Improvements in the Electrolysis of Chlorides, Iodides, Bromides, Nitrates, and other Salts, and in Apparatus therefor.
Year: 1893

page_text: Date of Application, 21st July, 1893
Complete Specification Left, 23rd Apr., 1894-Accepted, 21st July, 1894
PROVISIONAL SPECIFICATION.
Improvements in the Electrolysis of Chlorides, Iodides, Bromides,
Nitrates, and other Salts, and in Apparatus therefor.
We, JAMES HARGREAVES, of Farnworth-in-Widnes, in the County of
Lancaster, Chemical Engineer, and THOMAS BIRD, of Cressington, near Liverpool,
in the same County, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to the electrolysis of chlorides, iodides, bromides, nitrates
and other salts, especially when apparatus of the general character to which our
Applications for Letters Patent No. 18,871 of 1892, No. 5197 of 1893 and
No. 5198 of 1893 relate is employed; one of our present objects being to secure
a more efficient and convenient construction of apparatus. Our invention further
relates to a modified method of forming the porous diaphragm applicable for use
in electrolytic apparatus.
In carrying out the first part of our invention, we make the cell with three
compartments; the highest one containing the anode and salt solution, the central
one enclosing the cathode and steam or moistened waste gas from the motor engine,
and the lowest one receiving steam or the waste gas on its way to the central
compartment, the floor of which compartment it serves to heat. The highest and
central compartments are separated by a porous diaphragm which in conjunction
with the cathode forms the floor of the former compartment.
In the manufacture of carbonate of soda from a solution of sodium chloride, the
waste gas from a motor engine (or heated carbonic acid gas obtained from any other
available source), after passing through the lowest compartment, is conducted into
the central compartment and there combines with the caustic soda yielded on the
cathode, converting that substance into carbonate of soda. The whole of the waste
gas from the engine may pass through the lower compartments of the cells where a
series are employed; a regulated proportion being diverted to the central
compartments if carbonate is to be made. The heating of the floor of the central
or cathode compartiment by the waste gas on its way to or past that compartment
not only expedites the action of the apparatus, but produces evaporation of the
liquid lying on the floor of the central compartment, the vapour evolved being in
turn condensed on the cathode exposed on the under side of the floor of the topmost
cell and serving to dissolve and wash away the caustic soda or carbonate as it is
formed. Nozzles for directing jets or sprays of water against the cathode may also
be provided in the central compartment. The highest or anode compartment may
be of stoneware or other similar material, and the central and lowest compartments
of metal cast in one piece and furnished with lugs for holding the bolts by means
of which the two parts of the cell are connected together.
When bicarbonate instead of carbonate of soda is required, the apparatus may
be worked cold, the proportion of carbonic acid gas admitted to the central or
cathode compartment being at the same time suitably regulated.
When the apparatus is employed in the production of bicarbonate of soda or
other insoluble (or only slightly soluble) substance, the diaphragm will usually be
of a somewhat more porous character; and the product will be yielded as a solid
upon the exposed surface of the electrode. In such cases, a gaseous reagent will as
a rule be applicable; the water spray or steam being dispensed with.
In a cell constructed in accordance with our improved method, either or both
electrodes may be exposed, according to the nature of the particular substance it
is desired to manufacture.

page_text: In carrying out the second part of our invention, we make the diaphragm of pulp
composed of fibrous material, such as asbestos, and a binding agent, consisting of
an insoluble phosphate. Lime, baryta or other alkaline earth and the asbestos or
other fibrous material are or may be deposited on the wire gauze electrode, and
then dried; the surplus moisture being separated therefrom by gravity or otherwise.
The electrode and dried pulp constituting the diaphragm are then steeped in a
solution of phosphate of soda, potash, or ammonia. The lime, baryta or other
alkaline earth thus becomes converted into an insoluble phosphate; the soda, potash
or ammonia being left free. Soluble phosphate of lime or other earthy phosphate
may be substituted for the lime, baryta or other alkaline earth.
