Improvements in Electrolysis and Electrolytical Apparatus.
Year: 1899

page_text: Improvements in Electrolysis and Electrolytical Apparatus.
I, URBAIN LOUIS PAUL LE VERRIER, of 12, Avenue Bugeaud, Paris, France,
Chief Engineer of Mines, do hereby declare the nature of this invention to be
as follows:-
This invention relates to an electrolytic process which is more particularly
applicable to the separation of nickel in the pure state from pig nickel.
Some ores, such as those of New Caledonia, yield readily, on being reduced
in a cupola, pig material composed of iron and nickel. But up to the present,
this product has not been utilized because it has not been possible to refine it-
that is to say, to obtain pure nickel commercially therefrom. The process which
will now be described enables this treatment of the pig nickel to be effected;
it is also applicable to other cases of commercial electrolysis.
When pig nickel is electrolyzed by means of a pig anode and a cathode of pure
nickel (or of any other suitable conducting material), the two metals are dis-
solved at the anode, and the nickel is deposited at the cathode. The iron is
precipitated in the form of yellow hydrated oxide. The whole of the iron is pre-
cipitated and the nickel is deposited in a perfectly pure state if the liquor is
maintained by suitable additions in a slightly neutral or basic state with a
maximum degree of oxidation.
The liquor that yields the best results is a dilute solution of double chloride
of nickel and ammonium with an addition of chloride of sodium.
In order to secure the peroxidation, a little chloride of lime is added regu
larly, or air is stirred into the liquor, which is sufficient to precipitate small
quantities of iron if the liquor is neutral.
Other liquors may, however, be employed, such as for example the double
sulphate of nickel and ammonium. In this case an oxidizer-for example, the
hypochlorite of soda-must be added which does not give insoluble sulphates.
If necessary a little acid or soda or ammonia is added, according as the liquor
tends to become basic or acid.
The liquor should be filtered from time to time.
In order to insure that the renewal and the clarification will be continuous,
the apparatus may be employed that will now be described it being understood
that I do not limit myself to the use of this apparatus, and that I describe it
only by way of example.
It comprises a trough divided into two compartments I will call A and B.
The electrodes are situated in the compartment A. The other compartment B
is much narrower and communicates with the former at its lower part and
forms a siphon.
The bottom of the trough is in the form of a hopper, with the object of pro-
moting the accumulation of the precipitate.
After the liquor has undergone the treatment, it may be discharged through

page_text: cocks provided in the outer wall of the compartment B, in order to be returned
to the apparatus after having been filtered and having received the suitable
additions.
It may be useful, in certain cases, to rub the cathodes in order to render the
deposit more compact, or on the contrary to brush them in order to remove the
oxide of iron which is carried along mechanically.
This operation may be effected automatically by means of the following
arrangement.
Each cathode is fixed to a rod of iron which projects vertically and enters
a solenoid in such a manner that the rod is wholly contained therein when the
cathode is completely raised out of the bath.
Rollers arranged above the compartment A and under the action of springs are
applied to the two faces of the cathode and have for their object to produce the
compression of the deposit.
When a current is sent into the solenoid, the rod rises and carries the cathode
with it, and when the current ceases to flow, this rod consequently drops again
with the cathode, whose two faces have been traversed by the rollers, which have
compressed the deposit.
This operation may be effected periodically by sending a current into the
solenoid when desired. This periodical placing into circuit may be very simply
effected in the following manner.
The solenoid is served by a circuit which is derived from the electrolyzing cur-
rent and is interrupted between two brushes arranged at the upper part of the.
compartment B. These brushes may be electrically connected by means of one
or more metal pieces of olive-shape fixed on an endless cord which is suitably
mounted on rollers and has a continuous longitudinal movement. Each time
one of the metal plates moves over the two brushes, the derived circuit of the
solenoid is closed and the solenoid operates in the manner described
When, instead of being compressed, the deposit formed on the cathode is to be
brushed or scraped so as not to fall into the bath, there are substituted for the
rollers arranged above the compartment A, suitable brushes or scrapers and then
it is necessary to have an arrangement such that this brushing will take place
in one direction of travel only preferably in the downward direction. In this
case upon the rod to which the cathode is attached there is mounted a washer
which is capable of sliding with a considerable amount of friction, and which has
its travel limited by two plates that form stops. This washer is rigidly connected
to a frame which, according as it moves up or down, acts upon rollers that are
secured to scrapers so as to move the latter away from or nearer to the cathode.
The portion of the frame that causes the scrapers to move away, comprises two
inclined parts that converge at the top in order to move the scrapers apart
when the frame is moving up, and to allow them to approach each other when
the frame is moving down.
When the rod moves up, it carries with it from the beginning of its travel, the
washer and consequently the frame, which causes the brushes or scrapers to
move apart. The washer strikes against the upper of two plates almost imme-
diately but the rod continues its upward movement, the brushes remaining
apart.
When the rod moves down, it carries with it from the beginning of the down-
ward movement the washer and the frame, which is very soon stopped by the
striking of the washer against the lower of the two plates. The brushes or
scrapers are then placed into contact with the cathode from the beginning of
the downward travel and they effect the brushing of the deposit.
The process of electrolysis in a neutral and oxidizing liquor which I have just
described, may be employed in all cases where it is required to separate two
metals one of which can be precipitated in the state of peroxide-for example,
for the direct refining of the mattes of iron and copper, and for that of the alloys
of copper and nickel in the latter case, by increasing the density of the current

