Improvements in or relating to the Extraction of Gold, Silver, and other Metals from Ores and the like.
Year: 1896

page_text: Date of Application, 11th Feb., 1896
Complete Specification Left, 11th Dec., 1896-Accepted, 11th Feb., 1997
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Extraction of Gold, Silver, and
other Metals from Ores and the like.
.
I, JOSEPH BAXERES TORRES, Doctor-en-Sciences, of 17, St. Anne's Court,
Wardour Street, London W. do hereby declare the nature of this invention to be
as follows:-
1. This invention relates to the extraction of gold, silver and other metals by
cyanide, chlorination and other processes, from ores and other metal containing
compounds.
2. The object of this invention is to obtain a more perfect, rapid and cheaper
extraction of gold, silver and other metals, using cyanide, chlorine, bromine, or
salts or compounds therefrom with other halogenous elements, their salts, compounds.
or mixtures.
3. Instead of operating as it has been hitherto practised, chiefly in reference to
the cyanide and hyposulphite processes, by first lixiviating the tailings concentrates
and ores with leaching solutions, and then separating the precious metals and others
from the resulting solutions by means of zinc and other metals or by appropriated
reagents or through the agency of the electric current, I carry on these operations
by forming a voltameter or electric decomposing vat divided into two or several
compartments positive and negative, by means of porous partitions or diaphragms
or of perforated partitions or perforated trays. At the compartment connected
with the positive pole of the electric generator and forming therefore the anode,
I place the ore or metal containing material to be treated, alone or mixed in any
way with carbon, iron, mercury, manganese oxydes native sulphides, ores or minerals,
or a mixture of them in general with any material electro-negative in respect to
gold, to silver or to the metal or metals to be dissolved and separated from the
ores, in order to accelerate the solutions of the metal or metals therein contained.
4. When diaphragms or porous partitions are used in working this process, the
solution in each of the compartments formed by the partition may either be similar
or dissimilar, for instance, a solution of a cyanide or of any cyanogen compound
may be in contact with the ore or material under treatment at the compartment
forming or containing the anode :-the solution occupying the negative compartment
being formed by a solution of substances containing and evolving at the anode
(when decomposed through the action of the electric current) bromine, chlorine,
carbon, fluorine, iodine, nitrogen, cyanogen, oxygen ozone, selenium sulphur,
tellurium, or compounds or mixtures therefrom.
5. The solutions or electrolytes formed as herein before explained, may be of
any degree of strength, either weak or strong solutions.
6. The operations, when found suitable, may be conducted under pressure using
clused vessels, and also, if required, under varying conditions of temperature.
7. During the treatment, the solutions or electrolytes in each compartment may
be set in motion by injecting air or steam through it, or mechanically.
8. The composition of the electrolyte in each compartment may be kept uniform
by drawing it at the lower part of the voltameter by means of a tap or of a syphon
and pouring it again from the top, by means of a pump, or other convenient
apparatus. This forms a continuous lixiviation process during which the solutions
may be weakened or strengtheued, if convenient, without interrupting the march
of the process.

page_text: 9. In order to increase the dissolving power of the solutions used, compressed
steam and such gases as chlorine, bromine, air, oxygen, ozone, carbonic acid and
other suitable gases and gaseous mixtures or compounds are injected at the com-
partments forming the anode or the cathode, as found suitable.
10. The plates, rods or bars forming either or both the anode and the cathode at
the voltameter may be made of lead, copper, iron, mercury, carbon, or of any other
good conductor; if found desirable, these plates may be amalgamated.
11. The addition of fluorine salts or fluorine compounds to the solutions or to
the ores or material under treatment in connection with this process, will be found
greatly useful as it insures a good deposition of reguline metals at the cathode.
It acts at the same time as a powerful disintegrating agent of ores and silicates.
12. In forming the diaphragms or porous partitions dividing the cell, any porous
substance such as sand, pumice stone, saw dust, cocoanut fibre may be used.
