Improvements in the Manufacture of Dioxide of Barium.
Year: 1898

page_text: Date of Application, 13th Sept., 1898
Complete Specification Left, 24th Sept., 1898-Accepted, 17th Dec., 1898
[Communicated from abroad by LA SOCIÉTÉ BONNET, RAMEL, SAVIGNY GIRAUD ET
MARNAS, of Lyon, in the Republic of France, Dyers.]
Improvements in the Manufacture of Dioxide of Barium.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
In order to manufacture dioxide of barium (Ba0%) under favorable industrial
conditions, it is necessary to pass a current of air or of oxygen over anhydrous
baryta (BaO) which is as porous and as pure as possible, and at a dull red heat.
If the baryta is not porous, or if it is compact, or is not pure, a poor and impuro
dioxide of barium is obtained, and one which is not suitable for the uses for which
such product is intended.
Hitherto, in order to obtain this porous, anhydrous baryta, adapted for yielding
a rich dioxide of barium (82 to 90 per cent. of purity), nitrate of baryta has been
taken as the primary substance. By calcination of this nitrate, a porous and
relatively pure anhydrous baryta is obtained, upon which a current of air is caused
to pass at a dull red heat.
Numerous attempts have been made to obtain an anhydrous baryta, pure and
porous, without employing nitrate of baryta, because the element nitre is rela-
tively costly and is completely lost in the cycle of operations. Thus attempts
have been made to dioxidise an anhydrous baryta obtained by the calcination of
carbonate of baryta, but this, being dense and but very slightly porous, gives a
poor dioxide of barium (about 60%). This process has therefore not been com-
mercially successful.
Our invention consists in employing as a primary baritic substance, hydrated,
crystallized baryta, in order to obtain an anhydrous, porous and pure baryta.
We will not describe any process for the manufacture of hydrated baryta; the
essential point is to employ a product which is as pure as possible.
The hydrated baryta contains water the greater part of which may be expelled
at a relatively low temperature, but the last remainder of this water, that which
is termed "water of composition," it has not hitherto been possible to eliminate
by a commercially practicable process giving a porous, anhydrous oxide of barium,
capable of becoming dioxidised at a high standard of purity.
Now the essential, novel and characteristic feature of our invention consists
in the application of the reducing energy acquired by carbon in a finely divided
condition, when its action upon hydrate of baryta takes place at a suitable
temperature.
This operation of reduction may take place in ovens, muffles or retorts, but we
have obtained the best results by operating within a crucible of plumbago or
other refractory substance, provided with a lid and lined internally with a wall
or layer of a specially prepared agglomerated, organic substance.
This lining

page_text: assumes the form of the crucible as the calcination of the carbon, which forms
its framework or scaffolding so to speak, proceeds, and resists equally with the
crucible itself the high temperature employed. The crucible, in these conditions
with its double wall, regulates the operation and prevents any injurious oxidising
action, in such a manner that the hydrate of baryta is transformed rapidly and
integrally into anhydrous oxide of barium which is of great purity and extremely
porous, owing to which it is readily dioxidable.
This combination of circumstances enables the action of carbon upon hydrated
baryta to be carried out industrially without corrosion of the crucibles or loss of
material, which constitutes an important feature.
The dehydration of baryta by means of carbon is a novel and characteristic
feature; it is well known that the "water of combination" of hydrate of baryta
could not hitherto be eliminated, by means of an industrially practicable process,
with the production of a pure, porous and anhydrous baryta.
In order to carry out this operation practically we proceed in the following
manner;-
We take hydrated baryta, either crystallized or not, but as pure as possible;
we mix this intimately with an equivalent of carbon (about six kilogrammes of
pure carbon for 157 kilogrammes of pure crystallized baryta). Carbon of any
kind may be employed, provided it be as pure as possible, such as coal, lamp-
black, coke-dust, vegetable charcoal, or in short any substance capable of giving
carbon by calcination; it should be added that care should be taken to employ
these carboniferous substances in an infinitely divided condition if they are solid.
