IMPROVE- MENTS IN THE METHOD OF OBTAINING GOLD SILVER COPPER AND OTHER METALS FROM THEIR ORES BY ELECTROLYTIC ACTION AND IN APPARATUS ". THEREFOR
Year: 1883

page_text: LETTERS PATENT to Charles Denton Abel of N° 28 Southampton Buildings
Chancery Lane in the County of Middlesex for an Invention of IMPROVE-
MENTS IN THE METHOD OF OBTAINING GOLD SILVER COPPER AND OTHER
METALS FROM THEIR ORES BY ELECTROLYTIC ACTION AND IN APPARATUS
"
.
THEREFOR communicated to him from abroad by Michel Body of Liége in
the Kingdom of Belgium
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at
the Office of the Commissioners of Patents on the 10th May 1883.
CHARLES DENTON ABEL of N° 28 Southampton Buildings Chancery Lane in the
County of Middlesex "IMPROVEMENTS IN THE METHOD OF OBTAINING GOLD
"
SILVER COPPER AND OTHER METALS FROM THEIR ORES BY ELECTROLYTIC ACTION
AND IN APPARATUS THEREFOR [communicated to him from abroad by Michel
Body of Liége in the Kingdom of Belgium]
This invention relates firstly to the preparation of ores that are to be subjected
to clectrolytic action and secondly to lixiviating and electrolytic processes.
The preparation of the ores includes the application of the necessary means for
rendering the metallic particles soluble or more readily soluble.
For this purpose,
the ores are in the first instance crushed to fine powder, with the admixture of salts
that are capable of causing the solution of the metallic particles. The solvents
employed are the ferric salts either alone or mixed with common salt.
The chemical process involved in the lixiviation and separation of the metals
from their oxides and sulphur compounds, according to this invention, is based on
the reaction to which the acid ferric salts are subjected in the presence of the oxides
or sulphur compounds of the metals, in being converted into ferrous salts, in
particular under the influence of electric currents (which by this means effect the
separation of the metals) and on the facility with which the electric currents
reconvert these ferrous salts into ferric salts again, so that they can be again used
for the same purpose.
This process does not exclude the combined action of
Cmnon salt, which operates with such advantage upon these reactions in the case
.

page_text: of chlorine compounds of iron, or which determines the solution of the chlorine or
arsenic metals.
The ore, placed in a heap,, is first wetted and then left to the action of
the atmospheric air, being turned over repeatedly. The wetting may be effected
with the acids of spent baths. The ore can then be subjected to a rapid roasting
process in order to complete the preparation, such roasting being effected in
muffle or reverberatory furnaces, with condensing chambers, which are so useful
for the production of the necessary acids. In this case the ore is afterwards again
reduced to powder.
The circumstances which determine the use of the one or the other of the above
methods of preparation depend upon the nature of the ores and on the localities
where these operations have to be performed, as also upon the means which are
there available for the purpose.
After the ore has been prepared as above described, the electrolytic process is
applied thereto, either while it is in heaps or in receptacles. In both cases, the
surface on which the ore rests must consist of compressed carbon or of a metal
plate to which the negative pole of an electric machine is connected, while the
other pole is connected to one or more points of the ore. During the treatment,
the passage of the electric current through the heap of ore effects the more perfect
solution, the stronger the current and the more limited its duration. During the
latter part of the separation therefore the action of the current may be discontinued.
If the ore is treated in heaps, the floor must be surrounded with asphalted
channels.
In operating in receptacles, the solution of the metal is facilitated by stirring.
If the operation is correctly carried out, which is ascertained by taking samples
and applying the usual calorimetric method thereto, it will be found that a leap of
ore treated with the electric current as described and left for a certain time to the
action of the atmosphere, is capable of giving up the last traces of metal and that
all the metal will be converted into solution by a subsequent simple lixiviating
process. The solution thus obtained is then placed in special vats for the purpose
of precipitation.
