Improvements in the Preparation or Manufacture of Borax.
Year: 1897

page_text: Date of Application, 26th Apr., 1897
Complete Specification Left, 26th Jan., 1898-Accepted, 12th Mar., 1898
PROVISIONAL SPECIFICATION.
Improvements in the Preparation or Manufacture of Borax.
We, CHARLES MASSON, of Gembloux (Namur), and CHARLES TILLIERE, of 57, Rue
Botanique, Brussels, both in the Kingdom of Belgium, Chemists, do hereby declare
the nature of this invention to be as follows:-
This invention relates to a novel process for the preparation or manufacture of
borax and to apparatus therefor.
Hitherto in the manufacture of borax carbonate and bicarbonate of soda havé
been employed for the purpose of causing the lime of the mineral to pass into the
form of insoluble carbonate. But with this mode of treatment the vehicle of
the carbonic acid (soda) was not recoverable and certain minerals, too rich in
chloride and sulphate of sodium and in calcium sulphate, could not be utilised
economically.
In the process forming the subject of this invention we substitute for the soda,
another vehicle for the carbonic acid which is easily recoverable and which enables
those substances, namely, chloride of sodium, sulphate of sodium and sulphate of
calcium formerly considered injurious and non-utilisable to be utilised. To this
end we wholly or partially employ carbonate or bicarbonate of ammonia separately
or together instead of carbonate and bicarbonate of soda for the purpose of causing
the lime of the mineral to pass into the form of insoluble carbonate and we obtain
the element sodium directly from chloride of sodium.
We have found that if any mineral containing boracic or boric acid (Bo₂ 03)
combined with alkaline and other earths be acted upon by a mixture of neutra!
carbonate of ammonia and bicarbonate of ammonia, the boric acid is converted
into biborate of ammonia soluble in water and the alkaline or other earth becomes
converted into the corresponding insoluble carbonate.
The biborate of ammonia obtained in the manner described above is converted.
into biborate of soda by the chloride of sodium or the sulphate of sodium in the
presence of an excess of ammonia and in accordance with a well known reaction.
In carrying out our invention we employ a distilling column into which is fed a
solution containing the ammoniacal salt which yields ammonia at the lowest market
price, and we generate by means of quick lime, the quantity of ammonia necessary
for attacking the first charge of the mineral. This ammonia is passed into a
quantity of water which will serve as the solvent in the manufacture and after the
operation will constitute the first mother liquor.
This water is contained in an absorbing apparatus and after it has dissolved the
required quantity of ammonia, it is passed into a digester into which there is
forced a quantity of carbonic acid preferably obtained from a lime-kiln or from the
combustion of the fuel in the generators. The apparatus is gradually heated to a
moderate temperature. The charge of mineral is then put in and after the digester
has been closed it is put under pressure and maintained thereunder for some time.
The charging is commenced at about 30° C. and will finish at about 60° C. and

page_text: the digester must then be immediately removed (a higher temperature with an
open digester would cause a very considerable loss of carbonic acid and of ammonia
by reason of the dissociation of the bicarbonate of ammonia).
In an operation for treating say 5000 kilogrammes of pandermite (borate of
calcium of Asia Minor) giving 46 per cent. of anhydrous boric acid for example,
and containing this acid in the form of sesquiborate of lime, it is necessary in
order to obtain a complete reaction to employ heat, whilst vigorously agitating,
for about five hours at a working pressure of about two atmospheres.
After the reaction the contents of the digester are transferred to filter presses, the
cake deposits are washed and the liquor or filtrate is allowed to flow into a reaction
chamber; the desired quantity of chloride of sodium is then introduced into the
warm liquor in the chamber, the whole being at the same time agitated.
After the complete solution of the chloride of sodium, the liquor is retained in
the chamber for about an hour; a little water containing caustic ammonia is then
added to ensure a slight excess of the latter and to thus prevent the chloride of
ammonia generated from reacting upon the biborate of sodium formed to give
biborate of ammonia and chloride of sodium.
The contents of the reaction chamber are then allowed to flow, for example, into
crystallisers.
