Process for the Separation of Certain Rare Earths, and the Manufacture therefrom of Fabrics. for Use in Incandescent Gas-lighting.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
A Process for the Separation of Certain Rare Earths, and the
Manufacture therefrom of Fabrics. for Use in Incandescent
Gas-lighting.
I, DR. BERNHARD KOSMANN, of 68 Jagerstrasse, Berlin W, in the Empire of
Germany, do hereby declare the nature of this invention to be as follows:-
In the crude liquor resulting from the solution of monazitsand I have discovered
two new earths, to which I have given the names "Kosmia" or "oxide of
Kosmium" and "Neokosmia" or "oxide of Neokosmium."
The discovery as well as the separation of, these two earths is due to the im-
proved chemical process which I have imagined and employed, and which I will
describe hereinafter.
According to this process the said two earths are proved to form integral
constituent parts of earths of the cerium-group (ceriumi, didymium, lanthanum)
occurring in the monazitsand, as well as in other cerite (allanite) ores.
The said two earths were not heretofore known and differ from previously known
rare earths of the same group, namely the oxides of cerium, didymium and
lanthanum, as regard their reactions as well as the colour of their oxides and
salts (nitrate, sulphate) in connection with these reactions. The proof that these
two earths are not related to, or appertain to, the salts of the yttrium group, may
be dispensed with, because these latter salts are not precipitated at all together
with the salts of the cerium group, from the crude liquor of the monazit sand as
long as the said liquor remains acid.
The process of separating these earths, riz, kosmia, or oxide of kosmium and
neokosmia or oxide of neokosmium is as follows:
The crude liquor which is obtained by rendering the monazit sand, or cerite
ores soluble by means of sulphuric acid, is saturated with ammonia, until a per-
manent precipitate is produced; if hydrochloric acid is then added, the
said precipitate slightly dissolves and thereupon a crystalline precipitate
is deposited, which consists of sulphates of cerium, didymium and lantha-
num. This precipitate which likewise under other conditions settles down
in the crude liquors which have been at rest for some time, forms the starting
material for producing the new rare earths. In the solution, of the sulphates
which leaves a residue of silicic acid and a small amount of sulphate of thorium,
a series of precipitates are produced through the medium of a repeated fractional
precipitating process in which peroxide of hydrogen and ammonia are added, care
being taken however that the liquid always remains acid.
Thus first, a dark brown precipitate of perhydroxide of cerium is formed,
subsequently one or several red to orange coloured precipitates of perhydroxide of
didymium, and finally a straw yellow precipitate, which has the appearance of a

page_text: precipitate of hydroxide of lanthanum coloured by perhydroxide of didymium.
After these precipitates have been successively filtered off, and, after the solution
has become alkaline because of repeated precipitations, then, on further adding
ammonia, a white precipitate of a hydrate is formed, which, in order to be com-
plotely separated requires a surplus of ammonia, this precipitated hydrate however
will also remain white when peroxide of hydrogen is added.
The white precipitate proves to be the hydrate of the rare earth which I have
named "oxide of kosmium"; the first precipitate is not however pure.
When the precipitate is dissolved in nitric acid and the solution is concentrated,
it becomes gelatinous, so that real, pure crystals of the nitrated salt can not be
obtained.
For the purpose of purifying the oxide of kosmium, it is precipitated from the
nitric acid solution, as an oxalate by adding oxalic acid. The oxalate is decom-
posed by heating and the residue is dissolved in nitric acid. The solution is very
easily obtained contrary to solutions of roasted oxalates of cerium and didymium;
the solution is next treated with peroxide of hydrogen and ammonia in the manner
before described. During this operation, in an acid solution, first a light yellow
precipitato settles down."
After this latter has been filtered off, and on adding ammonia, in excess, the
white hydrate of kosmium is precipitated. If this precipitate is then nitrated
and the solution concentrated, a crystallized nitrate of kosmium is separated in
the mother liquor. This nitrate of kosmium is a salt of bluish white colour with
a faint violet tint.
