Improvements in the Electrolytical Production of Nickel and other Metals.
Year: 1893

page_text: Date of Application, 8th July, 1893
Complete Specification Left, 7th Apr., 1894-Accepted, 25th May, 1894
PROVISIONAL SPECIFICATION.
Improvements in the Electrolytical Production of Nickel and other
Metals.
I, CARL HOEPFNER, of 36 Frankfurterstrasse, Giessen, in the Empire of
Germany, Doctor of Philosophy, do hereby declare the nature of this invention to
be as follows:-
Solutions of nickel are purified from cobalt and other metals more electro-
negative than nickel contained therein. Then they are electrolysed in a neutral
state or acidulated by weak acids of small electrolytical conductivity for instance,
citric acid and phosphoric acid and the like. The electrolysis takes place by means
of insoluble anodes, immersed in a solution of metal or of metals more electro-
positive than nickel and commonly separated from the cathodes by a membrane
strong enough to resist chemical and mechanical actions. I use porous diaphragms
of nitrated liuen or cotton cloth, sometimes combined with asbestos.
At the anodes chlorine is produced, which is made use of in the known ways.
On the cathodes nickel is deposited. It is most useful to keep the cathodes in
motion. For this purpose I prefer to use as cathodes rotating vertical and parallel
metallic discs, mounted on a revolving horizontal axis just above the surface of the
electrolyte.
These rotating cathodes can be kept equal and free from spongeous matter by
brushes, cushions or the like. I sometimes inake use of vibrating cathodes only, or
the electrolyte is caused to rise and sink continuously by means of a pump.
Between two rotating cathodes there is an anode-cell. Instead of the insoluble
anodes in some cases, that is to say, whenever it appears to be advantageous to
produce solutions of zinc, anodes of zinc may be used, generally anodes consisting
of a metal more electropositive than the metal to be deposited.
In the same way I produce cobalt from pure cobalt solutions and in the same
way I get zinc from solutions of zinc, lead from solutions of lead, tin and copper
from their protochloride-solutions.
For the production of copper I make use of cuprous chloride solutions at the
cathodes.
These solutions of cuprous chloride I prepare in some cases electrolytically from
cupric chloride or cupric sulphate solutions mixed with hydrochloric acid, common
salt, chloride of calcium using cathodes kept in motion as above described.
Dated this 8th day of July 1893
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Electrolytical Production of Nickel and other
Metals.
1, CARL HOEPFNER, of 36 Frankfurterstrasse, 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 :-
Solutions containing nickel or cobalt are purified in the known manner from the
more electronegative metals which may be contained therein or separated from each
[Prine 27

