Table Of ContentOTHER TITLES IN THE SERIES ON
ANALYTICAL CHEMISTRY
Vol. 1. WEISZ—Microanalysis by the Ring Oven Technique
Vol. 2. CROUTHAMEL (Ed).—Applied Gamma-ray Spectrometry
Vol. 3. VICKERY—The Analytical Chemistry of the Rare Earths
Vol. 4. HEADRIDGE—Photometric Titrations
Vol. 5. BUSEV—The Analytical Chemistry of Indium
Vol. 6. ELWELL AND GIDLEY—Atomic Absorption
Spectrophotometry
Vol. 7. ERDEY—Gravimetric Analysis, Part 1
Vol. 8. CRITCHFIELD—Organic Functional Group Analysis
Vol. 9. MOSES—Analytical Chemistry of the Actiniae Elements
THE ANALYTICAL
CHEMISTRY
OF THORIUM
by
D. I. RYABCHIKOV and Ε. K. GOL'BRAIKH
Translated by
A. D. NORRIS
LECTURER IN PHYSICAL CHEMISTRY
THE UNIVERSITY OF HULL
Translation edited by
R. BELCHER and L. GORDON
P E R G A M ON PRESS
OXFORD · LONDON · NEW YORK · PARIS
1963
PERGAMON PRESS LTD.
Headington Hill Hall, Oxford
4 and 5 Fitzroy Square, London, W. 1
PERGAMON PRESS INC.
122 East 55th Street, New York, 22, Ν. Y.
GAUTHIER-VILLARS ED.
55 Quai des Grands-Aug us tins, Paris, 6e
PERGAMON PRESS G.m.b.H.
Kaiserstrasse 15, Frankfurt am Main
Distributed in the Western Hemisphere by
THE MACMILLAN COMPANY * NEW YORK
pursuant to a special arrangement with
Pergamon Press Limited
Copyright © 1963
Pergamon Press Ltd.
Library of Congress Catalogue Card Number 63-10065
This translation has been made from the Russian
ANALITICHESKA Y A KHIMIYA TORI Y A
Published in Moscow, 1960, by IzdateVstvo Akademii Nauk, SSSR
Set in Monotype Times New Roman 10 on 12 pt. and printed in Great Britian by
J. W. ARROWSMITH LTD., BRISTOL
GENERAL INTRODUCTION TO THE SERIES
THE V. I. Vernadskii Institute of Geochemistry and Analytical
Chemistry of the Academy of Sciences of U.S.S.R. has embarked
on the publication of a series of monographs on the analytical
chemistry of various elements. The series will include about 50
volumes in all, and will be issued over a period of about 5 years.
The need for such a series has been felt for a long time, and now
that a large amount of experimental material has been accumulated
in many laboratories it has become both possible and necessary
to proceed. The projected series will be the first of its kind.
The analytical chemistry of any element and its compounds is
in these days a complex subject with many aspects, both because
of the complicated nature of the results required and the wide
concentration range which must be reckoned with, and because of
the variety of available methods. A general plan has been laid
down for the monographs, both as to contents and as to arrange-
ment of material.
Each monograph will contain general information on the proper-
ties of the chosen element and its compounds. A description will
then be given of those chemical reactions which are of importance
for analytical purposes, followed by an account of physical,
physico-chemical and chemical methods which may be used in
the quantitative determination of the element—commencing with
the analysis of the ores, and continuing with end products such
as metals, alloys, oxides, salts and other compounds and materials.
As a general rule the principles of the method of determination
are first given, and are then followed when necessary by a detailed
description of the whole process. Rapid methods of analysis are
noted where necessary, and a separate place is given to the methods
of determination of the so-called impurity elements in pure mat-
erials.
Attention is given to the precision and sensitiveness of methods,
in accordance with the general tendency towards increased sensi-
tiveness in methods used to determine trace quantities of impurity
elements.
