Process for the Separation of Copper, Nickel, and Silver from Matts or Alloys containing the same, and the Treatment of the Residues resulting therefrom.
Year: 1891

page_text: Date of Application, 11th Mar., 1891
Complete Specification Left, 10th Nov., 1891-Accepted, 12th Dec., 1891
PROVISIONAL SPECIFICATION.
Process for the Separation of Copper, Nickel, and Silver from Matts
or Alloys containing the same, and the Treatment of the Residues
resulting therefrom.
I JULES STRAP, of No. 1 Boulevard St. Denis, Paris, France, do hereby declare
the nature of this invention to be as follows:-
Up to the present time it has not been possible to separate respectively the
copper, the nickel and the silver from the matts or alloys containing these metals
for example in combination with lead, arsenic, sulphur and silica, in such a manner
as to obtain them in a pure condition. Consequently it has not yet been possible
to utilise the numerous metalliferous materials containing considerable percentages
of both copper and nickel combined with a small proportion of silver and a gangue
of any description.
My invention has for its object an electrolytic process whereby the said separation
can be readily effected so as to obtain chemically pure metals.
It consists in the following operations
In a bath of sulphate of copper containing, say, from 125 to 250 grammes of
crystallised sulphate to the litre of water (the proportion of sulphate being made
to vary according to the quantity of matter treated), I introduce a certain quantity
of sulphuric acid for acidulating the bath, for example in the proportion of from
1 to 15 per cent. in volume, the best proportion being 5 per cent.
then pass through
the bath an electric current of from 25 to 30 ampères for a cathode having one
square metre of surface, and of the electromotive force of half a volt.
The matt to be treated is run into the form of plates and constitutes the anode,
while the cathode is formed of a thin plate of copper.
Under the action of the current, the copper of the sulphate is deposited at the
cathode, and the liberated sulphuric acid passes to the anrde, where it attacks
simultaneously the copper and the nickel contained therein, the proportion of
copper attacked being much greater than that of the nickel when these are present
in equal proportions in the matt. The nickel passes into the form of sulphate and
remains in the liquor; the copper again forms sulphate of copper in solution
which is again decomposed at the cathode.
In consequence of the formation of the sulphate of nickel, the bath becomes
gradually weaker in sulphate of copper, as the quantity of sulphuric acid remains
the same, and part thereof serves to form the sulphate of nickel, which is by
degrees substituted for the sulphate of copper, while the cathode rapidly increases
in volume.
Consequently a time will arrive when there will be no more sulphate of copper
in solution in the bath, which will consist entirely of sulphate of nickel, the copper
having been deposited at the cathode. Furthermore I greatly increase the richness
in sulphate of nickel by means of the free sulphuric acid added to the bath, as this
only attacks the nickel of the matt; by always maintaining the bath acid, the
sulphate of nickel is never decomposed.
When there is no more sulphate of copper in the liquor, this is passed into
another recipient where it is concentrated so as to crystallise the sulphate of
nickel.
Or I pass a strong electric current into the bath while adding sulphate of
ammonia, and thus obtain chemically pure metallic nickel electrolytically
deposited.
The sludge deposited at the bottom of the bath, which contains the silver
together with the other foreign matters, is dried and roasted for removing the

