Improvements in the Method of and Apparatus for the Electro- deposition of Copper and other Metals on Rotary Mandrels.
Year: 1897

page_text: Date of Application, 2nd Feb., 1897
Complete Specification Left, 1st Nov., 1897-Accepted, 18th Dec.,
1897
[Communicated from abroad by Emilien Dumoulin, of 23 Boulevard de Strasbourg,
Paris, in the French Republic, Electrical Engineer.]
.
Improvements in the Method of and Apparatus for the Electro-
deposition of Copper and other Metals on Rotary Mandrels.
I, WILLIAM EDWIN HEYS of 70 Market Street Manchester in the county of
Lancaster, Chartered Patent Agent. do hereby declare the nature of this invention to
be us follows:
This Invention relates to the Method of and Apparatus for the Electrodeposition
of Copper and other Metals upon Rotary Cathodes.
According to the Method followed by my Foreign Correspondent for the
electrodeposition of metals, and described in the specification of Letters Patent
No. 16360 dated the 31st. day of August A.D. 1895, he employed regulus, (antimony
and lead) anode supports, because in the first place they were unattacked by the
Copper Sulphate Solution, and in the second place, they were inexpensive. But at
the end of a certain time it was found that the regulus supports became oxidised
similarly to the positive plates of a Plantè Accumulator, and this above all when the
deposit was made rapidly and consequently with a current of great density. The
layer of lead oxide which was formed uot only introduced resistance into the circuit,
but also in some cases produced a counter E.M.F. which reversed the current in the
generating dynaino and inade the deposited cathode useless. One object of the
present Invention is to obvinte this difficulty.
For this purpose, my Foreign Correspondent constructs the anode supports of
Aluminium as hereinafter described. The use of this metal presents also other
advantages and its price now renders it practically available.
The new Aluminium Anode Supports may be constructed of perforated sheet
Aluminium, of a gauze or fabric composed of Aluminium wires, or of both. Each
support may consist of two parallel surfaces of the pervious Aluminium bent to the
shape of an inverted arch or to the profile of the cathode. The anode is contained.:
between the Aluminium surfaces and may be continuously supplied thereto during
use.
In substitution for the inner Aluminium surface, an equivalent pervious surface
of some suitable non-inetallic substance, such as celluloid, may be used.
This construction of the anode supports enables anodes of granular of of pulverulent
metal to be used, and particularly such substances as the Rio Tinto Precipitate.
When anodes of the latter class are employed, both the internal walls of the support.
may be lined or conted with a suitable textile fabric to retain the substance
mechanically until it is dissolved.
'
My Foreign Correspondent has found that by the use of the Anode Supportä
herein before described, it is possible to obtain deposits consisting of alloys of copper
and aluminium. For this purpose he introduces into the electrolyte, a proportion of.
Sulphate or other suitable salt of Aluminium having relation to the quantity of that "
metal which it is desired to deposit in alloy with the copper. Or, an equivalent
quantity of metallic Aluminium may be mixed with the copper of the anode, Under

page_text: these conditions and by suitably regulating the current, he is enabled to obtain
alloys containing a homogeneous deposit of the two metals.
$
He has also found certain inconveniences which accompany the use of rotary
cathodes generally. To obviate these, he prefers to employ copper mandrels coated
with a good mechanical insulator. which will prevent the adherence of the deposit to
the mandrel. For example, the mandrel may be thoroughly conted with a layer of
rubber solution, which, when it has nearly dried, is coated with fine plumbago. The
plumbago then adheres perfectly and is capable of taking a high polish. The
plumbago, forming a good electric conductor, receives the deposit freely. When
the deposit is complete, the polished surface of the plumbago and its natural
lubricative property enable the deposit to be slided off endwise, freely, and this
removal is facilitated by the mandrel being made slightly conical.
"It has also been found that when using impregnators such as are typically referred
to in the Specification herein before referred to, that is to say organic impregnators, it
is desirable to maintain the temperature of the electrolyte at about or a little below
a temperature of 16° C. This may be accomplished by heating or cooling the vats
by known means or by circulating the electrolyte beyond the vats and cooling or
heating it during circulation. Also, some of the organic matter may come into
solution or suspension in the electrolyte, from the impregnators. This can be removed
according to these Improvements, by filtration and by oxidation which may also be
carried out during the circulation of the electrolyte beyond the vats. The oxidation
may be effected by blowing warın or cold air through the electrolytic fluid, and this
insufflation may be utilised for wholly or partly obtaining the desired temperature in
the electrolyte as already hereinbefore set forth. Further, it has been found that if
the impregnators are stationary, the resulting deposit is unequal in strength
circumferentially and longitudinally. This defect is overcome by causing the
impregnator to have such a reciprocal longitudinal motion that any point in it
describes on the cathode, a path having an angle of 45°.
Dated this fund
Improvements in the Method of and Apparatus for the Electro-
deposition of Copper and other Metals on Rotary Mandrels.
I, WILLIAM EDWIN HEYS of 70 Market Street, Manchester, in the county of
Lancaster, Chartered Patent Agent, 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 method of and to apparatus for the electrodeposition
of copper and other metals upon rotary cathodes.
According to the method followed by my Foreign Correspondent for the
electrodeposition of metals, as described in the Specification of Letters Patent
No. 16360, dated the 31st day of August, A.D. 1895, he employed "regulus," that
is to say antimony and lead, anode supports because in the first place, they were
unattacked by copper sulphate solution and in the second place, because they were
inexpensive. But at the end of a certain time, it has been found that the regulus
supports become oxidised similarly to the positive plates of an electric storage
battery, and this above all when the deposit was made rapidly and consequently with a
current of great density. The layer of lead oxide which was formed not only
introduced resistance into the circuit but also, in some cases produced a counter