After cooling, the mother liquid is again used in the process by being passed into
the absorber, herein before described, wherein it is charged with the quantity of
ammonia necessary for re-treating a fresh charge of mineral.
After several operations the mother liquors become charged with chloride of
ammonia and no longer give commercial crystals. It is then necessary to remove
these mother liquors after the recovery of their ammonia which occurs in the form
of neutral carbonate of ammonia, of bicarbonate of ammonia, of chloride of
ammonia, of sulphate of ammonia and of biborate of ammonia. The boric acid is
simultaneously recovered, the said acid occurring in the form of sodium biborate
and of ammonium biborate.
To effect this recovery, the mother liquor is poured into the distilling column
above described. Upon the upper plates of this distilling column, the mother
liquor, after preliminary heating, is deprived of its neutral carbonate of ammonia
and of its bicarbonate of ammonia which are disengaged by volatilisation. In the
central portion of the distilling column, the same mother liquor is subjected to
the action of a fixed base preferably lime as in the example given above, which
lime, by acting upon the ammoniacal salts remaining, produces volatile ammonia
and the corresponding salts of lime, viz., carbonate of lime, sulphate of lime,
insoluble borate of lime and soluble chloride of lime. The lime by acting upon
the biborate of soda produces insoluble borate of lime and caustic soda. Finally
the mother liquor passes down into the lower part of the chamber or column and is
heated by a steam coil to be deprived of its last traces of ammonia. It is there
reduced to a solution of chloride of calcium and, after filtration, is removed.
The fixed residue in the column consists of a mixture of lime, borate of lime,
sulphate of lime and carbonate of lime. This residue is again used as poor
mineral.
The radical $0, in this cycle of operations is continuously reintroduced into the
.circulation and we obtain, after the lapse of a certain time, as a fixed residue in
the distilling column, an agglomerate increasingly rich in sulphate of lime. When
the amount of the sulphate of lime has reached from 25 to 30 per cent. of the
dry substance it is necessary to cease reintroducing the radical SO, into the
.circulation.
To this end our invention also consists in subjecting the agglomerate which
contains more than 25 to 30 per cent. of sulphate of lime in its dry state to a
treatment which also effects the recovery of the vehicle of the carbonic acid designed
to convert the sulphate of lime, that is to say, we treat the agglomerate in a cold
manner with neutral ammonium carbonate. The sulphate of lime produces soluble

page_text: sulphate of ammonia and insoluble carbonate of lime. The lime forms insoluble
carbonate of lime and ammonia.
The borate of lime is scarcely attacked. The mass is filtered and the separated
precipitate is reintroduced into the process as mineral being a mixture of carbonate
of lime and of borate of lime.
The filtrate is a solution of sulphate of ammonia which is treated separately in
the distilling column with quick lime so as to form insoluble sulphate of lime and
volatile ammonia which is set free and recovered. The water and the fixed residue
are removed.
Although we do not confine ourselves to any particular modification in carrying
out our process we, preferably, first react upon the borate of lime by means of
carbonate of ammonia and of bicarbonate of ammonia in a digester and then treat
with the biborate of ammonia and chloride or sulphate of sodium in another
vessel, viz., the reaction chamber.
We have heretofore only described the treatment of minerals such as the minerals
of Asia Minor or the like which do not contain chloride of sodium but the same
modus operandi can be applied to other minerals containing chloride of sodium.
such as the boronatrocalcites.
It is to be noted that the chloride of sodium contained in these minerals and
hitherto considered as a deleterious substance, because it renders the mother liquors.
impure, becomes in our process a useful substance and reduces the quantity of
sodium chloride necessary to be provided for producing the borax. It will also be
obvious that during the treatment of the boronatrocalcites, there is in the digester
chloride of sodium in contact with bicarbonate of ammonia and neutral carbonate
of ammonia. The formation of a certain quantity of carbonate of soda and of
bicarbonate of soda cannot be avoided but owing to the constant rise of temperature
in the digester the said temperature attaining 130° to 135° C. the carbonate of soda
and the bicarbonate of soda which are formed become destroyed by contact with
chloride of ammonium. Experience has shewn that this reaction takes place even
at ordinary temperatures. It is certain that the accidental carbonate of soda and
bicarbonate of soda will scarcely have time to react upon the mineral and that the
conversion of the latter will be effected exclusively by the carbonate of ammonia.
and the bicarbonate of ammonia.