The light yellow precipitate first obtained from the oxalate solution likewise
proves to be the hydrate of a new oxide, which in its reactions shows essential
deviations from the oxides of cerium, didymium and lanthanum and their salts,
as well as from the oxide of kosmium, and which I have therefore named "oxide
of neokosmium."
The essential features which distinguish these two rare earths as previously
unknown, are the following:-
1. "Oxide of Kosmium." The hydroxide initially, while containing a large
amount of water, presents a lightly bluish colour upon the filter, but is of a high
pinkish colour when dry and will retain this latter colour even if the water be
extracted therefrom at a temperature above 100 degrees Centigrade; when however
a dark red heat is attained the substance changes into a chocolate brown oxide.
This oxide is not, however, a peroxide like the brown or red coloured oxides of
cerium or didymium, since it does not liberate chlorine when treated with hydro-
chloric acid. The sulphate is a light claret-coloured salt containing four molecules
of water, according to the formula Ks (SO4)3 + H2O, and crystallizes in the
monoclinic system, romorphous with sulphate of didymium, into gypsum shaped
crystals; the crystals become readily decomposed by the atmosphere and in this
state present a turbid appearance. The nitrate has already been described. The
salts of the oxide of kosmium differ from the salts of didymium inasmuch as they
(the former) can be dissolved far more easily, while from the salts of lanthanum
they differ by their colour.
2. Oxide of neokosmium. The hydroxide is light yellow to straw yellow and
can be precipitated in this colour from its solutions by means of ammonia, without
the addition of peroxide of hydrogen. When dried it becomes dark yellow to
brown; when brought to glowing heat, the oxide assumes a greyish white colour
with a faint yellow tint. This hydrant or oxide respectively is not however a
perhydrate or penoxide. The sulphate is of a light claret colour and forms
crystals which are isomorphous with didymium sulphate. The nitrate, which is
likewise isomorphous with didymium nitrate, forms brilliant crystals having an
onion-red colour, which proves it (the nitrate) to be distinctly different from
didymium nitrate, since the latter forms crystals of whitish violet colour which 5
are difficultly soluble.

page_text: Nitrate:
Sulphate:
Greyish white, light yellow.
heat :
Chocolate brown
Bluish white to violet
Light pink-
Onion red.
Claret-red
These two earths have proved to be substances most advantageously applicable
for the production of incandescent bodies, effected by soaking woven materials of
appropriate shape in solutions of salts (nitrate, sulphate, acetate) obtained from
both the newly discovered earths.
Oxide of kosinium, when used separately, dyes the fabric to be used for in-
candescent lighting, dark (chocolate) brown, and imparts to it the quality of
producing an intense reddish yellow light. A still more intense radiation of
light is however produced when these earths are combined with other rare earths.
The combinations of oxide of kosmium with oxide of thorium, and of kosmia,
oxide of thorium and oxide of cerium, in which combinations the addition of
oxide of kosmium may amount to from 10 to 30 per cent-yield a white, yellowish
light of great intensity and of considerable radiating capacity. The stocking,
or mantle shaped fabric proves to be of a greater elasticity and resistance against
external influences than fabrics heretofore treated with oxide of thorium. The
radiating and light emitting capacity increases with the time of burning, and in
the same proportion the earths combined by the impregnating process become
gradually more intimately connected and incrustated.
Moreover the combinations of
1. Oxide of kosmium and oxide of zirconium;
2. Oxide of kosmium, oxide of zirconium and protoxide of barium,
3. Oxide of kosmium and magnesia yield an efficient incandescent light body
of white or amethyst coloured light, the intensity of which is dependent on the
amount of salts used. The quantity of oxide of kosmium may be raised to one
half that of the salt dissolved in the fluid.
