Improvements in Electro-depositing Copper. Brass, and Bronze, . parts of which Improvements are also applicable to other Electrolytic Purposes.
Year: 1891

page_text: Date of Application, 8th Apr., 1891
Complete Specification Left, 8th Jan., 1892-Accepted, 13th Feb., 1892
PROVISIONAL SPECIFICATION.
Improvements in Electro-depositing Copper. Brass, and Bronze,
. parts of which Improvements are also applicable to other
Electrolytic Purposes.
We WILLIAM HENRY WALENN of No. 9 Carleton Road Tufnell Park,
London, N. Consulting Electrician and ILLIUS AUGUSTUS TIMMIS of No. 2 Great
George Street Westminster London, S. W. Civil Engineer, do hereby declare the
nature of this invention to be as follows:-
This invention relates to electro-depositing copper brass and bronze upon iron or
upon similar metals.
The solution which is preferred for electro-depositing copper is worked at a
temperature of 130° Fahr. or thereabouts and is charged with copper partly by
electrolysis and partly by the subsequent addition of ammonia-cupric oxide. The
ingredients used to make the solution are of special character and are made in a
manner peculiarly suitable to their thoroughly efficient use in this invention: they
are:-
Cyanide of potassium containing 40 per cent. of real cyanide-KON.
Neutral tartrate of ammonium made by the addition of ammonia-water (specific
gravity 880) to an aqueous solution of tartaric acid of a certain strength.
Ammonia-cupric oxide made from freshly precipitated hydrated oxide of copper
dissolved in ammonia-water of specific gravity 880, in a closed vessel, until no
more hydrated oxide is taken up.
Water. Distilled water is preferred, but pipe water as used for the supply of
towns may be used.
to
The solution which is charged by electrolysis is hereinafter called the "solvent
solution" and is made as follows:-Standard solutions are made of the cyanide above"
described and of the neutral tartrate respectively. The proportions of the
standard cyanide are-to a gallon of water-2 pounds avoirdupois; the white
cakes of cyanide are dissolved in water, at the ordinary temperature, with stirring,
and, if cloudy the solution may be filtered. The standard tartrate of ammonium
solution is made by dissolving 23 ounces of tartaric acid in 5 pints of water
this solution ammonia water (specific gravity 880) is added gradually until the
crystalline precipitate at first formed is entirely dissolved-stirring the whole time.
The solution of the precipitate is, in this plan of making the tartrate, an index of
near approach to neutralisation of the acid; the addition of ammonia-water to the
acid solution is continued until it is distinctly alkaline, and the volume of liquid is
made up to a gallon by the addition of water. To neutralize the acid about
19 ounces of ammonia-water will be required.
In precipitating the hydrated oxide of copper from the sulphate by means of
caustic potash, a slight excess of potash added to the sulphate solution. After
being washed in many waters and then separated out on a filter, this precipitate,
whilst still wet, is dissolved in the ammonia-water, as above set forth, to make the
ammonio-cupric oxide used in this invention.
The solvent solution, for electro-depositing copper consists of:—
Standard cyanide solution, by measure
Standard tartrate solution, by measure
Ammonio-cupric oxide by measure -
-
32 parts.
1 part.
5 parts.
The solvent solution is charged with copper in the proportion of two or three
ounces of couner nor aallon and sufficient ammonia cupric oxide is afterwards added

