An Improved Process for the Manufacture of Aluminium, and Apparatus therefor.
Year: 1889

page_text: Date of Application. 9th Mar.. 1889
Complete Specification Left, 9th Jan, 1890-Accepted, 15th Feb., 1890
PROVISIONAL SPECIFICATION.
An Improved Process for the Manufacture of Aluminium, and
Apparatus therefor.
I, JOHN LEMAN ECKERSLEY DANIEL, of 3. Victoria Street, Westminster, Electrical
Engineer, do hereby declare the nature of this Invention, to be as follows:--
My improved process, which is based on the well known laboratory experiments
of Bunsen and St. Claire Deville, has for its object the manufacture of aluminiuin
on a commercial scale, certain improvements being made in such experiments, as
hereinafter described, to enable the manufacture to be successfully carried out.
In this process aluminium is produced by electrolysing the double chloride of
aluminium and sodium, and means are provided for maintaining the bath at all times
in a uniform state or condition.
An apparatus for carrying out my process comprises a furnace on which is set a
metal trough, and said furnace communicates, by a flue, or flues, with three
chambers, in each of which is placed a fire clay retort which, for purposes of
description, will be referred to as retorts 1, 2 and 3. At one end of the furnace
is an inlet for gas and air, and at the other and extreme, end thereof, that is to
say, in the outer wall of the third chamber, is fitted a steam jet exhauster com-
municating with the chimney, and employed to produce a draught in the furnace.
The retorts inay each be provided with a series of removeable trays, the purpose of
which is mentioned further on.
At the bottom of the trough extends a long chamber in which is mounted a
shaft carrying propellers.
In the trough are arranged a number of carbon anodes and metal cathodes
(preferably aluminium), the anodes being surrounded by porcelain. sleeves, and the
cathodes partially surrounding these sleeves.
From the sleeves project pipes which communicate with a main pipe, (or pipes)
which leads to the bottom of No. 2 retort. At top, this retort communicates, through
a pipe, with No. 1 retort, and the lower part this latter retort communicates, through
a pipe, with a trough. This trough is partially filled with the double chloride of
aluminium and sodium which is maintained in a liquid state by the heat from the
furnace. Nos. 1 and 2 retorts are filled with thoroughly dried alumina and carbon,
preferably in the form of balls, of about 2 inches diameter, which are placed. in the
trays provided for their reception; or if desired the trays may be dispensed with, and
the balls placed directly in the retorts. No. 3 retort. is also filled with like balls, but
in a moist state, and in this retort they are dried, previously to being placed in
either of the other retorts.
•
An electric current is caused to pass from the carbon anodes through the bath to
the aluminium cathodes, the effect of which is to decompose the bath, depositing
aluminium, with some salt, on the cathodes, while chloride of aluminium and chlorine
pass off from the carbon anodes through the main pipe into the bottom of No. 2 retort,
where they meet the carbon and alumina, the chlorine converting the alumina, by
chemical reaction, into aluminium chloride in the form of vapour.
This vapour
together with the chloride of aluminium, which entered with the chlorine, passes
through the pipe connecting retorts 2 and 1, through retort No. 1, and through the
pipe connecting retort No. 1 with the trough and enters this trough below the level
of the double chloride of aluminium and sodium in the same. By this means aɛ
fast as the bath loses aluminium which goes to the cathodes, and aluminium chloride
which escapes at the anodes, it is replenished or regenerated by the chloride of
aluminium which enters through the pipe below the level of the liquid double
chloride of aluminium and sodium.