Dated this 11th day of February 1896.
Improvements in or relating to the Extraction of Gold, Silver, and
other Metals from Ores and the like.
1, JOSEPH BAXERES TORRES, Doctor of Sciences of 17 St. Anne's Court,
Wardour Street, in the County of Middlesex, 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 :-
1. This invention relates to the extraction of gold, silver and other metals by
cyanide, chlorination and other processes, from ores and other metal containing
compounds and consists in the employment of hydrofluoric acid, fluorides or
compounds containing fluorine, in combination with other halogen or non-metallic
solvents.
2. The object of this invention is to obtain a more perfect, rapid and cheaper
extraction of gold, silver and other metals, using solvents such as cyanide, chlorine,
bromine, or salts or compounds thereof in combination with other halogenous
elements, such as fluorine, chlorine, bromine, their salts, compounds or mixtures,
acting as disintegrating or oxidising agents and the process which I will now
describe in its essential features and practical details is as follows:-
3. Instead of operating, as has been done hitherto, chiefly in reference to the
cyanide and hyposulphite processes, by first lixiviating the tailings, concentrates
and ores with leaching solutions, and then separating the precious metals and
others from the resulting solutions by means of zinc and other metals, or by
appropriate reagents or through the agency of the electric current, I carry on
these operations by first lixiviating the ores by a suitable solution or mixture of
solutions in conveniently shaped vats to extract as much of the precious metal as
possible at this stage of the process. I next place the partially treated ore
together with the solution in an electrolytic decomposing vat divided into two or
several compartments, positive and negative, by means of porous partitions or
diaphragms, or of perforated partitions, or perforated trays. In the compartment
connected with the positive pole of the electric generator, and forming therefore the
anode, I place the ore or metal containing material to be treated, alone or mixed
in any way with a suitable material electro negative in respect of gold silver or
the other metal to be extracted such for example as carbon, iron, mercury,
manganese oxides, native sulphides, or a mixture of them when the solvent is used
which is hereinafter described, in order to accelerate through galvanic action the

page_text: solution of the metal or metals therein contained. The result of the electric
current is to decompose the electrolyte obtained by the lixiviation of the ore at the
first stage of the process; the metals held in solution are deposited at the cathode,
and gases such as the halogenous and non-metallic substances are evolved at the
anode and react on the partially treated ore and by their disintegrating and dissolving
action complete the extraction of the precious or other metals desired.
4. When diaphragms, or porous partitions are used in working this process, the
solution in each of the compartments of the electrolytic tank may be either similar
or dissimilar, for instance, a solution of a cyanide or of any cyanogen compound,
may be in contact with the ore or material under treatment in the compartment
forming or containing the anode:-the solution occupying the negative compart-
ment being formed by a solution of substances containing or evolving at the anode
(when decomposed through the action of the electric current) bromine, chlorine,
fluorine, or fluo-compounds, cyanogen, oxygen, ozone, or compounds or mixtures
thereof.
5. The solutions, or electrolytes formed as herein before explained, may be of any
practicable degree of strength, either weak or strong solutions.
6. The operations, when it is found suitable, may be conducted under pressure,
using closed vessels, and also, if required, under varying conditions of temperature.
7. During the treatment, the solutions, or electrolyte in each compartment may
be set in motion by injecting air or steam through it, or nechanically. In order in
some cases of refractory ores to increase the dissolving power of the solutions
used, and in other cases to counteract the effects of climate, for instance when
the work has to be carried on in a severely cold temperature, or again in
other cases when it is desirable to alter the electric conductivity of the solution
employed, compressed steam or such gases as chlorine, bromine, air, oxygen, ozone,
carbonic-acid, or other suitable gases and gaseous mixtures may be injected in the
compartment forming the anode.
Speaking generally I find that a temperature approximating to 70° Fahr. is a
very suitable temperature in which to carry on my operations.
