Year: 1886

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the
nature of my 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 is a new method of depositing metallic aluminium electrolytically.
The aluminium is obtained in combination with either lead, zinc or tin, according
as the oxide of either metal is added to the electrolytic liquid as herein after
described. The lead, zinc or tin is then separated out in any well known way and
the metallic aluminium is thus gained. The current of electricity employed should
be of low electro motive force, and may be derived from any suitable source.
As the invention may be conveniently carried into effect, in the single decom-
position cell it is described in that connection. Said cell may consist of an outer
vessel, and an inner porous vessel. In said porous vessel is an element of amal-
gamated zinc, and an exciting liquid consisting of dilute sulphuric acid. In the
outer vessel is an element preferably of brass or copper. These parts are all well
hnown in galvanic cells and need no further description. The important feature
is the electrolytic liquid which is placed in the outer vessel. This liquid is prepared
as follows ;-
Alumina is treated with hydrochloric acid and hydrochlorate of aluminium in
fluid form is thus obtained. The specific gravity of said liquid is about 1-3 and
density 35° B. Said liquid as above stated is placed in the outer vessel of the cell
and circuit is closed between the elements.
As iron is usually present in the liquid, this metal is first electrolytically deposited
upon the brass or copper plate, as a cathode. The operation is to be watched until
the deposition of iron ceases and that of aluminium begins, which is apparent by
a perceptible change of color in the deposit. When this occurs, the iron has been
removed.
The operation is now arrested and the liquid is decanted into the outer vessel of
another cell similarly arranged to that already described. To said liquid is then
added about fifty per cent, by weight, of either lead oxide, tin oxide or zinc oxide.

page_text: The terminals of the cell are then connected and electro decomposition of the liquid
results in the deposition of aluminium and the metal of the added oxide at the
cathode.
When this deposition is completed, the deposit is removed from the cell and the
aluminium is separated from its accompanying metal in any suitable way, known
to metallurgists and chemists.
It will be observed that the function of the first mentioned cell is simply to
remove the iron by electro deposition The invention is not limited to this particular
mode of removing said iron because other methods of accomplishing a like result
may be adopted So also the invention is not limited to the deposition of the
aluminium in the single decomposition cell. Thus a galvanic bath may be made
containing the aforesaid electrolytic liquid, in which electrodes may be placed, and
to said electrodes the current always of low strength-may be conducted from
a dynamo or any other suitable source of electricity.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed as communicated
to me by my foreign correspondent I declare that what I claim is ;—
1. The process of electrolytically depositing aluminium, substantially as herein
set forth.
2. The process of first removing the iron present in an aluminium liquid and
then electrolytically depositing the aluminium therefrom, substantially as herein
Bet forth.
3. The process of electrolytically depositing aluminium in combination with
either lead, zinc or tin, substantially as herein set forth.
HASELTINE, LAKE & Co.,
Agents for the Applicant.