We would also point out that our process may be somewhat modified as the
same results can be obtained with sulphurous acid by using sulphite or bisulphite
of ammonia or both simultaneously for the purpose of causing the lime of the
mineral to pass into the form of an insoluble salt of ammonia.
The vehicle of the sulphurous acid will be recoverable as is the case when
carbonate or bicarbonate of ammonia is employed. This particular modus operandi
would be particularly advantageous in the case where sulphurous acid could be
produced more economically than carbonic acid, for instance by utilising certain
gases obtained in another manufacture and which would otherwise be lost or.
wasted.
The reaction is analogous to the reaction with the carbonate or the bicarbonate.
of ammonia, the boric acid of the mineral being converted into biborate.
of ammonia soluble in water and the alkaline or other earth passing into the form
of the corresponding insoluble sulphite. The succession of operations also remains
the same as herein before described. It is to be noted that with this modification
of our process sulphite of lime is produced which may be advantageously utilised
as an antiseptic.

page_text: Improvements in the Preparation or Manufacture of Borax.
We, CHARLES MASSON, of Gembloux (Namur), and CILARLES TILLIÈRE, of 57, Rue
Botanique, Brussels, both in the Kingdom of Belgium, Chemists, do hereby declare
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:-
This invention relates to a novel process for the preparation or manufacture of
borax and to apparatus therefor.
Hitherto in the manufacture of borax the salts of soda have been employed for
the purpose of causing the lime of the mineral to pass into the form of insoluble
salt. But with this mode of treatment the vehicle (soda) of the acid to be combined
with the lime of the mineral was not recoverable. Moreover, in this process
certain minerals, too .rich in chloride and sulphate of sodium and in calcium
sulphate, could not be utilised economically.
;
i
In the process forming the subject of this invention we substitute for the soda
another vehicle for the acid which serves to form the insoluble salt of lime, which
vehicle is easily recoverable and which enables those substances, namely, chloride
of sodium, sulphate of sodium and sulphate of calcium formerly considered injurious-
to be utilised. To this end we wholly or partially employ, as a type of precipitant,
a salt of ammonia instead of the salts of soda heretofore employed and we obtain
the element sodium directly from chloride. of sodium.
We have found that if any mineral containing boracic or boric acid (Bo, O.)
rombined with alkaline and other earths be acted upon by a suitable ammoniacal
salt, the boric acid is converted into biborate of ammonia soluble in water and the
alkaline or other earth becomes converted into the insoluble salt corresponding to
the acid for which the ammonia has served as a vehicle.
Such is the case, for example, if the mineral be acted upon by a solution of
carbonate of ammonia or sulphite or bisulphite of ammonia; the reaction then
produces biborate of ammonia and carbonate, bicarbonate, sulphite or bisulphite
of lime, etc.
In the example hereinafter given of the manner of carrying our invention into
practice we will take, as a type, the reaction of carbonate and bicarbonate of
ammonia.
It is to be noted that simultaneously with the herein before described reaction
there occurs the reaction of the corresponding salt of soda--for example
bicarbonate of soda, and even carbonate of soda if carbonate and bicarbonate of
ammonia be used when boronatrocalcites, that is to say, minerals containing
chloride of sodium, are subjected to the action of carbonate and bicarbonate of
ammonia and also that under certain but not economical conditions, bicarbonate of
ammonia alone if, for example, this salt be employed, could effect the transforma-
tion. Under the same conditions if the boronatrocalcites are employed a mixture
of bicarbonate of soda and of bicarbonate of ammonia effects the reaction; these
particular conditions would be attained if the ammoniacal solution designed to
bring about the reaction is saturated with carbonic acid, the said saturation being
carried to such a degree as to convert the carbonate of ammonia existing in the
solution into bicarbonate.
