An Improvement in the Electro Deposition of Heavy Metals with a Base Metal Alloy.
Year: 1894

page_text: Date of Application, 20th Apr., 1894
Complete Specification Left, 18th Oct., 1894-Accepted, 9th Feb., 1995
PROVISIONAL SPECIFICATION.
An Improvement in the Electro Deposition of Heavy Metals with a
Base Metal Alloy.
We WILLIAM ARTHUR THOMS, Electro-plater and WILLIAM HENRY BURGUM,
Electro-plater both of 6 Union Square New North Road London do hereby declare
the nature of this invention to be as follows:-
The deposition of heavy metals such as iridium, platinum palladium and the like
heavy metals either separately or alloyed with the addition of a base metal or an
alloy of base metals to form a suitable alloy deposit by electrolysis
And having for its object the obtaining deposits of a white hard reguline nature
and also of depositing an alloy of greater cheapness both with regard to the metals
used and to the chemicals that form part of this process than has hitherto
been in use.
We know that most of the heavy metals such as platinum, iridium, palladium
and metals of the same group have been deposited but to the best of our belief they
have never been satisfactorily deposited in conjunction with other metals of a much
cheaper nature.
We can by this process alloy the heavy or expensive metals with a large
number of the base or cheaper metals. The base metals used may be tin cadmium
zinc nickel cobalt, copper, aluminium &c. either separately or alloyed.
The alloy solution can be made so that the electrolytic bath may contain 95% of
the heavy or expensive metal with 5% of the base metal or it may contain 95% of
the base metal with 5% of the heavy or expensive metal, or again it may contain
50% of the heavy or expensive metal and 50% of the base metal so that a solution
can be formed of any desired percentage of the heavy metals to suit the deposit
required.
We find in actual working of the heavy metallic alloy solution for the deposition
of said alloy that rough or coarse articles or articles that are submitted to a great
amount of wear or friction or again work that has to be done cheaply are more
economically coated by firstly depositing an alloy with low percentage of the more
expensive metal and finally finish the articles to be coated with an alloy of high
percentage of the heavy metal or alloys of same, as an instance ships or railway
carriage fittings might have a first deposit of 10% platinum and 90% tin
and afterwards a deposit more or less thick composed of 90% platinum and
10% tin.
As an example of our improved process we take one oz. metallic platinum
and convert it into a chloride in the usual manner taking care that there is not an
excess of free acid, we then add to this a saturated solution of two ozs. of sodium
hydrate or potassium hydrate we then take one oz. of metallic tin commercially
pure and convert it into chloride in the usual manner we then add this to a solution
formed of 3 ozs. of sodium hydrate or potassium hydrate 40 ozs. of phosphate of
soda dissolved in hot water and when allowed to cool added to the tin and sodium
or potassium solution.
The two solutions the one of tin with sodium hydrate or potassium hydrate
& phosphate of soda and the other solution of platinum and sodium hydrate or
potassium hydrate are mixed, well stirring all the while when add 8 ozs. of cyanide
of potassium of good quality say 85%-water then added to make two gallons.

