IMPROVEMENTS IN THE DECOMPOSITION OF THE COMPOUNDS OF ALUMINIUM AND IN COATING METALS WITH ALUMINIUM OR ITS ALLOYS
Year: 1861

page_text: LETTERS PATENT to Thomas Bell, of Usworth House, Gateshead, in the
County of Durham, Ironmaster, for the Invention of "IMPROVEMENTS
IN THE DECOMPOSITION OF THE COMPOUNDS OF ALUMINIUM AND IN COATING
METALS WITH ALUMINIUM OR ITS ALLOYS."-A communication from abroad
by Louis Le Chatelier, of Paris, in the Empire of France.
Sealed the Sth November 1861, and dated the 13th May 1861.
PROVISIONAL SPECIFICATION left by the said Thomas Bell at the
Office of the Commissioners of Patents, with his Petition, on the 13th
May 1861.
I, THOMAS BELL, of Usworth House, Gateshead, in the County of Durham,
Ironmaster, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE DECOMPOSITION OF THE COMPOUNDS OF ALUMINIUM AND IN COATING
METALS WITH ALUMINIUM OR ITS ALLOYS," to be as follows:-
This Invention consists in effecting the decomposition of the compounds of
aluminium (for instance, the double chloride of aluminium and sodium) by the
agency of galvanic electricity, and also in coating metals with aluminium by
the same agency. By means of this process I am enabled to convert the surface
of copper (for instance) into alluminium bronze.
The bath is composed of the double chloride of aluminium and sodiuminan
anhydrous state, and which is kept melted at a temperature of 360° Fahrenheit.
17

page_text: The negative electrode is represented by the piece of copper or other metal
which it is intended to cover or coat with aluminium. The soluble positive
electrode may be of aluminium, but there is economy in using a composition
of carbon and anhydrous alumina. This composition is compressed in a mould
of a cylindrical or other suitable form, then calcined in a close vessel before
being used, and produces the chloride of aluminium, with the chlorine
which is disengaged by the action of the electric current. A mixture of
alumina and coal tar moulded and calcined answers very well. A positive
electrode made from the carbonaceous matter deposited in the interior of gas
retorts may also be employed. When a positive electrode composed of carbon,
mixed or not with alumina, is employed, small pieces of carbon become detached
during the operation and soil the bath; to remedy this the electrode may be
enclosed within a porous earthen vessel, which is placed within the bath con-
taining the double chloride. The bath, instead of being composed only of the
double chloride of aluminium and sodium may consist of a mixture of this
chloride with cryolite, which is fusible at a dull red heat.
Cryolite alone may be used, but it has the inconvenience of melting at a high
temperature. A deposit of aluminium on copper having been effected, if the
piece is heated ata suitable temperature, the aluminium and copper combine,and
the surface of the piece of metal will be converted into a bronze of aluminium.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Bell in the Great Seal Patent Office on the
13th November 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
BELL, of Usworth House, Gateshead, in the County of Durham, Ironmaster,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of May, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Thomas Bell, Her special licence that I, the said Thomas
Bell, my executors, administrators, and assigns, or such others as I, the
said Thomas Bell, 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

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN THE DECOMPOSITION OF THE COMPOUNDS OF ALUMINIUM AND
IN COATING METALS WITH ALUMINIUM OR ITS ALLOYS," being a communication
from abroad by Louis Le Chatelier, of Paris, in the Empire of France, upon
the condition (amongst others) that I, the said Thomas Bell, by an instrument
in writing under my hand and seal, should particularly describe and ascer-
tain 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 Thomas Bell, do hereby declare
the nature 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 consists in effecting the decomposition of the compounds of
aluminium (for instance, the double chloride of aluminium and sodium) by
the agency
of galvanic electricity, and also in coating metals with aluminium
by the same agency. By means of this process I am enabled to convert the
surface of copper (for instance) into aluminium bronze.
The bath is composed of the double chloride of aluminium and sodium in
an anhydrous state, and which is kept melted at a temperature of about three
hundred and sixty degrees Fahrenheit. The negative electrode is represented
by the piece of copper or other metal which it is intended to cover or coat with
aluminium. The soluble positive electrode may be of aluminium, but there is
cconomy in using a composition of carbon and anhydrous alumina. This
composition is compressed in a mould of a cylindrical or other suitable form,
then calcined in a close vessel before being used. This process produces the
chloride of aluminium, with the chlorine, which is disengaged by the action of
the electric current. A mixture of alumina and coal tar moulded and calcined
answers very well. A positive electrode made from the carbonaceous matter
deposited in the interior of gas retorts may also be employed. When a positive
electrode composed of carbon mixed or not with alumina is employed, small
pieces of carbon become detached during the operation and soil the bath; to
remedy this the electrode may be enclosed within a porous earthen vessel,
which is placed in the bath containing the double chloride. The bath, instead
of being composed only of the double chloride of aluminium and sodium, may
consist of a mixture of this chloride with cryolite, which mixture is fusible at
a dull red heat.
Cryolite alone may be used, but it has the inconvenience of melting at a

page_text: high temperature. A deposit of aluminium on copper having been effected,
if the piece be heatedata suitable temperature, the alumina and copper combine
and the surface of the piece of metal will be converted into a bronze of
aluminium.
Having now described this Invention of improvements in the decomposition
of the compounds of aluminium and in coating metals with aluminium or its
alloys, and having explained the manner of carrying the same into effect, I
claim as the Invention secured to ine by Letters Patent as aforesaid, the
mode herein set forth of effecting the decomposition of the compounds of
aluminium and of coating metals with aluminium or its alloys.
particularly the employment for the above mentioned purposes of galvanic
electricity in the manner above described.
I claim
In witness whereof, I, the said Thomas, Bell, have hereunto set
my hand and seal, the Twelfth day of November, in the year
of our Lord One thousand eight hundred and sixty-one.
THOMAS BELL. (L.S.)