published February 1996.
Annual Book of ASTM Standards, Vol 04.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1318
7.4 Filtering Funnel, TypeAE glass fiber paper, volumetric 10.3.2 EDTA Titration:
flasks (size as needed), 500 mL volumetric flasks, and various 10.3.2.1 From the diluted solution pipette 20 mL of sample
Class A pipettes. into a 500 mL Erlenmeyer flask and dilute with CO free
distilled water to an approximate volume of 100 mL.
8. Reagents
10.3.2.2 Determine the total dissolved calcium according to
8.1 1.0 Normal Hydrochloric Acid, standardize using pro-
Test Methods C 25, Paragraph 31.6.4. Record mL of EDTA
cedures in Test Methods C 25, Section 28.
required for titration.
8.2 Distilled Water,CO free.
2 10.3.2.3 Repeat 10.3.2 and determine the total dissolved
8.3 Calcium and Magnesium Standard Solutions (commer-
oxides according to Test Methods C 25, Paragraph 31.6.5.
cially available or use methods in Test Methods C 25, Section
Record mL of EDTA required for this titration.
31).
8.4 EDTAStandard Solution (0.4 %),standardizeaccording
11. Calculation of Results
to Test Methods C 25, Section 31.5, Standardization of EDTA.
11.1 Percent Total Neutralizing Capability (TNC):
9. Sample Preparation
A 3 B 3 C
% TNC ~as CaO! 5 (1)
W
9.1 The sampling and grinding of any li
...