Year: 1898

page_text: I, QUINTIN MARINO, Chemist, of 77, Rue des Foulons, Brussels, in Belgium, do
hereby declare the nature of this invention to be as follows:-
This invention relates to the electrolysis of metals or metallic salts, according to
which the electrolytic action takes place from one pole to the other with all the
initial intensity during the whole of the process, that is to say, without any
subsequent loss such as takes place in the processes hitherto used, which necessitate
a current of two volts at least and in which the migration of the ions is accompanied
by a decomposition of the water constituting the greater part of the bath, the
products of this decomposition, notably hydrogen, exercising an injurious action
on the metallic ions and producing dusty, powdery and tarnished deposits.
The new process according to this invention which obviates the above drawbacks
and gives brilliant and firmly adherent deposits of great density is characterised by
the suppression of water in the electrolytic baths and its replacement by glycerine,
which is a neutral liquid, soluble in all proportions in water and alcohol and has the
property of dissolving most of the bodies that are soluble in water; at the same
time it has a greater conductivity for the movement of the ions, which movement
takes place without any contrary reaction with all the electrolytic energy required
for obtaining the results mentioned.
Whilst enabling the electrolysis to take place with a very weak current and one of
small tension, the electrolytic bath with glycerine has the further advantage of
enabling the electrolysis to be effected with high tension currents without any draw-
backs and thus enables the work in electrometallurgical applications to be considerably
accelerated.
1. The preparation of glycerine electrolytes is very simple, notably for a number
of metallic salts which are directly soluble in glycerine in given proportions at the
ordinary temperature, such, for instance as the salts of zinc, copper, iron, aluminium,
lead, antimony and arsenic; these it is sufficient to dissolve in their respective
proportions, and they are then ready for being immediately submitted to the action
of the electric current.
It is well known that 100 parts of glycerine dissolve, at the ordinary tem-
perature:

page_text: Boracic acid
Sodium sulphide -
10
soluble.
This addition has a favourable influence on the adherence and quality of the
deposit, in the same manner as the addition of from 5 to 10 per cent. of concentrated
sulphuric acid or nitric acid to an electrolyte of copper sulphate which addition not
only increases the conductivity but also gives a perfectly normal deposit, neither
fragile nor crystalline, with very weak currents and with electrodes of large surface.
Finally the composition to the electrolytes is optional and may vary in accordance
with the final product to be obtained: permitting as in ordinary electrolytic processes
any suitable and advantageous additions and mixtures.
This observation as to the composition of electrolytes specially relates to the
formation of different metallic alloys. For instance, in order to obtain an electrolyte
giving a deposit of bronze a bath of copper is mixed with a bath of zine in proportion
varying according to the composition and colour of the metal which is to be
predominant in the deposit. The same proceeding takes place for aluminium bronze,
tin bronze, brittania metal etc. The same results can be obtained with soluble
anodes of metals, an alloy of which is to be obtained.
The glycerine baths are maintained in the usual manner either by the addition of
dissolved salts or by the use of metallic anodes or else by placing ore around the
anodes either as crystals of salts of metal or metals contained in the solution, the
same liberty of action existing for electrolysis by glycerine as for ordinary electrolysis
and consequently it is unnecessary to give a full description of each operation that is
to be effected.
Dated this 27th day of October 1898.
BOULT & WADE,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Electrolytic Baths.
I, QUINTIN MARINO, Chemist, of 77, Rue des Foulons, Brussels, in Belgium, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
This invention relates to electrolytic baths, according to which the electrolytic
action takes place from one pole to the other with all the initial intensity during the
whole of the process, that is to say, without any subsequent loss such as takes place
in the processes hitherto used, which necessitate a current of two volts at least and in
which the migration of the ions is accompanied by a decomposition of the water con-
stituting the greater part of the bath, the products of this decomposition notably
hydrogen, exercising an injurious action on the metallic ions and producing dusty,
powdery and tarnished deposits.
The new process according to this invention, which obviates the above drawbacks
and gives brilliant and firmly adherent deposits of great density is characterized by
the suppression of water in the electrolytic baths and its replacement entirely or
partially by glycerine, which is a neutral liquid, soluble in all proportions in water
and alcohol, and has the property of dissolving most of the bodies that are soluble in