page_text: electro-motive force which reversed the current in the generating dynamo and made
the deposited cathode useless. One object of the present invention is to obviate
this difficulty.
For this purpose my Foreign Correspondent constructs the anode snpports of
aluminium as hereinafter described with reference to the accompanying drawings.
The use of this metal also presents other advantages and its present price renders
it available. The new aluminium anode supports are illustrated in longitudinal and
transverse sections by Figures 1 and 2 as arranged in a vat carrying a single rotary
cathode. Figures 3, 4 and 5 represent a preferred form of construction, Figures 3
and 4 respectively representing a longitudinal section and a plan, with the central
pirt broken away, and Figure 5 a cross section. A, is the vat in which the
electrodeposition takes place, and B the rotary cathode.
The anode support bearers S are aluminium castings, the flanges S of which rest
upon and may be screwed to the npper edge of the vat sides. These castings are
shaped to the contour of the cathode in their lower part and are open at the top as
shown. The bearers may be cast to take two parallel cathodes in a single vat, if
desired, instead of one only. Each anode support has drilled or produced in it a
series of holes S³, preferably so that the holes in one of the supports correspond with
the similar holes in the other supports. In the upper parts of the supports there
are two rows of these holes as shewn by Figure 5. When the supports are in
position, wooden rods $ Figures 3 and 4, are threaded through the holes to form a
kind of cage, the wall of which in the upper part is double. Any suitable fabric,
as for example, a woollen cloth or aluminium gauze, or perforated aluminium,
or sheet celluloid, or other equivalent pervious or perforated material is arranged
upon the rods when required, as for example when Rio Tinto Precipitate or granular
metal is used as anode. The inner series of rods is required to prevent the anode
in the upper part of the support from falling inwards. In the lower part. there is no
such tendency and the inner rods are not therefore required. As the anode is
consumed its residue falls by gravity into the lower part and the supply can be
replenished as required on each side from the open upper ends of the support. The
two end supports may have internal flanges S to 'prevent, the anode material
accidentally falling off into the bottom of the vat. In the modification represented
by Figures 1 and 2, similar supports S2 are supposed to he employed except that the
rods are dispensed with and the anode is carried between two perforated or pervious
walls S, S¹ of suitable material such as aluminium gauze or sheet, or perforated
celluloid and the like, kept apart by flanges S.
This construction of the anode supports possesses considerable value since it
enables anodes of granular or of pulverulent metal to be used and particularly such
substances as the Rio Tinto precipitate.
My Foreign Correspondent has found that by the use of the anodo supports
herein before described, it is possible to obtain deposits consisting of alloys of copper
and aluminium. For this purpose he introduces into the electrolyte na proportion of
Bulphato or other suitable salt of aluminium having relation to the quantity of that
metal which it is desired to deposit in alloy with the copper. Or, an equivalent
quantity of metallic aluminiuin may be mixed with the copper of the anode.
Under these conditions and by suitably regulating the current, he is enabled to
obtain alloys having a homogeneons deposit of the two inetals.
He has also found certain inconveniences which attend the use of rotary cathodes
generally. To obviate these he prefers to employ copper mandrels coated with a
good insulator which will prevent the adherence of the deposit to the mandrel. For
example, the mandrel may he thoroughly coated with a layer of indiarubber solution,
which, when it has become dry, is coated with finely powdered plumbago. The
plumbago adheres firmly and is capable of taking a good polish. It forms a good
electric conductor which takes the deposit freely. When the deposit is completed,
the polished surface of the plumbago and its natural lubricative property enable the
deposit to be slided off the mandrel endwise or to be otherwise removed, freely.
The endwise removal is facilitated if the mandrel be made slightly tapered. It has

