Improvements in or relating to the Extraction of Precious Metals from certain of their Ores..
Year: 1899

page_text: Date of Application, 23rd Sept., 1899
Complete Specification Left, 22nd June, 1900-Accepted, 15th Sept., 1900
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Extraction of Precious Metals
from certain of their Ores..
We, THE GOLDEN LINK CONSOLIDATED GOLD MINES LIMITED, of 20 and 21,
Lawrence Lane, Cheapside, London, and HENRY JOSHUA PHILLIPS, Fellow of the
Institute of Chemistry, etc. etc., of 123, Palace Chambers, Westminster, London,
do hereby declare the nature of this invention to be as follows:
This invention has for its object improvements in or relating to the extraction
of precious metals from their ores and relates primarily to so treating refractory
or rebellious gold bearing ores that the gold therein can then be extracted by
means of the well-known cyaniding or amalgamation or other suitable processes
and furthermore, besides effecting the extraction of the gold, other metals pre-
sent in said ore may be also extracted for instance in treating telluride ore
according to this invention the tellurium arsenic antimony etc. (or any of them)
as well as the gold may be extracted.
There exists in certain parts of the world, notably in Hungary West Australia
and Colorado, a certain class of gold bearing minerals in which the gold is said
to be or appears to be in actual combination with such elements as tellurium
arsenic antimony etc.; and hitherto it has been found necessary or usual to
subject such ore to a preliminary roasting before treatment by the well-known
cyanide or chlorination process.
Now according to the present invention such preliminary roasting can be and
is dispensed with and the elements combined with the gold are dissolved in the
manner and by the means hereinafter described thus rendering the gold free
to be acted upon and extracted by the cyanide or other suitable process."
According to the present invention it has been found that if ores containing
telluride arsenide or antimonide of gold (or suchlike gold bearing ores) be acted
upon under heat and pressure by a weak or dilute solution of the poly-sulphides
of the alkalies or alkaline earths (say 0.5 to 3.0% of the poly-sulphide in solu-
tion) the said weak solution will have a selective action and will dissolve such
elements so combined with the gold without dissolving the gold or only an
inappreciable amount thereof (if any) thus leaving practically the whole of the
gold in a free metallic state which can then be treated by the well-known
cyanide or other desirable process for recovering gold-for instance the gold
having thus been dissociated from its combinations the latter may now be washed
out of the ore, leaving its gold in the free metallic state in the ore, and the
whole of the gold can then be treated by cyaniding etc. as aforesaid.
It is an object of the present invention to use only sufficient poly-sulphide
under heat and pressure-to exercise a selective action upon and dissolve the
elements combined with the gold, without dissolving the gold itself though a
minimum amount thereof may possibly go into solution.
This invention may be carried out as follows:-
The ore to be treated is first reduced to powder or a finely comminuted con-
dition, and placed in any suitable vessel or receptacle capable of being tightly
closed, and, when closed of withstanding considerable pressure when the mixture

page_text: The ore is mixed with the weak poly-sulphide solution say about equal weights
of the solution and of the ore and the vessel or receptacle having been sealed
or tightly closed the ore is now heated in said vessel by any suitable means to
a suitable temperature (say about 100° to 200° C.) and maintained under said
heat and the consequential pressure until such elements, so combined with the
gold, are dissolved. The dissolving of said combinations is effected very rapidly
under the heat and pressure say in 1 to 3 hours depending however upon vary-
ing conditions notably the temperature employed and the facilities provided for
mixing or stirring the ore while same is being acted on; for instance if the ore
be placed in a revolving drum and heated to say 200° C. or thereabouts the
solution of the combinations would be much sooner accomplished than if the
mixture was heated to 100° C. only, without agitation of the mixture.