According to one arrangement for this purpose the lixiviation and precipitation
are effected in separate receptacles, the lixiviating vessel being at the highest level,
below which is a subsidence vessel into which the solution is allowed to flow, and
below this are one or more precipitating vessels, into which are suspended the
precipitating plates connected to the electric machine. The liquid deprived of the
metal is allowed to flow thence into a tank, from which it is raised by a pump for
repeated use. The exhausted ore is taken from the uppermost vessel and placed in
a draining vat, from which it is then conveyed to the deposit yard. Steam may be
introduced into the lixiviating and depositing vessels. For the lixiviating vessel
may be used a slowly rotating wooden drum, into which the ore and lye are
introduced and where they are heated by steam.
According to another arrangement; the lixiviating and precipitating processes
can be carried out in one and the same set of vessels. These are made of portland
cement, which has been found to be a good non conductor of electricity, and which
is painted inside and outside with a suitable impermeable coating. The vessels are
constructed with rectangular outer walls within which are inner walls at a small
distance therefrom, and which pass down to within a small distance from the bottom
surface, this being coated with a layer of carbon. The openings left below the
inner walls are provided with perforated iron plates, and the inner surfaces of the
outer walls are coated with a layer of carbon. The parts of the bottom floor
between the outer and inner walls are situated at a lower level than the inner floor.
The electrical circuit is connected at one pole with the inner floor and at the other
pole with the precipitating plate suspended in the vessel. The solution enters at
the floor of the inner compartment, and after flowing upwards and over the tops of
the inner walls into the spaces between the latter and the outer walls, escapes
through openings near the bottom of these spaces.

page_text: By this arrangement the solution is subjected in the best manner to the action of
the precipitating plates and can be made to permeate in a continuous manner
through the ore.
Centrally in the inner compartment is a revolving stirrer.
For certain argentiferous ores the following arrangement for the lixiviating and
electrolytic process is employed, combined with electrical amalgamation.
The ore, prepared as above described, is placed in an electrolytic apparatus
consisting of a cast iron drum containing a number of cast iron balls, and which is
connected to the negative pole of a dynamo-electric machine and has a slow rotation
imparted to it. Through the drum passes a stationary shaft, insulated therefrom,
and connected to the positive pole of the dynamo machine. From this shaft are
suspended a number of plates of compressed coke or graphite, dipping into a bath
consisting of a solution of ferric salts in which the ore floats. The shaft is made
hollow and serves for the introduction of the liquids.
A steam supply pipe is also made to dip in the bath. The moment the electric
current is passed through, the ore, being in contact with the iron, begins to give off
its silver, which deposits upon the sides of the drum and the surface of the balls,
while the ferric salts are converted into ferrous salts.
After completion of this first reaction the requisite quantity of mercury is
introduced into the drum and under the action of the current it takes up the silver,
this being facilitated by the partial reduction of the silver.
The separation of the silver from the amalgam and of the latter from the ore is
effected by the known processes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Denton Abel in the Great Seal Patent Office on the
9th November 1883.
CHARLES DENTON ABEL of No. 28 Southampton Buildings, Chancery Lane, in the
county of Middlesex "IMPROVEMENTS IN THE METHOD OF OBTAINING GOLD,
SILVER, COPPER AND OTHER METALS FROM THEIR ORES BY ELECTROLYTIC ACTION
AND IN APPARATUS THEREFOR A communication to me from abroad by Michel
Body of Liège in the Kingdom of Belgium
This invention relates firstly to the preparation of ores that are to be subjected
to electrolytic action and secondly to lixiviation a electrolytic processes.
The preparation of the ores includes the application of the necessary means for
rendering the metallic particles soluble or more readily soluble. For this purpose,
the ores
are in the first instance crushed to fine powder with the admixture of
salts that are capable of causing the solution of the metallic particles. The solvents
employed are the ferric salts, either alone or mixed with common salt.
