Improvements in Apparatus for use in Electro-metallurgical Operations.
Year: 1890

page_text: The decision of the Chief Examiner, acting on behalf of the Comptroller, of the
12th day of September 1892, allowed, under Section 18 of the Patents, &c.
Act, 1883, an Amendment of this Specification.
Date of Application, 1st Sept., 1890
Complete Specification Left, 1st June, 1891-Accepted, 4th July, 1891
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for use in Electro-metallurgical
Operations.
I, CARL HOEPFNER, of Frankfurter Strasse 36 Giessen, in the Empire of
Germany, Doctor of Philosophy, do hereby declare the nature of this invention
to be as follows:-
This invention relates to an apparatus which is more especially designed for use
in carrying out the process for obtaining metals described in the Specification of
Letters Patent No. 4626, dated 26th March 1888, but also for similar electrolytic
or galvanic operations. The said apparatus consists of a series of frames made of
wood or other suitable material, which receive alternately the anodes and cathodes
usually adapted to be inserted from above, and which are pressed together after
membranes have been interposed, so that a series of chambers are formed. These
frames consist of a bottom beam and two vertical side posts, which are provided
with inwardly extending holes or channels for the introduction and discharge of
the liquid and with straight holes or channels which connect anode cell with anode
cell, and cathode cell with cathode cell, and enable the circulation of the lye
successively through the cells of the same name.
Between every two adjoining frames is interposed a porous membrane having
holes which coincide with the above-mentioned holes or channels for the passage of
the liquids.
The first, third, fifth, seventh etc., frames serve for the reception of the anodes,
and the second, fourth, sixth, eighth etc. frames for the reception of the cathodes.
All the frames are pressed firmly against each other in any suitable manner,
preferably by means of plates and screws. To provide the said channels on the
outside by using suitably bent tubes is impracticable because of the liability to
leakages, and also to stoppages or disturbances in the circulation owing to the
length of such channels.
The channels may be so arranged that the outlet of the liquid from the cells will
either always take place above or always below, and the inlet opposite thereto, that
is to say below or above. This may be effected inside or outside the cell.
The circulation of the liquid electrolyte is effected in the following manner.
The anode lye enters the first frame on the left hand side, flows through the same
to the right, passes through a bent channel in the vertical side post of the first
frame and a straight channel in the side post of the second frame to the bent
channel in the side post of the third frame the latter channel terminating in the
anode cell in the last-mentioned frame. The liquid flows through this anode cell
from the right to the left and passes through other channels arranged as above
described into the next anode cell and so on to the last anode cell, whence it is
conducted to the outside.
In like manner the cathode lye passes from the left hand side into the second
frame, flows through this frame to the right and passes through bent channels in

page_text: the posts of the second and fourth frames and through straight channels in the
post of the third frame to the next cathode cell and so on to the last cathode call
whence it is conducted to the outside of the apparatus.
By virtue of the described arrangement the cathode lye is conducted in a limited
space successively past the cathodes, so that when copper lye containing silver is
electrolysed the silver and impurities cau settle only upon a limited number of
catholes; great differences of pressure are obviated, thereby increasing the
durability of the membranes and diminishing the diffusion; furthermore the
inner metal covering otherwise required in electro-metallurgical baths becomes
superfluous.
A further advantage of the apparatus consists in that it can be very easily
arranged for the use of high tensions, and also for the galvanic production of the
same. It is then suflicient to provide between the several pairs of electrodes, in
lien of the porous membranes hereinbefore referred to, non conducting india-rubber
plates or between the several pairs of frames copper plates which may serve as
cathodes. Under these circumstances it will be expedient to combine the frames
in such a manner that a cathode frame is enclosed by two anode frames or rice versu,
which does not affect the principle on which this apparatus is constructed. In an
arrangement of this kind the first and third, the fourth and sixth, the seventh and
ninth frames and so forth may be used as anode frames, and the intermediate
second, fifth, eight frames and so forth may serve as cathode frames, copper plates
being provided between every two adjoining anode frames, that is to say, between
the third and fourth, the sixth and seventh and so on, whilst within each group
thus formed the several frames are separated from each other by non-conducting
india-rubber plates. For the adjoining third and fourth, sixth and seventh anode
frames and so forth the straight channels are not required in this arrangement,
because the bent channels of every two of these frames meet, whereas two
successive cathode frames are provided with a straight channel.
Between the anode frames and cathode frames can be placed auxiliary frames
which have for their object to separate the anode from the cathode by a double
solid membrane and an intermediate liquid membrane, thereby rendering the
diffusion more difficult. These intermediate cells can also communicate with each
other, as above described.
As a rule the membrane is made of parchment paper. This is strengthened
either on oue or on both sides by a membrane of a strong fabric. Of course, other
materials, such as leather, gelatine, vencer wood, asbestos cloth, can also be used
for this purpose.
In the electrolysis of chlorides I use, instead of the membranes hitherto
employed, prepared vegetable or animal organic materials which will affectually
resist the caustic action of acid salts and nuy chlorine which may be set free.
Such materials are obtained by impregnating paper, felt, leather, fabric, vencer
wood, or the like with nitric acid or similar liquids or gases for the purpose of
nitration.
The wooden parts of the baths which como in contact with the caustic substances
can also be impregnated in this manner.
For certain purposes, for instance when in the anode cells or in the cathode cells
solid substances are formed which will drop, the bottom of the cells is provided
with openings which permit the said solid substances to fall out. In this case the
apparatus must of course be placed in a water-tight vessel of suitable height.
Dated this 1st day of September 1890.

