Apparatus for Continuous Decomposition of Alkaline Chlorides by Electrolytic Fusion.
Year: 1892

page_text: Date of Application, 31st Aug., 1892
Complete Specification Left, 30th May, 1893-Accepted, 1st July, 1893
PROVISIONAL SPECIFICATION,
Apparatus for Continuous Decomposition of Alkaline Chlorides by
Electrolytic Fusion.
1, JEAN STOERK, of 23 Boulevard de Strasbourg, Paris, France, Chemist, do
hereby declare the nature of this invention to be as follows:-
This invention relates 'to apparatus for the continuous decomposition by
electrolytic fusion of alkaline chlorides such as potassium or sodium chloride,
producing free chlorine and the metal with which it was compounded. For this
purpose the chloride is mixed with about 25 per cent. of fluoride of the same metal
which, without being itself decomposed, aids the decomposition of the chloride.
The mixture when fused is subjected to electrolytic action whereby the chloride is
decomposed, the chlorine passing off as gas, and the metal as vapour which is
condensed in the presence of nitrogen or other gas that does not cause oxidation.
While the operation goes on fresh chloride is from time to time introduced, the
Aluoride remaining sufficient for a considerable period, during which the operation
can be continued until it is necessary to cleanse the apparatus of impurities. Such
being the process, the apparatus for carrying it on is of the following description.
A gas fire chamber of rectangular form is covered by a cast iron plate over which
is a plate of steel provided in case of fracture of the cast iron. On this as a base
within a flange projecting up from the base all round it is built a wall of refractory
material, lined with a number of carbon slabs cemented together with carbon and
tar putty. The interior is divided into three compartments by two partitions
extending about half way down towards the bottom, each partition being of iron
on the side facing the middle compartment, and of carbon on its other side. The
partitions are continued down in the form of a number of superposed carbon
troughs at a little distance apart so as to allow passage of liquid between them
from one compartment to another. The two outer compartments are covered with
refractory material such as is employed for crucibles; the middle compartment has
a lid of iron made with a flange extending nearly half way down, and it is covered
with a thick layer of non conducting material such as ashes. Through this lid
passes insulated into the middle compartment the negative electrode which is a
plate or slab of iron or nickel reaching down nearly to the bottom and has a
number of holes through it. Through the covers of the two side compartments
pass the positive electrodes each of which is a slab of carbon having horizontal
grooves extending along its face which is presented towards the middle compartment,
and numerous holes passing obliquely up from these grooves through the slab.
Through the covers of the compartments pass pipes for leading the chlorine to a
gasometer, and the metallic vapour to a condenser. A layer of lead is placed on
the bottom and the chamber being charged to about three fourths of its depth
with the mixture of chloride and fluoride, the charge is fused by gas flames applied
in the fire chamber below, and the melted lead serves as a liquid seal preventing
leakage of the fused material out at the bottom. Also the flange of the cover of
the middle compartment projecting down into the fused liquid prevents passage of
gas or vapour to or from that compartment.
The electrodes being then put in circuit with a suitable source of electricity,
decomposition of the chloride is effected, the chlorine passing to the gasometer
through a seal of brine and the inetallic vapour to a condenser whence the liquid
metal is delivered into a receptacle communicating with a gasometer charged with
nitrogen or other non-oxidising gas.
C A 1000
ABEL & IMRAY,
Agents for the Applicant..

page_text: COMPLETE SPECIFICATION.
Apparatus for Continuous Decomposition of Alkaline Chlorides by
Electrolytic Fusion.,
I, JEAN STOERK, of 23 Boulevard de Strasbourg Paris, France, 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 :-
This invention relates to apparatus for the continuous decomposition by
electrolytic fusion of alkaline chlorides such as potassium or sodium chloride,
producing free chlorine and the metal with which it was compounded. For this
purpose, the chloride is mixed with about 25 per cent. of fluoride of the same metal
which, without being itself decomposed, aids the decomposition of the chloride.
The mixture, when fused, is subjected to electrolytic action whereby the chloride
is decomposed, the chlorine passing off as gas, and the metal as vapour which is
condensed in the presence of nitrogen or other gas that does not cause oxidation.
While the operation goes on, fresh chloride is from time to time introduced, the
fluoride remaining sufficient for a considerable period, during which the operation
can be continued, until it is necessary to cleanse the apparatus of impurities.
Such being the process, the apparatus for carrying it on is constructed as shewn
in the accompanying drawings.
Fig. 1 is a vertical section, Fig. 2 is a sectional plan on X X and Fig. 3 is a plan.
A gas fire chamber A. of rectangular form is built in masonry M and is covered
by a cast iron plate over which is a plate a of steel provided in case of fracture of
the cast iron.
On this as a base within a flange, projecting up from the base all round it, is
built a wall B of refractory material such as is used for gas retorts, or it might
be iron, lined with a number of carbon slabs G preferably of compact graphite
cemented together with carbon and tar putty.
The interior is divided into three compartments by two partitions / extending
about half way, down towards the bottom, each partition being of iron on the side
facing the middle compartment, and of carbon on its other side. The partitions h
are continued down in the form of a number of surperposed carbon troughs at a
little distance apart so as to allow passage of liquid between them from one
compartment to another. The two outer compartments are covered with
refractory material t such as is employed for crucibles or gas retorts; the middle
compartment has a lid w of iron made with a flange u extending upwards and also
nearly half way down, and it is covered with a thick layer of non conducting
material such as ashes. Through this lid pass insulated into the middle compart-
ment the negative electrodes n, each of which is a plate or slab of iron or nickel
reaching down nearly to the bottom and has a number of holes through it.
Through the covers of the two side compartments pass the positive electrodes p,
cach of which is a slab of carbon having horizontal grooves extending along its
face which is presented towards the middle compartment, and numerous holes
passing obliquely up from these grooves through the slab.
Through the covers of the compartments pass pipes C for leading the chlorine to
a gasometer, and a pipe S for leading the metallic vapour to a condenser. The
upper ends of the electrodes above the covers are connected by copper bars e to
terminals E. A layer of lead e is placed on the bottom, and, the chamber being
charged to about three fourths of its depth with the mixture of chloride and
fluoride, the charge is fused by gas flames applied in the fire chamber A; the