8. The composition of the electrolyte in each compartment may be kept uniform
by drawing it away at the lower part of the electrolytic tank by means of a tap or
of a syphon and pouring it in again at the top, by means of a pump or other
convenient apparatus. This forms a continuous lixiviating process, during which
the solutions may be weakened or strengthened, and their contained salts extracted
or a part of them extracted by precipitation or settlement, if convenient, without
interrupting the progress of the process.
9. The plates, rods, or bars forming either, or both the anode and the cathode
of the electrolytic tank may be made of lead, copper, iron, mercury, carbon, or of any
other good conductor; or if found desirable, these plates may if necessary be
amalgamated.
10. The addition of fluorine salts, or fluorine compounds to the solutions, or
to the ores or material under treatment in connection with this process, will be
found very
useful not only for their primary purpose as disintegrators of the ore
but also incidentally as they ensure a good deposition of reguline metals at the
cathode.
11. In forming the diaphragms, or porous partitions dividing the cell, any
porous substance, such as sand, pumice-stone, sawdust, coke, or cocoanut fibre may
be used.
12. The leaching solution and electrolyte I generally use in connection with
this process is formed as follows, though I do not by any means confine myself to
composition

page_text: 13. In conjunction with the electrolytic part of the process and either
previously, or in any of the stages of the operation, the ore under treatment may
be also alternately lixiviated with solutions formed as herein before explained.
14. Speaking generally, this process consists in an electro-chemical treatment of
the ores or metal containing substances, by which these are attacked and thereby
disintegrated through the agency of the halogens, such as fluorine, chlorine,
bromine, or compounds or mixtures thereof, and of oxygen and the oxy-compounds.
The fluo-compounds act chiefly on the silicates; oxygen and the oxy-compounds
oxidise the other non-metallic elements, and through this dual agency liberate the
metals and consequently render them easily soluble in chlorine, bromine, cyanogen,
cyanides, their compounds and other suitable solvents. In this case the disin-
tegration splits or destroys the chemical combination forming the ore. The metals
are easily recovered after this treatment by the most suitable solvent in each case.
15. The invention will be best understood by reference to the apparatus I use in
connection with this process; and in the accompanying drawings.
Figure 1 is a vertical longitudinal section through the centre of lixiviating
tanks.
Figure 2 is a plan of same.
Figure 3 is a plan of the electrolytic tanks or voltameter.
Figure 4 is a vertical longitudinal section through the centre of the electrolytic
tanks.
Figure 5 is a transverse section and end view of electrolytic vats.
16. Referring to Figures 1 and 2 this lixiviating tank or vat consists in a series
of communicating vessels T, made of wood or other suitable material; at the upper
part of these vessels are placed one or more perforated trays t, to hold the material
to be treated with the lixiviating solution. To avoid the passage of fine particles
of the material under treatment through the perforations, the inner part of the tray
may be covered with a suitable filtering material, such as cocoa fibre, cloth, felt,
flannel, asbestos, glass wool or sizal so as to obtain a clear solution. The lower
part of the tanks T, may be utilised to receive the reagents and effect the separation
of the metallic elements dissolved from the material under treatment at the per-
forated trays t. In acting through the agency of electricity, these leaching tanks
may be turned into electrolytic decomposing voltameters, the anode being placed
at t and the conductor forming the cathode at T.
17. The whole of the structure may be fixed on a bed of concrete or suitable
material on the ground level, or placed on piers W as shown in Figure 1.
18. Referring to Figures 3, 4 and 5, the electrolytic decomposing voltameter or
vat consists of a series of perforated vessels t forming the anode, or in which the
anode and the material to be decomposed or disintegrated and dissolved is contained.
These trays rest on wooden beams and are contained in a tank T of any suitable
material. P and N are respectively the conductors, positive and negative,
connecting the anode and cathode with the electric generator.
19. The tanks, trays, and the apparatus above described may when non-
conductors be coated or lined with any kind of varnish, pitch, tar, asphalt, or
other suitable material to avoid percolation of the solutions or attack of the material
forming the apparatus.
