ASTM E815-17b(2023)

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: E815 − 17b (Reapproved 2023)
Standard Test Method for
Determination of Calcium Fluoride in Fluorspar by EDTA
Complexometric Titrimetry
This standard is issued under the fixed designation E815; 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 Determine Conformance with Specifications
E50 Practices for Apparatus, Reagents, and Safety Consid-
1.1 This test method covers the determination of calcium
erations for Chemical Analysis of Metals, Ores, and
fluoride in acid-grade fluorspar and other types of fluorspar that
Related Materials
can be rendered soluble by the procedure described in the test
E135 Terminology Relating to Analytical Chemistry for
method.
Metals, Ores, and Related Materials
1.2 The values stated in SI units are to be regarded as
E276 Test Method for Particle Size or Screen Analysis at
standard. No other units of measurement are included in this
4.75 mm (No. 4) Sieve and Finer for Metal-Bearing Ores
standard.
and Related Materials
E882 Guide for Accountability and Quality Control in the
1.3 This test method has been evaluated in accordance with
Practice E1601 and Guide E1763. Unless otherwise noted in Chemical Analysis Laboratory
E1601 Practice for Conducting an Interlaboratory Study to
the precision and bias section, the lower limit in the scope of
each method specifies the lowest analyte content that may be Evaluate the Performance of an Analytical Method
E1763 Guide for Interpretation and Use of Results from
analyzed with acceptable error (defined as a nominal 5 % risk
of obtaining a 50 % or larger relative difference in results on Interlaboratory Testing of Chemical Analysis Methods
(Withdrawn 2015)
the same test sample in two laboratories).
1.4 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions—For definitions of terms used in this test
responsibility of the user of this standard to establish appro-
method, refer to Terminology E135.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Summary of Test Method
1.5 This international standard was developed in accor-
4.1 The sample is decomposed by digesting with HNO and
dance with internationally recognized principles on standard-
HClO and the fluorine is expelled by fuming. The residue is
ization established in the Decision on Principles for the
dissolved in dilute HCl, the solution made alkaline, and the
Development of International Standards, Guides and Recom-
calcium titrated with standard EDTA solution. Calcium present
mendations issued by the World Trade Organization Technical
as carbonate is determined in a separate sample with EDTA
Barriers to Trade (TBT) Committee.
solution, after extracting the former with dilute acetic acid. A
2. Referenced Documents
correction for calcium fluoride, solubilized by dilute acetic acid
digestion, is applied by determining the fluoride in the acetic
2.1 ASTM Standards:
acid extract by fluoride ion-selective electrode. The CaF
D1193 Specification for Reagent Water 2
content is then calculated.
E29 Practice for Using Significant Digits in Test Data to
5. Significance and Use
This test method is under the jurisdiction of ASTM Committee E01 on
5.1 Fluorspar is used as a flux in the steelmaking and glass
Analytical Chemistry for Metals, Ores, and Related Materials and is the direct
industries, and in the manufacture of HF.
responsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-
lurgical Materials.
5.2 This test method is intended to be used for compliance
Current edition approved Nov. 15, 2023. Published November 2023. Originally
with compositional specifications for calcium fluoride content.
approved in 1981. Last previous edition approved in 2017 as E815 – 17b. DOI:
It is assumed that all who use these procedures will be trained
10.1520/E0815-17BR23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E815 − 17b (2023)
analysts capable of performing common laboratory procedures and stirring, add KOH solution B (8.9) to adjust the pH to 5.0
skillfully and safely. It is expected that work will be performed (approximately 350 mL of KOH solution B are required).
in a properly equipped laboratory and that proper waste
8.8 Potassium Hydroxide Solution A—Dissolve 225 g of
disposal procedures will be followed. Appropriate quality
KOH in water and dilute to 1 L with water. Store in a plastic
control practices must be followed such as those described in
bottle.
Guide E882.
8.9 Potassium Hydroxide Solution B—Dissolve 500 g of
6. Interferences
KOH in water and dilute to 1 L. Store in a plastic bottle.
6.1 None of the elements normally found in fluorspar
8.10 Sodium Fluoride Solution—Dissolve 0.2210 g sodium
interferes with this test method.
fluoride (NaF) in water in a polyethylene beaker and dilute to
1 L in a volumetric flask. Store in a stoppered polyethylene
7. Apparatus
−
bottle. This solution has a concentration of 1 mL = 0.10 mg F
7.1 Fluoride Ion-Selective Electrode.
and is stable for six months.
7.2 Magnetic Stirrer and TFE-Fluorocarbon-Coated Spin
8.11 Triethanolamine Solution (1 + 1)—Mix 50 mL of tri-
Bar.
ethanolamine (NC H O ) with 50 mL of water.
6 15 3
7.3 pH Meter with High Impedance—Suitable for ion-
9. Hazards
selective electrode.
7.4 Polyethylene Beakers, 100-mL. 9.1 For precautions to be observed in this method, refer to
Practices E50.
7.5 Single Junction Ag/AgCl Reference Electrode.
10. Sampling, Test Specimens, and Test Units
8. Reagents and Materials
8.1 Purity of Reagents—Reagent-grade chemicals shall be
10.1 Pulverize the test units so that 95 % passes a No. 100
used in all tests. Unless otherwise indicated, it is intended that
mesh sieve (150-μm) as directed in Test Method E276.
all reagents conform to the specifications of the Committee on
Analytical Reagents of the American Chemical Society where
11. Calibration and Standardization
such specifications are available. Other grades may be used,
11.1 Standardization—Weigh and transfer 2.4970 g of
provided it is first ascertained that the reagent is of sufficient
CaCO (dried at 110 °C for 1 h and cooled in a desiccator) to
high purity to permit its use without lessening the accuracy of
a 600-mL beaker. Using a hood and appropriate personal
the determination.
protective equipment, cautiously add 75 mL of HCl and warm.
8.2 Purity of Water—Unless otherwise indicated, references
Cool, transfer to a 1-L volumetric flask, dilute to volume with
to water shall be understood to mean reagent water conforming
water, and mix. This solution has a concentration of
to Type I or II of Specification D1193. Type III or IV may be
1 mL = 1.0000 mg of calcium.
used if they effect no measurable change in the blank or
11.1.1 Titration:
sample.
11.1.1.1 Transfer a 50.00-mL aliquot of this solution to a
8.3 Acetic Acid Solution (1 + 10)—Mix 1 volume of glacial
400-mL beaker, add 5 mL of triethanolamine (8.11), dilute to
acetic acid (CH COOH) with 10 volumes of water.
200 mL, make just alkaline with KOH solution A (8.8), using
a strip of litmus paper, and then add an additional 15 mL of
8.4 Calcium Carbonate, high purity (minimum 99.95 %
KOH solution A (8.8).
CaCO ).
11.1.1.2 Add 0.2 g of hydroxynaphthol blue indicator and
8.5 Ethylenediaminetetraacetic Acid Disodium Salt
titrate immediately with 0.025 M EDTA solution (8.5). At the
(EDTA)-—Na C H O N ·2H O Solution (0.025 mol/L)—
2 10 14 8 2 2
equivalence point, the color changes from pink to blue.
Dissolve 9.3062 g of EDTA in water, transfer to a 1-L
Determine the calcium equivalent of the EDTA solution as
volumetric flask, dilute to volume, and mix.
follows:
8.6 Hydroxynaphthol Blu
...