This having been done, we heat this mixture in basins of sheet, cast or
enamelled cast metal for two or three hours at a temperature of 100° to 150° C.,
thereby producing fusion of the mass and ebullition, finally giving a solid
blackish mass, more or less completely dried. The greater portion of the water
is thus removed.
We then prepare a crucible of plumbago, refractory earth or other substance
in the following manner; We arrange at the bottom of this crucible and over
the whole of its internal walls a sheet of cardboard which forms an internal
lining of the crucible. The magma obtained in the manner above described is
placed therein, and a piece of cardboard is then placed upon this magma, a cover
being finally placed upon the crucible which will allow the gases produced to
escape. The crucible is then introduced into an oven and heated to a bright red
(about 1000° to 1200° C.) for from five to eight hours, after which it is allowed
to cool, either in the oven or after removal from the same.
When the crucible has cooled, there is in it a mass of anhydrous oxide of
barium, extremely porous and of a greyish colour, which may be completely
detached from the carbonised skeleton left by the organic covering above referred
to. There is thus removed from the crucible;
1. A mass of oxide of barium excellently adapted for dioxidation, and
2. Carbonised debris.
The size of the crucibles may vary; they may be of sufficient size for industrial
operations.
A modification of this method of operating consists in heating by itself in cast
inetal basins, either enamelled or not, crystallized hydrated baryta, in such a
manner as to drive off the greater part of its moisture, and then to mix it with
finely divided carbon, subsequently heating it in the crucible as above described.
This does not, however, in anyway alter the characteristic reaction and we prefer
to first of all mix the carbon with the crystallized baryta, as above stated.
If necessary the operation of desiccation and of reduction could also be effected
in the same apparatus (muffle, retort, crucible, oven or the like) but it is prefer-
able to operate separately in the manner already described.
The anhydrous baryta thus obtained in the crucible is very porous and of great
purity, and it only remains to crush it superficially in order to dioxidise it. In
this crushed condition it is eminently adapted for dioxidation.

page_text: This operation is effected in the manner usual in dioxide manufacture, which
commences with oxide of barium obtained by the calcination of nitrate, that is
to say, this superficially crushed anhydrous baryta is introduced into iron tubes
heated to a dull red and which are maintained at this temperature for some hours,
air which has been freed as much as possible from its carbonic acid and its
humidity being caused to pass over the mass. Oxygen may be substituted for air.
When this operation is terminated, a whitish mass is withdrawn from the tubes;
this is dioxide of barium at from 86 to 94% of purity and containing fewer
impurities than dioxide of barium manufactured by the processes hitherto
employed. It is not, in fact, contaminated by the substances composing the ovens
or basins employed for the calcination of nitrate of baryta.
An important point in this process of manufacture is the care with which we
insert within the crucible, a fining of a substance capable of giving at a high
temperature a carbon envelope which isolates the baritic mass from the material
of the crucible. We do not indicate any special organic substance, those which
may be employed being very numerous; however we may cite as examples, card-
board, paper, wood pulp and sheets of various vegetable fibres, and finally, lining
the crucible with carbon.
By the use of this carbon envelope we obtain a mass of baryta which is not
contaminated by the various substances entering into the composition of the
crucibles; on the other hand, the block becomes more readily detached at the
termination of the operation, and finally it forms an envelope which is almost
tight and which facilitates the reaction.
The two principal advantages of our process are the following:
(a) More economical manufacture, because we avoid the losses occasioned by
the employment of nitrous elements whilst at the same time employing primary
substances of low cost and which may be readily procured. We also obtain a
high rate of yield in our various operations, thereby still further reducing the cost
of production.
(b) We obtain a dioxide of barium which is rich and more pure than dioxide
of barium manufactured by the processes hitherto. employed.
Dated this 13th day of September 1898
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
CODILMIN DI MUITICATION.
Improvements in the Manufacture of Dioxide of Barium.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
the nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
-
In order to manufacture dioxide of barium (Ba02) under favorable industrial
conditions, it is necessary to pass a current of air or of oxygen over anhydrous
baryta (Ba0) which is as porous and as pure as possible, and at a dull red heat.