20. A are conductors in the shape of rods, plates, or other form of metals or
alloys carbon, coke, magnetic iron ore, or other suitable electric conducting
substance, forming the anode.
C are similar conductors of iron, lead, zinc, carbon, or other suitable electric
conducting substance, forming the cathode.
S are beams serving to support the trays.
W are the walls of the tank.
21. The perforated vessels in Figures 3, 4, and 5, may be covered as in Figure 2
with suitable filtering materials, or instead of using voltameters or electrolytic
tanks in which the solution communicates freely from the trays t through the

page_text: perforations to the tank T; the tray t may be formed by a porous material such
as porcelain or the like.
I will now describe by way of illustration the application of my process to a
gold bearing ore of the following composition:-
A current of an electromotive force varying from 15 to 3.5 volts is passed for a
period of 5 to 10 hours; and once the ore is conveniently disintegrated, the current
is switched off and the ore is lixiviated, either at the lixiviating vessel T, or at the
vessel serving as anode for a further space of 10 hours, with the same solution
used formerly to disintegrate the ore to which 1% of potassium cyanide and the
same amount of potassium bromide is added. This leaching solution may be left in-
contact with the ore for a further period of 10 hours, at the end of which time the
ore is removed from vessel T, of the leaching vats and transferred to the anode
vessel of the electrolytic vat, or when the leaching has been worked at the anode, a
current is passed on it, using the same solution used for the lixiviation and passing
a current of ampere per square foot of electrode with an electromotive force of
about 1.5 to 3 volts; the current is passed for a period of 18 hours. The gold and
precious metals are thrown down on the plates, generally made of lead, forming
the cathode; the plates are then fused and cupelled to recover the gold and
precious metals and they will be found to yield from 50 to 99% of the gold and
precious metal contents of the ores. The amount of solution used is equal to the
weight of the ore.
In most cases I find it advantageous to keep the solvent solution circulating
through the ore and the cathode chamber, in order to facilitate the carrying of the
gold from the one to the other. For the purpose of maintaining this circulation,.
I employ a pump or other suitable contrivance according to circumstances.
At the conclusion of the dissolving process, I draw off the solvent liquid and
wash the residue of the ore for the recovery of the soluble salts in it. The
exhausted ore is then thrown away and the solutions used are all preserved for
subsequent operations.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The employment of hydrofluoric acid, fluorides or compounds containing
fluorine in combination with other halogen and non-metallic solvents or their
compounds, as leaching solutions or as electrolytes for the extraction of metals from
their ores, or other metal containing compounds substantially as described.
2. In the extraction of metals from their ores the employment of hydrofluoric
acid or other compound containing fluorine combined with halogenous or non-metallic
elements, their salts or compounds to form leaching solutions and electrolytes
substantially as described.
3. The process-for the treatment of ores consisting in first lixiviating the ore
with a suitable leaching solution as hereinbefore described then electrolyzing this
solution placing the-partially treated ore at the anode whereby the electrolyte is
decomposed, depositing the metals at the cathode and evolving disintegrating and
dissolving gases at the anode so as to fully extract the metallic elements from the
ore substantially as described.
4. Directly treating the ores, minerals or metal containing salts in a single
operation in which they are dissolved and disintegrated at the anode, and the
metallic elements therein contained, transformed into soluble salts which being
decomposed through the action of the electric current from an electrolyte such
as is hereinbefore described the metals are deposited at the cathode, substantially
as described.
5. In the treatment of ores the combination with a disintegrating agent, such
as a fluoride salt or any fluorine compound of a solvent or solvents such as the
chlorides, cyanides, bromides or other halogenous or non-metallic elements
substantially as described.
6. The complete process for the treatment of ores and other metal containing
materials and apparatus therefor substantially as described and illustrated in the
accompanying drawings.
Dated this 11th day of December 1896.
JOSEPH BAXERES TORRES.
Boult & Wade,
Agents for the Applicant.