AN IMPROVEMENT IN THE PROCESS OF MANU .FACTURING SODA AND POTASH
Year: 1858

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Mechanical Draughts-
man, for the Invention of "AN IMPROVEMENT IN THE PROCESS OF MANU
.FACTURING SODA AND POTASH,"-A. communication from M. le Chatelier,
Mining Engineer, of Paris, in the Empire of France.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton
at the Office of the Commissioners of Patents, with his Petition,, on the
2nd March 1858.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Mechanical Draughtsman, do hereby declare the
nature of the said Invention for "AN IMPROVEMENT IN THE PROCESS OF MANU
FACTURING SODA AND POTASH," to be as follows:-
-
This Invention has for its object the application of acids derived from fluor
(fluor spar) by. the agency of steam to the manufacture of soda and potash,
and of various salts which are the intermediate or accessory products
thereof.
To this end hydrofluo-silicic acid is prepared by causing steam to act at
a high temperature either in reverberatory furnaces, or in retorts of the form
of gas or zinc retorts, or other apparatus employed for heating matters in
closed vessels upon a mixture of fluate of lime (fluor spar) and silica or
siliceous matter.
The hydrofluo-silicic acid thus obtained may be collected in condensing

page_text: It
apparatus such as those employed in the manufacture of muriatic acid, or
brought into direct contact with the substances upon which it is to react.
may, if requisite, be concentrated by evaporation or distillation, to be employed
either for the purposes hereafter mentioned, or to be put into the market.
The hydrofluo-silicic acid, whether obtained by this means or by the ordi-
nary processes, is employed for the purpose of effecting the decomposition of
common or sea salt, either dry or in solution, or in the sea water. Hydro-
cliloric acid is by this means eliminated, and fluo-silicate of soda (double
fluoride of silicium and of sodium) is formed, which when a solution is acted
upon is precipitated and afterwards separated by decantation or filtration,
and dried if it be intended for the market. When sea water is acted upon
direct, the fluo-silicate precipitated may without disadvantage contain a small
quantity of potash.
Various products may be extracted from the fluo-silicate of soda by simple
means:-
Firstly, by causing the fluo-silicate to digest in the hot state with the
quantity of lime recessary for saturating both the fluor and the silicium, an
alkaline lye is obtained, which may be applied to any purposes for which
caustic soda is applicable, or which may be carbonated, by any known
processes.
The fluo-silicate of lime obtained, which.composes the residuum, will serve
for the preparation of hydrofluo-silicic acid.
Secondly, by causing fluo-silicate of soda to digest in the hot state with the
quantity of lime .necessary for taking up the fluor only, silicate of soda is
obtained, which is capable of being dissolved, and may be utilized in that
state or after dessication, or converted into carbonate of soda, and as a
residuum, fluoride of calcium, which may be employed for the production of
hydrofluo-silicic acid.
Thirdly, by heating at a low temperature the fluo-silicate of soda in an
atmosphere containing steam, the greater part of the hydrofluo-silicic acid will
be driven off, and may be collected by the processes already mentioned;
fluoride of sodium will remain, which may be converted into soda by means
of lime, or made commercially available for other purposes. Hydrofluoric
acid may, , if required, replace the hydrofluo-silicic acid by reason of the slight
solubility of the fluoride of sodium. The general processes indicated in this
Specification are equally applicable to it, provided it be prepared free from
contact with silica. The reactions above described may be applied to
potash.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Vincent Newton in the Great Seal Patent Office on
the 2nd September 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of March, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alfred Vincent Newton, Her special license, that I, the said Alfred
Vincent Newton, my executors, administrators, and assigns, or such others
as 1,the said Alfred Vincent Newton, my executors,administrators, and assigns,.
should at any time agree with, and no others, from time to time and atall times
thereafterduring the term therein expressed,should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "AN IMPROVE.
MENT IN THE PROCESS OF MANUFACTURING SODA AND POTASH," being a communi-
cation from M. le Chatelier, Mining Engineer, of Paris, in the Empire of
France, upon the condition (amongst others) that I, the said Alfred Vincent
Newton, by an instrument in writing under my hand and seal, should par-
ticularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alfred Vincent Newton, do hereby
declare the uature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement (that is to say):-
This Invention has for its object the application of acids derived from fluor
(fluor spar) by the agency of steam to the manufacture of soda and potash,
and of various salts which are the intermediate or accessory products thereof.
To this end hydrofluo-silicic acid is prepared by causing steam to act ata high
temperature (either in reverberatory furnaces or in retorts of the form of gas
or zinc retorts, or in other apparatus employed for heating matters in closed
vessels) upon a mixture of fluate of lime (fluor spar) and silica or siliceous
matter. The hydrofluo-silicic acid thus obtained may be collected in con-
densing apparatus, such as those employed in the manufacture of-muriatic-