The monographs will contain a comprehensive list of references
ix
χ GENERAL INTRODUCTION TO THE SERIES
to recent literature, which should be especially useful to a wide
circle of chemists, and especially analytical chemists in research
institutes and factory laboratories and in various other aspects
of public life, as well as for teachers of chemistry and students in
higher academic establishments.
The preparation of the monographs has been placed in the hands
of the most eminent specialists in the particular fields of analytical
chemistry concerned. The separate volumes will be issued inde-
pendently as they are ready. The monograph on thorium is at
present prepared, and those on the analytical chemistry of pluto-
nium, lithium and gallium, amongst others, are under preparation
for the press.
We should welcome suggestions and opinions from readers of
the monographs.
The Editorial Board.
FOREWORD
THE use of thorium as a raw material for the manufacture of nuclear
fuel, as well as in other recently developed technical fields, has
stimulated a comprehensive study of the element. A large number
of works have been published in recent years, giving detailed infor-
mation on the properties of the metal and its compounds, especially
those used in the isolation and determination of the element in
natural and industrial materials. The literature, especially that
published abroad, contains reviews of the chemistry and analy-
tical chemistry of thorium by C. J. Rodden and J. C. Warf [1710],
G. Moeller, D. Schweitzer and D. Starr [1503], G. T. Seaborg
[1816-20] and J. Katz [1180], and others. Unfortunately, however,
these reviews are far from comprehensive, and leave untouched
many investigations reported in various journals.
Because of this we have attempted here to give a systematic
treatment of the available factual material. The more than 2000
references to work used in the preparation of this volume com-
prise the great majority of those published in the last decade, but
it is impossible even for such a survey to keep pace with the new
publications, which appear constantly in a science which is develop-
ing so rapidly.
In addition to the strictly analytical section of this book, a chapter
is provided on the physico-chemical characteristics of the element.
The four following chapters describe the chemical and physico-
chemical methods of determining thorium, its removal from ele-
ments occurring with it, and its determination in various natural
and industrial materials, as well as the determination of impurities
in the metal. References to literature not actually used in the book,
but likely to be of interest to analytical chemists and specialists
in other fields of science, are given in the text in smaller print.
We have arranged the material in relation to the importance of
the various reagents, and have adhered to the commonly accepted
classification of organic substances.
The authors wish to express their gratitude to their colleagues in
the Institute who have helped with advice during the preparation
of the manuscript for the press, and would particularly express
xi
xii FOREWORD
their appreciation to Correspondent-Member of the Academy of
Sciences of U.S.S.R. I. P. Alimarin, to Doctors of Chemical
Science P. N. Palei and V. I. Kuznetsov, to Candidates of Chemi-
cal Science A. A. Nemodruk and A. N. Ermakov, as well as to
Candidate of Chemical Science V. K. Belyayev and Scientific
Assistant M. P. Volynets for their help in the literature survey.
D. I. RYABCHIKOV
Ε. K. GOL'BRAIKH
PREFACE
THE writer notes with interest that the Academy of Sciences of
the U.S.S.R. is sponsoring the publication of some fifty volumes
on the analytical chemistry of the elements. These volumes should
prove of great value to those working in this field, particularly as
they will undoubtedly cover recent U.S.S.R. work.
The present inaugural volume on the Analytical Chemistry of
Thorium must be regarded as one of the most important of the
series, dealing as it does with an important atomic energy material.
Its translation under the aegis of the Pergamon Institute will be
greatly welcomed. It is noted that the volume on plutonium will
be one of the next to follow.
The references given in the Russian text appear to cover the subject
up to the end of 1955, with a few 1959 entries. The present writer
has supplied further references (with titles of papers) to the end of
1961, with some 1962 entries. It is thought that this supplementary
bibliography should add to the value of the book. No attempt has
been made to classify the supplementary references, as this would
lead to much overlapping. The entries are alphabetical by first-
named Author, and their serial numbers are followed by the letter
"S".
