Improved Process for the Production of Electrolytic Copper.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improved Process for the Production of Electrolytic Copper.
I, MARCEL PERREUR-LLOYD of 5 Rue Cassette, Paris, France, Mining
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 :-
In the electrolytic production of copper processes have recently been adopted by
which products possessing qualities hitherto unknown have been placed on the
market, but the objection to these processes is their high cost as under present
conditions it is impossible in practice to deposit more than from one to two grammes
of copper per square decimetre of electrode and therefore to produce, say, one ton
of electrolytic copper per day it would be necessary to handle about one hundred
tons of copper which would represent considerable capital and necessitate the
employment of costly baths occupying a very large space.
The electrolytic refining of copper is for the above reasons an onerous operation
which is only capable of being applied in particular cases. If, however, it were
possible to operate with fifty ampères per square decimetre the operation would be
rendered much more economical and enable the production on a practical scale
and at a low cost of goods now made by rolling pressing and hammering, etc.
It is this object which is sought to be attained by the present invention.
By the
agitation either of the electrodes or of the solutions in which they are immersed, an
excellent highly-adhesive deposit of copper may be obtained when working with
fifty ampères per square decimetre, the metal being deposited of a thickness of one
millimetre in about 1 hours. This agitation as herein carried out constitutes an
entirely new electro-metallurgical process as the agitation of the electrodes or the
liquid in electro-metallurgical operations as heretofore practised has merely had
the effect of rendering uniform the deposit or the composition of the bath, this
being the only result possible in working with one or two ampères per square
decimetre.
In this improved electrolytic process using fifty, or even one hundred, ampères
per square decimetre (which gives a deposit of one hundred grammes of copper)
the agitation plays an entirely novel part. A deposit obtained under similar con-
ditions without agitation would be muddy and of no commercial value, whereas the
agitation as here applied has the effect not of rendering the deposit uniform but
of absolutely changing its nature by preventing the crystallization of the metal.
As in certain solutions of metallic salts it is possible to obtain the formation of
crystals presenting the appearance of ferns (Saturu's tree, etc.,) so in rapidly
depositing copper in a tranquil medium the points become charged and the metal
is obtained in the form of filaments or dust. By agitation however, crystallization
is prevented and the character of the copper deposited is absolutely changed, it
acquires the qualities of cast copper, is sonorous, and possesses the best mechanical
qualities. In a word, agitation has heretofore merely rendered the deposit uniform
without changing its character whereas in the present process it gives rise to a
deposit of an entirely new character and with the result that the same output can
be obtained with a plant and quantity of metal in use, from thirty to fifty times
less. Hence the commercial application of electro-metallurgy becomes more
economical in certain cases than the mechanical operations to which copper is
subjected in order to give it a merchantable form, such as rolling, hammering,
stamping, making tubes, etc. By the combined effect of intense action with
agitation a pure electrolytic copper may be rapidly obtained, possessing the
qualities of cast metal. In the same manner, copper can be economically applied
for coating all kinds of metals or alloys, so as to render them bi-metallic or generally
Price 8d 1

page_text: for copper plating, to any required thickness, articles which are conductive or
rendered so by suitable treatment.
I lay great stress on the fact that the products obtained possess all the qualities
of cast and rolled metal which is the reverse of that which takes place in the
processes actually in use.
The invention is entirely independent of the mechanical means employed for
effecting the agitation of the electrodes, or of the bath, as any suitable mechanical
arrangements may be adopted.
Having now particularly described and ascertained the nature of the said inven-
tion, and, in what manner, the same is to be performed, I declare that what I
claim, is:
1st. In the production of electrolytic copper the process of agitating either the
bath or the electrodes and of working at a rate of, say, fifty or even one hundred
ampères per square decimetre so as to deposit per decimetre and per hour from
sixty to one hundred grammes or more, of metal as specified, instead of using only
from one to two ampères per square decimetre yielding a deposit of from 1 to
2.30 grammes only per decimetre, as in the ordinary processes.
2nd. As a new commercial product electrolytic copper possessing the qualities
of cast metal and obtained direct, substantially in the manner herein described.
Dated this 20th day of February 1893
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M. PERREUR-LLOYD,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents..