Improvements in or relating to Electrolytes.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Electrolytes.
I, QUINTIN MARINO, Engineer, of 77, Rue des Poulons, Brussels, in the King-
dom of Belgium, do hereby declare the nature of this invention to
be as
follows:-
The present invention relates to the production of an electrolyte slightly acid
or alkaline, and very constant and not liable to decomposition, owing to the
principle upon which the electrolyte is produced which consists in the employ-
ment of the metals to be electrolysed in the form of carbonates, instead of such
salts as chlorides, sulphates, nitrates, acetates and the like, which are made use
of in the preparation of these baths only for the purpose of transforming them
into carbonates.
The salts used for the bath all have an acid base. The acidity of the bath is
neutralised by adding carbonate of soda to it equal to half the weight of the
salt employed. In this manner an incomplete carbonate is obtained by mixing
a certain quantity of a solution of the salt with half the quantity of a solution
of carbonate of soda, or of ammonia or potash, the two solutions being well
mixed so
as to produce a precipitate of the carbonate of the metal of the
said salt, which is then obtained by washing and filtering, so as to get rid of any
excess of chloride of sodium or ammonium; when chlorides are to be operated
upon and in. the same manner the corresponding excess of nitrates, sulphates,
acetates and the like are employed.
Inasmuch as this first operation, i.e., the transformation into carbonate, remains
the same for all salts, when once the carbonate precipitate is obtained, the pre-
paration of the bath for any kind of metal is characterised by making a saturated
solution of the carbonate precipitate in the liquid intended to form the bath,
and containing in solution determined proportions of an organic acid such as
butyric, acetic, benzoic, formie, lactic, malic, succinic, carbonic acid, or of
cyanide, ferrocyanide, or cyanate, or of oxalic acid, boric acid, tartaric acid o
citric acid in combination with a chloride of ammonium or of potassium or of
sodium, or of an organic acid and an alkali such as potash, caustic soda etc.
In practice the following proportion of ingredients gives very good results,
Bath liquid
Carbonate precipitate
Organic acid
-
75%
-15%
7%
Chloride of ammonium or notassium of cadium 201
These numbers are not empirical, especially the proportion of carbonate, which
may vary according to the solving power of the bath liquid. Thus water becomes
saturated with a much smaller quantity of carbonate than glycerine, so that
besides the advantage of being able to use metals in the form of carbonates,
glycerine will form a bath of far greater concentration than water.
According to the above, the formation of the bath remains constant for all the
metals which according to their nature only form a secondary variant as regards

page_text: their behaviour with an organic acid. Thus, for instance, oxalic acid answers
best in the case of aluminium, boric acid for zinc, and tartaric acid for lead. In
order to explain clearly the preparation of the bath in general, according to the
new process, the preparation of an aluminium will by way of example be
described.
If carbonate of aluminium is not ready at hand, a solution of 100% of
aluminium sulphate is mixed with a solution of 50% of carbonate of soda, and
allowed to stand for the carbonate of aluminium. to precipitate. Then the solu-
tion is decanted and the precipitate of the carbonate of aluminium thus obtained
is filtered and washed.
On the other hand, a mixture of 75% of ordinary glycerine, with 7% of oxalic
acid and 3% of chloride of ammonium is made, which is then saturated by dis-
solving in it 15% of the carbonate of aluminium obtained by the first process.
Finally the bath thus obtained is heated to about 60° C and then left to cool down
to the ordinary temperature.
The baths thus prepared always remain constant; they remain at the same
degree while at work, and are regenerated by the anodes proportionally and with-
out being able to dissolve more of the metal at the anode than what forms at the
cathode, as is the case with mineral acid electrolytes.
Dated this 11th day of September 1899.
BOULT, WADE & KILBURN,
Agents for the Applicant.
I, QUINTIN MARINO, Engineer, of 77, Rue des Poulons, Brussels, in the King-
dom of Belgium, 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:-
The present invention relates to the production of an electrolyte slightly acid
or alkaline, and very constant and not liable to decomposition, owing to the
principle upon which the electrolyte is produced which consists in the employ-
ment of carbonates of the metals to be electrolysed instead of such salts as chlo-
rides, sulphates, nitrates, acetates and the like, which are made use of in the
preparation of these baths only for the purpose of transforming them into
carbonates.
