AN IMPROVED CONSTRUCTION OF CARBON ELECTRODES FOR ELECTROLYTICAL PURPOSES to be as follows:
Year: 1884

page_text: I, HENRY LIEPMANN, Managing Director of the Liepmann Carbon Company,
Limited, of Nelson Wharf, Millwall, London, in the County of Middlesex,
Chemist, Ph. D., F.C.S., etc., do hereby declare the nature of my invention for
"AN IMPROVED CONSTRUCTION OF CARBON ELECTRODES FOR ELECTROLYTICAL
PURPOSES to be as follows:-
"
In electrolytical processes, such for instance as the treatment of ores by electro-
lysis, it is frequently necessary or advisable to keep one or both of the poles or
electrodes of the apparatus employed in motion, for the purpose of agitating the
electrolyte or electrolytic solution and also the substance or material it is desired
to decompose. The material employed in the construction of these poles or electrodes.
must be such that it does not undergo any decomposition, or as little as possible,
from the electrolytic action, and for this purpose carbon is generally used.
In the case where the poles or electrodes instead of being stationary, are
required to be actuated so as to keep in motion the electrolyte and the material or
substance to be decomposed, it is necessary that their size and strength be increased
sufficiently to enable them to bear the strain to which they are subjected. It is,
however, very difficult to manufacture carbons in one piece beyond a certain size and
thickness, which shall have the necessary density and strength throughout, and the
object of my invention is to obviate this difficulty. For this purpose I propose to
form the poles or electrodes of several carbons of comparatively small sectional area,
and which can consequently be readily produced of uniform density and strength
throughout, these small carbons being bound or secured together in such a manner
as to form practically one piece, thus giving them the necessary size and strength,,
and at the same time providing a considerably increased surface.
The groups of carbons are preferably arranged between discs of suitable material,
so that the whole forms a kind of paddle wheel which is caused to rotate upon its
axis, the different groups of carbons being connected together and also to the
positive or to the negative pole of the source of electricity, so as to form either the
anode or the cathode of the electrolytical apparatus.
Date :
:

page_text: I, HENRY LIEPMANN, Managing Director of the Liepmann Carbon Company,
Limited, of Nelson Wharf, Millwall, London, in the County of Middlesex,
Chemist, Ph. D., F.C.S.. etc., do hereby declare the nature of my invention for
"AN IMPROVED CONSTRUCTION OF CARBON ELECTRODES FOR ELECTROLYTICAL
PURPOSES and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:
"
=
In electrolytical processes, such for instance as the treatment of ores by electro-
lysis, it is frequently necessary or advisable to keep one or both of the poles or
electrodes of the apparatus employed in motion, in order to maintain in as constant
a state of agitation as possible the electrolyte or solution subjected to electrolysis
and also the material upon which it is desired to act. The substance employed in
the construction of these electrodes must be of such a nature that it does not itself
undergo any material electrolytical decomposition, and for this purpose carbon is
generally employed.
In the case where the poles or electrodes instead of being stationary are
required to be actuated so as to keep in motion the electrolyte and the material or
substance to be acted upon, it is necessary that their size and strength be increased
sufficiently to enable them to bear the strain to which they are subjected.
The manufacture of carbon in one piece, which shall have the necessary uniform
density, homogeneousness of material and strength throughout, beyond a certain
size and thickness, presents; however, considerable difficulties. The object of my
invention is to devise means by which these essential qualities of size combined'
with uniform strength, homogeneousness of material and density shall be produced
in the electrodes, without the necessity of manufacturing them in one continuous
piece or block. For this purpose I form the poles or electrodes of several carbon
pieces of any convenient shape and of comparatively small sectional area, which
can readily be produced of uniform density and strength throughout. These
small carbon pieces are united together so as to form a body, which shall behave as
far as electrical conductivity is concerned, as nearly as possible as one homogeneous
mass.
T..
The manner of binding or connecting together the separate carbon pieces of small
sectional area, so as to produce one large piece, may be varied according to require-
ments, but I prefer to employ one of the following methods:-
1st By securing the intimate contact of the individual carbon pieces forming the
compound carbon, by supporting them so that they shall be pressed together, either
at their ends or other convenient part, in the electrolytical apparatus.
2nd By ensuring a contact between the carbon pieces forming the compound
carbon; by casting a suitable metal, such as lead, at the ends or other part, between
or around the individual carbons of which the pole or electrode is built up. The
lead or other metal when applied at such part of the electrode where it would'
become exposed to the action of the electrolytic solution is protected by a suitable
non-conductive varnish or covering.
3rd By embedding the individual carbon pieces from which the compound carbon
is formed, at certain points where contact is desired, in a suitable plastic carbon
material, which when passed through the various stages of carbon manufacture
shall form as ultimate product at these points, a solid mass, as nearly as practical.
4th By treating the individual carbon pieces forming the compound carbon
throughout their entire length with such plastic carbon material, so that when
passed through the various stages of carbon manufacture they shall form throughout
their entire length a practically solid mass.

page_text: It will be readily understood that instead of employing only one of the above
methods, two or more of them may be combined for the purpose of ensuring the
contact of the individual pieces at the desired points.
By thus ensuring good electrical contact between all the pieces forming the
compound carbon, when the latter is connected to the source of electricity a thorough
efficiency of the whole electrode is practically obtained.
In the accompanying sheet of drawings
Fig. 1. Represents a bundle of seven carbons a, which when mounted in the
electrolytical apparatus are held securely together by compression, as described in
the first method of securing the carbon pieces together. A number of the compound
carbons are shown in Fig. 5, mounted between two discs d, d, for use in a revolving
electrolytical apparatus.
Fig. 2. Represents a bundle of seven carbons a, metallically connected (as
shown at b, b,), as described in the second method of securing the carbon pieces
together.
Fig. 3. Represents a bundle of seven carbons a, secured together by the plastic
carbon material c, at certain points, as described in the third method of securing
the carbon pieces together.
Fig. 4. Represents a bundle of seven carbons a, secured together by the plastic
carbon material c, throughout their entire length, as described in the fourth method
of securing the carbon pieces together.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :-
The manufacture of carbon electrodes of any convenient shape, consisting of a
number of pieces of carbon of comparatively small sectional area, bound together
so as to form one piece of practically uniformn density, strength and homogeneous-
ness of material throughout, the, compound carbon pieces being employed to form
one or both electrodes of electrolytical apparatus in which the electrolytic solution
and the materials to be treated are kept in motion.
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