If the baryta is not porous or if it is compact, or is not pure, a poor and impure
dioxide of barium is obtained, and one which is not suitable for the uses for which
such product is intended.
Hitherto, in order to obtain this porous, anhydrous baryta, adapted for yielding
a rich dioxide of barium (82 to 90 per cent. of purity), nitrate of baryta has been
taken as the primary substance. By calcination of this nitrate, a porous and

page_text: relatively pure anhydrous baryta is obtained, upon which a current of air is caused
to pass at a dull red heat.
Numerous attempts have been made to obtain an anhydrous baryta, pure and
porous, without employing nitrate of baryta because the element nitre is rela-
tively costly and is completely lost in the cycle of operations. Thus attempts
have been made to dioxidise an anhydrous baryta obtained by the calcination of
carbonate of baryta, but this, being dense and but very slightly porous, gives a
poor dioxide of barium (about 6%). This process has therefore not been com-
mercially successful.
Our invention consists in employing as primary baritic substance, hydrated,
crystallized baryta, in order to obtain an anhydrous, porous and pure baryta.
We will not describe any process for the manufacture of hydrated baryta; the
essential point is to employ a product which is as pure as possible..
The hydrated baryta contains water the greater part of which may be expelled
at a relatively low temperature, but the last remainder of this water, that which
is termed "water of composition," it has not hitherto been possible to eliminate
by a commercially practicable process giving a porous, anhydrous oxide of barium,
capable of becoming dioxidised at a high standard of purity.
Now the essential, novel and characteristic feature of our invention consists
in the application of the reducing energy acquired by carbon in a finely divided
condition, when its action upon hydrate of baryta takes place at a suitable
temperature.
This operation of reduction may take place in ovens, muffles or retorts, but we
have obtained the best results by operating within a crucible of plumbago or
other refractory substance, provided with a lid and lined internally with a wall
or layer of specially prepared agglomerated, organic substance. This lining
assumes the form of the crucible as the calcination of the carbon, which forms
its framework or scaffolding so to speak, proceeds, and resists equally with the
crucible itself the high temperature employed. The crucible, in these conditions
with its double wall, regulates the operation and prevents any injurious oxidising
action, in such a manner that the hydrate of baryta is transformed rapidly and
integrally into anhydrous oxide of barium which is of great purity and extremely
porous, owing to which it is readily dioxidisable.
This combination of circumstances enables the action of carbon upon hydrated
baryta to be carried out industrially without corrosion of the crucibles or loss of
material, which constitutes an important feature.
The dehydration of baryta by means of carbon is a novel and characteristic
feature; it is well known that the "water of combination" of hydrate of baryta
could not hitherto be eliminated, by means of an industrially practicable process,
with the production of a pure, porous and anhydrous baryta.
In order to carry out this operation practically we proceed in the following
manner―
We take hydrated baryta, either crystallized or not, but as pure as possible;
we mix this intimately with an equivalent of carbon (about six kilogrammes of
pure carbon for 157 kilogrammes of pure crystallized baryta). Carbon of any
kind may be employed, provided it be as pure as possible, such as coal, lamp-
black, coke-dust, vegetable charcoal, or in short any substance capable of giving
carbon by calcination; it should be added that care should be taken to employ
these carboniferous substances in an infinitely divided condition if they are solid.
This having been done, we heat this mixture in basins of sheet, cast or
enamelled cast metal for two or three hours at a temperature of 100° to 150° C.,
thereby producing fusion of the mass and ebullition, finally giving a solid
blackish mass, more or less completely dried. The greater portion of the water
is thus removed.
We then prepare a crucible of plumbago, refractory earth or other substance
in the following manner: We arrange at the bottom of this crucible and over
the whole of its internal walls a sheet of card board which forms an internal

page_text: lining of the crucible. The magma obtained in the manner above described is
placed therein, and a piece of cardboard is then placed upon this magma, a cover
being finally placed upon the crucible which will allow the gases produced to
escape. The crucible is then introduced into an oven and heated to a bright red
(about 1000° to 1200° C.) for from five to eight hours, after which it is allowed
to cool, either in the oven or after removal from the same.