Likewise the combinations of
1. Oxide of neokosmium and oxide of thorium, with or without the addition
of cerium,
2. Oxide of neokosmium and oxide of zirconium,
3. Oxide of neokosmium, oxide of zirconium and protoxide of barium,
4. Oxide of neokosmium and magnesia yield a white light with a yellowish or
amethyst tiut respectively, of powerful radiation and intensity.
An addition of earths of the yttrium group may be employed in order to produce
alterations in the colour of the light.
Dated this 26th day of August 1896.
COMPLETE SPECIFICATION.
A Process for the Separation of Certain Rare Earths, and the
Manufacture therefrom of Fabrics for Use in Incandescent
Gas-lighting.
I, DR. BERNHARD KOSMANN, of 68 Jagerstrasse, Berlin W, in the Empire of
Germany, do hereby declare the nature of this invention and in what manner

page_text: the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
In the cerium and didymium salts obtained from the crude liquor resulting
from the solution of Monuzitsand I have discovered a new earth, to which I have
given the name "oxide of Kosmium."
The discovery as well as the separation of the said new earth is due to the im-
proved chemical process which I have imagined and employed, and which I will
describe hereinafter.
According to this process the said new earth is obtained free from the oxides
of the cerium-group (cerium, didymium, lanthanum) as well as free from the
oxides of the yttrium-group and the erbium group.
The said new earth differs from previously known rare earths of the cerium-
group, to which it belongs, namely the oxides of cerium, didymium and lanthanum,
as rogards its reactions as well as the colour of its oxide and salts (nitrate,
sulphate) in connection with these reactions. The proof that the new earth is
not related to, or appertains to, the salts of the yttrium group, may be dispensed
with, because these latter salts are not precipitated at all together with the salts
of the cerium group, front the crude liquor of the monazit sand as long as the said
liquor remains acid.
The process of separating the new earth riz. oxide of kosmium is as follows:--
The crude liquor which is obtained by rendering the monazit sand soluble or
that obtained from cerite ores by means of sulphuric acid, is saturated with
ammonia, until a permanent precipitate is produced: if hydrochloric acid is then
added, the said precipitate slightly dissolves and thereupon a crystalline precipitate
is deposited, which consists of sulphates of cerium, didymium and lanthanum.
This precipitate which likewise under other conditions settles down in the crude
liquors which have been at rest for some time, forms the starting material for oh-
taining the new rare earth. In the solution of these sulphates which leaves a residue
of silicic acid and a small amount of sulphate of thorium, a series of precipitates
is produced through the medium of a repeated fractional precipitating process in
which peroxide of hydrogen and ammonia are added, care being taken however
that the liquid always remains acid. The latter condition is essential as it causes
the didymium and lanthanum to separate out in the form of hydroxide, or per-
hydroxide. Thus first, a dark brown precipitate of perhydroxide of cerium is
formed, subsequently one or several red to orange coloured precipitales of per-
hydroxide of didymium. After these precipitates have been successively filtered
off, and, after the solution has become alkaline because of repeated precipitations,
then, on further adding ammonia, a white precipitate of a hydrate is formed,
which, in order to be completely separated requires a surplus of ammonia, this
precipitated hydrate however will also remain white when peroxide of hydrogen
is added.
The white precipitate proves to be the hydrate of the rare earth which I have
named "oxide of kosmium"; this first white precipitate is not, however, pure, for
when it is dissolved in nitric acid and the solution is concentrated, the latter
becomes gelatinous, so that real, pure crystals of the nitrated salt cannot be
obtained.
For the purpose of purifying the oxide of kosmium, the said precipitate is
dissolved in nitric acid, and from this solution the new earthy oxide is pre-
cipitated, as an oxalate by adding oxalic acid, the latter being added to the hot
solution. The oxalate is washed with hot acidulated water and then decomposed
by heat; the residue is dissolved in nitric acid. The solution is very easily
obtained contrary to solutions of roasted oxalates of cerium and didymium. The
solution is next treated with peroxide of hydrogen and ammonia in the manner
before described, so that the solution remains acid. During this operation, first
a light yellow precipitate settles down, containing the traces of lanthanum oxide
that might not have separated out in the first fractional precipitating process.