page_text: We have found it beneficial to place the vessel containing this solution when
first made over any suitable form of heat the temperature showing on the
thermometer 150% to 200% F. for some two or three hours when the heat may
be reduced to 80% F. which we have found a suitable temperature for working
the alloy solution care being taken with this solution as with all alloy depositing
solutions that the proper heat is maintained otherwise an uniform coating will not
be produced upon the articles to be coated.
It may be found advantageous to add to the depositing bath a concentrated
solution of alloy solution.
The anodes to be used may consist of the heavy metals either separately or
alloyed or with a base metal or alloy of base metals and the heavy metals either
separately or alloyed or we may use an anode formed of the base metal or alloys
adding a concentrated solution of the heavy or expensive metals as required, or
again we may use a carbon anode-in this case the solution must be. made up with
a concentrated solution of the metallic alloy to take the place of the metals taken
out of the electrolytic bath.
The electrical current required must be of high electro motive force on account
of the low electrical conductivity of the solution. Dynamo power well regulated
being the most suitable.
We wish it understood that we do not limit ourselves to any special proportions
of the metals as such proportions may be varied according to the purpose for
which the alloy is required without departing from the nature of our invention.
Dated this 20th day of April 1894.
WILLIAM A. THOMS.
WILLIAM H. BURGUM.
An Improvement in the Electro Deposition of Heavy Metals with a
Base Metal Alloy.
We WILLIAM ARTHUR THOMS Electro-plater and WILLIAM HENRY BURGUM
Electro-plater both of 6 Union Square New North Road London do hereby
declare the nature of this invention and in what manuer the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
The deposition of heavy metals such as iridium platinum palladium and the like
heavy metals alloyed with the addition of a base metal or an alloy of base metals
to form a suitable alloy deposit by electrolysis and having for its object the
obtaining deposits of a white hard reguline nature and also of depositing an alloy
of greater cheapness both with regard to the metals used and to the chemicals that
form part of this process than has hitherto been in use.
We know that most of the heavy metals such as platinum, iridium palladium and
metals of the same group have been deposited but to the best of our belief they
have never been satisfactorily deposited in conjunction with other metals of a much
cheaper nature.
We can by this process alloy the heavy or expensive metals with a large number
of the base or cheaper metals. The base metals used may be, tin, cadmium, zinc,
nickel, cobalt copper, either separately or alloyed.
The alloy solution can be made so that the electrolytic bath may contain 95% of
the heavy or expensive metal with 5% of the base metal or it may contain 95% of
the base metal with 5% of the heavy or expensive metal, or again it may contain
50% of the heavy or expensive metal and 50% of the base metal so that a
solution can be formed of any desired percentage of the heavy metals to suit the
deposit required.

page_text: We find in actual working of the heavy metallic alloy solution for the deposition
of said alloy that rough or coarse articles, or articles that are submitted to a great
amount of wear or friction or again work that has to be done cheaply are more
economically coated by first depositing an alloy with low percentage of the more
expensive metals and finally finish the articles to be coated with an alloy of high
percentage of the heavy metals or alloys of same as an instance ships or railway
carriage fittings might have a first deposit of 10% platinum and 90% tin
and afterwards a deposit more or less thick composed of 90% platinum and
10% tin.
As an example of our improved process we take 1 oz. metallic platinum and
convert it into a chloride in the usual manner taking care that there is not an
excess of free acid. We then add to this a saturated solution of 2 ozs. of sodium
hydrate. We then take 1 oz. of metallic tin commercially pure and convert it into
chloride in the usual manner. We then add this to a solution formed of 3 ozs. of
sodinin hydrate 40 ozs. of phosphate of soda dissolved in hot water and when
allowed to cool added to the tin and sodium solution.
The two solutions the one of tin with sodium hydrate and phosphate of soda and the
other solution of platinum and sodium hydrate are mixed well stirring all the while
when add 8 ozs. of cyanide of potassium of good quality say 85% water then added
to make 2 gallons thus making an alloy solution composed of equal parts of platinum
and tin.
As another example of platinum tin alloy deposit we take 1 oz. of metallic
platinum and convert it into chloride in the usual manner taking care as in the
above example that there is not an excess of acid, we then add to this a saturated
solution of 2 ozs. of sodium hydrate. We then take 20 ozs. metallic tin and convert
it into chloride in the usual manner. We then add to this a solution formed of
60 ozs. of sodium hydrate. We have in another vat or vessel 800 ozs. of phosphate
soda dissolved in hot water (and then allowed to cool) when the tin and soda
hydrate solution may be mixed with the phosphate or soda solution care being taken
to stir well. The two solutions i.e. the one of tin with sodium hydrate and sodium
phosphate and the other solution of platinum and soda hydrate are mixed well
stirring all the while when add 16 oz. of cyanide of potassium of good quality
Fay 85%-water then added to make 40 gallons thus making a solution containing
5% of platinum and 95% of tin.
We have found it beneficial to place the vessel containing these solutions when
first made over any suitable form of heat the temperature showing on the ther-
mometer 150° to 200° F. for some two or three hours when the heat may be reduced
to 80° F. which we have found a suitable temperature for working the alloy solutions
care being taken with these solutions as with all alloy depositing solutions that the
temperature as above mentioned viz. 80° F. should have special attention as in
working the above or other platinum tin alloy solutions the deposit of alloy
metal will not be of an uniform nature if the temperature should be too hot or
too cold.
Or we may make an alloy solution composed of
Metallic platinum
Metallic tin
Metallic copper
1 oz.
2 ozs.
-
† oz.
The platinum is converted into chloride.
The tin is converted into chloride.
The copper
is converted into cyanide, all in the usual manner.
The platinum chloride is added to 3 ozs. of dissolved soda hydrate. The tin
chloride is added to 3 ozs. of dissolved soda hydrate and then added to a bath
composed of 40 ozs. of phosphate soda dissolved in water.
The copper cyanide is added to 2 ozs. of cyanide potassium (85%) dissolved in
We now place the solution of tin and soda phosphate and soda hydrate
water.

