Improvements in the Manufacture -of Aluminium and Aluminium Alloys, and the Electro-deposition of the same.
Year: 1894

page_text: Date of Application, 25th July, 1894
Complete Specification Left, 27th May, 1895-Accepted, 13th July, 1895..
.
Improvements in the Manufacture -of Aluminium and Aluminium
Alloys, and the Electro-deposition of the same.
I ALFRED FRANCIS BILDERBECK GOMESS, Chemist, of 24 Alfred Place West,
South Kensington, in the County of London; do hereby declare the nature of this
invention to be as follows
My invention relates to the electro-deposition of aluminium and aluminium. alloys
and consists in improvements upon my former invention for which I applied for
Letters Patent on the 11th day of April 1894, Number 7205-; for depositing
aluminium from an aqueous solution, and the present improvements consist in a
method or process of treating bauxite in combination with an electrolytical method
of treating the alumina obtained in the said. treatment, so that a puré aluminium
deposit obtained.
The said electrolytical process is by itself a novel process."
L
i.
My said improvements are equally adapted to the production of aluminium or
the plating of the same on other metals or materials.
According to my invention alloys of aluminiuin may also be deposited.
According to my present invention. I use an anode of carbon, platinum, or other
suitable material (e.g. one that will not dissolve to an appreciable extent in my
This is done by placing
electrolyte) surrounded by hydrated oxide of aluminium.
the anode in a-porous cell in the electrolyte, which cell is charged with hydrated
oxide of aluminium, so as to keep the same in close contact with the positive pole.
In some cases I employ an aluminium electrode in the porous cell surrounded by
the hydrated oxide of aluminium, for the purpose of conducting the electricity
(aluminium being a better conductor than the above named anodes) only a small
quantity of which aluminium will be dissolved; as the aluminium in the electrolyte
is supplied from the alumina which is continuously added as hereafter.stated.
In taking bauxite from which to extract the aluminium I first convert this into
aluminate of an alkali by any known method such as for example fusing it with a
sufficient quantity of carbonate of soda,.I .then dissolve in water the aluminate of
soda thus formed and filter which gets rid of any iron present. !
To prepare alumina from the above filtrate I proceed as follows. I neutralise
the solution (the filtrate) with hydrochloric acid and boil with a slight excess of
ammonium hydrate. This latter operation precipitates the alumina and silica and
a portion of the carbonaceous material (if present). This precipitate is washed in
a filter and thus ready for use.
2.
I prefer to add the hydrated oxide of aluminium in a continuous manner to the
materials in the porous cell, it may however be added to the bath in any other
position, but in this case the reactions do not take place so readily.
·
When an aluminium anode is used I have found that it is converted into its
oxide before entering into solution, it is thus evident that it is much cheaper and
better to use the method herein described of deposition direct from'alumina without
the necessity of employing an aluminium 'a'node:
When using the bath for plating alloys salts consisting of a tartrate on a chloride
of the proposed metal forming the alloy are also added in a similar manner.
When I use the chloride of the metal, the chloride iof the alkali; may be left
out of the bath. For instance in the case of an alloy of tin:l additomy-bath:or

page_text: place in the porous cell about 10 per cent. of chloride of tin. It is evident that the
proportions may at will be varied to any desired extent.
The electrolyte I employ is the same as that described in the Specification of
my aforesaid application Letters Patent viz. tartrate of aluminium in conjunction
with chloride of an alkali, either with or without the addition of iodide or bromide
of an alkali
- 9.
The following is the composition of a bath which I have found to answer well in
BROWNE & Co.,
9 Warwick Court, Gray's Inn, London, Agents for Applicant.
Improvements in the Manufacture of Aluminium and Aluminium
Alloys, and the Electro-deposition of the same.
ALFRED FRANCIS BILDERBECK GOMESS, of 24 Alfred Place West, South
Kensington, in the County of London, Chemist, do hereby declare the nature of
this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
-
My invention relates to the manufacture of aluminium and aluminium alloys and
the electro-deposition of the same, and consists in improvements upon my former
invention, for which I applied for Letters Patent on the 11th day of April 1894,
numbered 7205, for the deposition of aluminium from an aqueous solution, and
the present improvements consist in a method or process of treating bauxite in