page_text: After the precipitate has been filtered off, and on adding ammonia, in excess, the
white hydrate of kosmium is precipitated. If this precipitate is then dissolved
in nitric acid and the solution concentrated, nitrate of kosmium separates out in
crystals of bluish white colour with a faint violet tint.
The essential features which distinguish the new rare earth, are the following:
The hydroxide of kosmium initially, i.c. while containing a large amount of
water, presents a lightly bluish colour upon the filter, but is of a high pinkish
colour when dry and will retain this latter colour even if the water be extracted
therefrom at a temperature above 100 degrees Centigrade; when however a dark
red heat is attained the substance changes into a chocolate brown oxide. This
oxide is not, however, a peroxide like the brown or red coloured oxides of cerium
and didymium, since it does not liberate chlorine when treated with hydrochloric
neid. The sulphate is a light pink coloured salt containing four molecules of water,
according to the formula Ks, (SO4)3, 4H0, and crystallizes monoclinous, isomor-
phous with sulphate of didymium, into gypsum shaped crystals; the crystals
become readily decomposed by the atmosphere and in this state present a turbid
appearance. The nitrate has already been described. The salts of the oxide of
kosmium differ from the salts of didymium inasmuch as they (the former) can be
dissolved far more easily, while from the salts of lanthanum they differ by their
colour.
The new earth described has proved to be a substance most advantageously
applicable for the production of incandescent bodies, effected by impregnating a
fabric of appropriate shape with solutions of its salts (uitrate, sulphate, ucetate)
and calcining.
Oxide of kosmium, when used separately, produces a (chocolate) brown coloured
mantle which emits an intense reddish yellow light. A still more intense radiation
of light is however produced when the new earth is combined with other rare
earths.
The combinations of oxide of kosmium with oxide of thorium, oxide of kosmium,
oxide of thorium and oxide of cerium-in which combinations the addition of
oxide of kosmium may amount to from 10 to 30 per cent- yield a white, yellowish
light of great intensity and of considerable radiating capacity. The mantle proves
to be of a greater elasticity and resistance against external influences than the
mantles as heretofore manufactured with oxide of thorium. The radiating and
light emitting capacity increase with the time of burning and in the same
proportion the earths combined by the impregnating process frit together.
Moreover the combinations of
1. Oxide of kosmium and oxide of zirconium;
2. Oxide of kosmium, oxide of zirconium and protoxide of barium,
3. Oxide of kosmium and magnesia yield an efficient incandescent body
of white or amethyst coloured light, the intensity of which is dependent on the
amount of salts used. The quantity of oxide of kosmium may be raised to one
half that of the sults dissolved in the fluid.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. The process of obtaining a new earthy oxide (kosmia) from monazit sand
and other cerite minerals, which consists in first fractionally precipitating the
hydrates of cerium, didymium and lanthanum by adding peroxide of hydrogen
and ammonia so that the solution retains an acid reaction, then treating the
filtered off solution with the same reagents but adding so much ammonia that the
solution becomes alkaline, separating the precipitate thus obtained from the
liquor, dissolving the precipitate in nitric acid, treating this solution in the hot
state with oxalic acid, washing the precipitate with hot acidulated water, decom-
posing the washed oxalate by heat, dissolving the residue in nitric acid, treating
this solution with hydric peroxide and ammonia, so that the solution retains an

page_text: acid reaction, separating the precipitate from the liquor and adding ammonia in
excess whereby the hydrate of the new earthy oxide is obtained as a whitish
precipitate, substantially as described.
2. A body or mantle for use in incandescent lighting manufactured from the
earthy oxide alone or in combination with the oxides of cerium, thorium, and the.
other earthy metals or any of them, substantially as described.
Dated this 25th day of May 1897
HASELTINE, LAKE & Co.,
45 Southampton Buildings, W.C., Agents for the Applicant.