page_text: the solution of platinum and soda hydrate and lastly the solution of cyanide of
copper, water is then added to make up 3 gallons.
In working this solution the temperature should be about 80° F.
In all the above examples the only heavy or expensive metal used is platinum,
but iridium palladium and metals of the same group may be substituted for the
platinum either separately or alloyed or in conjunction with platinum and base
metals.
As an example
Metallic iridium
Metallic tin -
Metallic copper
The iridium is converted into chloride.
The tin is converted into chloride.
1 oz.
-
2 ozs.
-
+ oz.
The copper is converted into cyanide in the usual manner.
The iridium chloride is added to 3 ozs. of dissolved soda hydrate.
The tin chloride is added to 3 ozs. of dissolved soda hydrate and then added to a
bath composed of 40 ozs. of phosphate soda dissolved in water.
The copper cyanide is added to 2 ozs. of cyanide potassium (85%) dissolved in
water, we now place the solution of tin and soda phosphate and soda hydrate into
the solution of iridium and soda hydrate and lastly the solution of cyanide of
copper, water is then added to make up 3 gallons.
This solution should be worked at a temperature of about 80° F.
Or we may make an alloy solution composed of
Metallic platinum
Metallic iridium
Metallic palladium
Metallic tin
-
Metallic copper
-
1 oz.
-
1 oz.
1 oz.
4 ozs. and
1 oz.
The platinum, iridium and palladium are converted into chlorides.
The tin is converted into chloride.
The copper is converted into cyanide.
The platinum iridium and palladium chlorides are added to 9 ozs. of dissolved
soda hydrate.
The tin chloride is added to 6 ozs. of dissolved soda hydrate and then added to a
bath composed of 80 ozs. of phosphate soda dissolved in water.
The copper cyanide is added to 8 ozs. cyanide potassium (85%) dissolved in
water.
We now place the solutions of platinum iridium and palladium into the bath of
tin and the sodas. Very carefully stirring all the while and lastly the solution of
cyanide of copper water added to make 8 gallons.
This solution should be worked at a temperature of about 80° F.
It may be found advantageous to add to the depositing bath a concentrated
solution of alloy solution.
The anodes to be used may consist of the heavy metals either separately or
alloyed or with a base metal or alloy of base metals and the heavy metals either
separately or alloyed or we may use an anode formed of the base metal or alloys
adding a concentrated solution of the heavy or expensive metals as required or
again we may use a carbon anode-in this case the solution must be made up with
a concentrated solution of the metallic alloy to take the place of the metals taken
out of the electrolytic bath.
The electrical current required must be of high electro motive force on account
of the low electrical conductivity of the solution dynamo power well regulated
being the most suitable.
We wish it understood that we do not limit ourselves to any specific proportions

page_text: of the metals as such proportions may be varied according to the purpose for
which the alloy is required without departing from the nature of our invention.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is--
The method of depositing by electrolysis an alloy of the heavy metals such as
platinum, iridium, palladium, and the like metals with base metals such as tin
cadmium zinc, nickel, cobalt, copper, either separately or alloyed on metals or
other suitable articles substantially as described.
Dated the 18th October 1894
WILLIAM A. THOMS.
WILLIAM H. BURGUM.