page_text: acid. or brought into direct contact with the substances upon which it is to
react. It may, if requisite, be concentrated by evaporation or distillation,
to be employed either for the purposes hereafter mentioned or to be put
into the market.
The hydrofluo silicic acid, whether obtained by this means or by the
ordinary processes, is employed for the purpose of effecting the decomposition
of common or sea salt, either dry or in solution, or in sea water. Hydrochloric
acid is by this means eliminated, and fluo-silicate of soda (double fluoride of
silicium and of sodium) is 'formed, which, when a solution is-acted upon, is
precipitated, and afterwards separated by decantation or filtration, and dried
if it be intended for the market. When sea water is acted upon direct,
.the fluo-silicate precipitated may without disadvantage contain a small
quantity of potash.
Various products may be extracted from the fluo-silicate of soda by
simple means-
Firstly, by causing the fluo-silicate to digest in the hot state with the
quantity of lime necessary for saturating both the fluor and'the silicium, an
alkaline lye is obtained which may be applied to any purposes for which
caustic soda is applicable, or which may be carbonated by any known
processes. The fluo-silicate of lime obtained, which composes the residuum,
will serve for the preparation of hydrofluo-silicic acid.
Secondly, by causing fluo-silicate of soda to digest in the hot state'with
the quantity of lime necessary' for taking up the fluor only, silicate of sóda
is obtained which is capable of being dissolved, and may be utilized in that
state or after dessiccation, or it may be converted into carbonate of soda,
and as a residuum fluoride of calcium is obtained, and may be employed for
the production of hydrofluo-silicic acid.
Thirdly, by heating at a low temperature the fluo-silicate of soda in an
atmosphere containing steam, the greater part of the hydrofluo-silicic acid
will be driven off and may be collected by the processes already mentioned;
fluoride of sodium will remain, which may be converted into soda by means
of lime, or made commercially available for other purposes.
Hydrofluoric acid may, if required, replace the hydrofluo-silicic acid by
reason of the slight solubility ofthe fluoride of sodium. The general processes
indicated in this Specification are equally applicable to it, provided it be
prepared free from contact with silica. The reactions above described inay
be applied to potash.
In the above description, which includes all the points set forth in my
Provisional Specification, I have described the principal methods for-manu.

page_text: facturing soda and potassa industrially by means of the acids derived from
fluorine, these acids being either manufactured by the ordinary processes,
or with regard to one of them by a new process, which shews itself more
practically useful and advantageous on a large scale than when carried on
experimentally in laboratories.
I will now proceed to set forth, in addition to the above, such variations
in the process as the Inventor has found useful after carrying on various
careful experiments. I would observe that in the following description the
chemical formulæ are those adopted in France, in conformity to the observ-
ations and experiments of Mr. Gay Lussac.
i
With reference to the preparation of the hydrofluo-silicic acid, 'the ordi-
nary process consists in submitting a mixture of fluor spar (Ca Fl) and
silica (Si03) to the action of sulphuric acid (S 03), and this well-known.
process can be employed in soine cases, especially if the introduction of the
new method of manufacturing soda should lower the price of sulphuric acid.
The employment of sulphuric acid may be also rendered advantageous when
the sulphate of lime (forming the residuın) shall have any particular value,
for this material may be employed in place of plaster either for building or
agricultural purposes. When the residuum still contains an excess of
sulphuric acid, the latter may be extracted by washing, if there be no
advantage in leaving it in the residuum as when the latter is to be used for
agricultural purposes.
The process for preparing hydrofluo-silicic acid can be advantageously
modified so as to obtain some useful materials as intermediate products, which
may be valuable in industry or the arts. To this end the Inventor proposes,
instead of using silica under the form of siliceous sand, to employ feldspar,
porphyry, granite, in short, various natural rocks, containing, besides a large
proportion of silica and alumina, a tolerably large quantity of either potassa
or soda, or of both; but the Inventor prefers a rock in which potassa is in
excess. The mixture is to be heated until the whole of the fluo-silicic acid
(Si F13) or fluoride of silicium obtained by means of the action of concentrated
sulphuric acid is evolved and collected. For this purpose fluo-silicic acid is
to be put into vessels filled up with water, which requires to be stirred in order
to prevent the silica, which results from its decomposition, from settling into
a thick filmy paste. Fluo-silicic acid may be treated likewise according to any
other process suited to the manufacture of hydrofluo-silicic acid (3 (H Fl)
+ 2 (Si F13³), which is the chief product of this decomposition. One of the
processes consists in throwing a current of steam into the current of fluo-
silicic gas, so as to separate and levigate more easily the silica, which shrinks
.