The chemical process involved in the lixiviation and separation of the metals
from their oxides and sulphur compounds, according to this invention, is based on
the reaction to which the acid ferric salts are subjected in the presence of the
oxides or sulphur compounds, of the metals, in being converted into ferrous salts,
in particular under the influence of electric currents (which, by this means, effect
the separation of the metals) and on the facility with which these ferrous salts are
reconverted into ferric salts so that they can be again used for. the same purpose.
This process does not exclude the combined action of common salt which operates
with such advantage upon these re-actions in the case of chlorine compounds of
iron, or which determines the solution of the chlorine or arsenic metals.
The ore, placed in a heap, is first wetted and then left to the action of the
atmospheric air, being turned over repeatedly. The wetting may be effected with
the acids of spent baths. The ore can then be subjected to a rapid roasting process
in order to complete the preparation, such roasting being effected in reverberatory
or other furnaces, with condensing chambers, which are so useful for the produc-
tion of the necessary acids. In this case, the ore is afterwards again reduced to
powder.
The circumstances which determine the use of the one or the other of the above
methods of preparation depend upon the nature of the ores and on the localities
where these operations have to be performed, as also upon the means which are
there available for the purpose.
After the ore has been prepared as above described, the electrolytic process is
applied thereto, either while it is in heaps or in receptacles. In both cases, the
surfaces on which the ore rests must consist of compressed carbon or of a metal
plate to which the negative pole of an electric machine is connected while the
other pole is connected to one or more points of the ore. During the treatment,
the passage of the electric current through the heap of ore effects the more perfect
solution, the stronger the current, and the more limited its duration. During the
latter part of the separation therefore, the action of the current may be
discontinued.
If the ore is treated in heaps, the floor must be surrounded with asphalted
channels.
In operating in receptacles, the solution of the metal is facilitated by stirring.
If the operation is correctly carried out, which is ascertained by taking samples
and applying the usual calorimetric method thereto, it will be found that a heap

page_text: of ore treated with the electric current as described and left for a certain time to
the action of the atmosphere, is capable of giving up the last traces of metal, and
that all the metal will be converted into solution by a subsequent simple lixiviating
process The solution thus obtained is then placed in special vats for the purpose
of precipitation
According to one arrangement for this purpose, the lixiviation and precipitation
are effected in separate receptacles, as shewn at figs. 1, 2 and 3 of the accom-
panying drawings, in which fig. 1 shews a back elevation of the apparatus, fig. 2
a plan and fig. 3 a side view. The lixiviating vessel A into which the ore is
introduced is situated at the highest level, below which is a subsidence vessel B
into which the solution is allowed to flow from A, and below this are one or more
precipitating vessels c c into which the solution flows from B, and in which are
suspended the precipitating plates connected to the electric machine. The liquid,
deprived of the metal, is allowed to flow thence into a tank D, from which it is
raised by a pump for repeated use. The exhausted ore is taken from the upper-
most vessel and placed in a draining vat O from which it is conveyed to the
deposit yard.
Steam may be introduced into the lixiviating and depositing vessels A and C.
In place of the lixiviating vessel A may be used a slowly rotating wooden drum,
into which the ore and lye are introduced and where they are heated by steam
The material of the precipitating plates will vary according to the metal to be
treated, According to another arrangement, the lixiviating and precipitating
processes can be carried out in one and the same set of vessels. These are made of
portland cement which has been found to be a good non-conductor of electricity
and which is painted inside and outside with a suitable impermeable coating.
These vessels are constructed as shewn in vertical section and plan, figs. 4 and 5 ;
they consist of rectangular outer walls a a within which are inner walls b b
at a small distance therefrom, and which pass, down to within a small distance
from the bottom surface c, this being coated with a layer of carbon. The
openings left below the inner walls are provided with filtering surfaces formed of
felt, and the inner surfaces of the outer walls a are coated with a layer of carbon d.
The parts of the bottom floor between the outer and inner walls are situated at a
lower level than the inner floor. The electrical circuit is connected at one pole
with the inner floor, and at the other pole with the precipitating plate suspended
in the vessel. The solution enters at the floor c of the inner compartment and
after flowing upwards and over the tops of the inner walls b into the spaces
between the latter and the outer walls, escapes through openings o near the bottom
of these spaces.