page_text: The propellers within the long chamber are revolved sufficiently fast, by mechanical
means, to interchange all portions of the bath, at least once every minute.
The gases produced by chemical decomposition in retorts Nos. 1 and 2 are allowed
to escape through a condenser.
The porcelain sleeves surrounding the anodes are made sufficiently long to ensure
the chlorine and chloride of aluminium making their passage as before described.
By this arrangement of apparatus the state of the bath is maintained constantly
the same, for as fast as it becomes weakened by the loss of aluminium deposited on
the cathodes, and by aluminium chloride escaping from the anodes, it is replenished
or regenerated by the said chloride of aluminium which escapes in addition to the
chloride of aluminiumn which is produced by chemical reaction of the chlorine on
the carbon and alumina in retorts Nos. I and 2.
For producing chloride of aluminium the well known process, is used for, such
purpose, that is to say an upright retort is filled with alumina and carbon, and is
maintained heated, while dry chlorine is caused to pass through the same.
If desired, an additional furnace may be employed for heating the retorts.
1000
:
ERNEST DE PASS,
68, Fleet Street, Londón, Agent for the Applicant.
COMPLETE SPECIFICATION"
1
An Improved Process for the Manufacture of Aluminium, and
Apparatus therefor.
I, JOHN LEMAN ECKERSLEY DANIEL, of 3. Victoria Street, Westminster, Electrical'
- Engineer, do hereby declare the nature of this.Invention and in what manner the
same is to be performed, to he particularly described and ascertained in and by
the following statement, reference being had to the accompanying drawings and to
the letters and figures marked thereon, that is to say :-
L
-
My improved process, which is based on the well known laboratory experiments of
Bunsen.and St. Claire-Deville, has for its object the manufacture of aluminium on a
commercial scale, certain improvements, as hereinafter described, being made in such
experiments as to ensure the manufacture being successfully carried out.
In this process aluminium is produced by electrolysing the double chloride of
aluminium and sodium; and means are provided for maintaining the bath at all times
in a uniform state or condition.
And in order that my invention may be readily understood and carried into
effect, I proceed to describe the same with reference to the accompanying drawings.
Fig. 1 is a vertical section of my apparatus.
Fig. 2 a plan, half in section, and
Fig. 3 a transverse section on the line.m, x, of fig. 1..
:
The apparatus for carrying out my process comprises a furnace A, on which is set a
metal trough B. and said furnace communicates by a flue f; or flues, with three
chambers C, D, E, so arranged as to allow the heat from the furnace to circulate
therein. Each of these chambers contains a fire clay retort C¹; D', and E', which
may be provided with a series of removable trays (perforated or not) the purpose of
which is hereinafter mentioned.
At the end, A¹, of the furnace is an inlet, for gas and air (when employing a gas
-furnace) and at the opposite end Ex, is fitted a steam jet exhauster E2, which may
communicate with a chimney and is employed to produce a draught in the furnace.
But neaus for heating other than a gas furnace may be used, as for instance, an
ordinary furnace.
Beneath the trough B, and communicating therewith through an opening 61 (see
fig. 3) or openings, is a chamber B1, in which is mounted a shaft b, carrying propellers
or stirrers 6x, revolved sufficiently fast, by mechanical means, to interchange all
portions of the bath at least once every minute.

page_text: In the trough B, are arranged carbon anodes F, and metal cathodes H (preferably
aluminium). The anodes F, are surrounded by porcelain sleeves G, and the cathodes H
partially surround these porcelain sleeves.
From the sleeves G, project pipes g, which communicate, on each side of the
apparatus, with main pipes J, which lead to the bottom of the retort D¹.
At the top
of this retort is a pipe D2 which leads into the top of retort C₁, and this latter retort
communicates with the trough B through a pipe C. This trough is partially filled
with the double chloride of aluminium and sodium which is maintained in a liquid
state by the heat of the furnace. The retorts, C¹ and D', are filled with thoroughly
dried alumina and carbon, preferably in the form of balls of about 2 inches diameter,
which are placed in the trays t, provided for their reception. But, if desired, these
trays may be dispensed with and the balls placed directly in the retorts. The
retort E, is also filled with like balls, but in a moist state, wherein they are dried
previously to being employed in the other retorts.
In carrying out the process an electric current is caused to pass from the carbon
anodes F, through the bath to the metal cathodes H, the effect of which is to
decompose the bath, thus depositing aluminium, with some salt, on the cathodes H,
while chloride of aluminium and chlorine pass off from the carbon anodes F, through.
the mains J, into the bottom of the retort D1, wherein they meet the carbon and
alumina, the chlorine converting the alumina, by chemical reaction, into aluminium
chloride in the state of vapour. This vapour, together with the chloride of aluminium
which entered with the chlorine, passes through the pipe D, retort C' and pipe C2
and enters the trough B below the level of the double chloride of aluminium and
sodium in the same.
2
By this means, as fast as the bath loses aluminium, which goes to the cathodes, and
aluminium chloride and chlorine, which escape at the anodes, it is replenished or
regenerated by the chloride of aluminium which enters through the pipe C² below
the level of the liquid double chloride of aluminium and sodium, in addition to the
chloride of aluminium which is produced, by chemical reaction of the chlorine, on the
carbon and alumina in the retorts C¹, and D².
The gases produced by chemical decomposition in the retorts C¹, and D¹, are
allowed to escape through the condenser L..
The porcelain sleeves G, surrounding the anodes, must be made sufficiently long
to ensure the chlorine and chloride of aluminium making their passage as above
described.
Instead of connecting the main pipes J, to the bottom of the retort. D', I nay, if
preferred, connect them to the top, in which case the pipe D2, would be situated at
the bottom of retort D¹, and would lead into the bottom of retort C, and the bent
pipe C, would be connected to the top of the retort C¹.
If desired, an additional furnace may be employed for heating the retorts; and one
set of anodes, and one main, may be dispensed with.
It will thus be seen from the foregoing description, and the drawings accompanying
the same, that a perfectly simple process is devised for continuously producing
aluminium on a commercial scale.
Having now particularly described and ascertained the nature of my invention,
and in what manner the same is to be performed, I claim:
1. Maintaining a constant and continuous replenishment or regeneration of the
bath with chloride of aluminium as fast as it loses the same while undergoing
electrolysis, substantially in the manner described.
2. The construction and use of apparatus substantially as described and shewn by
the accompanying drawings for the continuous manufacture of aluminium on a
commercial scale.
Dated this 9th day of January 1990.
ERNEST DE PASS,
68, Fleet Street, London, 'Agent for the Applicant.