page_text: sulphur, the sulphurous acid being collected by condensation for producing
sulphuric acid, while the silver is obtained from the roasted sludge by cupellation.
In place of using sulphuric acid in the above described process other acids such
as nitric or hydrochloric acid, may be used, that will form salts of nickel and
copper of which only the latter will decompose under the action of an electric
current under certain conditions.
Dated this 11th dor of March 1901
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process for the Separation of Copper, Nickel, and Silver from Matts
or Alloys containing the same, and the Treatment of the Residues
resulting therefrom
I, JULES STRAP, of No. 1 Boulevard St. Denis, Paris, France, 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 :-
:―
Up to the present time it has not been possible to separate respectively the
copper, the nickel and the silver from the matts or alloys containing these metals,
for example, in combination with lead, arsenic, sulphur and silica, in such a manner
as to obtain them in a pure condition. Consequently it has not yet been possible
to utilise the numerous metalliferous materials containing considerable percentages
of both copper and nickel combined with a small proportion of silver and a gangue
of any description.
My invention has for its object an electrolytic process whereby the said
separation can be readily effected so as to obtain chemically pure metals. It
consists in the following operations:-In a bath of sulphate of copper, containing,
say, from 125 to 250 grammes of crystallised sulphate to the litre of water (the
proportion of sulphate being made to vary according to the quantity of matter
treated) I introduce a certain quantity of sulphuric acid for acidulating the bath,
for example in the proportion of from 1 to 15 per cent. in volume, the best pro-
portion being 5 per cent. I then pass through the bath an electric current of
from 25 to 30 ampères for a cathode having one square metre of surface, and of the
electro motive force of half a volt.
The matt to be treated is run into the form of plates and constitutes the anode,
while the cathode is formed of a thin plate of copper.
Under the action of the current, the copper of the sulphate is deposited at the
cathode, and the liberated sulphuric acid passes to the anode, where it attacks
simultaneously the copper and the nickel contained therein, the proportion of
copper attacked being much greater than that of the nickel when these are present
in equal proportions in the matt. The nickel passes into the form of sulphate and
remains in the liquor; the copper again forms sulphate of copper in solution which
is again decomposed at the cathode.
In consequence of the formation of the sulphate of nickel, the bath becomes
gradually weaker in sulphate of copper, as the quantity of sulphuric acid remains
the same, and part thereof serves to form the sulphate of nickel, which is by
degrees substituted for the sulphate of copper, while the cathode rapidly increases
in volume.
Consequently a time will arrive when there will be no more sulphate of copper
in solution in the bath, which will consist entirely of sulphate of nickel, the copper
having been deposited at the cathode.
Furthermore greatly increase the richness in sulphate of nickel by means of
the free sulphuric acid added to the bath, as this only attacks the nickel of the
matt; by always maintaining the bath acid, the sulphate of nickel is never
decomposed,

page_text: When there is no more sulphate of copper in the liquor, this is passed into
another recipient where it is concentrated so as to crystallise the sulphate of
nickel.
Or I pass a strong electric current into the bath while adding sulphate of
ammonia, and thus obtain chemically pure metallic nickel electrolytically
deposited.
The sludge deposited at the bottom of the bath, which contains the silver
together with the other foreign matters, is dried and roasted for removing the
sulphur, the sulphurous acid being collected by condensation for producing
sulphuric acid, while the silver is obtained from the roasted sludge by cupellation.
In place of using sulphuric acid in the above described process, other acids such
as nitric or hydrochloric acid, may be used, that will form salts of nickel and
copper of which only the one or the other kind will decompose under the action
of an electric current under certain conditions.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An electrolytic process for separating the copper the nickel and the silver
contained in matts or alloys with or without other metals or metalloids, such
process consisting in passing an electric current into a bath of acidulated sulphate
of copper, the matt or alloy to be treated being formed into slabs constituting the
anode of the bath, while the cathode is formed by a thin plate of copper,
substantially as described.
2. In the electrolytic process referred to in the first claim the method effecting
the separation of the nickel and copper separately from the matt or alloy forming
the anode, employing as electrolyte an acidulated solution of such a nature that
while the acid employed will form salts with both metals only one of these salts
will be decomposed by the electric current under certain conditions, substantially
as described.
3. In the electrolytic process referred to in the preceding claim, the method of
effecting the separation of the nickel of the matt or alloy by the combination
therewith of the sulphuric acid liberated by the current, forming sulphate of
nickel which is either concentrated and crystallised, or electrolytically decomposed,
substantially as described.
4. In the electrolytic process referred to in the first claim, the method of adding
to the electrolytic bath an excess of acid in order to increase the proportion of
sulphate of nickel produced and to prevent its decomposition by the current,
such acid being made to attack the nickel of the anode and not the copper,
substantially as described.
5. In combination with the electrolytic process referred to in the first claim the
method of extracting the sulphur contained in the sludge produced by the
electrolytic process and converting it into sulphuric acid, substantially as
described.
Dated this 10th day of November 1891.
ABEL & IMRAY,
Agents for the Applicant.