•
The salts used for the bath have all an acid base. The acidity of the bath is
neutralised by adding a carbonate, say carbonate of soda to it to the extent of
one half of the weight of the metallic salt employed. In this manner an incom-
plete carbonate is obtained by mixing a given quantity of a solution of the salt
with half this quantity of a solution of carbonate of soda, ammonia or potash,
the two solutions being sufficiently dilute so as to allow of their being well
mixed in order to produce a precipitate of the carbonate of the metal of the
said salt, which is then obtained by washing and filtering, so as to get rid of any
excess of chloride of sodium, potassium or ammonium, when chlorides are
employed, and in the same manner the corresponding excess of nitrates, sulphates,
acetates and the like, when such salts are used.
Inasmuch as this first operation, i.e. the transformation into carbonate, remains
the same for all salts, when once the carbonate precipitate is obtained, the pre-
paration of the bath for any kind of metal is characterised by making a saturated
solution of the carbonate precipitate in the liquid intended to form the bath,
and containing in solution determined proportions of an organic acid such as

page_text: butyric. acetic, benzoic, formic, lactic, malic, succinic, carbonic acid, or of
yanide, ferrocyanide or cyanate, or of oxalic acid, boric acid, tartaric acid
citric acid in combination with a chloride of ammonium or of potassium or of
sodium, or an organic acid and an alkali such as potash caustic soda, &c.
In practice the following proportion of ingredients give very good results.
yanide, ferrocyanide or cyanate, or of oxalic acid, boric aciu,
citric acid in combination with a chloride of ammonium or of potassium or of
sodium, or an organic acid and an alkali such as potash caustic soda, &c.
In practice the following proportion of ingredients give very good results.
Bath liquid
Carbonate precipitate
-
75%
15%
Organic acid or a cyanide, ferrocyanide or cyanate 7%
Chloride of ammonium, or potassium, or sodium 3%
These numbers are not empirical, especially the proportion of carbonate, which
may vary according to the soiving power of the bath liquid. Thus water becomes
saturated with a much smaller quantity of carbonate than glycerine, so that
besides the advantage of being able to use metals in the form of carbonates,
glycerine will form a bath of far greater concentration than water.
According to the above, the formation of the bath remains constant for all the
metals which according to their nature only form a secondary variant as regards
their behaviour with the acid employed. Thus, for instance, oxalic acid answers
best in the case of aluminium, boracic acid for zinc, and tartaric acid for lead.
In order to explain clearly the preparation of the bath in general, according to
the new process, the preparation of an aluminium bath, will by way of example,
be described.
•
If carbonate of aluminium is not ready at hand, a solution of 100% of
aluminium sulphate is mixed with a solution of 50% of carbonate of soda, and
allowed to stand for the carbonate of aluminium to precipitate. Then the solu-
tion is decanted and the precipitate of the carbonate of aluminium thus obtained
is filtered and washed.
On the other hand, a mixture of 75% of ordinary glycerine, with 7% of oxalic
acid and 3% of chloride of ammonium is made, which is then saturated by dis
solving in it 15% of the carbonate of aluminium obtained by the first process.
Finally the bath thus obtained is heated to about 60° C and then left to cool down
to the ordinary temperature.
The baths thus prepared always remain constant; they remain at the same
degree while at work, and are regenerated by the anodes proportionally and with
out being able to dissolve more of the metal at the anode than what forms at the
cathode, as is the case with mineral acid electrolytes.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A process of preparing an electrolytic bath characterised by the solution of
a carbonate obtained by mixing in solution a salt of the metal to be electrolysed
with half the weight of an alkaline carbonate-in glycerine, water or other
electrolytic liquid with the addition of an organic acid or of a cyanide or ferro-
cyanide or boric acid or a cyanate and a chloride, or with the addition of an
organic acid and an alkali substantially as described.
Dated thin 0th day of January 1900
BOULT, WADE & KILBURN,
Agents for the Applicant.
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