As a modification of the fore-going process; the ore in the condition, herein-
before described, and the aforesaid weak or dilute solution hereinbefore described,
may be placed together in a suitable vessel or receptacle capable of being sealed
or tightly closed (advantageously a receptacle of very large size) and allowed
to remain in said vessel for a prolonged period out of contact with the external
air, and without applying artificial heat pressure (or only very moderate
heat
or
and
or
and
pressure may be applied for instance the closed vessels may be exposed
to the heat of the sun with a view to shortening such period) and ultimately
the gold will be dissociated and its combinations dissolved and the former can
then be recovered by the ordinary cyaniding or other suitable, process as
aforesaid.
TYL 3 L
1
1
1000
TONGUE & BIRKBECK,
Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.
Improvements in or relating to the Extraction of Frecious Metals
from certain of their Ores.
We, THE GOLDEN LINK CONSOLIDATED GOLD MINES LIMITED, of 20 and 21,
Lawrence Lane, Cheapside, London, and HENRY JOSHUA PHILLIPS, Fellow of the
Institute of Chemistry, etc. etc., of 123, Palace Chambers, Westminster, London,
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 fol-
lowing statement :-
-
This invention has for its object improvements in or relating to the extraction
of precious metals from certain of their ores and relates primarily to so treating
refractory or rebellious gold bearing ores (especially refractory sulphide or tellu-
ride ores) that the combined gold therein is dissociated and can then be extracted
(together with any free gold originally present in the ore) by means of the well-
known cyaniding or amalgamation or other suitable processes for recovering
free gold; and furthermore, besides effecting the extraction of the gold, other
imetals (such as tellurium arsenic or antimony) present in said ore may be pre-
served therein and subsequently also extracted for instance in treating telluride
ore according to this invention the tellurium arsenic antimony etc. (or any of
them) as well as the gold may be extracted as hereinafter set forth.
There exists in certain parts of the world, notably in Hungary West Australia
and Colorado, a certain class of gold bearing minerals in which the gold is said

page_text: to be or appears to be in actual combination with such elements as tellurium
arsenic antimony etc.; and hitherto it has. Deen found necessary or usual to
subject such ore to a preliminary roasting before treatment by the well-known
cyanide or chlorination process.
Now in carrying out the present invention such preliminary roasting can be,
and is, dispensed with; the elements which are combined with the gold being
dissolved in the manner and by the means hereinafter described without dis-
solving the gold thus dissociating the gold from its combinations and thereby
rendering the gold free to be acted upon and extracted by any well-known
cyanide or other suitable process for recovering free gold from the ore.
According to the present invention it has been found that if ores containing
telluride arsenide or antimonide of gold (or such like gold bearing ores) be acted
upon under heat and pressure by a weak or dilute solution or the poly-sulphides
of the alkalies or alkaline earths such as those of sodium, potassium, ammonium
or calcium (say 05% to 30% of the polysulphide in solution) the said weak
solution will have a selective action and will dissolve such elements so combined
with the gold without dissolving the gold or only an inappreciable amount
thereof (if any) thus leaving practically the whole of the gold in a free metallic
state which can then be treated by the well-known cyanide or other desirable
process for recovering gold—for instance the gold, having thus been dissociated
from its combinations the latter may now be washed out of the ore, leaving its
gold in the free metallic state in the ore, and the whole of the free gold in the
ore can then be treated by cyaniding etc. as aforesaid.
It is an object of the present invention to use only sufficient poly-sulphide―
under heat and pressure-to exercise a selective action upon and dissolve the
elements which are combined with the gold without dissolving the gold itself.
This invention may be carried out as follows:-
The ore to be treated is first reduced to powder or a finely comminuted con-
dition and placed in any suitable vessel or receptacle capable of being tightly
closed, and when closed of withstanding considerable pressure when the mixture
is heated.
The ore is mixed with the weak (say 05 to 3% as aforesaid) polysulphide
solution say about equal weights of the solution and of the ore and the vessel or
receptacle having been sealed or tightly closed the ore is now heated in said
vessel by any suitable means to a suitable temperature (say about 100° to 200°
C:) and maintained under said heat and the consequential pressure until the
combinations (i.e. the elements combined with the gold) have been dissolved.
