ASTM E316-00(2005)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E316 – 00 (Reapproved 2005)
Standard Test Method for
Determination of Iron in Manganese Ores by Hydrogen
Sulfide Reduction-Dichromate Titration
This standard is issued under the fixed designation E316; 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 tion, and the excess hydrogen sulfide is expelled by boiling.
After cooling, the reduced iron is titrated with a standard
1.1 This test method covers the determination of iron in
potassium dichromate solution using sodium diphenylamine
manganese ore in the range from 2 to 20 %.
sulfonate as the indicator.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
5. Significance and Use
standard.
5.1 This test method is intended to be used for compliance
1.3 This standard does not purport to address all of the
with compositional specifications for iron content in manga-
safety concerns, if any, associated with its use. It is the
nese ores. It is assumed that all who use these procedures will
responsibility of the user of this standard to establish appro-
be trained analysts capable of performing common laboratory
priate safety and health practices and determine the applica-
proceduresskillfullyandsafely.Itisexpectedthatworkwillbe
bility of regulatory limitations prior to use.
performed in a properly equipped laboratory and that proper
2. Referenced Documents waste disposal procedures will be followed. Appropriate qual-
ity control practices must be followed such as those described
2.1 ASTM Standards:
in Guide E882.
E50 Practices for Apparatus, Reagents, and Safety Consid-
erations for Chemical Analysis of Metals, Ores, and
6. Interferences
Related Materials
6.1 None of the elements normally found in manganese ore
E135 Terminology Relating to Analytical Chemistry for
interfere with this test method.
Metals, Ores, and Related Materials
E882 Guide for Accountability and Quality Control in the
7. Reagents and Materials
Chemical Analysis Laboratory
7.1 Purity and Concentration of Reagents—The purity and
3. Terminology concentration of the common chemical reagents used shall
conform to Practices E50. Special apparatus and reagents
3.1 Definitions—For definitions of terms used in this test
required are located in separate sections preceding the proce-
method, refer to Terminology E135.
dure.
4. Summary of Test Method 7.2 Ferrous Ammonium Sulfate Solution (approx. 0.10
N)—Dissolve 40 g of ferrous ammonium sulfate
4.1 The sample is decomposed by treatment with hydro-
(FeSO (NH ) SO ·6H O) in sulfuric acid (1+19).Transfer to a
4 4 2 4 2
chloric, hydrofluoric, and sulfuric acids.Any residue is treated
1-L flask and dilute to volume with the same acid. When the
for the recovery of insoluble iron. The iron is reduced with
sample solution is ready for titration, standardize the
hydrogen sulfide, the insoluble sulfides are removed by filtra-
FeSO (NH ) SO ·6H O solution against the standard potas-
4 4 2 4 2
sium dichromate solution (0.1000 N) as described in 11.1.
This test method is under the jurisdiction of ASTM Committee E01 on
Calculate the millilitres of standard potassium dichromate
Analytical Chemistry for Metals, Ores, and Related Materials and is the direct
solution equivalent to 1 mL of the FeSO (NH ) SO ·6H O
4 4 2 4 2
responsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-
solution.
lurgical Materials.
Current edition approved Oct. 1, 2005. Published October 2005. Originally
7.3 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
approved in 1967. Last previous edition approved in 2000 as E316 – 00. DOI:
chloric acid (HCl).
10.1520/E0316-00R05.
2 7.4 Hydrofluoric Acid (48 %)—Concentrated hydrofluoric
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
acid (HF).
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
7.5 Hydrogen Sulfide (H S).
the ASTM website.
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E316 – 00 (2005)
7.6 Hydrogen Sulfide Wash Solution. 10.3 Filter off any residue through a medium texture paper
into a 400-mL beaker and wash the paper and residue with hot
7.6.1 Saturate H SO (1+99) with hydrogen sulfide (H S).
4 2
water until the iron color is removed from the paper. Reserve
Prepare fresh as needed.
the filtrate.
7.7 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
10.4 Ignite the paper and residue in a platinum crucible,
(HNO ).
cool, moisten with a few drops of water and add 3 to 4 drops
7.8 PhosphoricAcid(85 %)—Concentratedphosphoricacid
ofH SO (1+1)and5mLofHF.Evaporateslowlytoexpelthe
2 4
(H PO ).
3 4
silica and the excess H SO.Add3gofNa S O to the
2 4 2 2 7
7.9 Potassium Dichromate, Standard Solution (0.1000 N)
crucible and fuse over a burner until a clear melt is obtained.
7.9.1 Dissolve 4.9035 g of Primary Standard Grade potas-
Dissolve the cool melt in a few millilitres of water and add this
sium dichromate (K Cr O ) in water, transfer to a 1-L volu-
2 2 4
solution and the washings of the crucible and cover to the
metric flask, dilute to volume, and mix.
reserved filtrate.
7.10 Sodium Diphenylamine Sulfonate Indicator Solution (2
10.5 Dilute the solution with water to a volume of 250 mL
g/L).
and heat to boiling. Remove from the heat source and pass a
7.10.1 Dissolve 0.20 g of sodium diphenylamine sulfonate
rapid stream of H S through the solution for 15 min. Digest at
in 100 mL of water. Store in a dark-colored bottle.
60°Cfor15minandfilterthroughamediumtexturepaperwith
7.11 Sodium Pyrosulfate (Na S O ).
2 2 7 theaidofpaperpulpintoa500-mLErlenmeyerflask.Washthe
7.12 Sulfuric Acid (sp gr 1.84)—Concentrated sulfuric acid pre
...