page_text: melted lead prevents action on the plate a and serves as a liquid seal preventing
leakage of the fused material out at the bottom.
Also the flange of the cover we of the middle compartment projecting down into
the fused liquid prevents passage of gas or vapour to or from that compartment.
In operating with the apparatus, it is preferred to employ for heating, gas
flames of a non oxidising character so as to avoid rapid wear of the metal bottom
which serves as a good conductor of heat.
The carbon forming one side of each partition rests on the uppermost of the
troughs below, which is of iron, and above the cover is bolted to the iron.
The partitions are luted into the cover and their ends as well as those of the
carbon troughs below are inserted in the end carbon walls. These troughs are so
shaped and set that the outer edges of each are higher than the bottom of the
trough above so that the fused liquid can freely, but gases cannot, pass from
compartment to compartment. The grooves of the positive electrodes p and the
inclined holes through them serve to catch the gas as it is produced and direct it
towards the pipes G. The covers t are preferably slabs of clay which before
being made up into slabs are cleared from metallic oxides and lime by treatment
with hydrochloric acid, so that the chlorine produced may not by acting on these
substances tend to break up the slabs. Through one of these slabs passes the
charging tube T which is plugged at the top and descends nearly to the bottom.
The cover w rests at its ends on additional slabs of carbon which make the middle
compartment somewhat shorter than the two outer compartments.
The chlorine conveyed by the tubes G is passed through a seal of brine, about
two centimetres deep, on its way to the gasometer. The vapour of the metal
sodium or potassium is led by the pipe S to a condenser which may be a coil of
iron pipe in a tank containing boiling water saturated with some suitable salt so
that its boiling temperature is sufficiently high to keep the condensed metal liquid
in the coil, from which it is drawn, by opening a cock or valve at the bottom, into
a receptacle which is in communication with a gasometer charged with nitrogen or
other non oxidising gas, which should be thoroughly dried by passing over chloride
of calcium.
In order to maintain constant pressure in the middle compartment it communi-
cates by a pipe g with the nitrogen gasometer, which should be loaded to give a
pressure of about three centimetres of water, so as to nearly balance the liquid seal
for the chlorine.
The dimensions and proportions of the apparatus may be varied, and, instead of
three compartments, it may have only two, in which case the negative electrode
would be formed like the positive, as it might be when there
are three
compartments, the negative electrode being doubled. Obviously several sets of
the apparatus may have one source of heat and one source of electricity, and it is
to be understood that the apparatus is furnished with all necessary safety and
governing appliances, such as volt meters, ampere meters, rheostats, switches,
pyrometers &c.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. Apparatus for decomposition of alkaline chlorides by their electrolytic fusion
along with fluorides, constructed and operating substantially as described.
2. Forming the bottom of the chamber of iron and steel plates the latter flanged,
with a layer of lead or the like, to protect the steel and to operate as a seal.
3. Lining the sides with carbon to resist action of the materials treated.
4. Shaping the electrodes and partitions so as to facilitate escape of the gas
through the former and to give passage to liquid but not to gas through the latter.
5. The construction of the middle cover with a downwardly projecting flange to
prevent escape of gas.
6. The combination of condenser, receptacle and a gasometer charged with

page_text: nitrogen or equivalent gas, communicating with the receptacle for the produced
metal to prevent its oxidation, and with the middle compartment to regulate the
pressure therein.
n
11.
ديمه
1
r
1000
ABEL & IMRAY,
Agents for the Applicant.