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Ref. No.: BO/ R 312 - 1963 (E)
IS0
I NT ERN AT IO NA L ORGAN IZAT IO N FOR STANDARD I2 AT I ON
IS0 R ECOM MENDATI ON
R 312
METHODS OF CHEMICAL ANALYSIS OF MANGANESE ORES
DETERMINATION OF ACTIVE OXYGEN
CONVENTIONALLY EXPRESSED AS MANGANESE DIOXIDE
1st EDITION
July 1963
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The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only 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.
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BRIEF HISTORY
The IS0 Recommendation R 312, Methods of Chemical Analysis of Manganese Ores-
Determination of Active Oxygen conventionally expressed as Manganese Dioxide, was drawn
up by Technical Committee ISO/TC 65, Manganese Ores, the Secretariat of which is held
by the Komitet Standartov, Mer i Izmeritel’nyh Priborov pri Sovete Ministrov SSSR.
Work on this question by the Technical Committee began in 1954 and led, in 1957,
to the adoption of a Draft IS0 Recommendation.
In October 1958, this Draft IS0 Recommendation (No. 245) was circulated to all
the IS0 Member Bodies for enquiry. It was approved by the following Member Bodies:
Austria Hungary Port u g a 1
Bulgaria India Republic of
Burma Ireland South Africa
Romania
Chile Italy
Czechoslovakia Japan Spain
France Netherlands United Kingdom
Germany Poland U.S.S.R.
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 July 1963, to accept it as an IS0 RECOMMENDATION.
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iSO/ R 312 - 1963 (E)
IS0 Recommendation R 312 July 1963
METHODS OF CHEMICAL ANALYSIS OF MANGANESE ORES
DETERMINATION OF ACTIVE OXYGEN
CONVENTIONALLY EXPRESSED AS MANGANESE DIOXIDE
(Atomic mass Mn: 54.94; molecular mass MnO,: 86.94)
This IS0 Recommendation contains two parts:
I. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . section 1,
II. Volumetric method, by reducing with ferrous ammonium sulphate . . . sections 2 to 6.
I. INTRODUCTION
1. GENERAL INSTRUCTIONS
I
1.1 In the following analysis, use a sample for chemical analysis of air-dried manganese ore,
which has been crushed to a size not exceeding 0.10 mm and checked on a sieve of appro-
priate size.
Simultaneously with the collection of samples for the determination of active oxygen (con-
ventionally expressed as manganese dioxide), take three more test saniples for the determina-
tion of hygroscopic moisture.
Calculate the content of active oxygen (conventionally expressed as manganese dioxide) in
ore which is absolutely dry by multiplying the numerical results of the determination of
active oxygen by the conversion factor K, as found from the following formula:
A = hygroscopic moisture content, per cent.
where
1.2 The determination of active oxygen (conventionally expressed as manganese dioxide) in
of ore, with two
manganese ore is carried out by simultaneously analysing three samples
blank determinations to enable a corresponding correction in the result of the determination
to be made.
Simultaneously and under the same conditions, carry out a check analysis of a standard
sample of manganese ore, for active oxygen (conventionally expressed as manganese dioxide)
content.
The arithmetical mean of the three results is accepted as the final result.
I
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iSO/ R 312 - 1963 (E)
The following conditions should be observed:
The maximum difference between the highest and the lowest results should not exceed
double the absolute value of the permissible tolerance on the result of the analysis (for
the corresponding interval of manganese dioxide content) shown in the table under clause 6.2,
" Accuracy of method ".
The average result of the simultaneous check analysis of the standard sample of manganese
ore for active oxygen (conventionally expressed as manganese dioxide) content should not
differ from the result shown in the certificate by more than the f value of the permissible
tolerance (for the corresponding interval of manganese dioxide content), shown in the
table under clause 6.2, " Accuracy of method ".
For the analysis, take a standard sample of the type of ore to which the sample being analysed
belongs.
1.3 The test samples and the residues should be weighed to an accuracy of f 0.0002 g.
1.4 Distilled water should be used during the procedure and for the preparation of solutions.
1.5 Meanings of the following expressions :
hot water (or solution) implies a temperature of the liquid of 60 to 70 OC;
warm water (or solution) implies a temperature of the liquid of 40 to 50 OC;
diluted 1 : 1, 1 : 2, 1 : 5, etc. means that
of
the first figure gives the number of parts by volume
concentrated acid or some other solution, and
the second figure gives the number of parts by volume
of water.
1.6 indications as to the concentration of solutions show the q
...