|
Ref. No.: ISO/R 621 - 1967 (E)
IS0
I NT ERN AT1 ON AL ORGANIZATION FOR S TA N DA RD IZATl O N
IS0 RECOMMENDATION
R 621
METHODS OF CHEMICAL ANALYSIS OF MANGANESE ORES
DETERMINATION OF METALLIC IRON CONTENT
(Photometric method for metallic iron content up to and including 2%)
1st EDITION
September 1967
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore oniy
by the national standards organization of that country, being
a member of ISO.
For each individual country the oniy valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
---------------------- Page: 1 ----------------------
BRIEF HISTORY
The IS0 Recommendation R 621, Methods of Chemical Analysis of Manganese Ores -
Determination of Metallic Iron Content, was drawn up by Technical Committee ISO/TC 65,
Manganese Ores, the Secretariat of which is held by Komitet Standartov Mer i Izmeritel’nyh
Priborov pri Sovete Ministrov S.S.S.R. (GOST).
Work on this question by the Technical Committee began in 1954 and led, in 1964, to the
adoption of a Draft IS0 Recommendation.
In April 1965, this Draft IS0 Recommendation (No. 780) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial
nature, by the following Member Bodies:
Argentina Hungary Spain
Austria India Switzerland
Chile Italy Turkey
Czechoslovakia
Korea, Rep., of U.A.R.
France Netherlands United Kingdom
Germany Poland U.S.S.R.
Greece Romania Yugoslavia
No Member Body opposed the approval of the Draft.
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council,
which decided, in September 1967, to accept it as an IS0 RECOMMENDATION.
-2-
---------------------- Page: 2 ----------------------
ISO/R 821 - 1967 (E)
IS0 Recommendation R 621 September 1967
METHODS OF CHEMICAL ANALYSIS OF MANGANESE ORES
DETERMINATION OF METALLIC IRON CONTENT
(Photometric method for metallic iron content up to and including 2%)
(Atomic mass Fe : 55.85)
1. GENERAL INSTRUCTIONS
1.1 In the following analysis use a sample for chemical analysis of air-dried manganese ore,
sampled and prepared in accordance with IS0 Recommendation R 309, Methods of Sampling
Manganese Ores.
Simultaneously with the collection of test samples for the determination of metallic iron,
take three more test samples for the determination of hygroscopic moisture.
Calculate the content of metallic iron in ore on the dry basis, by multiplying the numerical
results of the determination of metallic iron by the conversion factor K, as found from the
following formula :
1 O0
K= ____-
100 - A
where
.
A is the percentage hygroscopic moisture content.
1.2 The determination of metallic iron in manganese ore should be carried out by analysing three
parallel-weighed test samples of the ore together with two blank tests to allow the necessary
corrections to be made to the results of the determination.
The arithmetical mean of the three results should be accepted as the final result.
The difference between the highest and the lowest results should not exceed double the
absolute value of the permissible tolerance for the corresponding interval of metallic
iron content, shown in the Table under clause 5.2 “Accuracy of method”.
-3-
---------------------- Page: 3 ----------------------
ISO/R 621 - 1!%7 (E)
1.3 If an average sample of manganese ore contains metallic iron, the necessary corrections
should be made to the result of the analysis.
1.4 The test samples should be weighed to an accuracy of f 0.0002 g.
1.5 Distilled water should be used during the procedure and for preparation of the solutions.
1.6 Meanings of particular expressions :
60 to
hot water (or solution) implies a temperature of the liquid of
70 OC;
implies a temperature of the liquid of 40 to
warm water (or solution)
50 OC;
diluted 1 : 1, 1 : 2, 1 : 5 etc. the first figure gives the number of parts by
volume of concentrated acid or some other
solution ;
the second figure gives the number of parts by
volume of water.
1.7 The following abbreviations and symbols are used:
CP = chemically pure
d = relative density
g = gramme
1 = litre
ml = millilitre
nm = nanometre
PFA = pure for analysis
2. PRINCIPLE OF METHOD
The method is based on the selective solution of the metallic iron in methyl alcohol solution of
mercuric chloride and sodium salicylate. The latter eliminates completely the formation of
insoluble basic ferric salt and methanol prevents the solution of ferric oxides.
The metallic iron in the solution is determined by the photometric method in the pr
...