page_text: up or collects itself more effectually. In this case the condensation of the
hydrofluo-silicic acid will take place in the same manner as the hydrochloric
acid. The residuum from the action caused by sulphuric acid is to be
levigated with boiling water, which will drive out the sulphate of alumina
and alkaline sulphates if the liquor contains the sulphate of potass, or if this
sulphate, or sulphate of ammonia be added, and the cooling of the liquor
will.at once give out crystals of alum.
The second method of manufacturing the hydrofluo-silicic acid employed
by the Inventor consists in submitting (in retorts like those employed for
manufacturing gas or zinc, or in a reverbatory furnace, or in any other
similar apparatus) to a very high temperature, a mixture of fluo spar and
silica or of siliceous materials, such as clay. In heating these materials by
means of a jet or current of steam, the reaction of the fluor spar on the silica
is facilitated, and owing to the excess of steam it determines (as soon as the
temperature of the gaseous mixture is sufficiently reduced) the formation of
hydrofluo-silicic acid, which is collected without any trouble arising from the
gelatinous silica, which partly remains in the retort or in the furnace, and partly
in the first compartments for condensation. The use of a reverberatory or.
puddling furnace has the advantage of allowing the surface of the materials
to be renewed.or stirred by means of the poker or fire iron.
The third method of manufacturing the hydrofluo-silicic acid consists in
melting a mixture of fluor spar with silica or siliceous materials, such as clay,
and, what is preferable, with natural silicates highly dosed with silica and con-
taining a rather large proportion of alkalies, such as feldspar, porphyry,granite,
and others, which render the mixture more fusible. The fusion may be done
in a smelting blast furnace, such as an ordinary blast cupola furnace, or any
other provided with cold or hot blast, the admixture being effected more or
less intimately according to the height and construction of the furnace. The
composition of the mixture or the proportions of the ingredients are calculated
according to the nature of the elements and to the proportion and nature of
the ashes of the fuel, so as to obtain a fusible slag, and, if possible,at the same
time,a complete reaction, which affords in the crucible of the furnace a melted
slag. Mixed with the gases from the combustion of the fuel is some gaseous
fluo-silicic acid, which will begin to decompose under the influence of the
moisture held in the fuel and in the materials to be operated upon. The
decomposition is completed either by wetting or damping the materials intro-
duced into the furnace, or by throwing in a thin stream of water or jet of steam.
The furnace of course is suitably arranged or covered in by an apparatus
suitable for the collection of gases,and it is within its empty receptacle, as well

