Alloys, and Especially Auriferous Ores by Electrolysis.
Year: 1885

page_text: Alloys, and Especially Auriferous Ores by Electrolysis.
I, HENRY RENNER CASSEL, of 33 Verulam Street, London, in the County
of Middlesex, Metallurgist do hereby declare the nature of my invention for
"AN IMPROVED PROCESS AND APPARATUS FOR TREATING METALS, ALLOYS, AND
ESPECIALLY AURIFEROUS ORES BY ELECTROLYSIS' to be as follows:-
"
The object of my invention is to treat metals, alloys, and ores, and especially
auriferous compounds, by electrolysis in an apparatus in which nascent chlorine
and oxygen are generated, by means of which the metals are dissolved and are
then deposited at the negative pole and subsequently in specially provided
tanks.
The most powerful solvent which can be produced on a large and commercial
scale for gold and most other metals is nascent chlorine, and this can easily be
generated by electrolysing a solution of common salt. The chlorine and oxygen
are set free at the anode and if this pole be of metal, it will be readily dissolved
and carried over to be deposited at the cathode, but if the anode be composed of
carbon, any particle of metal coming in contact with the same during electrolysis
will also be readily dissolved.
Gold ores containing antimony, sulphur, arsenic, tellurium, bismuth and many
other compounds are called refractory or rebellious, and are also commonly
designated as "pyrites." Their treatment offers great difficulty and hitherto it
was always necessary to roast or calcine them in order to oxidise the sulphur,
arsenic, antimony, etc., and to set the gold free. This becomes unnecessary in my
process as the nascent chlorine and oxygen are the means of oxidising the pyrites,
and set the gold free, which is then converted into auric chloride, and when lime
is added as explained in my previous patent of 13th October 1883, N° 4879, the
gold is deposited at the cathode, in the form of a black slime.
The apparatus I intend to use for this purpose is calculated to reduce manual
labour as much as possible and to render the process as far as practical an almost
continuous one.
A drum containing a necessary number of carbons is mounted on a hollow
shaft. This shaft into which a number of holes are bored is covered with asbestos
or other filtering compound not liable to be attacked by the solutions. The shaft

page_text: .
passes through stuffing boxes, into tanks or standards. The carbons either in rods
or plates may be arranged in any suitable manner in the drum, but they are
connected with each other by metal bands or otherwise, preferably at the pro-
truding ends outside of the drum; leakage must be prevented by any suitable
means. These carbons serve as anodes or positive pole and are connected by any
suitable means with the corresponding pole of a source of electricity, while the
shaft or the standard is connected with the other pole, thus the shaft will be the
axis for the drum and also the negative pole or cathode of the apparatus,
the asbestos upon the shaft separating the two poles. Instead of the shaft being
the cathode the ends of the drum may be made of iron and these form the
cathode; the asbestos cloth is then also arranged horizontally so as to separate
anode from cathode. In this case the shaft need not traverse the whole drum and
also need not be hollow, but means must be provided to allow an escape
hydrogen to take place. Openings, closed by springs and means for pressing on
these springs may be arranged for this purpose.
of
The ores are fed into the drum through openings, which are then closed; the
drum is then kept revolving by suitable gearing and the current switched on.
The electrolyte being chloride of sodium, a strong disengagement of chlorine and
oxygen will take place in the drum, and this will dissolve the gold and convert
any silver present into a chloride, the other metals being prevented from passing
into solution by the addition of lime as described in my former patent of 13th
October 1883, N° 4879.
The gold is precipitated inside the hollow shaft in form of a black slime and is
conveyed by means of archimedian or winding screws into the standards. When
a sufficient quantity of these slimes have accumulated they are collected and
melted.

