ASTM C1318-15a(2020)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1318 − 15a (Reapproved 2020)
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.
1. Scope 2. Referenced Documents
1.1 This test method covers analysis of magnesian, dolo-
2.1 ASTM Standards:
mitic and high-calcium limes for total neutralizing capability C25 Test Methods for Chemical Analysis of Limestone,
anddissolvedmajoroxides.Dissolvedcalciumandmagnesium Quicklime, and Hydrated Lime
are the major species that neutralize acid under the conditions
C51 Terminology Relating to Lime and Limestone (as Used
of the test. by the Industry)
C110 Test Methods for Physical Testing of Quicklime,
1.2 The test conditions are chosen to measure the acid-
Hydrated Lime, and Limestone
neutralizing capacity of both calcium hydroxide and magne-
C1301 Test Method for Major and Trace Elements in Lime-
sium hydroxide contained in slaked lime. By controlling the
stone and Lime by Inductively Coupled Plasma-Atomic
neutralization pH at 6, magnesium hydroxide and magnesium
Emission Spectroscopy (ICP) and Atomic Absorption
oxide are titrated in addition to calcium hydroxide fraction.
(AA)
1.3 ThistestmethodalsodeterminesthefractionofMgions
E11 Specification for Woven Wire Test Sieve Cloth and Test
present in the lime that will dissolve under lime flue gas Sieves
2+
desulfurization (FGD) conditions. Because the Mg ion alters
FGD performance, it is important to know its concentration.
3. Terminology
3.1 Definitions:
1.4 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
3.1.1 Unless otherwise specified, for definitions of terms
standard. used in these test methods refer to Terminology C51.
1.5 This standard does not purport to address all of the
4. Summary of Test Method
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4.1 Lime is slaked by boiling and is reacted with acid at a
priate safety, health, and environmental practices and deter-
pH and residence time similar to those found in full-scale FGD
mine the applicability of regulatory limitations prior to use.
reaction tanks.
1.6 This international standard was developed in accor-
4.2 A sample of lime is titrated with 1N hydrochloric acid,
dance with internationally recognized principles on standard-
maintaining a pH of 6 for 30 min. After 30 min, the acid
ization established in the Decision on Principles for the
consumption is recorded. The total neutralizing capacity is
Development of International Standards, Guides and Recom-
calculated from the acid consumption and reported as % CaO.
mendations issued by the World Trade Organization Technical
Dissolved magnesium is determined by spectrometry or by
Barriers to Trade (TBT) Committee.
EDTA titration and reported as percent dissolved Magnesium
Oxide (as MgO).
This test method is under the jurisdiction of ASTM Committee C07 on Lime
andLimestoneandisthedirectresponsibilityofSubcommitteeC07.05onChemical
Tests. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Dec. 1, 2020. Published January 2021. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2015 as C1318 – 15a. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1318-15AR20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1318 − 15a (2020)
5. Significance and Use 9.3 The prepared sample shall be stored in a tightly capped
container.
5.1 There are existing lime-based flue gas desulfurization
units in operation that require a method to measure the oxides
10. Procedure
available for sulfur dioxide absorption. Dissolved magnesium
oxide varies among limes depending on the limestone sources
10.1 Slaking of Lime Sample:
and calcination conditions.
10.1.1 Weigh rapidly 1.402 g of the finely pulverized
sample and brush carefully into a 250 mL Erlenmeyer flask
6. Interferences
containing about 50 mL of CO free deionized or distilled
6.1 Any substance reacting with acid under the conditions
water and immediately stopper the flask.
of the test will contribute to the total oxide and dissolved oxide
10.1.2 Remove the stopper. Swirl the flask, place on a hot
values.
plate, and boil actively 1 min for complete slaking. Remove
from the hot plate, stopper the flask loosely, and place in a
6.2 Magnesium in forms other than MgO, which dissolve
under test conditions, may affect the dissolved MgO and total cold-water bath to cool to room temperature.
oxide values.
10.2 Titration of Sample:
10.2.1 Set the pH electrode, burette tip, and temperature
7. Apparatus
sensing device in place, while maintaining agitation.
7.1 Digital Readout pH Meter, with combination electrode
10.2.2 Begin the titration by adding standard 1.0 normal
readable to 0.01 pH units, or an autotitrator with an automatic
hydrochloric acid solution. Titrate to and maintain a pH of 6.0
temperature compensator capable of titrating to a preset
within 0.4 pH units for 30 min (Note 2). Time begins from
endpoint (Note 1).
initial addition of acid.
NOTE 1—Use of an automatic titrator is recommended.
NOTE 2—When doing a manual titration, the increment of acid addition
7.2 Stirrers and Stir Bars.
may require the use of partial drops (suspend a small amount of titrant on
the buret tip and wash into the titration flask with CO free deionized or
7.3 Inductively Coupled Plasma Spectrometer or Atomic
distilled water) to avoid exceeding the 0.4 unit limit of pH 6.
Absorption Spectrometer, if not
...