page_text: as in the pipes or spaces before the condensing apparatus properly so called,
thatsteam injected from the outside or generated by the water poured into the
furnace completes the transformation of the fluo-silicic acid into hydrofluo-
silicic acid. Notice is required to be taken of the silica precipitated during.
this reaction, and which may remain in a more or less great proportion in the
charge; and as cast iron or lead and copper ores can be melted in a reverberatory
furnace, the mixture intended for the formation of the gaseous fluo-silicic acid
can be submitted likewise to the action of a high temperature in a reverberatory.
furnace in order to obtain by way of fusion the reaction of fluorine upon silica.
The transformation of fluo-silicic acid into hydrofluo-silicic acid can be
effected by means of water or steam out of the receptacle where the melting.
takes place. This modification of the third method can be combined with
the second, and steam can be intermittently injected into the furnace upon
the fused or pasty materials, or else water may be projected in its liquid
state in order to facilitate at the same time the working of the poker or
stirring iron and the renewal or stirring of the surfaces.
For the second and third process any fuel that is usually employed in
similar processes.in the arts can be used.
As in the third process, the fluor spar introduces a great proportion of
line into the dross, by using feldspathic rocks it is easy to obtain a dross
which will have more or less the composition of common glasses, and which'
could be added to the elementary materials for glass making if it is not
immediately used for blowing glass articles.
The condensation of hydrofluo-silicic acid vapours obtained in closed
apparatus will be effected in the second process exactly as in manufacturing
with closed apparatus hydrochloric acid. When these vapours are mixed
with the gases of combustion, it will be easy to proceed, as with the con-
densation of the muriatic acid produced under similar circumstances.
In every case it will be easy, through some mechanical contrivance, to
multiply the points of contact of that quantity of water which is to effect
the whole or partial condensation, so as to deprive the gases of the com-
bustion, as far as may be desired, of the hydrofluo-silicic acid which is
carried off by them. This method of condensation may, moreover, be
profitably modified by making use of an agent which either completes or
dispenses with the dissolving and cooling action of water, such as a solution
of sea salt or of the mother waters of sea- marshes, or of salt or sea water,
or some clay diluted in water, or such like substances:
In order to multiply the points of contact, several mechanical contrivances'
can be made use of; for instance, the liquor of condensation can be set into-

page_text: in
motion by means of stirring arms, or the liquid may be drawn up by means of
a pump, or any other hydraulic mechanism, and then let or thrown down in
the shape of very fine rain through the jet of gases, or the gases may be forced
very thin jets by means of a blowing engine or any analogous contrivance
through the liquid of condensation. In this special case is comprehended the
contrivance which would be intended to utilize the pressure of the blast in a
cupola furnace. The mechanical operation can be repeated in one or several
successive apparatuses through which the liquor of condensation would
successively pass in order to wash the gases arising from the combustion.
These gases being thus deprived, more or less completely, of the hydrofluo-
silicic acid carried off by them, may be burnt under boilers, evaporating
apparatus, concentrating or calcining furnaces, reverberatory furnaces, stoves,
&c., and after their combustion, whether the disengaged heat has been utilized
or not, they may act as sources of carbonic acid, in order to carbonate alkalios
or for any other purposes.
Whichever of these processes be adopted, the fluoride of calcium (Ca Fl)
used will be of course the fluor spar, which is to be found in nature in a more
or less pure state; the fluoride of calcium, which may be artificially formed
either by means of the methods herein described or by any other known
process, may also be used. The fluoride of calcium can be replaced either by
other fluorides, such as the fluoride of barium, by double natural or artificial
fluorides, such as cryolite, or by the fluo-silicates and mixtures of fluorides
and silica, precipitated simultaneously and in a state of intimate mixture.
The hydrofluo-silicic acid produced in a liquid state, if it has not been
condensed by its reacting upon the very materials into which it is to resolve,
can be concentrated by evaporation until that point where it would begin to
distil. The state of concentration in which it may be convenient to sell it
commercially for such applications as are known will usually be when the
liquid will contain about thirty to thirty-five per cent. of dry hydrofluo-silicic
acid.
In the preparation of the alkaline fluo-silicates the hydrofluo-silicic acid
combines itself with the bases in order to form salts, which are called fluo-
silicates; the combinations of this acid with soda and potassa are but very
little soluble in pure water or water containing an excess of hydrofluo-silicic
acid or muriatic acid. The hydrofluo-silicic acid, on the contrary, has the
property of forming with certain earths, such as alumina, magnesia, and
others, soluble fluo-silicates, which through double decomposition can be
used in order to prepare alkaline fluo-silicates.
From this it will be seen that two methods of preparing the alkaline

