Improvements in or relating to the Extraction of Gold, Silver, and other Metals from Ores and the like.
Year: 1898

page_text: Improvements in or relating to the Extraction of Gold, Silver, and
other Metals from Ores and the like.
I, JOSEPH BAXERES DE ALZUGARAY, Metallurgist, of Lola Villa, Shortlands,
Kent, do hereby declare the nature of this invention to be as follows:-
My invention relates to the extraction of gold and other metals from ores and
other metal containing compounds, and consists in moistening the ground ore
with water, or with water holding in solution a cyanide or any cyanogen salt, or
cyanogen evolving compound. The solution may be of any degree of strength,
and the ore under treatment is moistened with it, so that no portion remains dry;
and the proper amount of moisture may be ascertained by compressing a handful
to form a lump which should retain its shape until handled. If too dry, more
water may be added, and if too wet, more dry material. A proportion of about
5 per cent. of the weight of the ore of water or of the solution prepared as before
explained will generally suffice.
'
The moistened ore is then sifted into a gas-tight vat, in such a way that it is
evenly distributed, and once the vat has been charged, bromine, or bromine com-
pounds, alone, or combined or mixed with such gases or gaseous compounds as
air, steam, carbonic acid, oxygen, ozone, chlorine, or iodine is caused to pass
through the mass of ore, prepared as aforesaid. These gaseous elements, com-
pounds or mixtures are generated outside the gas-tight vessel, chamber or vat
used in connection with this process, and then forced with the suitable amount of
The gaseous elements or
pressure through the mass of ore under treatment.
mixtures may be injected in a cold state, or heated to a convenient degree, if it
is required to increase the chemical activity of the re-action. During the pro-
gress of the treatment the ore may be agitated, either by means of suitable
stirrers, or by placing it in air-tight revolving cylinders. The chemical solvents
contained in the solution and the gaseous elements, mixtures, or compounds used
conjointly or successively are permitted to operate on the ores for a period varying
from 1" 30' to 16 hours, and in some cases even for a longer period.
After the alloted time, the ore is lixiviated with water alone, or with solutions
or mixtures of chlorides, bromides, hypochlorites, hyposulphites, cyanides, or
suitable cyanogen compounds, or with mixtures, compounds, or combinations
thereof the water and other leaching solutions may be either warm or cold.
The gaseous elements, their chemical combinations or mixtures thereof used
in connection with this process may be injected through the mass of the material
or ore under treatment, either pure or in the highest degree of concentration
obtainable, or diluted in a suitable volume of air, steam, carbonic acid, aitrogen,
hydrogen, or other convenient gaseous element, or combination or mixture thereof.
The metals to be held in solution in the lixiviating solution are recovered by
precipitation, using zinc, magnesium, iron, copper, or suitable alloys: charcoal,
or suitable re-agents may likewise be used for this purpose. The metal or metals
can also be separated from the solution by electrolysis.