page_text: other, and electrolysed, in the neutral state or slightly acidulated by any bad-
conducting, weak oxy-acids, such as for instance citric acid, phosphoric acid, in
a bath with insoluble anodes, for which among other materials use may be made of
carbon, platinum, iron silicide, which are surrounded by the chloride solution of one
or more metals which are more electropositive, such as by solutions of say sodium
chloride, potassium chloride, calcium chloride, magnesium chloride, and are
separated from the cathodes suitably by a membrane resisting mechanical and
chemical actions and which will hereinafter be referred to.
At the anodes, chlorine is generated and conducted away and utilized at will.
At the cathodes, nickel or cobalt is precipitated.
It is expedient to keep the cathodes in rotary or oscillatory (vibrating) motion.
This takes place preferably by making the same of vertical metallic discs fixed upon
a horizontal axis provided above the level of the liquid and set in rotation.
These moving cathode discs may be kept regular by suitably arranged brushes,
rubbing cushions or the like.
Between each two cathode discs is an anode cell. Instead of the insoluble
anodes, use may also be made of wholly or partially soluble anodes of more
electropositive metal than the metal to be separated, which do not at the
same time render the nickel or cobalt precipitate impure; thus zinc anodes may in
most cases be employed as soluble anodes. The metallic (zinc) solution obtained
from the soluble metal of such anodes may then be treated electrolytically or
otherwise at will.
The electrode plates are preferably arranged parallel to each other and some or
all of them may be separated by membranes.
The production of nickel or cobalt thus succeeds very well. In an analogous
manner I obtain according to the present invention zinc from zinc solutions, lead
from lead chloride solutions, and tin and copper from stannous and cuprous chloride
solutions. For the production of copper, solutions of copper sulphate and cupric
chloride are not adapted, but cuprous chloride solutions yield double as much
copper as these, that is to say pure copper of good quality, which, as known, is not
the case with the other copper solutions. The preparation of the cuprous chloride
solutions adapted for the before-described electrolysis may take place in any desired
and known manner. For this purpose metallic copper may be caused to act upon
a cupric chloride solution which contains a solvent of cuprous chloride (such as
for instance sodium chloride or calcium chloride) at the ordinary temperature, or
with the use of some heat. If desired they may also be produced electrolytically
by conducting by means of electrodes an electric current through copper sulphate
or cupric chloride liquors, which are mixed with a comparatively large quantity of a
solvent of cuprous chloride, such as for example hydrochloric acid common salt or
calcium chloride; at the cathodes, which may be set in motion, a reduction takes
place to form cuprous chloride which if desired is purified.
The before-mentioned membranes used in this method, and which resist chemical
and mechanical actions, consist according to the present invention of nitrated
cellulose, such as for instance nitrated cotton or nitrated linen.
If the membrane is to be particularly strong, which is very desirable especially
for the electrolysis of copper, I use according to the present invention asbestos for
the said membrane, so that it is composed of nitrocellulose (nitro-cloth, nitro-linen
or the like) and asbestos. In such a case the membrane may be so composed
that it consists of nitro-cloth, nitro-linen or the like, against which is placed, on the
cathode side, asbestos which on this side is held together with a cheaper material,
It is moreover
such as woollen or jute fabric, and fixed to the nitro-membrane.
expedient to protect the membranes towards the cathode side by a strong grate or
sieve of wood, glass, stone or other durable material from mechanical injuries which
may be caused by the rotating cathodes thickening in the course of the electrolysis
in consequence of electrolytic depositions.
It is also advantageous, for obtaining a better electrolytic action, to keep the
electrolyte in motion by means of a pump or the like, so that the level of the

page_text: liquid is alternately raised and lowered which operation may be wholly or partially
substituted for the movement of the cathodes.
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 what I
claim is :-
First. The electrolytic production of nickel and cobalt by electrolysing their
solutions in a neutral or slightly acidulated state at the rotary or oscillatory
vibrating cathodes of a bath with electrolytically insoluble anodes, which are
separated from the cathodes suitably by a membrane resisting mechanical and
chemical actions, and are surrounded by a chloride solution, chlorine and nickel or
cobalt being produced at the same time.
Second. In the process for the electrolytic production of nickel and cobalt the
employment of moving cathodes in such a manner that these are fixed, as vertical
discs rotating between the anode cells, upon an axis above the level of the liquid,.
or that the said cathodes, in the form of vertical plates are kept in oscillating or
vibrating movement, the membranes being if desired mechanically protected in a.
suitable manner.
Third. In the process for the electrolytic production of nickel and cobalt the
substitution of the insoluble anodes wholly or partially by zinc or more electro-
positive metals which are dissolved without at the same time rendering the nickel.
or cobalt precipitate impure.
Fourth. In the process for the electrolytic production of nickel and cobalt the
keeping of the solutions in question at the cathodes in an acidulated state by
bad-conducting weak oxy-acids, for example citric acid, phosphoric acid or
the like.
Fifth. The application of the above described process with vertical, moving
cathodes to the electrolytic production of zinc from zine solutions, lead from
lead chloride solutions, tin from stannous chloride solutions, and copper from cuprous
chloride solutions, which latter may also be produced if desired by the electrolytic
treatment of cupric chloride solutions mixed with solvents of cuprous chloride,
such as for instance common salt or similarly acting substances, at the moving
cathodes.
Sixth. In the described process for the electrolytic production of metals.
besides that of chlorine the substitution of the movement of the cathodes
wholly or partially by alternately raising and lowering the level of the liquid-
electrolyte.
Seventh. In the process for the electrolytic production of nickel and cobalt the
employment of diaphragms, consisting of a fabric of nitrated cotton or nitrated
linen which may be thickened and strengthened in a suitable manner by asbestos.
and also mechanically protected in a suitable manner, such as by a grate or sieve of
wood, stone or glass or the like, against being injured by the moving cathodes.
A 1 1004
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.