AN IMPROVED PROCESS FOR EXTRACTING ALUMINIUM FROM ITS COMPOUNDS, AND OBTAINING AT THE SAME TIME PROTOCHLORIDE OF MERCURY
Year: 1858

page_text: LETTERS PATENT to Luigi Ferrari Corbelli, of Florence, in the Grand
Duchy of Tuscany, Commander of the Order of Malta, for the Invention
of "AN IMPROVED PROCESS FOR EXTRACTING ALUMINIUM FROM ITS COMPOUNDS,
AND OBTAINING AT THE SAME TIME PROTOCHLORIDE OF MERCURY."-Partly a
communication from Vincent Riatti, of Modena.
Sealed the 4th May 1858, and dated the 12th March 1858.
PROVISIONAL SPECIFICATION left by the said Luigi Ferrari Corbelli at
the Office of the Commissioners of Patents, with his Petition, on the
12th March 1858.
I, LUIGI FERRARI CORBELLI, of Florence, in the Grand Duchy of Tuscany,
Commander of the Order of Malta, do hereby declare the nature of the said
Invention for "AN IMPROVED PROCESS FOR EXTRACTING ALUMINIUM FROM ITS
COMPOUNDS, AND OBTAINING AT THE SAME TIME PROTOCHLORIDE OF MERCURY," to
be as follows:-
This Invention relates to a mode of obtaining aluminium from its compounds
by the aid of the electric current, and at the same time of producing proto-
chloride of mercury. To this end I take suitable proportions of rock alum and
chloride of calcium, or of rock alum and chloride of sodium, or of sulphate of
alumina and chloride of calcium (or other salts having alumina for their base
may be substituted for those above mentioned.) One of these mixtures when
well dried and pulverized is placed in a suitable non-metallic receptacle, and to
it water is added to dissolve it. After filtration, the liquid is placed in a vessel

page_text: composed of a material which is a non-conductor of electricity, and containing
mercury in a fluid state. A weak current of electricity is now to be passed
through the mercury and the filtered liquid, for which purpose an insulated
iron wire is introduced into the vessel and brought into contact with the
mercury at the bottom of the vessel. This iron wire is brought into commu-
nication with the positive pole of a galvanic battery, the negative pole of
which communicates with a plate of zinc immersed in the filtered liquid, but
suspended so as not to touch the mercury. A galvanic action being now
set up, the salt of alumina will be decomposed, and the aluminium will be
deposited upon the zinc plate, either in the form of a blackish powder or in a
thin compact sheet. During this operation the chlorine will be set at liberty,
and having a great affinity for mercury, it will combine with that metal, and
form therewith protochloride of mercury (commonly known in commerce as
calomel), which will be found deposited on the surface of the mercury at the
bottom of the vessel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Luigi Ferrari Corbelli in the Great Seal Patent Office on
the 11th September 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LUIGI
FERRARI CORBELLI, of Florence, in the Grand Duchy of Tuscany, Commander
of the Order of Malta, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth 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
Luigi Ferrari Corbelli, Her special license that I, the said Luigi Ferrari
Corbelli, my executors, administrators, and assigns, or such others as I, the
said Luigi Ferrari Corbelli, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during 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
IMPROVED PROCESS FOR EXTRACTING ALUMINIUM FROM ITS COMPOUNDS, AND OBTAINING
AT THE SAME TIME PROTOCHLORIDE OF MERCURY," being partly a communication
from Vincent Riatti, of Modena, upon the condition (amongst others) that I,
the said Luigi Ferrari Corbelli, by an instrument in writing under my hand

page_text: and seal, should particularly 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 Luigi Ferrari Corbelli, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
The chief object of this Invention is to obtain aluminium in a simpler and
much more economical manner than by the processes heretofore employed for
that purpose. The Invention also applies to the manufacture of protochloride
of mercury, the production of which latter substance is the result of part of
the process for obtaining aluminium. In order to obtain aluminium by the
improved method, I take of,-
Rock alum
Chloride of calcium
Or of rock alum
Chloride of sodium
Or of sulphate of alumina
Chloride of calcium
-
5,931 parts, and of
-
2,076 parts;
5,931 parts, and
-
4,167 parts, and
2,190 parts;
2,076 parts.
Or, other salts having alumina for their base may be substituted for those
above mentioned.
One of these mixtures well dried and pulverized is to be placed in a suitable
receptacle, which must not be made of metal, and to it must be added about
two and a half times its weight of water, in which it is to be dissolved and
allowed to settle. The liquid is then to be filtered and placed in a vessel
composed of a material which is a non-conductor of electricity, and a quantity
of mercury in a fluid state having been placed in the vessel, a weak current
of electricity is to be passed through the mercury and the filtered liquid, for
which purpose an insulated iron wire is introduced into the vessel, and brought
into contact with the mercury at the bottom of the vessel. This iron wire is
brought into communication with the positive pole of a galvanic battery, the
negative pole of which communicates with a plate of zinc immersed in the
filtered liquid, but suspended so as not to touch the mercury. A galvanic
action being now set up, the salts of alumina will be decomposed, and the
aluminium will be deposited upon the zinc plate either in the form of a
blackish powder, or in a thin compact sheet. During this operation the
chlorine will be set at liberty, and having a great affinity for mercury, it will
combine with that metal, and form therewith protochloride of mercury (com-

page_text: monly known in commerce as calomel), which will be found deposited on the
surface of the mercury at the bottom of the vessel.
Having thus set forth the improved mode of extracting aluminium from its
compounds, I wish it to be understood that I claim the process as above
described for facilitating, the extraction of aluminium from its compounds;
and particularly I claim the employment of rock alum, chloride of calcium,
common salt (chloride of sodium), sulphate of alumina, or other salts of that
base in the manner above described for obtaining the metal aluminium by the
wet method.
I also claim the simple and economical means above described for obtaining
protochloride of mercury, commonly known as calomel.
In witness whereof, I, the said Luigi Ferrari Corbelli, have hereunto set
my hand and seal, the Twenty-ninth day of July, in the year of our
Lord One thousand eight hundred and fifty-eight.
LUIGI FERRARI CORBELLI. (L.S.)