page_text: To work the depositing solution at a heat of 130° Fahr. it is necessary to add
boiling water from time to time to make up for evaporation. The solution may
be worked from 20° to 30° Twaddell without inconvenience; the determination of
specific gravity should be taken at 60° Fahr.
The solution which is preferred for electro depositing brass is made and worked
in a similar way to that described above for the copper solution, but, in making the
solvent solution, equal parts of standard cyanide and tartrate solutions are used.
For bronze the solution is made and worked in a similar way to that described
above for the copper solution, but six parts of the cyanide to one part of the
tartrate are used to make the solvent solution.
The anode for electro-depositing brass may be a compound one composed of
copper and zinc, the relative proportion of the surface of each metal being the
same as that of the metals in the alloy to be deposited. This is also the case
with bronze, in which a compound anode of copper and tin may be used.
It is an essential part of this invention that no other kind of cyanide is used
than that containing 40 per cent. of real cyanide.
In the first part of the invention set forth in No. 1639 A.D. 1882, 70 per cent.
real cyanide was used but this was found upon extensive practice, to yield a
solution that varied in the amount of copper retained in solution during deposition
to such an extent that it frequently would not work.
per cent.
In consequence of the 60 per cent. of impurity or diluent of the 40
cyanide being principally composed of carbonate of potash, the stability of the
solution is ensured and its equable action is secured.
It is also an essential part of this invention that the tartrate of ammonium
standard solution is made as set forth above and that it should be slightly alkaline;
the tartrate solution should always be added gradually, in the cold, to the cyanide
solution. Any other plan of making the solvent solution than that set forth herein
has proved ineffectual.
It is also an essential part of this invention that the ammonio-cupric oxide is
made as set forth above, for when so made, the maximum amount of copper is
retained in solution and the chemical union of the ammonio-cupric oxide with the
cyanide is more nearly perfect than it can be by any process to produce a stable
ammonio-cyanide.
The making and charging of these solutious is entirely done in the cold.
The electric power may be a single volt in each of the above described solutions,
but to save time-that is to deposit faster-three volts or more may be employed.
To test the amount of metal per gallon in a depositing bath, equal sized anodes
and cathodes are arranged in the bath, and it is heated or not, so as to put it in a
truly normal condition for electro-deposition a suitable amount of current being
used. Then a polished steel bar, or wire, of a known area and weight, is immersed in
the solution whilst it is in action, and momentarily connected with the cathodes.
If a pink coating of copper, in the alkaline copper bath for instance, appears on
the polished steel immediately and with the shortest time of electric contact that is
possible, the solution is in good order and contains not less than 4 ounces per
gallon. A table may be constructed for a given electro-motive force and giving
the amounts of copper per gallon which correspond to various times of electric
contact and the corresponding increase of weight of the steel bar for those times.
This part of the invention is applicable to all electro-depositing solutions and
obviates the necessity for chemical analysis of the solution from time to time.
It is necessary that the water added to the electro-depositing solution, auto-
matically or otherwise, from time to time should be boiling, otherwise the solution
is apt to yield a precipitate which takes out a portion of its copper or other
metal.
. Dated this 8th den at du 1001

page_text: COMPLETE SPECIFICATION.
Improvements in Electro-depositing Copper, Brass, and Bronze,
parts of which Improvements are also applicable to other
Electrolytic Purposes.
We WILLIAM HENRY WALENN of No. 9 Carleton Road, Tufnell Park,
London N. Consulting Electrician and ILLIUS AUGUSTUS TIMMIS of No. 2 Great
George Street, Westminster London S.W. Civil 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:-
This invention relates to electro depositing copper brass and bronze upon iron
or upon similar metals.
The solution which is preferred for electro-depositing copper is worked at a
temperature of 130° Fahrenheit or thereabouts and is charged with copper partly
by electrolysis and partly by the subsequent addition of ammonio-cupric oxide.
The ingredients used to make the solution are of special character and are made
in a manner peculiarly suitable to their thoroughly efficient use in this invention ;
they are:-
Cyanide of potassium containing 40% of real cyanide-KCN.
Neutral tartrate of ammonium made by the addition of ammonia-water (specific
gravity 880) to an aqueous solution of tartaric acid of a certain strength.
Ammonio-cupric oxide made from freshly precipitated hydrated oxide of copper
dissolved in ammonia-water of specific gravity 880, in a closed vessel, until no
more hydrated oxide is taken up.
Water Distilled water is preferred, but pipe water as used for the supply of
towns may be used.
The solution which is charged by electrolysis is hereinafter called the "solvent
solution" and is made as follows:-Standard solutions are made of the cyanide
above described and of the neutral tartrate respectively. The proportions of the
standard cyanide are to a gallon of water-2 pounds avoirdupois; the white
cakes of cyanide are dissolved in water, at the ordinary temperature with stirring,
and, if cloudy, the solution may be filtered. The standard tartrate of ammonium
solution is made by dissolving 23 ounces of tartaric acid in 5 pints of water; to
this solution ammonia water (specific gravity 880) added gradually until the
crystalline precipitate at first formed is entirely dissolved stirring the whole time.
The solution of the precipitate is, in this plan of making the tartrate, an index of
near approach to neutralisation of the acid; the addition of ammonia-water to the
acid solution is continued until it is distinctly alkaline, and the volume of liquid is
made up to a gallon by the addition of water. To neutralise the acid, about
19 ounces of ammonia-water will be required.
In precipitating the hydrated oxide of copper from the sulphate by means of
caustic potash, a slight excess of potash is added to the sulphate solution. After
being washed in many waters and then separated out on a filter, this precipitate,
whilst still wet, is dissolved in the ammonia water, as above set forth, to make the
ammonio-cupric oxide used in this invention.
The solvent solution, for electro-depositing copper, consists of :—
Standard cyanide solution, by measure
Standard tartrate solution, by measure
Ammonio-cupric oxide, by measure
32 parts.
1 part.
5 parts.
The solvent solution is charged with copper in the proportion of two or three
ounces of copper per gallon and sufficient ammonio-cupric oxide is afterwards
added to change it from a light brown to a sea green colour.
To work this depositing solution at a heat of 130° Fahrenheit it is necessary to
add boiling water from time to time to make up for evaporation. The solution

