An Improved Apparatus for Obtaining Metals of the Alkalies from Molten Chlorides.
Year: 1889

page_text: Date of Application, 8th Oct., 1889
Complete Specification Left, 23rd June, 1890-Accepted, 16th Aug., 1890
PROVISIONAL SPECIFICATION.
An Improved Apparatus for Obtaining Metals of the Alkalies from
Molten Chlorides.
I, LUDWIG GRABAU of 41 Schiffgraben Hanover, in the Empire of Germany Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
Attempts which have hitherto been made to obtain metals of the alkalies on a large
scale from molten or liquid chlorides by means of electrolysis have not proved
successful inasmuch as it has been found impossible to keep up a regular course of
operation for a sufficient length of time, owing to therapid destruction of the apparatus,
this destruction taking place in the cell of the pole designed for the reception of the
metal deposited.
'
As these cells must be made of a fireproof material which is also a non-conductor of
electricity, such for instance as porcelain, firebrick, or the like, the rapid destruction
of the said cells would appear to be due to the chemical action of the metals of the
alkalies, assisted by the comparatively high temperature of the molten chlorides.
It has however been ascertained by more careful enquiry into the case, that the
speedy destruction of the pole-cells is not attributable to the direct destructive action
of the metal of the alkalies, but that the, real cause of this action is in the fact, that
the electric current passes through the walls of the cell. In fact even well glazed
porcelain cells have been found capable of conducting electric currents, so that their
walls were soon broken through.
Consequently it has been found advisable to employ a pole cell which would not
permit a current of electricity to pass through its walls.
This result is obtained according to the present invention by introducing a wall or
division reaching from the lower edge of the bell shaped pole-cell to above the surface
of the molten mass by which means conduction between the said mass inside the pole-
cell and that on the outside of it can only take place through the opening or orifice of
the cell but not through the wall of the same.
The apparatus consists of a melting chamber which is surrounded by an air jacket
or bath and heated preferably by hot gases which pass through channels the said
chamber comprising a bell-shaped pole-cell made of porcelain or other refractory
material and also the carbon electrodes arranged round the pole cell the said chamber
being closed at the top by a lid.
A wall or partition extends from the lower edge of the cell up through and projects
beyond the surface of the molten mass. A space is thus left between the walls of the
cell and the partition from which the molten mass is excluded the said molten mass
therefore does not come in contact with the interior surface of the wall and it becomes
impossible for an electrical connection to form between the molten masses inside and
outside the pole-cell through the walls of the cell.
The cell is firmly connected to one end of a hollow iron body from which a discharge
pipe leads passing over the edge of the melting chamber into a collector. The said
hollow iron body forms the negative pole and is placed in perfect electrical connection
with the molten mass in the pole cell by a bar-shaped prolongation. A boring device
arranged at the top of the hollow iron body is occasionally used to remove
obstructions.
The specific gravity of the metals of thealkalies being less than the molten chlorides
the liquid metal collected in the pole cell is forced upwards by the molten mass and as
it forms in the cell it is forced through the discharge pipe and collected outside of the
decomposing apparatus.
The receiver employed for collecting the metal may consist of a vessel or receiver
proper filled with petroleum one end of a bell shaped or cylindrical vessel dips into the