A.E.R.E. Harwell R. W. CLARKE
xiii
CHAPTER I
OCCURRENCE OF THORIUM AND ITS MOST
IMPORTANT PROPERTIES
ORES AND DISTRIBUTION OE THORIUM
Thorium was discovered by Berzelius in 1828 during his investi-
gations of a mineral later called thorite, obtained from the island
of Loveoya, near Brevik in Norway [371, 820]. It was given its name
in honour of Thor, a god in Scandinavian mythology, as early as
1817, when Berzelius formed the erroneous view that the phosphate
of a rare earth element of the yttrium subgroup, occurring in a
mineral obtained from Finnbo, belonged to a new, at that time
unknown, element [369, 370]. For the history of the discovery of
thorium see also [364, 1555].
The element is widely distributed in the earth's crust [22, 42, 105,
198, 220, 1564], of which, according to Vinogradov [47] it con-
stitutes 8 χ 10~4 per cent. It is, however, only rarely encountered in
appreciable concentrations. The thorium content of basic rocks
is considerably smaller than that of acidic rocks [42, 1629, 1698].
Thus, its proportion by weight is 1-2 χ 10-3 in granites, compared
with 5xl0-4 in dunites [47, 198]. The thorium content of the
hydrosphere varies between 10~5 and 10~9 g/1. [144, 178, 1153,
1609, 1610, 1835, 2047-8]. Its weight proportion in iron meteorites
varies from 0-9 χ 10-6 to 4-3 χ 10-8 per cent, while that in stone
meteorites is 2-4 χ 10~5 per cent [189].
Thorium minerals are most often encountered in igneous rocks,
pegmatites, veins and alluvia, of which the last are the most
important industrial sources.
Almost all thorium minerals are resistant to natural attack,
so that there is little tendency for the concentration of the metal
in secondary minerals as a result of such attack.
The most important thorium minerals are monazite, thorite,
and thorianite. Although monazite contains only from 1-4-28
1
2 THE ANALYTICAL CHEMISTRY OF THORIUM
per cent of thorium [177], the monazite deposits are the most
important primary sources of the metal. Thorium is a major com-
ponent of thorite and thorianite. but these minerals are quite
rare and have no practical importance.
Recent evidence [1560, 1856, 2036] discloses the discovery of
vein deposits containing thorium in the White Mountains, near
Powderhorn in Colorado, as well as in California [1560], New
Mexico, Montana, Wyoming and Idaho [1981]. Deposits of
industrial importance [4, 139, 303, 1021, 1384, 1921, 2027] occur
in Brazil, India, Ceylon, Tasmania, Nigeria, and the Scandinavian
peninsula. In the U.S.A., in addition to the locations mentioned
above, deposits occur in Colorado, North Carolina and Virginia
and other states.
A large part of the world production is obtained from Brazil,
India, Ceylon and U.S.A. [925, 1193, 1336, 1513, 2028]. Reserves
of monazite in India are estimated to exceed 2,000,000 tons. Indian
monazite from the Malabar coast and Travancore contains from
8 to 10 per cent of thoria, TI1O2, while Brazilian monazite from the
Baia coasts and Santo Esperito contains on the average ca. 6
per cent [1744].
Monazite is obtained in U.S.A. from the sand dunes near
Jacksonville in Florida, and from California, Colorado, Oregon
and Washington [1981], as well as from the auriferous sands of
Central Idaho. Concentrations of monazite with around 7-5
per cent thoria occur in isolated places in the iron-mining region
of Marquette in northern Michigan [2018].
Monazite sands are also encountered in large quantities along the
sea shores, in river beds and in coastal banks in western Taiwan.
The thoria content of the last named varies from 4-2 to 6-8 per
cent [2142].
Information presented at the First Geneva Conference on the
Peaceful Uses of Atomic Energy reveals that new sources of
thorium have been found in South Korea [2142], Sweden [1919],
Norway [1848], Jugoslavia [1702], Greece, Thailand and Aust-
ralia [1642].
The nominal price per metric ton of monazite concentrates has
changed thus with time: $120-180 in 1922-29; $50-75 in 1929-46;
$100-150 in 1947; and $140-200 in 1948. Since 1949 the price
price has further increased to $245[1744].