page_text: may be worked from 20° to 30° Twaddell without inconvenience; the determination
of specific gravity should be taken at 60° Fahrenheit.
The solution which is preferred for electro-depositing brass is made and worked
in a similar way to that described above for the copper solution, but in making the
solvent solution, equal parts of standard cyanide and tartrate solutions are used.
For bronze, the solution is made and worked in a similar way to that described
above for the copper solution, but six parts of the cyanide to one part of the
tartrate are used to make the solvent solution.
The anode for electro-depositing brass may be a compound one composed of
copper and zinc, the relative proportion of the surface of each metal being the
same as that of the metals in the alloy to be deposited. This is also the case
with bronze, in which a compound anode of copper and tin may be used.
It is an essential part of this invention that no other kind of cyanide is used
than that containing 40% of real cyanide. In the first part of the invention set
forth in No. 1639, A.D. 1882, 70 per cent. real cyanide was used, but this quality
was found, upon extensive practice, to yield a solution that varied in the amount
of copper retained in solution during deposition to such an extent that it frequently
would not work. In consequence of the 60% of impurity or diluent, of the 40%
cyanide, being principally composed of carbonate of potash, the stability of the
solution is ensured and its equable action is secured.
It is also an essential part of this invention that the tartrate of ammonium
standard solution is made as set forth above and that it should be slightly alkaline;
the tartrate solution should always be added gradually, in the cold, to the cyanide
solution. Any other plan of making the solvent solution than that set forth herein
has proved ineffectual.
It is also an essential part of this invention that the ammonio-cupric oxide is
made as set forth above, for when so made the maximum amount of copper is
retained in solution and the chemical union of the ammonio-cupric oxide with the
cyanide is more nearly perfect than it can be by any process to produce a stable
ammonio-cyanide.
The making and cliarging of these solutions is entirely done in the cold.
The electric power may be a single volt, in each of the above-described
solutions, but to save time that is to deposit faster-three volts or more may be
employed.
To test the amount of metal, per gallon, in a depositing bath, equal sized anodes
and cathodes are arranged in the bath, and it is heated or not, so as to put it in a
truly normal condition for electro-deposition, a suitable amount of current being
used. Then a polished steel bar, or wire, of a known area and weight, is immersed
in the solution, whilst it is in action, and momentarily connected with the cathodes.
If a pink coating of copper, in the alkaline copper bath for instance, appears on
the polished steel immediately and with the shortest time of electric contact that is
possible, the solution is in good order and contains not less than 4 ounces per
gallon. A table may be constructed for a given electro-motive force and giving
the amounts of copper per gallon which correspond to various times of electric
contact and the corresponding increase of weight of the steel bar for those times.
This part of the invention is applicable to all electro-depositing solutions and
obviates the necessity for chemical analysis of the solution from time to time.
It is necessary that the water added to the electro-depositing solution, auto-
matically or otherwise, from time to time should be boiling, otherwise the solution
is apt to yield a precipitate which takes out a portion of its copper or other
metal.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
First The use of a solution made for depositing copper, brass, or bronze with
the specially-made ingredients, as described and for the purposes set forth.

page_text: Secondly The use of a coppering solution in which the proportion of 40 per
cent. cyanide to tartrate is as 32 to 1.
Thirdly The use of a specially-made cyanide of potassium containing 40 per
cent. real cyanide, as described and for the purposes set forth.
Fourthly In combination with the other ingredients of the solvent solution
and with the methods of making and working herein set forth, the use of the
specially-made neutral tartrate of ammonium subsequently made slightly alkaline.
Fifthly In combination with the other ingredients of the solvent solution and
with the methods of working herein set forth, the use of the specially made
ammonio-oxide of copper.
Sixthly-The electro-coppering, brassing and bronzing solutions and their
methods of working as described.
Seventhly The method of working the solutions at 130° Fahrenheit, within
reasonable limits and of compensating for their evaporation by the addition of
boiling water.
:
Eighthly The method of testing, as described and for the purposes set forth.
Ninthly The making up for evaporation by the addition of boiling water as
described and for the purposes set forth.
Dahi ort ɔ
1003
W. H. WALENN.
I. A. TIMMIS.