Double Fluoride with Sodium or Potassium, of Aluminium.
Year: 1885

page_text: Double Fluoride with Sodium or Potassium, of Aluminium.
I LORENTZ ALBERT GROTH K.G.V. Civil Engineer and Proprietor of the
Patent Industrial and Financial Agency 30 Finsbury Pavement London E.C. do
hereby declare the nature of said invention for "A NEW OR IMPROVED METHOD
OF MANUFACTURING THE FLUORIDE OR DOUBLE FLUORIDE WITH SODIUM OR
POTASSIUM OF ALUMINIUM a communication to me from abroad by Richard Grätzel
Chemical Manufacturer of 25 Glocksee Strasse in the City of Hanover German
Empire to be as follows:--
The object of this invention is the manufacture of fluorides of aluminium &
double fluorides of aluminium and potassium or aluminium and sodium as well as
the corresponding fluoride of beryllium from fluorides of alkali metals and
chlorides of aluminium or beryllium.
It consists in mixing a watery solution of fluoride of sodium or potassium with
a watery solution of chloride of aluminium and according as either 1st single
fluoride of aluminium or 2nd double salts of fluoride of aluminium with fluoride of
sodium or potassium are required the following proportions are to be used, viz
Through the 2nd combination is obtained artificial' sodium or potassium-cryolite.
In both cases the newly formed fluoride is precipitated and separated from the
solution of chloride of potassium or sodium and then washed with water.
Price 4d 1

page_text: It will be easily understood by chemists that the proportion as given in (2) can
be varied in order to obtain correspondingly varied double salts.
Fluoride of aluminium can be manufactured from natural combinations of fluorine
for instance cryolite so as to leave the mineral in a powdered condition with a
watery solution of chloride of aluminium.
By doing so the mineral changes for instance the fluoride of alkali in cryolite
with the chloride of aluminium changes into fluoride of aluminium and chloride
of alkali while the fluoride of aluminium already present remains and forms with
the newly prepared substance an unsoluble settling which is then separated and
washed with water.
Combinations of fluoride of beryllium are manufactured in the same way.

page_text: D NOW proved to I actig
Double Fluoride with Sodium or Potassium, of Aluminium.
I, LORENTZ ALBERT GROTH K.G.V., Civil Engineer and Proprietor of the
Patent Industrial and Financial Agency 30 Finsbury Pavement London E.C., do
hereby declare the nature of said invention for "A NEW OR IMPROVED METHOD
OF MANUFACTURING THE FLUORIDE, OR DOUBLE FLUORIDE WITH SODIUM OR
POTASSIUM, OF ALUMINIUM," and in what manner the same is to be performed,
as communicated to me from abroad by Richard Grätzel, Chemical Manufacturer,
of 25 Glocksee Strasse in the City of Hanover, German Empire, to be particularly
described and ascertained in and by the following statement :—
The object of this invention is the manufacture of fluoride of aluminium and
double fluorides of aluminium and potassium, or of aluminium and sodium, as well
as the corresponding fluorides of beryllium, from fluorides of alkali-metals and
chloride of aluminium. The invention also involves the production of fluoride of
aluminium whether alone or in combination with an alkalic fluoride from certain
natural compounds of fluorine, for instance cryolite, by means of chloride.of
aluminium.
In case a simple fluoride of an alkali-metal is to be used in the process, this
substance as well as the aluminium chloride (which are both soluble) are dissolved
in water, which may be warm or cold, and the solutions mixed together. By double
decomposition fluoride of aluminium and alkalic chloride will then be formed, the
former of which, being insoluble, falls to the bottom. The precipitate is separated
from the liquid and washed with water if required.
The proportion in which the said substances should be employed in order to
produce, by their action on each other, simple salts, are 6 chemical equivalents of
alkalic fluoride to 1 equivalent of aluminium chloride. With sodium fluoride the
process will then come off according to the equation :
6 Na F+ Al, Cl = Al, F +6 Na Cl.
In case a greater relative quantity of alkalic fluoride is employed, the exceeding
portion will combine with the aluminium fluoride produced, or a portion thereof,
to form a double or compound salt of the constitution of cryolite. Thus with
12 equivalents of sodium fluoride instead of 6 equivalents, as before, the process
taking place will be as follows:
12 Na F + Al, Cl = (Al, F + 6 Na F) + 6 Na Cl.
6
The proportion in which the two substances are mixed, may however be varied
for the purpose of producing double salts containing more or less fluoride of
aluminium.
When a compound fluoride of aluminium and of an alkali-metal, such as
cryolite, is to be subjected to the treatment with aluminium chloride, in view of
producing simple aluminium fluoride, it is finely powdered and mixed with a
solution of aluminium chloride containing so much of this salt as is required to

page_text: decompose the whole of the alkalic fluoride contained in the compound fluoride.
With native cryolite (Al, F. + 6 Na F) the reaction may be rendered by the
equation
8
2
0
(Al, F, 6 Na F) + Al, Cl, =2 Al, F, + 6 Na Cl.
That is to say, the fluoride of sodium in the cryolite is transformed by the chloride
of aluminium into fluoride of aluminium and chloride of sodium, while the fluoride
of aluminium already present remains and forms, with the newly produced like
substance, an insoluble precipitate, which is then separated from the solution of
chloride of sodium and washed, as before.
In this case one equivalent of the aluminium chloride has been supposed to be
employed with one equivalent of the compound fluoride. But if the quantity of
the chloride used is less in proportion to the latter, only a portion of the alkalic
fluoride will be transformed into aluminium fluoride, and a modified compound
fluoride will be obtained, which contains a higher percentage of aluminium fluoride
than the original salt. Thus with three equivalents of cryolite (in powdered state)
and one equivalent of aluminium chloride, dissolved in water, a compound fluoride
will be produced, containing twice as much aluminium fluoride as the cryolite.
This is shown by the equation:
3 (Al, F +6 Na F) + Al, Cl
=
(4 Al, F12 Na F) + 6 Na Cl.
In similar manner as the fluoride of aluminium and the compound fluorides of
aluminium and alkali-metals, the corresponding salts of beryllium may be produced,
but I do not claim the process in so far as it relates to these.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my correspondent, I declare that what I claim is
1. The process of causing aluminium chloride to act in solution on an alkalic
fluoride, and of separating the precipitate obtained from the liquor, substantially
as and for the purpose described.
2. The process of causing a solution of aluminium chloride to act on an alkalic
fluoride combined with aluminium fluoride, and of separating the solid from the
liquid portion, substantially as and for the purpose specified.
Dated this 5th day of January 1885