page_text: Alloys, and Especially Auriferous Ores by Electrolysis.
I, HENRY RENNER CASSEL, of 33 Verulam Street, London, in the County of
Middlesex, Metallurgist, 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 object of my invention is to treat metals, alloys and ores, and especially,
auriferous compounds, by electrolysis in an apparatus in which nascent chlorine
and oxygen are generated, by means of which the metals are dissolved at the
positive pole and are then deposited at the negative pole.
The most powerful solvent which can be produced on a large and commercial.
scale for gold and most other metals is chlorine, and this can easily be generated.
by electrolysing a solution of common salt. The chlorine and oxygen are set free
at the anode and if this pole be of metal, it will be readily dissolved and the
dissolved metal will be carried over to be deposited at the cathode, but if the,
anode be composed of carbon, any particle of metal coming in contact with the
same during electrolysis will also be readily dissolved.
Gold ores containing antimony, sulphur, arsenic, tellurium, bismuth and many
other compounds, are called refractory or rebellious, and are also commonly.
designated as "pyrites." Their treatment offers great difficulty and hitherto it
was always necessary to roast or calcine them in order to oxidize the sulphur,
arsenic, antimony, etc., and so set the gold free. This becomes unnecessary in my
process as the nascent chlorine and oxygen are the means of oxidizing the pyrites,
and setting the gold free, which is then converted into auric chloride, and when:
lime is added as explained in my previous patent of 13th October 1883, No 4879,"
the gold is deposited at the cathode, in the form of a black slime.
The apparatus which I use to accomplish the above is constructed as follows:-
Fig. 1 is a side elevation of the apparatus complete.
Fig. 2 is an end view thereof.
Fig. 3 is a transverse section thereof.
Fig. 4 is a section through the shaft showing the holes and internal screw.
a is a drum, made of wood or other suitable material, and if of metal must be
thoroughly insulated inside. This drum contains any number of carbon rods or
plates as anodes, and in fact the inside thereof may be completely lined with
carbon or plumbago. I prefer to arrange the carbons inside the drum horizontally,
as indicated by 6 in Fig. 3, and to prevent leakage at the protruding ends, rubber
solution, marine glue or any other compound may be used. The ends of these
carbons I render metallic by either depositing suitable metal thereon, or by wires,
soldering or otherwise. These carbons are connected with each other by a band
or rod of metal c, Figs. 1 and 2, which is soldered or screwed to the protruding
Jas

page_text: ends of the carbons b; one or more rows of carbons may be introduced into the
drum and these must then be suitably connected. The drum may be of any
desired dimensions and if large the carbons may be introduced into both ends.
The drum is mounted upon a hollow shaft d of copper, iron, or other suitable
metal. In that portion of the shaft within the drum are bored a number of holes e
of any desirable size (Fig. 4), due regard being given to the strength of the shaft.
After well insulating the outer surface of the shaft, asbestos cloth is fastened
around it so as to cover the holes, and if desired also all those parts outside the
shaft exposed to the solution in the drum. It is advisable to make the asbestos
adhere to the shaft by means of rubber solution, marine glue or otherwise. Instead
of the asbestos cloth slag-wool, or both, may be used, or any other suitable material
through which the current passes, but which prevents any of the crushed ore from
doing so. The drum is fixed upon the shaft in any suitable manner, and to prevent
leakage rubber or other washers may be used. The ends of the asbestos are
fastened under flanges against the sides of the drum, or they may be fastened on
the shaft by means of suitable rings of hard rubber, or otherwise.
The ends of the hollow shaft pass through stuffing boxes f, in metal standards
or tanks g. On the drum is fixed a cog wheel h with which gears a pinion i,
driven by a pulley k. Inside the shaft is arranged an archimedian or other
winding screw (Fig. 4), for the purpose of causing the solution to circulate when
the drum is revolving, and also for removing into one or both standards any slime
that has gathered in the shaft. The screw may be of the same length as the shaft
or any fraction of the length. Both tanks are connected with each other by a
suitable sized pipe m, to enable the solution to circulate freely. The anode as
indicated by b (Figs. 2 and 3), consists of a number of carbons arranged in the
drum in one or more rows. I use carbons; for the simple reason that metals would
immediately be attacked and dissolved by the chlorine. The current is conveyed
to the carbons by means of brushes n or by rollers; the brushes or rollers bear
upon the metal rods or band c, and are fastened in brackets o to standards g, care
being taken to properly insulate them, and they are connected at p with one pole
of the source of electricity by wire q, while the other pole is connected with the
shaft or standards themselves at r, so that both shaft and standards form the
negative pole in the apparatus.
Upon the drum being set in motion, and the current switched on, the current is
conveyed by wire q, to brushes n, bearing upon band c, to the carbons 6 forming
the anode; then through the electrolyte to the shaft d and standards g, and back
to the battery or source of electricity.
The electrolyte is common salt water. The drum is charged with the ores
through openings 8, provided with means for tight-shutting, a rubber ring being
inserted to prevent leakage. The metals in the pulverized ores are constantly
thrown against the anodes when the drum is revolving, and thus form frequently
part of the anode itself, and thereby are brought into most intimate contact with
the nascent chlorine and oxygen generated at the positive pole, and are readily
dissolved. The metals in solution are deposited electrolytically in the shaft (this
being the negative pole), as a black slime, and are then conveyed into the tanks
by the archimedian screw provided for that purpose; it can then be easily collected
and smelted.
The shaft may be made stationary if desired and the drum caused to revolve
thereon, but I prefer to cause the shaft also to revolve to ensure the delivery of
the slime into the tanks by means of the screw as above described.
Several of these apparatus may be placed in the circuit.
The passing of the shaft through the interior of the drum may be dispensed with
in the manner shown in Figs. 5, 6 and 7.
In these Figs. a is the drum, containing the carbons as before described, and
having a large opening t in each side (Fig. 6); this opening may be of any con-
venient size and the larger it is the less the resistance of the apparatus will be.