In some cases, we carbonate the lime, baryta or other alkaline earthy matter,
whereof the diaphragm is in part composed, by steeping the same (after being
deposited) in a solution of carbonate of soda or other suitable carbonate, and we
subsequently steep it in a solution of a phosphate or silicate; the effect of this
treatment being to impart greater density to the porous diaphragm and to render
it less liable to split or laminate.
To regulate the density of the diaphragm, we first soak the diaphragm in a
solution of lime or any of the soluble salts of lime, and, after redrying the same,
again soak it in a solution of a silicate or of a phosphate. A solution of magnesia,
baryta, or other suitable earthy salt may, however, be used instead of the solution
of lime for the preliminary soaking.
Dated this 21st day of July 1893.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in the Electrolysis of Chlorides, Iodides, Bromides,
Nitrates, and other Salts, and in Apparatus therefor.
We, JAMES HARGREAVES, of Farnworth-in-Widnes, in the County of
Lancaster, Chemical Engineer, and THOMAS BIRD, of Cressington, near Liverpool,
in the same County, Electrical 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:-
This invention relates to the electrolysis of chlorides, iodides, bromides, nitrates
and other salts, especially when apparatus of the general character to which our
Letters Patent No. 18,871 of 1892, and our Applications for Letters Patent
No. 5197 of 1893 and No. 5198 of 1893, relate is employed; one of our present
objects being to secure a more efficient and convenient construction of apparatus.
Our invention further relates to a modified method of forming the porous diaphragin
applicable for use in electrolytic apparatus.
In the accompanying drawings,
Fig. 1 represents in side elevation apparatus constructed in accordance with the
first part of this invention.
Fig. 2 is a corresponding longitudinal vertical section.
Fig. 3 is a plan.
Fig. 4 is a view, partly in transverse vertical section and partly in end elevation,
showing two cells connected in series.
A C is a cell having three compartments B, H and K; the highest one (B)
containing the anodes F F F F and salt solution G, the central one (H) enclosing
the cathode E and steam or moistened waste gas from the motor engine, and the
lowest one (K) receiving steam or the waste gas on its way to the central
compartment (H), the floor of which compartment it serves to heat. The highest
and central compartments B and H are separated by a porous diaphragm D
which in conjunction with the cathode E forms the floor of the former
compartment. J is the inlet for steam or waste gases. M is the inlet for

page_text: the brine or other solution to be decomposed. N is the outlet for the
0 is the outlet for the solution
exhausted or partially exhausted solution.
containing the caustic soda or other product. P is the outlet for the chlorine or
other gas evolved. S are conductors for the electric current.
In the manufacture of carbonate of soda from a solution of sodium chloride, the
waste gas from a motor engine (or heated carbonic acid gas obtained from any
other available source), after passing through the lowest compartment K, is
conducted by way of the pipe L into the central compartment H and there
combines with the caustic soda yielded on the cathode, converting that substance
into carbonate of soda. The whole of the waste gas from the engine may pass
through the lower compartments of the cells where a series are employed; a
regulated proportion being diverted to the central compartments if carbonate is to
be made. The beating of the floor of the central or cathode compartment H by
the waste gas on its way to or past that compartment not only expedites the action
of the apparatus, but produces evaporation of the liquid lying on the floor of the
central compartment, the vapour evolved being in turn condensed on the cathode E
exposed on the under side of the floor of the topmost cell B and serving to dissolve
and wash away the caustic soda or carbonate as it is formed. Nozzles for directing
jets or sprays of water against the cathode E may also be provided in the central
compartment H. The highest or anode compartment may be of stoneware or
other similar material, and the central and lowest compartments H and K of metal
cast in one piece and furnished with lugs c for holding the bolts R by means of
which and the bars Q the two parts of the cell are connected together.
When bicarbonate instead of carbonate of soda is required, the apparatus may
be worked cold, the proportion of carbonic acid gas admitted to the central or
cathode compartment H being at the same time suitably regulated.