page_text: fluo-silicates may be adopted, both of which can supply some useful accessory
products.
I will now proceed to describe the reactions of these acids, and will take
soda as an example. I would, however, observe that I must also claim their
application to the treatment of potassa salts and to their preparation for
manufacturing the fluo-silicate of potassa. The hydrofluo-silicic acid can be
brought to react on a very dilute solution of sea salt, especially upon common
sea water; in this case it would be convenient to make use of the surplus sea
water employed for condensing the hydrofluo-silicic acid produced by the
fusion of the elementary materials in a cupola or reverberatory furnace. The
precipitate of fluo-silicate of soda (3Na Fl,) + 2 (Si Fl³,) will be collected
by means of deposition and decantation. In the mother water will remain
some free muriatic acid, which, owing to its feeble degree of concentration,
will not generally be collected with profit, but as at the same time the solution
will contain a certain quantity of fluo-silicate of soda, and if used in excess,
some hydrofluo-silicic acid, these mother waters may be brought into contact
with calcareous fragments, which little by little, through their reacting on
the fluo-silicate and fluo-silicic acid, will form some fluoride of calcium, which
will be deposited mixed with silica. This double reaction, and chiefly the
saturation of the muriatic acid, will give out some carbonic acid, which can
be turned to profit. The same method of operating is applicable to the
water supplied by brine springs. If it be required to diminish the bulk of
the apparatuses to be used, and the losses caused by the large quantities of
water in contact with the precipitates, the sali solution may be previously
concentrated and operated either by collecting in it the gaseous hydrofluo-
silicic acid or by the liquid acid; the residue will then be a solution more or
less concentrated of muriatic acid, which can be applied to several purposes,
and chiefly to one of the processes described in the present Specification.
Finally, the dry sea salt can be submitted to the action of concentrated hydro-
fluo-silicic acid, then the operation will follow, as in the manufacturing of
sulphate of soda and in similar utensils or apparatus. In this case the
muriatic acid will be collected in a state of sufficient.concentration to be
commercially sold, and will be condensed in the usual way.
In all cases the fluo-silicate should be levigated or washed, in consequence
of the sandy state in which it is found after simply drying it.
Alumina can be profitably made use of as an intermediate agent for the
manufacturing of the fluo-silicate of soda by means of mutual decomposition.
Magnesia, too, would act in precisely the same manner. The hydrofluo-silicic
acid is made to react either upon the alumina obtained during the manu-

page_text: facture, and which is incessantly regenerated, or when there is any profit
in selling the alumina thus obtained, upon common clays, refractory clays,
pipe and porcelain clays. It yields silica, which precipitates itself and forms
a soluble fluo-silicate of alumina, which is separated through decantation,
and is submitted to the contact of a sea-salt solution. Fluo-silicate of soda
is formed as well as chloride of aluminium (Al³, Cl³,) in 'solution, which is
separated; if it is not sufficiently concentrated, it is rendered so by evaporating
it to a proper consistence in a retort or in a reverberatory furnace; the
muriatic acid in a pure and concentrated state is thereby separated, and
alumina remains as a residuum.
The hydrofluo-silicic acid can be made to react upon feldspar or upon a
natural silicate with a pulverized alkaline basis, and besides the soluble fluo-
silicate of alumina some fluo-silicate of potassa or of soda, or fluo-silicate
of both, which remains with the silica, and the material unacted upon is
obtained as an accessory product.
.
The alumina obtained through this process can be deprived of iron, if
necessary, by adding in the solution of chloride of aluminium a convenient
proportion of yellow prussiate of potassa; but the best method consists in
treating it with a solution of caustic soda, resulting from the action of the
fluo-silicate of soda in the processes described in the present Specification,
or in melting it with kelp or with pure soda. It yields some aluminate of
soda, which being decomposed in its solutions by a current of carbonic acid
gas will thus give out some alumina perfectly pure.
The alkaline fluo-silicates can also be prepared by means of the hydrofluoric
acid (H FI,) obtained by the known methods (as engravers upon glass do) in
a cast-iron boiler with a head or cupola of cast iron, lead, or copper, by means
of the reaction of the sulphuric acid upon the fluor spar. The hydro-fluoric
acid may be condensed in order to be employed in a liquid state, but it will
turn out more advantageous to get it to act at once upon a clay kaolin or
feldspathic rock, pulverized or unpulverized, which will be deposited in the
vessel where the hydro-fluoric acid is condensed; care must be taken to stir
the liquor in order to renew the points of contact. Except the silica, which
has been used totally or partially for the formation of the fluo-silicates, the
same products will be obtained as when the hydrofluo-silicic acid is made to
act. When it is desired to obtain by this process hydrofluo-silicic acid free
from such matters in solution as alumina, the hydrofluo-silicic acid must be
agitated with sand or pulverized. quartz; this is, in many cases, a preferable
means of preparing it to that usually employed in laboratories.
apparatuses with sulphuric acid may also be arranged, one for disengaging
Two