page_text: improvements in Apparatus for use in Electro-metallurgical
Operations.
1, CARL HOEFFNER, of Frankfurter Strasse 36 Giessen in the Empire of
Germany, Doctor of Philosophy, 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 which is more especially designed for use in
carrying out the process for obtaining metals described in the Specification of
Letters Patent No. 4626, dated 26th March 1888, but the said apparatus may also
be used for similar electrolytic or galvanic operations.
The said apparatus consists of a series of frames made of wood or other suitable
material, which receive alternately the anodes and cathodes usually inserted in the
said frames from above, a membrane being arranged between each adjacent pair of
frames and the whole secured by clamping pieces and screw bolts so as to form a .
series of chambers.
In the accompanying drawing
Figures 114, 1 and 1 represent a frame for receiving the carbon anodes.
Figures 22 2 and 20 show a frame for receiving the copper cathode.
Figure 3 is a horizontal section on the line m n of Figures 1 and 2 showing
several frames arranged together and
Figure 4 is a modified form of the improved apparatus.
Each of these frames consists of a bottom beain B3 and two vertical side posts A.
As shown at a and c and at b and d in Figure 3 the left hand side posts of the
frames are provided with holes or channels for the introduction and discharge of
the liquid. All the anode cells are in communication with each other through
curved passages in the side posts of the anode frames and straight passages in
the side posts of the cathode frames thus forming a continuous circuit. All the
cathode cells are connected in a similar manner by means of passages and y so
as to enable the circulation of the lye successively through all the cells of the same
name.
Between each pair of adjacent frames is interposed a porous membrane M having
holes which coincide with the above mentioned holes or channels x and y for the
passage of the liquids. The first, third, fifth, seventh, etc. frames serve for the
reception of the anodes C and the second, fourth, sixth, eighth, etc. frames for
the reception of the cathodes K. All the frames are pressed firmly against each
other in any suitable manner preferably by means of plates P which are firmly
clamped together by means of screw-bolts S. To provide the said channels a
and y on the outside by using suitably bent tubes is impracticable because of the
liability to leakages and also to stoppages or disturbances in the circulation owing
to the length of such channels.
The channels may be so arranged that the outlet of the liquid from the cells will
either always take place above or below, and the inlet opposite thereto that is to
say, below or above. This may be effected inside or outside the cell.
The
The circulation of the liquid electrolyte is effected in the following manner.
anode lye enters the frame 1 on the left hand side at a, flows through the same to
the right, and through the curved channel in the vertical side post of the frame 1
and through the straight channel y in the side post of the frame 2 to the curved
channel in the side post of the frame 3 the latter channel terminating in the
anode cell in the last mentioned frame. The liquid then flows through this anode
cell 3 from the right to the left hand and passes through other channels and
arranged as above described into the next anode cell, 5, and so on to the last anode
cell from which it passes to the outside at b.
む
y
In a similar manner the cathode lye passes through the inlet at c and flows