When the apparatus is employed in the production of bicarbonate of soda or
other insoluble (or only slightly soluble) substance, the diaphragm D will usually
be of a somewhat more porous character; and the product will be yielded as a
solid upon the exposed surface of the electrode E. In such cases, a gaseous
reagent will as a rule be applicable; the water spray or steam being dispensed
with.
In carrying out the second part of our invention, we make the diaphragm of
pulp composed of fibrous material, such as asbestos, and a binding agent, consisting
of an insoluble phosphate. Lime, baryta or other alkaline earth and the asbestos
or other fibrous material are or may be deposited ou the wire gauze electrode, and
then dried; the surplus moisture being separated therefrom by gravity or
otherwise. The electrode and dried pulp constituting the diaphragm are then
steeped in a solution of phosphate of soda, potash or ammonia. The lime, baryta
or other alkaline earth thus becomes converted into an insoluble phosphate; the
soda, potash or ammonia being left free. Soluble phosphate of lime or other
earthy phosphate may be substituted for the lime, baryta or other alkaline earth.
In some cases, we carbonate the lime, baryta or other alkaline earthy matter,
whereof the diaphragm is in part composed, by steeping the same (after being
deposited) in a solution of carbonate of soda or other suitable carbonate, and we
subsequently steep it in a solution of a phosphate or silicate; the effect of this
treatment being to impart greater density to the porous diaphragm and to render it
less liable to split or laminate.
To regulate the density of the diaphragm, we first soak the diaphragm in a
solution of lime or any of the soluble salts of lime, and, after redrying the same,
again soak it in a solution of a silicate or of a phosphate. A solution of magnesia,
baryta, or any suitable earthy salt may, however, be used instead of the solution of
lime for the preliminary soaking.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we claim :-
1 The improved annaratus for use in the electrolysis of chlorides, iodides,

page_text: bromides, nitrates and other substances constructed substantially as described with
reference to the accompanying drawings.
2. The herein-described apparatus for use in the electrolysis of chlorides,
iodides, bromides, nitrates and other substances, the same comprising a com-
partment B containing the anode and the solution to be decomposed, a diaphragm D
and an exposed cathode E forming the bottom of the compartment B, a
compartment H beneath the diaphragm and cathode in which the cation or
derivative product is obtained, and a compartment K beneath the compartment H
for the steam or gas employed in heating the apparatus.
3. In electrolytic apparatus, the employment of a porous diaphragm consisting
of fibrous material bound together by an insoluble phosphate obtained substantially
as herein described.
4. For use in electrolytic apparatus, the combined diaphragm and cathode formed
substantially as herein described, and consisting of fibrous material deposited on
wire gauze, the fibres being bound together by an insoluble phosphate.
5. In the manufacture of a combined diaphragm and cathode for use in electro-
lytic apparatus, depositing the lime or its equivalent and the asbestos or other
fibrous material on the wire gauze cathode, then drying the same, and finally
steeping the cathode and dried pulp in a solution of phosphate of soda, of potash
or of ammonia in order to convert the lime or its equivalent into an insoluble
phosphate.
6. In the manufacture of a combined diaphragm and electrode for use in
electrolytic apparatus, depositing the lime or its equivalent and the asbestos or
other fibrous material on the wire gauze electrode, drying the same, then steeping
it in a solution of carbonate of soda or other suitable carbonate, and, after
redrying, steeping it in a solution of a phosphate or of a silicate.
7. In the manufacture of a combined diaphragm and electrode for use in
electrolytic apparatus, soaking the dried diaphragm in a solution of lime or of any
of the soluble salts of lime, or of magnesia, baryta or other suitable earthy salt,
redrying the diaphragm, and subsequently soaking it in a solution of a phosphate
For of licate
Dated the 17th day of April 1894.
For the Applicants,
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C., Chartered Patent Agent.