page_text: fluoride of silicium or fluo-silicic gas, and the other hydro-fluoric gas. These
two products are brought into the same condenser, where they will produce
hydrofluo-silicic acid, the hydro-fluoric acid acting on the silica deposited by
the fluoride of silicium.
The hydro-fluoric acid may be made to act directly upon the sea salt or on
any soluble salt of soda, and yield some fluoride of sodium (Na, FI). This
salt can be used, as will be noticed subsequently, for manufacturing soda or
artificial cryolite. This reaction, which applies to soda, does not take place
with potassa, which gives a soluble fluoride, unless it be wanted to use it as
a method for separating both the alkalies, potassa and soda, from substances
in which they are intermingled.
One of the processes which is likely to fix most particularly the attention of
manufacturers consists in the use of muriatic acid obtained by whatsoever
process, and chiefly through an operation which is one of the chief objects of
the present Invention. This acid, more or less diluted with water and sea
salt, is mixed with fluoride of calcium, and in preference with the one
prepared in a previous operation, or artificially prepared by any method what-
soever; then with soluble natural or artificial silica, and by preference with
silica obtained in a previous operation, or by any other process. Instead of
silica, powdered feldspathic rocks can be used whenever potassa is wanted at
the same time as soda; or if it be desired to increase the production of soda,
the fluoride of calcium and silica can be replaced by an already formed
mixture of fluoride of calcium and silica obtained in a previous operation.
From the digestion of these materials, the mixture of which is heated by
throwing against the bottom of the vessel a jet or current of steam, or by any
other means used in the arts for heating liquids to a moderate temperature,
the following results may be obtained:―
First, fluo-silicate of soda mixed with fluo-silicate of potassa, if feldspathic
rocks with potassa as a basis has been used.
Secondly, chloride of calcium.
Thirdly, the muriatic acid, which has only, been employed in excess.
Instead of putting silica in the mixture, fluo-silicic acid may be brought
into it, which would give hydrofluo-silicic acid, and would supply the silica
necessary to the reaction. The muriatic acid which remains in excess mixed
with the chloride of calcium, and, if required, with the chloride of aluminium,
is used until the liquor is too overdosed with these chlorides, in order that the
operation may be rapid and economical. Whenever its use is done with, it
can be separated by distillation, and to the acid thus produced is added when
it occurs the one derived from the decomposition of the chloride of aluminium.

page_text: It is of no consequence if the deposited fluo-silicate is mixed with ingredients
that have not been acted upon, their presence adding no difficulty to those
reactions which will be subsequently described for extracting alkalies.
Excepting the case mentioned with regard to the direct action of the hydro-
fluoric acid upon sea salt, the present reactions are applicable to potassa, and
can be made use of as with soda for manufacturing the fluo-silicate; which
divides the alkali from the bodies with which it is combined.
1!
EXTRACTION OF THE
ALKALIES.
Lime and carbonate of lime, earths which show analogous, reactions, and
the use of which would be more expensive, are not mentioned, but lime and
carbonate of lime are the agents by means of which the alkalies isolated under
the form of fluo-silicates or fluorides can be brought to a state in uniformity
with the actual uses of commerce and industry; in future there may be some
direct applications found for the alkaline fluo-silicates or fluorides. ..
The fluo-silicate of soda submitted to the action offa moderate temperature
becomes converted into fluoride of sodium by abandoning the two-thirds of
fluo-silicic gas or the fluoride of silicium which enters into its composition.
This decomposition is rendered very easy, and very complete if a current of air
or other gas or of the vapour of water be made to pass over the matter.
The fluc-silicate of potash decomposes with more difficulty; it requires, a
higher temperature. The operation, is much facilitated by the intervention of
steam after having mixed the fluo-silicate with a certain quantity of coal to
protect the cast iron,.if it is in a vessel, of thin material that the process is
conducted. The alkaline fluoride is acted upon by an equivalent proportion
of chalk or carbonate of lime. The two materials are made to digest at a
moderate temperature, or even cold for fluorides, and an insoluble re siduum
of fluoride of calcium is obtained,.also an alkaline carbonate which, is made
to crystallize or is evaporated to dryness. In acting with, lime the result
would be an alkaline lye, and the preparation is so easy that this fluoride of
sodium could be purchased at once in order to prepare the soda lye whenever
soda is used in that state, and the natural fluor. spar is cheap.
t
The alkaline fluo-silicate is likewise acted upon by the carbonate of lime or
caustic lime. In the first case an alkaline carbonate and a mixture of, fluoride
of calcium and of gelatinous silica are obtained, which mixture can be brought
back into the rotation of the manufacturing processes without being in need of
isolating its elements.. In the second case, according to the proportion of lime
employed,some soluble silicate of sodaor potassa, with somefluoride of calcium
as a residue, or caustic soda or potassa with a mixture. of fluoride of calcium