The dissolving of said combinations is effected very rapidly under the heat and
pressure say in 1 to 3 hours depending however upon varying conditions notably
the temperature employed and the facilities provided for mixing or stirring the
ore while same is being acted on; for instance if the ore be placed in a revolv-
ing drum and heated to say 200° C. or thereabouts the solution of the combina-
tions would be much sooner accomplished than if the mixture was heated to
100° C. only without agitation of the mixture.
As a modification of the fore-going process; the ore in the condition, herein-
before described, and the aforesaid weak or dilute solution hereinbefore described,
may be placed together in a suitable vessel or receptacle capable of being sealed
or tightly closed (advantageously a receptacle of very large size) and allowed
to remain (closed up) in said vessel for a prolonged period out of contact with
the external air, and without applying artificial heat pressure (or only very
or
or
and
moderate heat
and pressure may be applied for instance the closed vessel may
be exposed to the heat of the sun with a view to shortening such period) and
ultimately the gold will be dissociated and its combinations dissolved and the
former can then be recovered by the ordinary cyaniding or other suitable process
as aforesaid.

page_text: The amount of the polysulphide employed in the aforesaid weak solution is pro-
portioned according to the amount of and nature of the constituents of the ore
soluble in said solution--this proportion being determined either from the
known constitution of said ore or ascertained by chemical analysis of said ore;
for instance with an ore containing tellurium in other states than--as well as-
telluride of gold such tellurium as well as the tellurium combined with the gold
will be dissolved and therefore a sufficient amount of the aforesaid solution of
polysulphide must be introduced to dissolve all such tellurium but always such
polysulphide must be introduced in such a weak solution as not to dissolve the
gold and for this purpose any amount of the said weak solution may be intro-
duced until the combined gold has been dissociated.
This also applies equally in the case of antimony or arsenic in the ores.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. The herein described method of extracting precious metals from refractory
or rebellious ores of the character specified which consists in subjecting the
powdered ore to the action of a weak (say 05 to 3%) solution of alkaline poly-
sulphides the amount of polysulphide employed being insufficient to dissolve the
gold itself but proportioned as described so that it will dissolve the elements com-
bined with the gold without dissolving the gold whereby the latter is dissociated
and can then be recovered by the well-known cyaniding or other suitable process
for recovering free gold.
2. The herein described method of extracting precious metals from refractory
or rebellious ores of the character specified which consists in subjecting the
powdered ore under heat and pressure-to the action of a weak (say 05 to 3%)
solution of alkaline polysulphides the amount of polysulphides employed being
insufficient to dissolve the gold itself but proportioned as described so that it will
dissolve the elements combined with the gold without dissolving the gold
whereby the latter is dissociated and can then be recovered by the well-known
cyaniding or other suitable process for recovering free gold.
3. The herein described method of extracting precious metals from refractory
sulphide or telluride ores without roasting which consists in subjecting the ore
in the form of a powder and without roasting to the action of alkaline poly-
sulphides in solution of such weakness and so proportioned that same will have
a selective action namely will dissolve the elements which are combined with the
gold and for which the polysulphides have a greater affinity than for gold with-
out dissolving the gold itself which latter is thus dissociated and can then be
recovered by any known suitable process for recovering free gold substantially
as herein before set forth.
4. The herein described method of extracting precious metals from refractory
sulphide or telluride ores without roasting which consists in subjecting the ore
without roasting and in the form of a powder-under heat and pressure-to the
action of alkaline polysulphides in solution of such weakness and so proportioned
that same will have a selective action namely will dissolve the elements which
are combined with the gold and for which the polysulphides have a greater
affinity than for gold without dissolving the gold itself which latter is thus dis-
sociated and can then be recovered by any known suitable process for recover-
ing free gold substantially as hereinbefore set forth.
Dated this 22nd day of June 1900.
TONGUE & BIRKBECK,
Birkbeck Bank Chambers, Chancery Lane, London, W.C.,
Agents for the Applicants.