page_text: This opening is entirely covered with asbestos cloth or other suitable material.
Over the asbestos cloth and to each side of the drum is fastened the flange of
shaft d, d, (which I prefer to make bell or funnel shaped as shown) by means of
screws or in any other suitable manner, care being taken to prevent leakage.
of current and solution; and this shaft passes as before through stuffing boxes fin
tanks g. Upon the drum being charged and set in motion, the current as in the
former case enters the drum through the carbons and leaves it again through the
bell shaped shaft ends, the asbestos dividing the two poles. The auric chloride is.
deposited in the shaft and in the tanks, all of which form the negative pole..
Hydrogen is generated from the decomposition of the water at the negative
pole, and to allow this to escape, and further to prevent polarization, and also to
allow any slimes which may accumulate to be withdrawn, openings provided with
valves u are arranged in the bell, which on reaching a certain point are opened
automatically to allow the escape of hydrogen, and on passing a given point are
automatically closed again;
1
Instead of the bell shaped ends terminating through stuffing boxes in the
standard tanks, the drum may simply be provided on each side with a large iron
cap serving as cathode, asbestos being fastened between the iron and the drum so
as to separate the carbons from the iron, which latter forms the negative pole; the
drum may then rest upon four wheels and suitable gearing be provided by which
it may be revolved. Of course proper means must be applied to allow the hydrogen
to escape.
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 :-
In the process for treating metals, alloys and especially auriferous compounds by
means of nascent chlorine generated by electrolysis:
1. The use of a drum containing carbons forming the positive pole, such drum
being mounted upon a hollow shaft the ends of which pass into tanks forming the
cathode, the drum being caused to revolve by suitable gearing, and that portion
of the shaft within the drum being perforated and its outer surface well insulated
and covered with asbestos or other suitable material.
2. An apparatus having a drum fixed upon a hollow shaft as described.
3. A drum as described fixed upon a hollow shaft, which shaft serves as cathode
and axis for the drum.
4. An apparatus having a hollow shaft provided with holes and covered with
asbestos or other suitable material, as and for the purpose specified.
5. A hollow shaft having the archimedian screw or screws for causing the solution
to circulate and for the removal of the slimes.
6. An apparatus having two standards serving as tanks, in which the hollow
shaft ends, passing through stuffing boxes, as and for the purpose specified.
7. An apparatus having the stuffing boxes, as and for the purpose specified.
8. Means of conveying a current of electricity into a revolving apparatus as
described, which consists in connecting the carbons by means of metallic rods or
bands, which are soldered to the ends of the carbons, the said bands or rods being
connected with one pole of the source of electricity by means of brushes or rollers,
or otherwise, while the shaft on which the drum is mounted may be connected
with the other pole, or the standards in which such shaft ends may be connected
therewith.
9. Means of separating the hollow shaft serving as cathode, from the carbons
serving as anodes, which consists in providing said shaft with a covering of
insulating material and asbestos or other suitable material, as and for the purpose
specified.
10. The use of a drum containing carbons forming the positive pole, the ends
of such drum being provided with openings, covered with asbestos or other suitable

page_text: material, and over which fit the open ends of a shaft connected to the drum with
which it is caused to revolve, and the opposite ends of which shaft terminate in
tanks and form the cathode.
11. In the apparatus described in claim 10, providing the ends of the shaft which
are connected to the drum with openings fitted with valves acting automatically as
the drum revolves, as and for the purpose specified.
12. The use in the apparatus described in claim 10, in place of the hollow shaft
on which the drum is mounted, of iron caps fitting over the asbestos which covers
the openings in the ends of the drum, and such caps serving as cathode, as and for
the purpose specified.