page_text: water at the same time it has a greater conductivity for the movement of the ions,
which movement takes place without any contrary reaction with all the electrolytic
energy required for obtaining the results mentioned.
Whilst enabling the electrolysis to take place with a very weak current and one of
small tension, the electrolytic bath with glycerine has the further advantage of
enabling the electrolysis to be effected with high tension currents without any draw-
backs and thus enables the work in electro-metallurgical applications to be con-
siderably accelerated.
1. The preparation of glycerine electrolytes is very simple, notably for a number of
metallic salts which are directly soluble in glycerine in given proportions at the ordi-
nary temperature, such, for instance, as the salts of zinc, copper, iron, aluminium,
lead, antimony, and arsenic; these it is sufficient to dissolve in their respective pro-
portions, and they are then ready for being immediately submitted to the action of
the electric current.
It is well known that 100 parts of glycerine dissolve, at the ordinary temperature:
Silver
Nitrate of silver
Chloride of zinc
Zinc
Sulphate of zinc
Iodide of zine
Copper Sulphate of copper
Acetate of copper
Iron
Ferrous sulphate
Ferrous lactate
Tartrate of iron
Ferrous chloride
Ferrous iodide
Aluminium alum
Lead Acetate of lead
-
-
-
very soluble
50 parts
35 "
40 "
30
10 "
25"
16
8
37
وو
"
very soluble
soluble
40 parts
20 "
Antimony Emetic (tartrate of antimony and potash)
Arsenic Arsenious acid
-
5.50 parts
soluble
In case it is desired to obtain a more highly charged bath, it is sufficient to raise
the temperature of the glycerine or of the mixture of glycerine dissolved salt.
2. Salts of some other metals which are only slightly or not at all soluble in
glycerine at the ordinary temperature, do not present any difficulties in the prepara-
tion of the respective electrolytes as to dissolve them it is only necessary to raise the
temperature of the glycerine to that required for each salt, which can be done with-
out even partially decomposing the glycerine.
This is prepared by taking a double sulphate of nickel and ammonium in a
pulverised state and dissolving it completely in glycerine at the temperature of
60 to 80°.
EXAMPLE B. ELECTROLYTE OF TIN.
This is prepared by dissolving protochloride of tin in glycerine at the same
temperature as for nickel viz.: 60-80°.
3. For other metallic salts, insoluble in glycerine at any temperature, but soluble
in other solvents, such as alcohol, potash, mineral and organic acids etc., the salts are
dissolved in such solvents, glycerine, being added either with the solvents, or subse-
quently, and thus the chief mineral combinations regarded as insoluble may be easily
and perfectly dissolved.

page_text: EXAMPLE.
Copper electrolyte by means of tartrate of copper. This electrolyte is prepared by
dissolving the tartrate in potash mixed with glycerine. This bath is used for coating
iron and zinc. It is known to be impossible to plate iron and zinc with a simple
solution of sulphate of copper owing to the chemical decomposition which takes place
in these metals in the ordinary state, so that a badly adhering deposit would be
obtained, as the two metals undergo a molecular change on their surfaces before a
precipitate of copper has time to form a deposit on them, the sulphuric acid liberated
by the decomposition of sulphate of copper reacting on the surface of the said metals.
The electric conductivity can be increased by adding to the electrolytes prepared
as herein before described, alkaline and ammonium salts which do not give precipi-
tates of insoluble salts with the salts of the metals which it is desired to deposit,
organic acids may also be employed.
Suitable salts and acids for increasing the conductivity of the bath are the follow-
ing, the number of parts soluble in one hundred parts of glycerine being indicated.
EXAMPLE.
Copper electrolyte by means of tartrate of copper. This electrolyte is prepared by
dissolving the tartrate in potash mixed with glycerine. This bath is used for coating
iron and zinc. It is known to be impossible to plate iron and zinc with a simple
solution of sulphate of copper owing to the chemical decomposition which takes place
in these metals in the ordinary state, so that a badly adhering deposit would be
obtained, as the two metals undergo a molecular change on their surfaces before a
precipitate of copper has time to form a deposit on them, the sulphuric acid liberated
by the decomposition of sulphate of copper reacting on the surface of the said metals.
The electric conductivity can be increased by adding to the electrolytes prepared
as herein before described, alkaline and ammonium salts which do not give precipi-
tates of insoluble salts with the salts of the metals which it is desired to deposit,
organic acids may also be employed.
Suitable salts and acids for increasing the conductivity of the bath are the follow-
ing, the number of parts soluble in one hundred parts of glycerine being indicated.
Carbonate of soda
Borate of soda
Carbonate of ammonia
Ammonium chloride
Bi-carbonate of soda
Hydrate of potassium
Hydrate of sodium
Chloride of sodium
Chloride of baryum
Boracic acid
Sodium sulphide
وو
98 parts
50
20
"
20
"
8
"
very soluble
do do
20 parts
10 "
10 "
soluble
This addition has a favourable influence on the adherence and quality of the
deposit, in the same manner as the addition of from 5 to 10% of concentrated
sulphuric or nitric acid to an electrolyte of copper sulphate, which addition not only
increases the conductivity but also gives a perfectly normal deposit, neither fragile
nor crystalline, with very weak currents and with electrodes of large surface.
Finally, the composition to the electrolytes is optional and may vary in accordance
with the final product to be obtained: permitting as in ordinary electrolytic pro-
cesses any suitable and advantageous additions and mixtures.
This observation as to the composition of electrolytes specially relates to the for-
mation of different metallic alloys. For instance, in order to obtain an electrolyte
giving a deposit of bronze a bath of copper is mixed with a bath of zinc in proportion
varying according to the composition and colour of the metal which is to be pre-
dominant in the deposit. The same proceeding takes place for aluminium bronze,
tin bronze, britannia metal etc. The same results can be obtained with soluble
anodes of metals, an alloy of which is to be obtained.
The glycerine baths are maintained in the usual manner either by the addition of
dissolved salts or by the use of metallic anodes or else by placing ore around the
anodes either as crystals of salts of metal or metals contained in the solution, the
same liberty of action existing for electrolysis by glycerine as for ordinary electrolysis
and consequently it is unnecessary to give a full description of each operation that is
to be effected.
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 :-
1. The use of glycerine, wholly or chiefly, in place of water, in electrolytic baths,
substantially as described.

page_text: 2. Electrolytic baths characterized by glycerine being employed instead of water in
the case of salts directly soluble in glycerine, or by a mixture of glycerine with water
or other solvent in which salts slightly or not at all soluble in glycerine have been
previously dissolved, said liquid not being decomposable by the electric current
owing to the presence of glycerine, substantially as and for the purpose
described.
BOULT & WADE,
Agents for the Applicant.