The biborate of ammonia obtained in the manner described above is converted
into biborate of soda by the chloride of sodium or the sulphate of sodium in the
presence of an excess of ammonia and in accordance with a well known reaction.
The accompanying drawing is a sectional view illustrating an apparatus suitable
for the manufacture of borax by our improved process and enabling the successive

page_text: be fully nderstocu
operations to
economical commercial result and the simultaneous recovery of the ammonia and
the boric acid.
By means of a distilling column A into which is fed a solution containing the
ammoniacal salt which yields ammonia at the lowest market price we generate, by
means of quick lime, the quantity of ammonia, necessary for attacking the first
charge of the mineral. This ammonia is passed into a quantity of water which at
the start will serve as the solvent in the manufacture and, after the operation, will
constitute the first mother liquor.
This water is contained in an absorbing apparatus B and after it has dissolved the re-
quired quantity of ammonia, it is passed into a digester C into which there is forced a
quantity of carbonic acid preferably obtained from a lime-kiln or from the com-
bustion of the fuel in the generators. The apparatus is gradually heated to a
moderate temperature. The charge of mineral is then put in and after the
digester C has been closed it is put under pressure and maintained thereunder for
some time.
The charging is commenced at about 30° Centigrade and will finish at about
60° Centigrade and the digester must then be immediately removed (a higher
temperature with an open digester would cause a very considerable loss of carbonic
acid and of ammonia by reason of the dissociation of the bicarbonate of ammonia).
In an operation for treating say 5000 kilogrammes of pandermite (borate of
calcium of Asia Minor). giving 46 per cent. of anhydrous boric acid for example,
and containing this acid in the form of sesquiborate of lime, it is necessary in
order to obtain a complete reaction to employ heat, whilst vigorously agitating, for
about five hours at a working pressure of about two atmospheres.
After the reaction the contents of the digester are transferred to filter presses D),
the cake deposits are washed and the liquor or filtrate is allowed to flow into a
reaction chamber E; the desired quantity of chloride of sodium is then introduced
into the warm liquor in the chamber, the whole being at the same time agitated.
After the complete solution of the chloride of sodium, the liquor is retained in
the chamber for about an hour; a little water containing caustic ammonia is then
added to ensure a slight excess of the latter and to thus prevent the chloride of
ammonia generated from reacting upon the biborate of sodium formed to give
biborate of ammonia and chloride of sodium.
The contents of the reaction chamber are then allowed to flow, for example, into
crystallisers G.
After cooling, the mother liquor is again used in the process by being passed into
the absorber B, hereinbefore described, wherein it is charged with the quantity of
ammonia necessary for re-treating a fresh charge of mineral.
After several operations the mother liquors become charged with chloride of
ammonia and no longer give commercial crystals. It is then necessary to remove
these mother liquors after the recovery of their ammonia which is in the form of
neutral carbonate of ammonia, of bicarbonate of ammonia, of chloride of ammonia,
of sulphate of ammonia and of biborate of ammonia. The boric acid is simul-
taneously recovered, the said acid being in the form of sodium biborate and of
ammonium biborate.
To effect this recovery, the mother liquor is poured into the distilling column A
above described. Upon the upper plates of this distilling column, the mother
liquor, after preliminary heating, is deprived of its neutral carbonate of ammonia
and of its bicarbonate of ammonia which are disengaged by volatilisation. In the
central portion of the distilling column, the same mother liquor is subjected to the
action of a fixed base, preferably lime, as in the example given above, which lime,
by acting upon the ammoniacal salts remaining produces volatile ammonia and the
corresponding salts of lime, viz., carbonate of lime, sulphate of lime, insoluble borate
of lime and soluble chloride of lime. The lime by acting upon the biborate of
soda produces insoluble borate of lime and caustic soda. Finally the mother liquor
passes down into the lower part of the chamber or column and is heated by a steam

page_text: .
coil to be deprived of its last traces of ammonia. It is there reduced to a solution
of chloride of calcium and, after filtration, is removed.
The fixed residue in the column consists of a mixture of lime, borate of lime,
sulphate of lime and carbonate of lime. This residue is again used as a kind of
poor mineral.
