Sulphate.
Year: 1899

page_text: Date of Application (in United Kingdom), 9th May, 1899
Date of Application (in United Kingdom), 9th May, 1899
Complete Specification Left 8th Feb 1900-Accepted. 17th Mar.. 1900
Sulphate.
We, HIPPOLYTE PALAS and FÉLIX COTTA, both of 118, Grand Chemin de
Toulon, Marseilles, France, Chemists, do hereby declare the nature of this inven
tion to be as follows:-
This invention relates to a process for manufacturing copper sulphate or
other metallic sulphate, by the application of electrolysis to a solution of sodium
sulphate or potassium sulphate.
This process enables crystals of metallic sulphate prepared in an absolutely
pure state, to be obtained, and avoids all loss of sulphuric acid as does take place
in the ordinary preparation of copper sulphate by the action of sulphuric acid
on waste copper; in this operation, a strong proportion of sulphuric acid
disappears in the state of sulphurous acid.
Cu + 2 SO.H₂
==
CuSO + SO2 + 2 H₂O.
Our process ensures, in addition to the preparation of sulphate, the production
of the base, sodium or potassium, of the electrolysed alkaline sulphate.
For the purpose of carrying our process into effect, we may employ any suitable
electrolysing apparatus; for greater simplicity, we shall consider an elementary
electrolytic apparatus comprising two compartments separated by a diaphragm.
In one of these compartments we place a solution of sodium sulphate or of
potassium sulphate of a strength of about 25° Beaumé and which is heated to
a temperature of about 70° Centigrade so as to diminish as much as possible
the electrical resistance.
Within this compartment is arranged a plate or strip of iron or other metal
which will not be acted upon by the sodium and which forms the cathode.
In the other compartment is located a plate forming the anode and which
consists of the metal which is to be transformed, for example, copper, if it is
wished to manufacture copper sulphate; this compartment is filled with a solution
of sulphate of this metal and which is intended to prime the reaction; this
solution ought to have a density and a temperature corresponding with the
greatest electrical conductivity.
If there be set up between the two electrodes a difference in potential of 25
to 3 volts, according to the resistance of the bath, the sulphate of sodium
01'

page_text: potassium separates into sodium (or potassium) and sulphuric acid in the form
of SO,, the sodium (or potassium) remains in the compartment of the cathode
and the ion SO, passes from this compartment into that of the anode across or
through the diaphragm. On the other hand, the copper sulphate contained in the
compartment of the anode is electrolysed in the following manner; the copper Cu
meeting through the diaphragm the ion SO, immediately reforms sulphate of
copper as for the ion SO, from the decomposed copper sulphate, it at once acts
upon the copper anode in contact with which it frees itself and thus forms copper
sulphate which enriches the solution..
Here takes place a phenomenon which diminishes in notable proportions the
quantity of energy necessary to decompose the sodium sulphate (or potassium
sulphate). The action upon the anode by SO, gives rise to an electrical current
of the same direction as the principal electrolytic current and which is added
thereto; it thus increases the quantity of electro-chemical work, which is equiva-
lent to an economy of current.
There is, finally, in the cathode compartment a mixture of caustic soda (or
potash) and of sodium (or potassium) sulphate. This latter can be easily separated
by crystallization of the evaporated lixivium of soda (or potash).
With regard to the anode compartment, it contains a solution of copper sulphate,
or sulphate of the metal treated, entirely free from soda (or potassium) and which
furnishes absolutely pure crystals.
Our process thus allows the manufacture of metallic sulphates and, in particular
copper sulphate, by borrowing sulphuric acid directly from the sodium (or
potassium) sulphate without loss of sulphurous acid and with a small expenditure
of energy. This sulphuric acid is transformed immediately and in the electro-
lysing apparatus itself, proportionally or according to its formation.
The caustic soda (or potash) obtained as a sub-product and whose selling-price
is fairly high, diminishes in very large proportions the nett cost of the sulphates
and, particularly, of copper sulphate.
We wish to observe that the copper anode may be formed either of a plate
or strip of this metal or of waste or chips, or ores of any form whatever. The
said anode might also be, composed of the residues from the roasting of copper
pyrites; we should in that case extract the copper directly from these residues
in the state of sulphate.
1 יז
1000
Process of Manufacturing Copper Sulphate or other Metallic
Sulphate.
We, HIPPOLYTE PALAS and FELIX COTTA, both of 118, Grand Chemin de
Toulon, Marseilles, France, Chemists, do hereby declare the nature of this inven
tion 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 a process for manufacturing copper sulphate or
other metallic sulphates, by the application of electrolysis to a solution of sodium
sulphate or potassium sulphate.

