ASTM D3872-86(1999)

Standard Test Method for Ferrous Iron in Iron Oxides

SCOPE
1.1 This test method covers the quantitative determination of ferrous oxide (FeO) by oxidation of ferrous iron (Fe  ) in an acid solution to the ferric state (Fe   ) and titration with potassium dichromate using diphenylamine as the indicator.  
1.2 This test method is applicable to synthetic black iron oxide, natural black iron oxide, magnetite or brown iron oxide where part of the iron content is present in the ferrous state (Note 1). It is applicable to iron oxides where the ferrous iron content ranges from 50 to 0.20%.  Note 1-Natural iron oxides and magnetite may contain traces of metallic iron that will be combined with and analyzed as FeO.
1.3 This standard does not purport to address the safety problems 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: 09-May-1999
• ICS: 71.060.20 - Oxides
• ICS: 77.080.10 - Irons
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.31 - Pigment Specifications

Relations

• Replaced By: ASTM D3872-05 - Standard Test Method for Ferrous Iron in Iron Oxides
• Effective Date: 01-Sep-2005
• Referred By: ASTM D769-01(2019) - Standard Specification for Black Synthetic Iron Oxide
• Effective Date: 10-May-1999
• Referred By: ASTM D3724-01(2019) - Standard Specification for Synthetic Brown Iron Oxide Pigment
• Effective Date: 10-May-1999

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D3872–86(Reapproved1999)
Standard Test Method for
Ferrous Iron in Iron Oxides
This standard is issued under the fixed designation D 3872; 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. Apparatus
1.1 This test method covers the quantitative determination 4.1 The digestion apparatus consists of a standard 500-mL
++
of ferrous oxide (FeO) by oxidation of ferrous iron (Fe )inan Erlenmeyer flask fitted with a two-hole rubber stopper and
++ +
acid solution to the ferric state (Fe ) and titration with glass tubing, as shown in Fig. 1, to provide for the introduction
potassium dichromate using diphenylamine as the indicator. of the inert gas and vent for gas and digestion fumes.
1.2 This test method is applicable to synthetic black iron
5. Reagents
oxide, natural black iron oxide, magnetite or brown iron oxide
where part of the iron content is present in the ferrous state 5.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
(Note 1). It is applicable to iron oxides where the ferrous iron
content ranges from 50 to 0.20 %. all reagents shall conform to the specifications of the Commit-
tee onAnalytical Reagents of theAmerican Chemical Society,
NOTE 1—Natural iron oxides and magnetite may contain traces of
where such specifications are available. Other grades may be
metallic iron that will be combined with and analyzed as FeO.
used, provided it is first ascertained that the reagent is of
1.3 This standard does not purport to address the safety
sufficiently high purity to permit its use without lessening the
concerns if any, problems associated with its use. It is the
accuracy of the determination.
responsibility of the user of this standard to establish appro-
5.2 Purity of Water—Unless otherwise indicated, references
priate safety and health practices and determine the applica-
to water shall be understood to mean Type II of Specification
bility of regulatory limitations prior to use.
D 1193.
5.3 Diphenylamine Indicator—Dissolve1gof dipheny-
2. Referenced Documents
lamine in 100 mL of concentrated (H SO ) (sp gr 1.84).
2 4
2.1 ASTM Standards:
5.4 Hydrochloric Acid (1+1)—Dilute concentrated hydro-
D 50 Test Methods for Chemical Analysis of Yellow, Or-
chloric acid (HCl, sp gr 1.19) with an equal volume of reagent
ange, Red, and Brown Pigments Containing Iron and
water.
Manganese
5.5 Iron Ore, Standard, Sibley No. 27-f .
D 280 Test Methods for Hygroscopic Moisture (and Other
5.6 Potassium Dichromate, Standard Solution (0.1 N)—
Matter Volatile Under the Test Conditions) in Pigments
Dissolve 4.904 g of K Cr O in water and dilute to 1 L.
2 2 7
D 769 Specification for Black Synthetic Iron Oxide
Standardize against National Institute of Standards and Tech-
D 1193 Specification for Reagent Water
nology standard sample No. 27f of Sibley iron ore. Calculate
D 3722 Specification for Natural Red and Brown Iron
the Fe factor in grams per millilitre for the solution as:
Oxide Pigments
Fe 5 W/V (1)
D 3724 Specification for Synthetic Brown Iron Oxide Pig-
ment
3. Significance and Use
3.1 This test method may be used for production quality
control or specification acceptance.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
This test method is under the jurisdiction of ASTM Committee D-1 on Paint listed by the American Chemical Society, see Analar Standards for Laboratory
and Related Coatings, Materials, andApplications and is the direct responsibility of Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Subcommittee D01.31 on Pigment Specifications.
MD.
Current edition approved April 25, 1986. Published June 1986. Originally
May be secured from National Institute of Standards and Technology, Depart-
published as D 3872 – 79. Last previous edition D 3872 – 79.
Annual Book of ASTM Standards, Vol 06.03. ment of Commerce, Washington, DC 20234. Other recognized primary iron
Annual Book of ASTM Standards, Vol 11.01. standard may be substituted.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3872–86 (1999)
FIG. 1 Digestion Apparatus
7. Procedure
where:
W = weight of Fe in the standard iron ore (not the
7.1 Weigh0.5gofoxideto1mgandtransfertothe500-mL
solution, as there is none), and
Erlenmeyer flask.Wash down the sides of the flask with 15 mL
V =K Cr O required for titration of standard, mL.
V 2 2 7
1 of water.
5.7 Sulfuric-Phosphoric Acid Solution— Prepar
...