page_text: "
also been found that when using membranes of animal origin or impregnators
such as are described in the Specification of Letters Patent No. 16300 of A.D. 1895,
hereinbefore referred to, it is desirable to maintain the temperature of the bath in
the vats at or below 16° C or 60° F. This cooling may be effected by continuously
withdrawing the electrolyte from and returning it to the vats and passing it through
cooling tanks or a cooling apparatus. A suitable cooling apparatus is sectionally
illustrated by Figure 7. It consists of a tank containing a serpentine pipe or
coil w.
This may be used in either of two ways, that is to say the electrolyte may
be caused to pass through the pipe immersed in a cooling mixture in the tank, or by
passing the electrolyte through the tank and a freezing or cooling fluid through the
pipe.
"
Also, some of the organic matter from the animal membranes or impregnators"
may come into solution or suspension in the electrolyte. This can be removed
according to these improvements by oxidation and filtration. When the electrolyte
is continually withdrawn from and returned to the depositing vats as bereinbefore
described these processes of oxidation and filtration may be carried on outside the
vats. The oxidation may be effected, in the case of copper by the addition of copper
oxide, and in other cases by the addition of other suitable oxidising agents such as
potassium permanganate. To avoid the introduction of foreign matter in the process
of oxidation, the liquid may be conveniently treated by blowing air into and through
it. The oxygen of the insufflated air combines with the contained organic matter.
The filtration may be economically carried out by means of the series of filters
represented in vertical longitudinal section by Figure 6. Each filter consists of a
tank o¹, in one end of which there is an inclined transverse filtering medium which
may be composed of a suitable woollen fabric o, stretched on the under side of a
wooden framing. On its passage through the tank the electrolytic fluid has to pass
from the under to the upper side of the filtering medium, and the solid matters will
be separated on the underside and fall to the bottom of the tank. As the passage
of the liquid through the tank is comparatively slow, the separation of the solid
matters will be aided by sedimentation. The liquid can be arranged to pass through
the filtering tanks arranged parallel or in series. The series arrangement is
represented. In either case it is desirable to provide appliances whereby any
particular tank or tanks can be cut out of the circulatory system for repairs. This
inay be accomplished by means of bye-pass pipes and control cocks as will be readily
understood. The liquid enters each tank at n, and is pumped out through the
pipes n'.
"It will be understood that for the purpose of this invention the cooling is requisite
because of the heating effect of the heavy electric current through the electrolyte in
the depositing vats, which heating effect may be modified by the temperature of the
surrounding air to some extent.
It is known that if the "impregnators" are kept stationary on the rotary cathode,
the resulting deposit is unequal in strength circumferentially and longitudinally.
This may be modified by reciprocating the "impregnator" so that any point describes
paths having angles of about 45° to the axis of the cathode.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the saine is to be performed, as communicated to me by my
Foreign Correspondent, I declare that what I claim is :-
1. In apparatus for the electrodeposition of copper and other metals, aluminium
anode supports constructed substantially as and for the purpose hereinbefore
described and as illustrated by the accompanying drawings.
2. The herein before described method for the electrodeposition of copper and other
metals derived from anodes composed of Rio Tinto precipitate or other granular or
pulverulent form of the metal to be deposited, which consists of armnging the anode
in an aluminium supported cage or partial enclosure lined with suitable perforated
or pervious material: substantially as set forth.
3. The hereinbefore described method for the electrodeposition of aluminium and

page_text: copper alloys which consists in using an aluminium anode support and in adding to
the copper anode a suitable quantity of aluminium or to the electrolyte an equivalent
proportion of an aluminium salt: substantially as set forth.
4. The herein before described method for facilitating the removal of electrodeposited
metals from rotary mandrels, which consists in coating the mandrel with an adhesive
insulating material and covering this material with finely powdered plumbago:
substantially as set forth.
5. In the electrodeposition of copper and other metals on rotary cathodes with
which there is animal membrane in contact, maintaining the temperature of the
electrolyte in the vat at or below 60° F., substantially as and by the means set forth.
6. In the electrodeposition of copper and other metals on rotary cathodes with
which there is animal membrane in contact, injecting air into the electrolyte
substantially as and for the purpose herein before set forth.
7. The herein before described method of filtration of an electrolytic fluid,
substantially as and by the means set forth and illustrated by the accompanying
drawings.
Dated this 1st du af November & D 1907