ASTM D715-86(2014)

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D715 − 86 (Reapproved 2008) D715 − 86 (Reapproved 2014)
Standard Test Methods for
Analysis of Barium Sulfate Pigment
This standard is issued under the fixed designation D715; 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
1.1 These test methods cover the analysis of barium sulfate pigment.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address the safety concerns 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.
2. Referenced Documents
2.1 ASTM Standards:
D185 Test Methods for Coarse Particles in Pigments
D280 Test Methods for Hygroscopic Moisture (and Other Matter Volatile Under the Test Conditions) in Pigments
D1193 Specification for Reagent Water
D1208 Test Methods for Common Properties of Certain Pigments
E832 Specification for Laboratory Filter Papers
3. Significance and Use
3.1 These test methods are used to determine the purity of barium sulfate and to determine the concentration of known
impurities. This information is useful to producers and users as an aid in the manufacture of coatings.
4. Purity of Reagents
4.1 Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform
to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are
available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use
without lessening the accuracy of the determination.
4.2 Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to Type II of
Specification D1193.
BARIUM SULFATE
5. Reagents
5.1 Ammonium Hydroxide (sp gr 0.90)—Concentrated ammonium hydroxide (NH OH).
5.2 Ammonium Sulfate ((NH ) SO ).
4 2 4
5.3 Hydrochloric Acid (sp gr 1.19)—Concentrated hydrochloric acid (HCl).
5.4 Hydrochloric Acid (1+1)—Mix equal volumes of concentrated HCl (sp gr 1.19) and water.
These test methods are under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and are the direct responsibility of
Committee D01.31 on Pigment Specifications.
Current edition approved Feb. 1, 2008Dec. 1, 2014. Published February 2008December 2014. Originally approved in 1943. Last previous edition approved in 20032008
as D715 – 86 (2003).(2008). DOI: 10.1520/D0715-86R08.10.1520/D0715-86R14.
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’sstandard’s Document Summary page on the ASTM website.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D715 − 86 (2014)
5.5 Methyl Red Indicator Solution—Dissolve 0.2 g of methyl red in 100 mL of methanol, ethanol, or isopropanol.
5.6 Sodium Carbonate Solution (30 g/L)—Dissolve 30 g of Na CO in water and dilute to 1 L.
2 3
6. Procedure
6.1 Weigh to 0.1 mg approximately 0.5 g of the sample into a platinum crucible, add 3 g of Na CO , mix thoroughly, and fuse
2 3
until the melt is clear. Allow the melt to cool and then leach in a platinum dish with hot water until it is entirely disintegrated. Filter
on a close-texture paper and wash thoroughly with hot Na CO solution (30 g/L).
2 3
6.2 Transfer the filter paper containing the insoluble carbonates to a 250-mL beaker and acidify with concentrated HCl (sp gr
1.19). Wash the fusion crucible with HCl (sp gr 1.19) so that no barium is lost. Boil the solution, filter into a 600-mL beaker, and
wash well with water. Add methyl red indicator solution, 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 add 5 g of (NH ) SO dissolved in 40 mL of water. If low-grade material is being analyzed,
4 2 4
the (NH ) SO solution should be added drop by drop from a buret to minimize inclusion. If the barytes is a rather pure product
4 2 4
(95 to 99 % BaSO ), this is not necessary, since the only nonvolatile constituents of the solution will be barium salts. Allow the
precipitate of BaSO to digest for 4 h or overnight, and filter through a close-texture paper. Wash the precipitate with as little cold
water as possible (consistent with the purity of the precipitate), ignite in an oxidizing atmosphere, and weigh as BaSO .
7. Calculation
7.1 Calculate the percent of BaSO as follows:
BaSO , %5 P/S 3100 (1)
~ !
4 1
where:
P = BaSO , g, and
S = sample used, g.
FERRIC OXIDE
8. Apparatus
8.1 Colorimetric Apparatus—Nessler type or other similar 100-mL colorimetric tubes.
9. Reagents
9.1 Ammonium Thiocyanate Solution (76.1 g/L)—Dissolve 76 g of ammonium thiocyanate (NH CNS) in water and dilute to 1
L.
9.2 Iron, Standard Solution (100 mL = 0.00002 g Fe)—Dilute and divide a ferric solution of known iron content so as to obtain
0.4 mg of iron. Dilute the solution to 2 L with water containing 200 mL of iron-fre
...