page_text: from the left hand side of the frame 2, to the right hand side thereof and
through the curved channels in the posts of the frames 2 and 4 and through
straight channels y arranged in the posts of the frame 3 to the next cathode cell 4
and so on to the last cathode cell from which it is conducted to the outside of the
apparatus at d.
By virtue of the above described arrangement the cathode lye is conducted in a
limited space successively past the cathodes so that when copper lye containing
silver is electrolysed the silver and impurities can settle only upon a limited number
of cathodes, great differences of pressure are obviated, thereby increasing the
durability of the membranes and diminishing the diffusion; furthermore the inner
metal covering otherwise required in electro-metallurgical baths becomes super-
fluous.
A further advantage of the apparatus consists in that it can be very easily
arranged for the use of high tensions, and also for the galvanic production of the
same. It is then sufficient to combine two or more of the above described
apparatus (or groups of cells which need not contain more than one pair of
electrodes), with each other in such a way that the communication takes place
between the cells of the same name of this entire arrangement, in the same manner
as between the cells of the same name of the single apparatus, and between the
several apparatus are included non-conducting india-rubber plates (or between
the several pairs of frames copper plates II which latter may serve as cathodes.
Under these circumstances it will be expedient to combine the frames in such a
manner that a cathode frame is enclosed by two anode frames or vice versa as
represented in horizontal section Figure 4. Such a combination would not affect
the principle on which this apparatus is constructed. In an arrangement of this
kind as represented in Figure 4 the frames 1 and 3 and 4, 67 and 9 and so on can
be used as anode frames, and the intermediate frames 2, 5, 8 and so forth may
serve as cathode frames, copper plates being provided between every two
adjoining anode frames that is to say; between 3 and 4 6 and 7 and so on, whilst
within cach group thus formed the several frames are separated from each other by
non-conducting indiarubber plates G. For the adjoining anode frames 3 and 4
6 and 7 and so on the straight channels y are not required in this arrangement
because the curved channel of every two of these frames meet whereas two
successive enthode frames are provided with a straight channel y.
Between the anode frames and cathode frames can be arranged other auxiliary
frames which have for their object to separate the anode from the cathode by a
double solid membrane the intermediate membrane consisting of liquid or semi-
liquid substances and thereby rendering the diffusion more difficult. These
intermediate cells can also communicate with each other as above described.
The membrane is made of parchment paper, and strengthened either on one, or
ou both sides by a membrane composed of a strong fabric. Other materials, such
as leather, gelatine veneer wood, asbestos cloth or the like, may, if desired, be used
for this purpose.
In the electrolysis of chlorides I use, instead of the membranes hitherto
employed, prepared vegetable or animal organic substances with or without an
admixture of animal ingredients, such as for instance asbestos, which organic sub-
tances will effectually resist the caustic action of acid salts and any chlorine which
may be set. free. Such substances are obtained by impregnating paper, felt,
leather, fabric, veucer wood or the like with nitric acid or similar liquids or gases
for the purpose of nitration.
The wooden parts of the baths which come in contact with the caustic substances
can also be impregnated in this manner.
For certain purposes, for instance when in the anode cells or in the cathode cells
solid substances are formed which will descend to the bottom of the same; the
bottoms of the said cells are provided with openings which permit the said solid
substances to fall out. In this case the apparatus must of course be placed in a
water-tight vessel of suitable height.

page_text: 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 wish it under-
stood that I am aware of Letters Patent No. 1220888 and that I do not wish to claim
anything which is described or claimed in the said Patent, but what I claim is :-
First. An apparatus designed for electrolytic or galvanic purposes, composed of
a single or a series of single frames open or closed above, which are separated from
each other by membranes of animal vegetable or mineral substances and which are
pressed together water-tight by screw-rods S so as to form several cells separated
from each other by membranes which cells receive alternately the anodes and cathodes
whilst the circulation of the liquids takes place through channels or tubes from one anode
cell to another and from one cathode cell to another, so that the cathode lye in succession
flows through all the cathode cells and in like manner if necessary the anode lye in
succession through all the anode cells.
Second. An apparatus designed for electrolytic or galvanic purposes, composed
of frames separated by membranes which frames may be open above and receive
alternately the anodes and cathodes whilst the circulation of the liquids takes place
through channels provided in the frames themselves from one anode cell to another
and from one cathode cell to another so that the anode lye in succession flows
through all the anode cells and in like manner the cathode lye in succession through
all the cathode cells.
Third. The combination of two or more of the apparatus characterized in the
first and second claims to form a single system, in such a manner that the cells of
the same name communicate with each other from apparatus to apparatus whilst
the several apparatus are separated from each other electrolytically.
Fourth. The modification of the apparatus described in the first, second and
third claims in which the bottom of the cells in which the formation of loose solid
bodies takes place is provided with an opening for enabling them to fall out auto-
matically.
Fifth. In the apparatus above described employment of a membrane, consisting
of two or more pieces of cloth or leather adapted to be held by mechanical means,
or their substitute between which parchment paper is interposed.
Sixth. In the electrolysis or galvanic employment of halogen salts of the heavy
and light metals, or halogen, hydracids especially in the above described apparatus,
the use of a diaphragm resisting chlorine, bromine, iodine and their oxidized com-
pounds, consisting of vegetable or animal substances enabling the electrolytic
diffusion, with or without an admixture of mineral ingredients which substances
have been previously nitrated for ensuring durability and also the nitration of such
wooden parts as come in contact with the caustic substances.
Dthin 20th day of May 1801
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.