page_text: or the oxidizing action of the liquor, the precipitation of peroxide of nickel can
be promoted.
Apparatus according to my invention, or the special features thereof, may of
course be employed in processes of electrolysis other than that herein above
described.
Dated this 16th day of March 1899.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
Improvements in Electrolysis and Electrolytical Apparatus.
I, URBAIN LOUIS PAUL LE VERRIER, of 12, Avenue Bugeaud, Paris, France,
Chief Engineer of Mines, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to an electrolytic process which is more particularly
applicable to the separation of nickel in the pure state from pig nickel.
Some ores, as, for example, those of New Caledonia, yield readily, on being
reduced in a cupola, pig material composed of iron and nickel. But up to the
present, this product has not been utilized because it has not been possible to
refine it that is to say, to obtain pure nickel commercially therefrom. The
process which will now be described enables this treatment of the pig nickel
to be effected; it is also applicable to other cases of commercial electrolysis.
When the pig nickel is electrolyzed by means of a pig anode and a cathode of
pure nickel (or of any other suitable conducting material), the two metals are
dissolved at the anode, and the nickel is deposited at the cathode. The iron is
precipitated in the form of yellow hydrated oxide. The whole of the iron is pre-
cipitated, and the nickel is deposited in a perfectly pure state if the liquor is
maintained by suitable additions in a neutral or slightly basic state with a
maximum degree of oxidation. The liquor that yields the best results is a dilute
solution of double chloride of nickel and ammonium with an addition of chloride
of sodium. In order to secure the peroxidation, a little chloride of lime is
added regularly, or air is stirred into the liquor, which is sufficient to precipitate
small quantities of iron if the liquor is neutral. Other liquors may, however,
be employed, such as for example the double sulphate of nickel and ammonium.
In this case an oxidizer-for example, the hypochlorite of soda-must be added
which does not give insoluble sulphates. If necessary a little acid or soda or
ammonia is added, according as the liquor tends to become basic or acid. The
liquor should be filtered from time to time.
In order to insure that the renewal and the clarification of the liquor will be
continuous, the apparatus may be employed that will now be described with
reference to the accompanying drawings, in which
Fig. 1 shows the apparatus in vertical section, and
Fig. 2 shows the same in partial section at right angles to the plane of sec-
tion of Fig. 1, a portion of the apparatus being in elevation;
Fig. 3 is a view similar to Fig. 2 of a modification.
It is to be understood that I do not limit myself in the process above described
to the use of this apparatus, and that I describe it only by way of example.
This apparatus comprises a trough divided into two compartments A and B.
The electrodes are situated in the compartment A. The other compartment B