The radical $ 0, in this cycle of operations is continuously reintroduced into the
manufacture and we obtain, after the lapse of a certain time, as a fixed residue iu
the distilling column A, an agglomerate increasingly rich in sulphate of lime.
When the amount of the sulphate of lime has reached from 25 to 30 per cent. of
the dry substance of this agglomerate it is necessary to cease reintroducing the
radical SO, into the circulation.
To this end our invention also consists in subjecting the agglomerate which
contains more than 25 to 30 per cent. of sulphate of lime in its dry state to a
treatment which also effects the recovery of the vehicle of the carbonic acid
designed to convert the sulphate of lime, that is to say, we treat the agglomerate
in a cold manner with neutral ammonium carbonate. The sulphate of lime pro-
duces soluble sulphate of ammonia and insoluble carbonate of lime. The lime
forms insoluble carbonate of lime and ammonia.
The borate of lime is scarcely attacked. The mass is filtered and the separated
precipitate is reintroduced into the process as mineral being a mixture of carbonate
of lime and of borate of lime.
The filtrate is a solution of sulphate of ammonia which is treated separately in
the distilling column with quick lime so as to form insoluble sulphate of lime
and volatile ammonia which is set free and recovered. The water and the
fixed residue are removed.
We first react upon the borate of lime by means of carbonate of ammonia and
of bicarbonate of ammonia in a digester and then treat with the biborate of
ammonia and chloride of sodium in another vessel, viz., the reaction chamber.
By making the two operations wholly distinct from one another we ensure:
1. The action of the carbonate of ammonia and of the bicarbonate of ammonia
upon the borate of lime exclusively. The bicarbonate of soda and the neutral
carbonate of soda cannot take part in the reaction which is an advantage as the
action of the borate of lime is more complete with a mixture of carbonate of
ammonia and of bicarbonate of ammonia than with a mixture of carbonate of soda
and bicarbonate of soda.
2. When operating as described, the presence of the slight excess of ammonia
which should exist during the reaction of the sodium chloride upon the biborate of
ammonia.
If, on the contrary, the two reactions took place simultaneously, under such
conditions as would be simultaneously produced in the same apparatus, the excess
of ammonia which it would be necessary in this case to introduce into the absorber
would effect, on the introduction of carbonic acid into the digester, the conversion
of a certain quantity of bicarbonate of ammonia into the neutral carbonate of
ammonia. Caustic ammonia would no longer be present.
We do not confine ourselves to particular modifications in the carrying out of
our process such, for instance, as that wherein the liquor issuing from the filter is
conducted into the crystallisers in which case the crystals of ammonium biborate
separating out on cooling are re-introduced into the reaction chamber to be there
subjected to the action of chloride of sodium as above described. The mother
liquor having given crystals of ammonium biborate would pass into the absorber.
This mother liquor would contain a considerable portion of ammonium biborate
which on contact with ammonia would give neutral borate of ammonia yielding
with chloride of sodium neutral borate of soda. This method of operation would
give rise to economical disadvantages which any practical man would at once
appreciate.
We have heretofore only described the treatment of minerals such as the minerals
of Asia Minor or the like which do not contain chloride of sodium but the same

page_text: modus operandi can be applied to other minerals containing chloride of sodium
such as the boronatrocalcites.
It is to be noted that the chloride of sodium contained in these minerals and
hitherto considered as a deleterious substance, because it renders the mother
liquors impure, becomes in our process a useful substance and reduces the quantity
of sodium chloride necessary to be provided for producing the borax. It will also
be obvious that during the treatment of the boronatrocalcites, there is in the
digester chloride of sodium in contact with bicarbonate of ammonia and neutral
carbonate of ammonia. The formation of a certain quantity of carbonate of soda
and of bicarbonate of soda cannot be avoided but owing to the constant rise of
temperature in the digester the said temperature attaining 130° to 135° Centigrade
the carbonate of soda and the bicarbonate of soda which are formed become
destroyed by contact with chloride of ammonium. Experience has shewn that this
reaction takes place even at ordinary temperatures. It is certain that the acci-
dental carbonate of soda and bicarbonate of soda will scarcely have time to react
upon the mineral and that the conversion of the latter will be effected exclusively
by the carbonate of ammonia and the bicarbonate of ammonia.