page_text: and of silicate of lime as a residue will be obtained. The silicates of soda and
potassa are employed in the industrial arts, besides they can be deprived of
their silica by means of lime, or by means of a current of carbonic acid
obtained by the third manufacturing process for hydrofluo-silicic acid above
described, or by any other known process; the silica thus obtained will be
perfectly pure, easy to be collected, and levigated. This matter being entirely
free from iron, can be disposed of to manufacturers who require to use pure
silica, such as porcelain, colourless glass, or crystal manufacturers. It should
be understood that with regard to the washing of precipitates the best methods
in use for levigating as completely as possible with the least quantity of water
should be employed. The silica and the other dépcsits, such as fluorides
or fluo-silicates, can be separated from the largest portion of alkaline
matters which remain in it in the state of solution by the agency of a press
which will drive out almost all the liquid. For some operations, as the one
in which the muriatic acid acts a productive element, or for determining the
reaction, the alkaline matter left in the deposits will not be lost, and in no
case will its presence embarrass the operations. The Inventor also recom-
mends the use of a turbine or centrifugal hydro-extractor, either with the
mixture of fluoride of calcium and silica or with silica alone.
The hydrofluo-silicic acid, either pure or combined in the state of soluble fluo-
silicate, can be made use of to isolate soda or potassa whenever they are mixed
in a soluble combination with chlorides, acetates, etcera, and especially in bect-
root juices. In the last-named instance the excess of acid treated by a small
excess of carbonate of lime or of caustic lime, being constantly resolved into
fluoride of calcium and silica, or silicate of lime, which are totally insoluble,
will be easily driven out of the sweet liquors. The gelatinous silica, if it
happens to be produced, will favor the discoloration of the syrups, owing to
its absorbing nature. The alkaline fluo-silicate obtained in this operation
will be utilized, as has been already mentioned. The alkalies can likewise
be extracted from the brine waters of salt marshes, and if the mixture of
fluo-silicates can be reduced to the state of fluorides, potassa may
be sepa-
rated from soda, owing to the different solubility of these fluorides. The
potassa and the soda may also be separated in the state of fluo-silicates by
adding successively to the solution (suitably diluted with water) proper
quantities of hydrofluo-silicic acid equivalent to the proportion of each alkali.
Thus with the mother waters of marshes bordering on the Mediterranean
(when they are brought to a suitable state of dilution) all the potass may
separated before precipitating the soda.
The principles which have been developed in the present Specification lead

page_text: to an application which is the direct consequence or result thereof, for the
manufacture of the acetate of alumina. By causing hydrofluoric acid or
hydrofluo-silicic acid to react upon clays, kaolins, or other aluminiferous
matters, soluble fluo-silicates of alumina are obtained.
On the other hand, for the manufacture of acetic acid, the process is com-
menced by making the acetate of soda. By making the two salts react by
means of double decomposition a precipitate of fluo-silicate of soda will
be obtained, leaving an acetate of alumina in solution.
The fluo-silicate of soda may be employed for making salts of soda; it may
also be employed in the series of processes which have produced it by treating
it with sulphuric acid, or it will disengage the hydrofluo-silicic acid, which may
be again employed to produce fluo silicates of alumina; the sulphate of soda
may be used in the manufacture of acetate of soda.
Several other useful applications of these reactions might be pointed out,
but the whole of them depend or are based upon,-
Firstly, the principle herein set forth for the application of the acids
derived from fluorine to the preparation of alkalies.
Secondly, on the possibility of manufacturing on a large scale these acids,
and of making use of them whilst the elementary materials are continuously
regenerated.
Thirdly, on the reactions described in the present Specification, and which
could be varied under very different forms, according to the nature and
properties of the bodies that are employed in the various processes.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto
set my hand and seal, the Second day of September, in the year of
our Lord One thousand eight hundred and fifty-eight.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. V. NEWTON. (L.S.)