page_text: petroleum in the receiver whilst the upper end of the same is in connection with the
discharge pipe the said vessel being preferably kept filled with any suitable gas such
as hydrogen or nitrogen through a pipe in the top of the same.
The chlorine developed is removed through a pipe connected with the melting
chamber while the sali supply is admitted through à suitable opening in the top of
the said chamber.
"Dated this Sth day of Odaber 1889
HASELTINE, LAKE & Co.,
45, Southampion Buildings, Loudon, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Apparatus for Obtaining Metals of the Alkalies from
Molten Chlorides.
I, LUDWIG GRABAU, of 41 Schiffgraben, Hanover, Civil Engineer 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:-
Attempts which have hitherto been made to obtain metals of the alkalies on a large
scale from molten or liquid chlorides by means of electrolysis have not proved
successful, inasmuch as it has been found impossible to keep up a regular course of
operations for a sufficient length of time, owing to the rapid destruction of the
apparatus, this destruction taking place in the cell of the pole designed for the
reception of the metal deposited.
As these cells must be made of a fireproof material, which is also a non-conductor
of electricity, such, for instance as porcelain, firebrick, or the like.the rapid destruction
of the said cells would appear to be due to the chemical action of the metals of the
alkalies, assisted by the comparatively high temperature of the molten chlorides.
It has however been ascertained by more careful enquiry into the case, that the
speedy destruction of the pole-cells is not attributable to the direct destructive action
of the metal of the alkalies, but that the real cause of this action lies in the fact, that
the electric current passes through the walls of the cell.. In fact, even well glazed
porcelain cells have been found capable of conducting electric currents, so that their
walls were soon broken through.
Consequently it has been found advisable to employ a pole-cell which would not
permit a current of electricity to pass through its walls.
This result is obtained according to the present invention by introducing a wall or
division reaching from the lower edge of the bell shaped pole-cell to above the surface
of the molten mass, by which means conduction, between the said mass inside the
pole-cell and that on the outside of it, can only take place through the opening or
orifice of the celf but not through the wall of the same.
The accompanying drawing shows in vertical section an apparatus constructed
according to the present invention for obtaining metals of the alkalies.
The apparatus consists of a melting chamber A which is surrounded by an air
jacket or bath L and heated, preferably by hot gases which pass through channels G
the said chamber A comprising a bell-shaped pole-cell B made of porcelain or other
refractory materials, and also carbon electrodes C arranged round the pole-cell the
said chamber A. being closed at the top by a lid D.
A wall or partition extends from the lower edge of the cell B up through and
projects beyond the surface N N of the molten mass. A space is thus left between
the wall of the cell and the partition from which the molten mass is excluded, the
said molten mass therefore does not come in contact with the exterior surface of the
wall P. and it becomes impossible for an electrical connection to form between the
molten masses inside and outside the pole-cell, through the walls of the cell.
The cell B is firmly connected to one end of a hollow iron body E from which a
discharge pipe a leads the said pipe passing over the edge of the melting chamber,
into a collector S. The said hollow iron body E forms the negative pole and is placed

page_text: in perfect electrical connection with the molten mass in the pole-cell by a bar-shaped
prolongation n. A boring device 11 arranged at the top of the hollow iron body E
is occasionally used to remove. obstructions.
The specific gravity of the metals of the alkalies being less than the molten
chlorides, the liquid metal collected in the pole-cell is forced upwards by the molten
mass and, as it forms in the cell it is forced through the discharge pipe and collected
outside of the decomposing apparatus.
"
The receiver employed for collecting the metal may consist of a vessel or receiver
proper S filled with petroleum. One end of a bell shaped or cylindrical vessel M dips
into the petroleum in the receiver whilst the upper end of the same is in connection
with the discharge pipe a the said vessel being preferably kept filled with any suitable
gas such as hydrogen or nitrogen through a pipe e in the top of the sanie.
The chlorine developed is removed through a pipe connected with the melting
chamber while the salt supply is admitted through a suitable opening e in the top of
the said chamber.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
The improved apparatus for obtaining metals of the alkalies from molten chlorides,
consisting in the arrangement of bell-shaped pole cells of porcelain, fire-clay or other
refractory material, being a non-conductor of electricity, from the lower edge of which
a wall extends around the pole-cell wall at a certain distance from the latter,--
and rises above the level of the molten chlorides, so as to prevent the same from
touching the external surface of the cell-wail p, substantially as described and shown,
Dated this 19th day of June 1890.
HASELTINE, LAKE & Co..
45, Southampton Buildings, London, Agents for the Applicant.