When describing the treatment of borate of lime not containing chloride of
sodium, we stated that the two operations (the production of biborate of ammonia
and the conversion of the biborate of ammonia into biborate of soda) could be
effected simultaneously and in the same apparatus and we specified the dis-
advantages of this mode of operation. The same disadvantages also occur in this
case and it is advisable to separate the two operations.
Our novel process of manufacture of borax, has, in addition to the important
recovery results, the following advantages:-
1. The attack upon borates (alkaline earths and earths) by the mixture of
carbonate of ammonia and of bicarbonate of ammonia is more complete than by a
mixture of carbonate of soda and of bicarbonate of soda.
2. Loss of boric acid no longer takes place through the mother liquors saturated
with foreign salts. The recovery, by lime or by another fixed base, of the boric
acid, contained in these mother liquors in the form of a soluble borate is complete.
3. The substances, viz., chloride of sodium and sulphate of sodium which ordin
arily depreciate the value of the boronatrocalcites in our process become useful
substances.
4. By our process the poorest minerals related to the borate of lime and to the
boronatrocalcite classes can be treated.
5. During the treatment of boronatrocalcites and analogous minerals crystals of
commercial borax are obtained of the finest quality; in the ordinary process the
impurities of the mineral such as chloride of sodium and sulphate of sodium
become mixed with the mother liquors and give rise to imperfect crystallisation.
In our process, on the contrary, the chloride of sodium and the sulphate of
sodium are destroyed as they enter the process. By these means re-crystallisation
is avoided and the costs of manipulation and fuel, and other expenses are reduced.
We would point out that our process may be somewhat modified as the same
results can be obtained with sulphurous acid by using sulphite or bisulphite of
ammonia or both simultaneously for the purpose of causing the lime of the mineral
to pass into the form of an insoluble salt of ammonia.
The vehicle of the sulphurous acid will be recoverable as is the case when car-
bonate or bicarbonate of ammonia is employed. This modus operandi would be
particularly advantageous in the case where sulphurous acid could be produced more
economically than carbonic acid, for instance by utilising certain gases obtained in
other manufactures and which would otherwise be lost or wasted.
The reaction is analogous to that which separates, with carbonate or bicarbonate
of ammonia, the boric acid of the mineral being converted into biborate of ammonia
soluble in water and the alkaline or other earth passing into the form of the
corresponding insoluble sulphite. The succession of operations also remains the
same as hereinbefore described. It is to be noted that with this modification of

page_text: our process sulphite of lime is produced which may be advantageously utilised as
an antiseptic.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. A process for the manufacture of borax in which the sodium salts hitherto
employed are replaced by ammoniacal salts for the purpose of allowing of the
recovery of the vehicle of the acid serving to combine with the alkaline or other
earth, substantially as hereinbefore described.
2. In the herein described process for the manufacture of borax the employment
of carbonate or bicarbonate of ammonia as a vehicle for carbonic acid when this
acid is used to combine with the alkaline or other earth, substantially as set forth.
3. In the herein described process for the manufacture of borax the employment
of sulphite or bisulphite of ammonia as a vehicle for sulphurous acid when this acid
is used to combine with the alkaline or other earth, substantially as set forth.
4. In the process for the manufacture of borax claimed in Claim 1 the introduc-
tion of the sodium element by chloride of sodium or sulphate of sodium the said
element passing into the borax through the medium of biborate of ammonia
obtained by the process forming the subject of Claim 1, substantially as set forth.
5. In the process for the manufacture of borax claimed in Claim 1 the
simultaneous recovery of the boric acid and ammonia by lime or by any other fixed
base, substantially as set forth.
6. For carrying out the herein described process combined with the complete
recovery of the boric acid and ammonia-the whole in a continuous and complete
cycle of operations-the employment of a distilling column A and an absorber B
in combination with a digester, filter presses and a reaction chamber, substantially
as set forth.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants