Year: 1886

page_text: Date of Application, 1st Nov., 1886.
Complete Left, 27th July, 1887.
Complete Accepted, 27th Sept., 1887,
RESERV
I, CHARLES DENTON ABEL of No. 28 Southampton Buildings, Chancery Lane,in
the County of Middlesex, Fellow of the Institute of Patent Agents, do bereby declare
the nature of this invention to be as follows :-
This invention relates to the arrangement of electrolytic batteries and employment
therein of materials in such a manner as to obtain continuous decomposition of salts
and deposition of their metals without causing polarisation and with a very moderate
expenditure of electrical energy. For this purpose, according to one arrangement,
the battery is divided into pairs of cells, the one cell of each pair containing an anode
or several anodes made of wood charcoal that has been subjected to a very high
temperature, and the other cell of the pair containing a cathode or several cathodes of
metal, generally of the metal that is to be deposited. The two cells are separated from
one another by a porous non-metallic diaphragm. The liquid to be decomposed is
admitted in continuous flow at the bottom of the cathode cells, ascends in these around
and along the cathodes depositing part of its metal upon them, overflows the diaphragms
into the anode cells, and after descending these, finally issues as spent liquid from the
bottom of the anode cells.
Instead of dividing the electrolytic battery into pairs of cells as described above,
the cathodes may be suspended open in the tank, each anode being surrounded by a
porous diaphragm or bag constituting a cell immersed in the liquid of the tank. The
liquid rising along the surfaces of the cathodes will then overflow the diaphragms
surrounding the anodes and pass away as spent liquor. Or the liquid, after passing
the cathodes in the first of a series of tanks, may be made to pass those of the second,
and of the others in succession, to be then returned through the anode cells in the
successive tanks and finally to pass away as spent liquor.

page_text: The liquid employed depends on the metal that has to be deposited and the nature
of the salt of which it forms a part, as will be understood by the following illustrative
examples. For obtaining deposit of copper from copper sulphate, a mixture of
copper and iron sulphates with sulphuric acid is employed; for obtaining it from the
chloride, a mixture of copper chloride with iron proto-chloride is used. In like
manner, zinc can be deposited from a solution of zinc and iron sulphates or from a
mixture of zinc chloride with iron proto-chloride. In all these cases, iron salts are
present which are alternately reduced and oxidised and in the latter state act upon the
solution, so that while reduction takes place in the cathode cells, oxidation or farther
oxidation takes place in the anode cells, and thus peroxide salts from protoxides,
perchlorides, from protochlorides ferricyanides from ferrocyanides and so on, can
be produced.
The spent liquid can in many cases be applied to lixiviate the roasted ores. Thus,
for instance, powdered copper pyrites roasted at a moderate temperature can be treated
with the spent liquid to produce fresh solution for electrolysis. When the spent liquid
is thus applied, the solution produced gives by the electrolytic process described
equivalent spent liquid that can be again applied for lixiviation, and so on repeatedly,
the difficulty of disposing of spent liquid being thus avoided.
Dated this 1st day of November 1886.
ABEL & IMRAY,
Agents for the Applicant.

page_text: An Improvement in Electrolysis.
I, CHARLES DENTON ABEL of No. 28 Southampton Buildings, Chancery Lane in
the County of Middlesex Consulting Engineer and Patent Agent 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:-
:-
Copper has hitherto been obtained electrolytically by using as anodes either plates
of impure copper or of copper regulus-By the electric current copper, or iron and
copper, was dissolved from the anode and copper was galvanically deposited on the
cathode-In this case however the solution soon becomes poor in copper and has to
be replaced by fresh solution the preparation of which from the ores is attended with
various difficulties and expenses. In addition, the preparation of the anodes from
melted regulus necessitates a preliminary smelting process of the roasted sulphurated
copper ore, the casting of the anode plates is difficult and uncertain, and the electrolytic
process is very much interfered with by the crumbling of the anodes before they are
entirely dissolved. According to the present invention, instead of using soluble anodes
for the purpose of depolarisation as in existing processes a liquid is used as depolarising
medium in combination with insoluble anodes, and the copper salt to be decomposed
at the cathode is separated from the liquid to be oxidised at the anode by means of a
non-metallic diaphragm. The liquid subjected to electrolysis consists of a solution of
sulphate of iron and sulphate of copper with the addition of some free sulphuric acid
in order to improve its conductivity. This liquid, when single decomposing cells are
used, is best introduced continuously near the bottom into the liquid surrounding the
cathode plates, and rises up against these, when, by means of the electric current, a
portion of the copper will be deposited in a metallic state upon the cathodes.
The liquid then flows over the upper edge of the diaphragm into the spaces con-
taining the anodes, and flowing downward through these, is eventually discharged at
the bottom as shewn at Fig. 1 of the accompanying drawing.
During this descent the ferrous sulphate is first converted into basic ferric sulphate
and then, owing to the taking up of the free sulphuric acid arising from the decompo-
sition of the sulphate of copper, into neutral ferric sulphate, which latter sinks to the
bottom at the carbon rods, owing to its greater specific gravity. The discharged
liquid has therefore become poorer in copper and consists partly of a solution of
neutral ferric sulphate. This solution has the property of converting cuprous sulphide,
cupric sulphide, as also cupric oxide into Sulphate of copper. With the first of the
solutions of the two copper compounds, the ferric sulphate is converted back into
ferrous sulphate, while the liberated oxygen oxidizes the cupric sulphide.
By the previous roasting of the copper pyrites at a low temperature a product is
obtained in which the copper is mostly contained as cuprous sulphide, and the iron as
oxide, the latter being therefore in a form which is not acted upon at all by ferric
sulphate and only slightly by sulphuric acid, while the cuprous sulphide is energetically
dissolved by ferric oxide solution.

page_text: Ine present improved mode or obtaining copper consequently consists in roasting
the powdered copper pyrites at a moderate temperature, preferably in a Gerstenhöfer
furnace, until the iron is almost entirely oxidized, while the copper exists partly as
sulphate but mainly as cuprous sulphide.
This pulverulent material is now lixiviated by means of the liquid discharged from
the decomposing cells.
This is best effected in a series of lixiviating troughs through which the lye is caused
to flow consecutively in such manner that the lye is made to flow last through the
trough last charged with roasted ore. The solution thus enriched with sulphate of
copper and in which there is no more iron oxide salt, is now led back into the galvanic
decomposing cells where it is consequently again deprived of its copper, after which
it is again oxidized and led through the roasted ore in order to take up fresh copper,
and so on, and thus forming a continuous process in which one and the same body of
liquid can serve until it becomes too impure for the galvanic process on acccount of
the foreign metals contained in the ore which have been taken up by it.
The chemical reactions which occur during the electrolysis and the lixiviating
process are shewn by the following formulae.
1. Reactions during the electrolysis :-
x H, SO, +2 Cu SO, + 4 Fe SO₁ = 2 Cu +2 Fe, (SO4)2 + x H₂SO₁.
2. Reactions during the lixiviation :-
4
a) x H, SO + Cu S2 + 2 Fe, (SO4)2 = 2 Cu SO, + 1 Fe SO₁ + S + æ H₂SO.
6) Cu O + H, SO.: Cu SO + HO.
c) 3 CuO+ Fe, (SO), = 3 Cu SO + Fе, O..
d) Cu O + 2 Fe SO, + H2O = CuSO4 + (F₁₂ O₂ + SO₂) + H₂
-
On comparing the formulae 1 and 2 a it will be seen that if the ore contains the
whole of the copper in the form of cuprous sulphide, the electrolytic liquid after
passing the lixiviating troughs will contain exactly the same amount of sulphate of
copper, sulphate of iron and free sulphuric acid as before the electrolysis, and that it
is consequently perfectly regenerated and again available for the process. If however
the copper exists partly as oxide in the ore it will be seen from the equations b, c, d,
that in this case the electrolytic liquid, after lixiviation, will be richer in copper but
poorer in iron and free sulphuric acid than it was before the electrolysis.
analogous method for electrolytically separating copper may be used if the solution
of the copper is prepared by the chloridizing process. The electrolytic liquid then
consists of chloride of copper and protochloride of iron, from which copper and
chloride of iron will be obtained in the decomposing cells according to the following
formula
Cu Cl₂+ F, Cl₁ = Cu + F, Cl¸.
An
The chloride of iron thus formed has the property of converting protochloride of
copper dissolved in common salt, as also the cuprous sulphate not decomposed by the
roasting, into chloride of copper. In both cases the chloride of iron is reconverted
into proto-chloride.
With this process therefore the electrolytic lye is also regenerated, so as to be
capable of repeated use. It is true, the percentage of copper is increased in this
process by the lixiviation.
It is to be observed that with the galvanic processes described no polarisation takes
place and that the varied position of the anode and cathode in the tension series does
not produce any counter electro motive force.
While, when using anodes of copper regulus, a difference of potential of about 1.5
Volts is consumed with the processes described, only a difference of potential of
about 07 Volt is required for the same strength of current. Furthermore, while with
anodes of copper regulus about of the quantity of current is used for effecting other
reduction-processes and is consequently lost, with the process described no such loss
takes place.
The same process can also be used for obtaining zinc electrolytically from zinc
sulphide ores by means of a solution of sulphate of zinc and sulphate of iron. Zine

page_text: formula:
Zn SO 2 Fе SO₁ = Zn + Fe, (SO4)3.
4
The ferric sulphate thus formed has the property of dissolving zinc from slightly
roasted zinc sulphide ores, sulphate of zinc, and ferrous sulphate are produced
according to the formula:
Zn S+ Fe, (SO4)3 = Zn SO4 + 2 Fe SO, + S.
A comparison of this and the previous formula shews that after the lixiviation of
slightly roasted zinc sulphide ores by the electrolytically oxidized liquid, the percentage
of zinc and iron becomes quite as great as before the electrolysis.
An analogous method may be employed for obtaining zinc by means of a solution
of zinc chloride and proto-chloride of iron; zinc and chloride of iron are then formed
in the electrolytic decomposing cells and the chloride of iron again dissolves zinc
from sulphide ores, becoming reduced to proto-chloride again.
With these zinc processes, the necessary difference of potential between the anode
and cathode of the electrolytic bath is about twice as great as with the before
described copper processes, on account of the electrical difference of potential between
zinc and carbon.
The novel fact upon which the processes described are based, namely, that oxidisable
solutions conducting electricity become oxidized to a higher degree without polarisation
under certain circumstances by a galvanic current when in contact with an anode of
carbon, platinum, gold &c., may also be employed for other chemical operations, by
arranging the decomposing apparatus in such manner that the liquid to be oxidised
circulates in the cells surrounding the anodes, and a liquid to be reduced circulates
through the cells surrounding the cathodes.
As it is generally more convenient to generate and use electrical currents of high
tension, which require the arrangement of a considerable number of decomposing
cells in series, it will be necessary to arrange the flow of liquid through the several
cells in such manner that the regenerated liquid first flows consecutively through all
the cathode cells then through all the anode cells, and lastly through the regenerating
troughs charged with roasted ore.
By this means the result is obtained that the liquid contained in the cathode cells
contains no iron oxide salt which would be reduced by the electric current, and
would thereby interfere with the separation of copper as well as with the enrichment
with iron oxide salt in the lixiviating process at the end.
In order to obtain a rapid flow of liquid through all the cells, which is necessary
for perfect action, the decomposing cells are arranged in a step like ascending row,
as shewn at Fig. 3 and all the cathode compartments K, K, K, as also all the anode
compartments A, A, A, of the cells are connected with each other by means of
siphons h₁ k₁. h₁, ka, h3 kg.
In order to maintain the liquid level in each independent of the supply, the siphon
limbs leading to the lower cells are bent upward to the extent a, which is equal to the
difference of height of two consecutive cells.
Figs. 1 and 2 of the drawings shew respectively a cross section and a longitudinal
section of one of the cells on a larger scale operating as first described. In the
vessel E is suspended firstly the diaphragm D containing the anode C consisting of
carbon rods, and secondly the cathode Cu consisting of a copper plate. The liquid
is introduced into the bottom of the outer vessel E through the tube R, and after
flowing up in contact with the cathode Cu enters the diaphragm D through the holes
at its upper edge; hence it descends along the carbon anodes C C and then flows off
through the siphon pipe Ra.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is:-
1. The method of obtaining copper or zinc directly from their sulphur-compounds
hy a continuous electrolytical process wherein firstly the liquid surrounding the anodes

page_text: is separated from that surrounding the cathodes by an iron metallic diaphragm
secondly the anodes consist of electrolytically insoluble conducting bodies such as
carbon or platinum, thirdly a mixture of copper or zinc solution is used as electrolyte,
and fourthly the flow of this electrolyte through the apparatus is so conducted that it
first passes through the cathode cells, then through the anode cells and lastly through
the roasted or melted sulphur ore after which the regenerated liquid is led back to the
cathode cells.
2. In the process referred to in the preceding claim, causing two different liquids
which are to be subjected to electrolytic action to flow continuously through the
positive and negative cells, which are separated from each other by non metallic
diaphragms, the one liquid being made to flow consecutively through all the negative
cells, and the other consecutively through all the positive cells, whereby the one will
be subject to a reducing action and the other to an oxidizing action.