When the crucible has cooled, there is in it a mass of anhydrous oxide of
barium, extremely porous and of a greyish colour, which may be completely
detached from the carbonised skeleton left by the organic covering above referred
to. There is thus removed from the crucible:.
1. A mass of oxide of barium excellently adapted for dioxidation, and
2. Carbonised debris.
The size of the crucibles may vary; they may be of sufficient size for industrial
operations.
A modification of this method of operating consists in heating by itself in cast
metal basins, either enamelled or not, crystallized hydrated baryta, in such a
manner as to drive off the greater part of its moisture, and then to mix it with
finely divided carbon, subsequently heating it in the crucible as above described.
This does not, however, in anyway alter the characteristic reaction and we prefer
to first of all mix the carbon with the crystallised baryta, as above stated.
If necessary the operation of desiccation and of reduction could also be effected
in the same apparatus (muffle, retort, crucible, oven or the like) but it is prefer-
able to operate separately in the manner already described.
In
The anhydrous baryta thus obtained in the crucible is very porous and of great
purity, and it only remains to crush it superficially in order to dioxidise it.
this crushed condition it is eminently adapted for dioxidation.
This operation is effected in the manner usual in dioxide manufacture, which
commences with oxide of barium obtained by the calcination of nitrate, that is
to say, this superficially crushed anhydrous baryta is introduced into iron tubes
heated to a dull red and which are maintained at this temperature for some hours,
air which has been freed as much as possible from its carbonic acid and its
humidity being caused to pass over the mass. Oxygen may be substituted for air.
When this operation is terminated a whitish mass is withdrawn from the tubes;
this is dioxide of barium at from 86 to 94% of purity and containing fewer
impurities than dioxide of barium manufactured by the processes hitherto
employed. It is not, in fact, contaminated by the substances composing the ovens
or basins employed for the calcination of nitrate of baryta.
An important point in this process of manufacture is the care with which we
insert within the crucible a lining of a substance capable of giving at a high
temperature a carbon envelope which isolates the baritic mass. from the material
of the crucible. We do not indicate any special organic substance, those which
may be employed being very numerous; however we may cite as examples, card-
board, paper, wood pulp and sheets of various vegetable fibres, and finally, lining
the crucible with carbon.
By the use of this carbon envelope we obtain a mass of baryta which is not
contaminated by the various substances entering into the composition of the
crucibles on the other hand, the block becomes more readily detached at the
termination of the operation, and finally it forms an envelope which is almost
tight and which facilitates the reaction."
The two principal advantages of our process are the following:
a. More economical manufacture, because we avoid the losses occasioned by
the employment of nitrous elements whilst at the same time employing primary
substances of low cost and which may be readily procured. We also obtain a
high rate of yield in our various operations, thereby still further reducing the cost
of production.
b. We obtain a dioxide of barium which is rich and more pure than dioxide
of barium manufactured by the processes hitherto employed.

page_text: Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, as communicated to me by my
foreign correspondents, I declare that what I claim is;-
1. In the manufacture of dioxide of barium, and commencing with hydrated
baryta, the novel process above described consisting in intimately mixing an equi-
valent of hydrated baryta with an equivalent of carbon in a finely divided
condition, in raising this mixture first of all to the temperature of about 150° C.
for the purpose of driving off the greater part of the water, in then placing this
desiccated magma in a crucible of plumbago or other refractory substance lined
internally with a carboniferous substance or one capable of yielding carbon, in
then heating this crucible to a high temperature for the purpose of enabling the
complete transformation of the hydrated baryta into anhydrous and porous baryta
owing to the reducing action of the finely divided carbon, intimately mixed with
the mass, upon the remaining elements of water, and finally dioxidising this
anhydrous baryta by means of the processes usually employed.
2. In the manufacture of dioxide of barium the use of the modified methods of
production herein before described.
Dated this 24th day of Santember 1808
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.