page_text: pure state, to be obtained, and avoids a loss of sulphuric acid as does take place
in the ordinary preparation of copper sulphate by the action of sulphuric acid
on waste copper; in this operation, a strong proportion of sulphuric acid
disappears in the state of sulphurous acid.
Cu + 2 SOH
=
CuSO + SO2 + 2 H₂O.
Our process ensures, in addition to the preparation of sulphate, the production
of the base, sodium or potassium, of the electrolysed alkaline sulphate.
For the purpose of carrying our process into effect we may employ any suitable
electrolysing apparatus; for greater simplicity, we shall consider an elementary
electrolytic apparatus comprising two compartments separated by a diaphragm.
In one of these compartments we place a solution of sodium sulphate or of
potassium sulphate, of a strength of about 25 degrees Beaumé and which is
heated to a temperature of about 70 degrees Centigrade so as to diminish as much
as possible the electrical resistance.
Within this compartment is arranged a plate or strip of iron or other metal
which will not be acted upon by the sodium and which will form the cathode.
In the other compartment is located a plate forming the anode and which
consists of the metal which is to be transformed, for example, copper, if it is
wished to manufacture copper sulphate; this compartment is filled with a solution
of sulphate of this metal and which is intended to prime the reaction; this
solution should have a density and a temperature corresponding with the
greatest electrical conductivity.
If there be set up between the two electrodes a difference in potential of 25
to volts, according to the resistance of the bath, the sulphate of sodium (or of
potassium) separates into sodium (or potassium) and sulphuric acid in the form
of SO, the sodium (or potassium) remains in the compartment of the cathode
and the ion SO, passes from this compartment into that of the anode across or
through the diaphragm. On the other hand, the copper sulphate contained in the
compartment of the anode is electrolysed in the following manner; the copper Cu
mecting through the diaphragm the ion SO, immediately reforms sulphate of
copper as for the ion SO, from the decomposed copper sulphate it at once acts
upon the copper anode in contact with which it is evolved and thus forms copper
sulphate which enriches the solution.
Here takes place a phenomenon which diminshes in notable proportions the
quantity of energy necessary to decompose the sodium sulphate (or potassium
sulphate). The action upon the anode by SO, gives rise to an electrical current
of the same direction as the principal current and which is added thereto; it
thus increases the quantity of electro-chemical work, which is equivalent to an
economy of current.
There is, finally, in the cathode compartment a mixture of caustic soda (or
potash) and of sodium (or potassium) sulphate. This latter can be easily separated
by crystallization of the evaporated lixivium of soda (or potash).
With regard to the anode compartment, it contains a solution of copper sulphate,
or sulphate of the metal treated, entirely free from soda (or potassium) and which
furnishes absolutely pure crystals.
Our process thus allows the manufacture of metallic sulphates and, in particular
copper sulphate, by borrowing sulphuric acid directly from the sodium (or
potassium) sulphate without loss of sulphurous acid and with a small expenditure
of energy. This sulphuric acid is transformed immediately and in the electro-
lysing apparatus itself, proportionally or according to its formation.
The caustic soda (or potash) obtained as a sub-product or by-product and whose
selling-price is fairly high, diminishes in very large proportions the nett cost
of the sulphates and, particularly, of the copper sulphate.
We wish to remark that the copper anode may be formed either of a plate
or strip of this metal or of waste or chips or ores of any form whatever. The

page_text: said anode might thus be composed of the residues from the roasting of copper
pyrites; we should in that case extract the copper directly from these residues
in the state of sulphate.
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:-
=:
(1). A process of manufacturing copper sulphate or other metallic sulphates,
with a simultaneous production of an alkali as a sub-product, by the application
of the electrolysis of a solution of an alkaline sulphate (of soda or of potash) in
presence of a soluble anode of the metal to be transformed into sulphate.
(2). In the process of manufacturing copper sulphate or other metallic sulphates
by means of electrolysis, the use at the anode of a solution of the sulphate of the
metal forming the said anode.
(3). A process of manufacturing metallic sulphates characterized by the
application of electrolysis to a solution of sodium sulphate or potassium sulphate,
the said sulphate solution being contained in any suitable electrolytic apparatus,
the anode being formed of a plate of the metal to be transformed, which plate
is surrounded by a solution of the metal sulphate, and the cathode being composed
of a plate or strip of metal which will not be attacked by the sodium, the metallic
sulphate being formed in the anode compartment, and furnishing pure crystals,
substantially as above described.
(4). The extraction of copper directly in the state of sulphate from the residues
of copper pyrites, with the obtaining of an alkali as a sub-product, by the
application of the electrolysis of an alkaline sulphate in presence of these
residues.
For the Applicants,
GEDGE & FEENY,
Chartered Patent Agents, 60, Queen Victoria Street, London, E.C.