page_text: is much narrower and communicates with the former at its lower part and forms
with it what may be regarded as an inverted siphon.
The bottom of the trough is in the form of a hopper, with the object of
promoting the accumulation of the precipitate. After the liquor has undergone
the treatment, it may be discharged through cocks provided in the outer wall
of the compartment B, in order to be returned to the apparatus after having
been filtered and having received the suitable additions.
It may be useful, in certain cases, to rub the cathodes in order to render the
deposit more compact, or on the contrary to brush them in order to remove the
oxide of iron which is carried along mechanically. This operation may be
effected automatically by means of the following arrangement.
Each cathode D (Figs. 1 and 2) is fixed to a rod of iron d which projects
vertically and enters a solenoid E in such a manner that the rod is wholly con-
tained therein when the cathode is completely raised out of the bath. Rollers I
arranged above the compartment A and under the action of springs i, are applied
to the two faces of the cathode and have for their object to produce the com-
pression of the deposit. When a current is sent into the solenoid, the rod d
rises and carries the cathode 1 with it, and when the current ceases to flow,
this rod d consequently drops again with the cathode, whose two faces have
then been traversed by the rollers I, which have compressed the deposit.
This operation may be effected periodically by sending a current into the
solenoid when desired. This periodical placing into circuit may be very simply
effected in the following manner. The solenoid is served by a circuit J which
is derived from the electrolyzing current and is interrupted between two
brushes arranged at the upper part of the compartment B. These brushes
can be electrically connected by means of one or more metal pieces K of olive
shape fixed on an endless cord k, which is suitably mounted on rollers k' and
has a continuous longitudinal movement. Each time one of the metal pieces k
moves over the two brushes j j, the derived circuit of the solenoid is closed and
the solenoid operates in the manner described.
When, instead of being compressed, the deposit formed on the cathode is to
be brushed or scraped so as not to fall into the bath, there are substituted for the
rollers I arranged above the compartment A. suitable brushes or scrapers
(Fig. 3) and then it is necessary to have an arrangement such that this brushing
or scraping will take place in one direction of travel only--preferably in the
downward direction. In this case upon the rod d there is mounted a collar F
which is capable of sliding with a considerable amount of friction, and which
has its travel limited by two plates G G₁ that form stops. The collar F is
rigidly connected to a frame H which, according as it moves up or down, acts
upon rollers that are secured to the brushes or scrapers so as to move the latter
away from or nearer to the cathode. The portion of the frame that causes the
brushes or scrapers to move away, comprises two inclined parts that con-
verge upwards in order to move the brushes or scrapers apart when the frame
is moving up, and to allow them to approach each other when the frame is
moving down. When the rod d moves up, it carries with it from the begin-
ning of its travel, the collar F, and consequently the frame H, which causes
the brushes or the scrapers to move apart. The collar F strikes against the upper
of the two plates G almost immediately, but the rod d continues its upward
movement, the brushes or scrapers remaining apart. When the rod d moves
down, it carries with it from the beginning of the downward movement the
collar F and the frame H, which is very soon stopped by the striking of the
collar against the lower of the two plates G¹. The brushes or scrapers are then
placed into contact with the cathode from the beginning of the downward travel
and they effect the brushing or scraping of the deposit.
The process of electrolysis in a neutral and oxidizing liquor which I have
just described, may be employed in all cases where it is required to separate two
metals one of which can be precipitated in the state of peroxide-for example,

page_text: for the direct refining of the mattes of iron and copper, and for that of the alloys
of copper and nickel; in the latter case, by increasing the density of the cur-
rent or the oxidizing action of the liquor, the precipitation of peroxide of nickel
can be promoted.
Apparatus according to my invention or the special features thereof, may, of
course, be employed in processes of electrolysis other than that hereinbefore
described.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1. For refining pig nickel or for separating one metal from another which is
present with it in an alloy or mixture and which can be precipitated in the state
of peroxide, electrolyzing the said pig nickel, alloy, or mixture in a neutral
and oxidizing liquor.
2. For renewing and clarifying the liquor employed in electrolytic processes,
troughs constructed substantially as hereinbefore described.
3. For automatically brushing off or compressing the deposits formed on cath-
odes in electrolytic processes apparatus constructed substantially as herein before
described.
4. Electrolytic apparatus constructed, arranged, and operating substantially
as hereinbefore described with reference to and shown in Figs. 1 and 2 and in
Fig. 3 respectively of the accompanying drawings.
101
• December 1899
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.