By this arrangement, the solution is subjected in the best manner to the action
of the precipitating plates and can be made to permeate in a continuous manner
through the ore.
Centrally in the inner compartment is a revolving stirrer e.
For certain argentiferous ores, an arrangement for the lixiviation and electrolytic
process is employed, combined with electrical amalgamation. This arrangement is
shewn respectively in longitudinal and cross section in. figs 6 and 7 of the
drawings The ore, prepared as above described, is placed in an electrolytic
apparatus consisting of a cast iron drum E containing a number of cast iron balls F,
and which is connected to the negative pole of a dynamo-machine and has a slow
rotation imparted to it, Through the drum, passes a stationary shaft G insulated
therefrom and connected to the positive pole of the dynamo machine. From this
shaft are suspended a number of plates H of compressed coke or graphite, dipping
into a bath consisting of a solution of ferric salts in which the ore is immersed.
The shaft is made hollow and with perforations and serves for the introduction of
the liquids at I.
A steam supply pipe, not shewn, is also made to dip in the bath. The moment
the electric current is passed through, the ore, being in contact with the iron,

page_text: begins to give off its silver, which deposits upon the sides of the drum and the
surface of the balls, while the ferric salts are converted into ferrous salts.
After completion of this first reäction, the requisite quantity of mercury is
introduced into the drum and under the action of the current, it takes up the
silver. The mercury in the first instance adheres to all the metallic surfaces where
the silver is deposited; afterwards, it agglomerates and separates from the surfaces,
thererby shewing that all the silver has been taken up. The contents of the drum
are then discharged into the vat K below and the separation of the silver from the
amalgam, and of the latter from the ore is effected by any of the processes now
employed for the purpose.
The above described electrical amalgamating process is so efficacious that it can
be used with advantage with ores containing as little silver as 16 ounces to the
ton. In the other modes of operating above- described, the electrically precipitated
metallic mass is submitted to the usual smelting and refining processes, according
to the nature of the metal. The separation of the silver from the amalgam and of
the latter from the ore is effected by the known processes.
Having thus described the nature of this invention and in what manner the
same is to be performed, as communicated to me by my foreign correspondent,
I claim:-
First: In the separation of gold, silver, copper and other metals from their ores
by electrolysis, the method of treating the ores with ferric salts whereby the
metals are rendered soluble, while the ferrous salts, produced by the reaction are
reconverted into ferric salts, substantially as herein described.
Second The combined process of first treating metallic ores to a lixiviating
process with ferric salts, and, after subsidence, subjecting them to an electrolytic
process whereby the metals are rendered soluble and separated from their ores
substantially as herein described.
Third: In apparatus for the separation of gold, silver, copper and other metals
from their ores by electrolysis the combination of the lixiviating vessel A,
subsidence vessel B and precipitating vessel C with electrolytic preciptating [sic]
plates, arranged and operating substantially as described with reference to figs 1,
2 and 3 of the accompanying drawings.
Fourth: The method of simultaneously subjecting the ores to a lixiviating
process with ferric salts and to the electrolytic process in a vessel constructed and
operating substantially as described with reference to figs 4 and 5 of the drawings.
Fifth The method of first subjecting gold and silver ores to the action of ferric
salts in combination with the electrolytic process and the subsequent amalgamation
of the metals with mercury under the continued action of the electric current.
Sixth The construction of Apparatus for effecting the separation of gold and
silver from their ores and the amalgamation of the metal with mercury consisting
of the drum E containing iron balls F, and connected to the negative pole of an
electric machine, the hollow perforated shaft G, insulated from the drum and
connected to the positive pole of the electric machine, which shaft serves for the
introduction of the lye, and has suspended from it the carbon precipitating plates H
arranged and operating substantially as herein described with reference to the
accompanying drawings.
In Witness whereof I the said Charles Denton Abel have hereunto set my
hand and seal this ninth day of November in the year of our Lord, one thousand
eight hundred and eighty-three.