ASTM D715-86(1999)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 715 – 86 (Reapproved 1999)
Standard Test Methods for
Analysis of Barium Sulfate Pigment
This standard is issued under the fixed designation D 715; 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 high purity to permit its use without lessening the accuracy of
the determination.
1.1 These test methods cover the analysis of barium sulfate
4.2 Unless otherwise indicated, references to water shall be
pigment.
understood to mean reagent water conforming to Type II of
1.2 This standard does not purport to address the safety
Specification D 1193.
concerns associated with its use. It is the responsibility of the
user of this standard to establish appropriate safety and health
BARIUM SULFATE
practices and determine the applicability of regulatory limita-
tions prior to use.
5. Reagents
5.1 Ammonium Hydroxide (sp gr 0.90)—Concentrated am-
2. Referenced Documents
monium hydroxide (NH OH).
2.1 ASTM Standards:
5.2 Ammonium Sulfate ((NH ) SO ).
4 2 4
D 185 Test Methods for Coarse Particles in Pigments,
5.3 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
Pastes, and Paints
chloric acid (HCl).
D 280 Test Methods for Hygroscopic Moisture (and Other
5.4 Hydrochloric Acid (1+1)—Mix equal volumes of con-
Matter Volatile Under the Test Conditions) in Pigments
centrated HCl (sp gr 1.19) and water.
D 1193 Specification for Reagent Water
5.5 Methyl Red Indicator Solution—Dissolve 0.2 g of me-
D 1208 Test Methods for Common Properties of Certain
thyl red in 100 mL of methanol, ethanol, or isopropanol.
Pigments
5.6 Sodium Carbonate Solution (30 g/L)—Dissolve 30 g of
E 832 Specification for Laboratory Filter Papers
Na CO in water and dilute to 1 L.
2 3
3. Significance and Use
6. Procedure
3.1 These test methods are used to determine the purity of
6.1 Weigh to 0.1 mg approximately 0.5 g of the sample into
barium sulfate and to determine the concentration of known
a platinum crucible, add3gofNa CO , mix thoroughly, and
2 3
impurities. This information is useful to producers and users as
fuse until the melt is clear. Allow the melt to cool and then
an aid in the manufacture of coatings.
leach in a platinum dish with hot water until it is entirely
disintegrated. Filter on a close-texture paper and wash thor-
4. Purity of Reagents
oughly with hot Na CO solution (30 g/L).
2 3
4.1 Reagent grade chemicals shall be used in all tests.
6.2 Transfer the filter paper containing the insoluble carbon-
Unless otherwise indicated, it is intended that all reagents shall
ates to a 250-mL beaker and acidify with concentrated HCl (sp
conform to the specifications of the Committee on Analytical
gr 1.19). Wash the fusion crucible with HCl (sp gr 1.19) so that
Reagents of the American Chemical Society, where such
no barium is lost. Boil the solution, filter into a 600-mL beaker,
specifications are available. Other grades may be used, pro-
and wash well with water. Add methyl red indicator solution,
vided it is first ascertained that the reagent is of sufficiently
and add NH OH (sp gr 0.90) until the solution is slightly
alkaline. Add 6 mL of HCl (1+1), and dilute to 300 mL.
6.3 Heat the solution to boiling, and add5gof(NH ) SO
These test methods are under the jurisdiction of ASTM Committee D-1 on Paint
4 2 4
and Related Coatings, Materials, and Applications and are the direct responsibility
dissolved in 40 mL of water. If low-grade material is being
of Committee D01.31 on Pigment Specifications.
analyzed, the (NH ) SO solution should be added drop by
4 2 4
Current edition approved Sept. 26, 1986. Published November 1986. Originally
e1
drop from a buret to minimize inclusion. If the barytes is a
published as D 715 – 43. Last previous edition D 715 – 75 (1981) .
Annual Book of ASTM Standards, Vol 06.03.
rather pure product (95 to 99 % BaSO ), this is not necessary,
Annual Book of ASTM Standards, Vol 11.01.
since the only nonvolatile constituents of the solution will be
Annual Book of ASTM Standards, Vol 14.02.
5 barium salts. Allow the precipitate of BaSO to digest for 4 h
Reagent Chemicals, American Chemical Society Specifications, American
or overnight, and filter through a close-texture paper. Wash the
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory
precipitate with as little cold water as possible (consistent with
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
the purity of the precipitate), ignite in an oxidizing atmosphere,
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
and weigh as BaSO .
MD. 4
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 715
7. Calculation HYDROGEN ION CONCENTRATION
7.1 Calculate the percent of BaSO as follows:
12. Procedure
BaSO ,% 5 ~P/S ! 3 100 (1)
4 1
12.1 Determine the pH in accordance with Test Methods
D 1208.
where:
P 5 BaSO ,g,and
MATTER SOLUBLE IN WATER
S 5 sample used, g.
13. Procedure
FERRIC OXIDE
13.1 Determine the amount of water soluble material
8. Apparatus
present in accordance with Test Methods D 1208.
8.1 Colorimetric Apparatus—Nessler type or other similar
MOISTURE AND OTHER VOLATILE MATTER
100-mL colorimetric tubes.
14. Procedure
9. Reagents
14.1 Determine the moisture and other volatile matter in
9.1 Ammonium Thiocyanate Solution (76.1 g/L)—Dissolve
accordance with Test Method D 280.
76 g of ammonium thiocyanate (NH CNS) in water and dilute
to1L.
COARSE PA
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