Improvements in Means to be employed in the Electrical Deposition of Copper and the Obtainment of Products from the Operation.
Year: 1891

page_text: Date of Application, 29th July, 1891
Complete Specification Left, 8th Sept., 1891-Accepted, 10th Oct., 1891 ·
PROVISIONAL SPECIFICATION.
Improvements in Means to be employed in the Electrical Deposition
of Copper and the Obtainment of Products from the Operation.
I, THOMAS PARKER, Works Director, to the Electric Construction Corporation
Limited of Wolverhampton, in the County of Stafford, do hereby declare the
nature of this invention to be as follows:-
In the commercial electro-deposition of copper great difficulty is found in
getting pure copper deposited. This is due to the presence in the copper from
which the deposit is made of foreign metals such as arsenic, iron, bismuth and
antimony which foreign metals are dissolved into the solution with the copper_so
that the solution becomes gradually charged with these foreign metals which render
it impure and unfit for prolonged use. Gold and silver may also be present. Also
if the electro motive force is by any reason raised across the vessels in which the
process is carried on or the solution becomes charged by the foreign metals there
is a continual tendency of the said foreign metals to deposit with the copper
rendering it impure and reducing its value as a final product. for electrical or other
purposes where pure copper is required.
.
Pure copper will deposit reguline and satisfactorily with a pure solution of
sulphate of copper and excess of sulphuric acid, up to approximately 15 ampères
per square foot of area of the anodes, such ampèreage requiring from half to three
quarters of a volt electrical pressure across the anodes in the vessels in which the
process is carried on; but as the solution becomes charged with the dissolving of the
foreign metals they become deposited with the copper at this voltage, thus
rendering the copper impure.
According to my invention I arrange with the vessels a special vessel or special
vessels in which the area of the anode plates is reduced, so that to drive the
thereby increased current across the reduced anode section in the special vessel
or vessels and taking the whole current used in the other vessels a raised voltage
is obtained and by this increased voltage the aforesaid foreign metals are con-
tinuously deposited from the solution giving an impure copper in the special. vessel
or vessels and maintaining the solution in a normal condition. The whole solution
is kept in continual circulation through the whole series of vessels the current in
the special vessel or vessels as described operating on the whole solution as it
circulates through the series of vessels. The foreign metals are thus obtained
combined with the copper in the special vessel or vessels thus giving greatly
lengthened activity to the solution and enabling the deposition of copper to be
continued at a much higher speed than has been hitherto practicable.
I may treat the residue chemically while in the finely divided state and extract
the various metals in the form of their various salts and deposit them by electricity
thereby obtaining the bismuth, tin, antimony or the like which is now chiefly lost.
I can also obtain the gold and silver pure and separate as any gold and silver
which may be precipitated at the bottom of the vessel or vessels may be melted up
with a flux and an alloy is obtained which may then be treated for the obtainment
of the gold.
Dated this 29th day of July 1891
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Means to be employed in the Electrical Deposition
of Copper and the Obtainment of Products from the Operation.
I THOMAS PARKER, Works Director to the Electric Construction Corporation
Limited of Wolverhampton in the County of Stafford, 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 commercial electro-deposition of copper great difficulty is found in getting
pure copper deposited. This is due to the presence in the copper from which the
deposit is made, of foreign metals, such as arsenic, iron, tin, bismuth and antimony,
which foreign metals are dissolved into the solution with the copper, so that the
solution becomes gradually charged with these foreign metals, which render it
impure and unfit for prolonged use. These eventually becoming deposited with
the copper, render it impure and reduces its value as a final product for electrical
or other purposes where pure copper is required. The gold and silver do not
become soluble in the solution, but fall as oxides or sulphides or in the metallic
state to the bottom of the vessels..
Pure copper will deposit reguline and satisfactorily, with a pure solution of
sulphate of copper and excess of sulphuric acid up to approximately 15 amperes
per square foot of area of the anodes, such amperage requiring from half to
three quarters of a volt electrical pressure across the electrodes in the vessels in
which the process is carried on, but as the solution becomes charged with the
foreign metals, they become deposited with the copper at this voltage, thus
rendering: the copper impure. According to my invention I arrange in the series
circuit with the vessels in which deposition is carried on a special vessel or vessels;
in which the area of the anode plates is reduced, so that to drive the current across
the reduced anode section, in the special vessel or vessels, taking the whole current
used in the other vessels a raised voltage is obtained in the special vessel or vessels,
and by this increased voltage the arsenic iron, bismuth and antimony that may be
present in the solution in the special vessel or vessels are deposited from the
solution at the cathode in the said special vessel or vessels giving an impure copper
therein and maintaining the solution in a normal condition in the other vessel or
vessels. The whole solution is kept in continual circulation or passage through
the whole series of vessels the electric current in the special vessel or vessels as
described operating on the whole solution as it circulates through the series of
vessels.
The accompanying drawing illustrates in elevation in Figure: 1 and plan in
Figure 2 an arrangement according to this invention:
A are the ordinary electrolytic vessels: and B is a special vessel in the same
electric circuit and having an anode or anodes of an area less than those in the
vessels A. C are the outlets for the circulation or passage of the electrolyte as
indicated by the arrows in Figure 2. A suitable superficial area for the anodes in
superficial area of the anodes in the other
proportion.
the vessel or vessels B is or of the
vessels but I do not limit myself to that
The foreign soluble metals are thus obtained combined with the copper in the
special vessel or vessels, thus giving greatly lengthened activity to the solution
and enabling the deposition of copper to be continued at a much higher speed than
has been hitherto practicable.
The deposit removed from the vessels consists chiefly of sulphide of copper and
silver, gold and bismuth, either as sulphides or oxides or in the metallic state.
This is preferably roasted and then the copper is dissolved out therefrom with
dilute sulphuric acid, leaving behind the gold, silver and bismuth. I then treat
the residue with hot concentrated sulphuric acid and remove the silver and then
the residue is treated with a solution of cyanide of potassium to obtain the

page_text: gold. The solutions are then subjected separately by electrolysis to obtain the
metals therefrom.
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. In the electro deposition of copper the combination with the electrolytic
vessel or vessels of a special vessel or special vessels with anodes of less area than
those in the electrolytic vessel or vessels in the series substantially as and for the
purpose hereinbefore described.
2. In the electro deposition of copper substantially as herein before described
the treatment of the deposit from the special vessel or vessels substantially as
hereinbefore described for the recovery of the metals separately.
Dated this 8th day of September 1891.
J. H. JOHNSON & Co.,
Agents.