page_text: '
combination with an electrolytical method of treating the alumina obtained in the
said treatment, so that a pure aluminium deposit is obtained.
The said electrolytical process is in itself a novel process.
My said improvements are equally adapted to the production of aluminium, or
to the plating of the same on other metals or materials.
According to my invention' alloy's'of aluminium may also be deposited.
According to my, present invention, I use an anode of carbon, platinum or other
suitable material (e.g. one that will not dissolve to an appreciable extent in my
electrolyte) surrounded by hydrated oxide of aluminium. This is done by placing
the anode in a porous cell in the electrolyte, which cell is charged with hydrated
oxide of aluminium, so as to keep the same in close contact with the positive pole.
Since aluminium is a better conductor than the above named anodes I employ in
some cases au aluminium electrode in the porous cell, surrounded by hydrated oxide
of aluminium; for the purpose of conducting the electricity, only a small quantity
of which aluminium will be dissolved, as the aluminium in the::electrolyte is
supplied from the alumina, which is continuously added as hereafter stated:
In taking bauxite from which to extract the aluminium, I first convert this into
aluminate of an alkaline base, by any known method, such, for example, as fusing
it with a sufficient quantity of carbonate of soda: I-then dissolve the aluminate of
soda thus formed in water; and filter to get rid of any iron present:
To prepare alumina from the above filtrate I proceed as follows: I neutralise
the solution (the filtrate) with; for example, hydrochloric acid. This latter
operation precipitates the alumina and silica, and a portion of the carbonaceous
material (if present). This precipitate is washed in a filter, and then, ready
for use. Je! ] L..
I prefer to add the hydrated oxide of aluminium in a continuous manner to the
materials in the porous cell, it may however be added to the bath in any other
position, but in this case the reactions do not take place so readily:..
When an aluminium anode is used; as described in the Specification of the
aforesaid application for Letters Patent No.7205 of 1894; have found that it is
converted into its oxidé before entering into solution, it is thus evident, that it is
much better, and cheaper to use the method herein described of depositing.direct
from the alumina, without the necessity of employing an aluminium anode! .
When using the bath for plating alloys, salts, consisting of a tartrate or a
chloride of the proposed metal forming the alloys are also added..in. a: similar
manner.
When I use the chloride of the metal, the chloride of the alkaline base may be
left out of the bath. For instance, in the case of an alloy of tin; I add to; my
bath or place in the porous cell, about ten per cent. ofichloride ofatin... A
It is evident that the proportions may be varied at will to any desired.extent.
The electrolyte I employ is the same as that described in the Specification of
my aforesaid application for Letters Patent, viz.: tartrate. of aluminium Al,
(CHO) in conjunction with chloride of an alkaline base, either with or without
the addition of iodide or bromide of an alkaline base.
The following are the compositions of baths, which I have found to;answer in
practice:
..
}

page_text: 7
דיון
salt derived from other suitable acid; containing two carboxyl groups COOH.in
the molecule. For example the salt derived from oxalic acid (COOH), or C,H₂O
succinic acid. C₂H (COOH), or H.CHO malic acid C,H.(COOH),(HO)
or H,CHO. Phthalic acid, CH(COOH), or CHO, might also be used.
1.
The bath may of course, be made-up in such other proportions. as may be found
suitable in the various uses to which it is put.
Although I have described a porous cell for keeping the hydrated oxide of
aluminium in close contact with the positive pole, which I have found desirable in
practice .1 maуemploy apуother, diaphragm or screen to attain the same
object.
By the use of the porous cell diaphragm or screen, the silica present with the
oxide, and also any carbonaceous particles, are retained and do not pass to the
cathode. As silica would-enter.into. an.alkaline, solution, especially when soda or
potash is used, it is desirable to keep the bath neutral or acid, when silica is
present.
The bath may be worked in a cold state..
I prefer to use hydrated oxide of aluminium freshly precipitated.
The voltage employ is about eight, volts.
f.in
"
By the use of the porous scell; diaphragm or screen, I can cheapen the manu-
facture of aluminium, by the use of an impure, and cheap alumina, and avoid the
..extraction of the silica, which is essential in all methods. at present, employed for
the production of aluminium by electricity
713
D
•
a
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner. the same is to he performed, I declare that what I
claim is
74
27...
1. The manufacture and electro-deposition of aluminium by the employment of
..tartrate: ofi aluminium, substantially, as, herein before described:
''
2! The manufacturetánd electro-deposition of aluminium in conjunction with
other metals-inaan aqueous bath so as to form alloys, by the employment of
tartrate of aluminium,.substantially laalherein before described.
3. In the manufacture.and.electro-deposition of aluminium and aluminium alloys,
in an-aqueous bath, the employment of tartrate of aluminium in. conjunction with
chloride of an alkaline base, substantially as hereinbefore described.
4. In the manufacture and electro-deposition of aluminium and aluminium alloys,
in van aqueous-ibath;. the employment of double- tartrate of aluminium and an
alkaline base, substantially as herein before described.
.I
47
5. In the manufacture-and electro-deposition of aluminium and aluminium alloys
in an aqueous bath, the employment of double tartrate of aluminium and an
alkaline base, in conjunction with. chloride of an alkaline base, substantially as
--hereinbefore described..
...i6. In the manufacture and electro-deposition, of aluminium and aluminium alloys
in an aqueous bath, the employment of tartrate of aluminium or the double tartrate
of aluminium andran alkaline, base, in conjunction, with iodide or bromide of an
alkaline base, with the addition of chloride of an alkaline base, substantially as
herein before described.
7- The process of obtaining pure: aluminium by the use of an impure alumina,
containing silica and carbonaceous matter, but free from iron and other metals,
and placing the said alumina within a porous cell or diaphragm, containing the
anode, so that only the salt of the pure metal passes through the said porous cell
or diaphragm to the cathode, where it is deposited as pure metal..
8. In the manufacture, electro-deposition and plating of aluminium; surrounding
the anode or positive pole with hydrated oxide of aluminium, so that such oxide
may be kept in close proximity to the positive pole, at the same time allowing the
acidulous radical to pass readily to and from the positive pole, for the purposes
⚫ described.
9. In the manufacture, electro-deposition and plating of aluminium, the use of

page_text: salts of Aluminium derived from other suitable acids, containing two carboxyl
groups in the molecule.
10. In the manufacture, electro-deposition and plating of aluminium alloys, the
use of salts of aluminium derived from other suitable acids containing two carboxyl
groups in the molecule.
11. The improved process for the manufacture and electro-deposition of
aluminium, substantially as herein before described.
12, The improved process for the manufacture and electro-deposition of
aluminium alloys, substantially as hereinbefore described.
Dated this Twenty-seventh day of Max 1895.
BROWNE & Co.,
9 Warwick Court, Gray's Inn, London, W.C.,
Agents for the Applicant.
BROWNE & Co.,
9 Warwick Court, Gray's Inn, London, W.C.,
Agents for the Applicant.