page_text: Instead of moistening the ore to be dealt with as already described with a
cyanide solution, alone or mixed with other re-agents, the ore may also be
moistened only with water, or with any, or with several of the other chemical
compounds afore described. In either case cyanogen, or cyanogen gaseous com-
pounds are caused to pass through the ore, either alone or mixed with, or diluted
in the other gaseous elements or compounds as described.
In the treatment of ores by this process, cyanide solutions of great strength
may be used without increasing the amount of cyanide usually employed for a
given weight of ore. Thus instead of dissolving one part of cyanide in 15 or
20 cwt. of water, forming a solution of one in a thousand, or thereabouts, the
same amount of cyanide is dissolved in one cwt. of water, thus forming a con-
centrated solution, holding about 2 per cent. of cyanide. These concentrated
solutions are the only ones which allow of the successful treatment of refractory
ores, and dissolve coarse gold, which has hitherto been impossible by the cyanide
and chlorinating processes as actually practised.
The injection of the gaseous elements, mixtures or combinations described
through the mass of ore impregnated with these highly concentrated solutions of
cyanide greatly add to their dissolving power, increasing the rapidity with which
the precious metals are converted into soluble salts.
Dated this 11th October 1898.
Improvements in or relating to the Extraction of Gold, Silver, and
other Metals from Ores and the like.
I, JOSEPH BAXERES DE ALZUGARAY, Lola Villa, Shortlands, Kent, Chemist, 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 this invention is to effect the extraction of precious metals from
their ores in a quicker, simpler, and more efficient manner than heretofore, with-
out the formation of slimes, and the invention consists, broadly, in submitting
crushed ore, which has been only slightly moistened, to the action of cyanogen
in a concentrated form, in combination with a gaseous mixture of bromine and
oxygen.
I may here state I am aware that ores of precious metals have been treated
with cyanogen and bromine, both separately and together, for the purpose of
extracting the precious metals, and I desire therefore to state, at the outset, that
I make no claim to the use of these substances per se.
In carrying out this invention, the ore is crushed as usual, but not pulverized
(20 mesh or coarse sand is suitable for general purposes), and the crushed ore
is moistened with a cyanide solution to such an extent that it will "ball" in the
hand.
In general, the proportion of liquid employed may be about five per cent. of
the weight of the ore to be treated.
Hitherto, it has been usual to use the cyanogen in the form of a dilute solution,
it being assumed that in that form it would act only on the precious metals,
leaving other metals in the ores practically untouched, but I have discovered that
this is altogether fallacious, and therefore I use the cyanogen in a concentrated
state.
To produce the concentrated cyanogen solution which I require, I dissolve one

page_text: pound of cyanide in one hundred pounds of water, thus forming what I term a
concentrated solution, holding about one per cent. of cyanide, instead of a solution
of one in a thousand or thereabouts, as heretofore. Owing to the speed at which
the action takes place, I obtain the desired results without increasing the quantity
of cyanide employed.
I have discovered that, be the solution weak or strong, the same result takes
place, but with the strong solution the effect on the ore is expedited to such an
extent that even assuming the proportion of other metals dissolved to be greater,
the saving of time and labour is enormous.
The moistened ore is then sifted into a suitable vessel (which I term the
extractor, and which is capable of being hermetically sealed) in such a way that
it will be evenly and lightly distributed in the vessel, and a gaseous mixture of
bromine and oxygen, in varying proportions, is caused to pass slowly upwards
through the mass.
The excess
The gaseous mixture, in its passage through the crushed ore, will operate on
the metals (precious and otherwise) to form soluble salts of the same.
of the gaseous mixture will pass away to a condenser.
After sufficient treatment with the gaseous mixture (which will be determined
by the nature of the ore under treatment, and which may last from 1½ hours to
16 hours or more), the mass of ore will be washed with water, either cold or hot,
which will dissolve out the soluble salts of the metals, and hold them in a state
of solution, and from this solution the precious metals will be recovered by pre-
cipitation with zinc or other suitable metal in the usual way, or by electrolysis
or otherwise.
"
By the process above described, refractory ores can be successfully treated, and
what is known as coarse gold" may be dissolved, two results which have been
impossible by the cyanide and chlorination processes heretofore employed.
In some cases, for example, with very good ores, I may moisten the crushed
ore with water only, using the cyanogen in a gaseous form with the bromine and
oxygen in like form, but for general purposes the moistening with the cyanide
solution is preferred.
I would here remark that, by the term cyanogen or cyanide, I intend to include
any "cyanogen salt" or cyanogen-evolving compound, and that "bromine com-
pounds are included in the word "bromine."
By the word "oxygen," I intend to include air, steam, carbonic acid, ozone,
and the oxygenated compounds of chlorine or other oxygen-producing compounds.
An important feature of this invention may be here pointed out, rizt., that
as the ore is not pulverized, but only crushed, and as the amount of moisture
employed is so slight comparatively, slimes are not produced, an effect which will
be at once appreciated by practical miners.
The gaseous elements, compounds, or mixtures, are in most cases generated out-
side the extractor, and they will be forced with a convenient amount of pressure
through the mass of ore under treatment, and the elements will obviously be in
a more or less concentrated form when used.
If it be desired to increase the chemical activity of the reaction, the gaseous
elements may be heated to a convenient degree.
In the accompanying drawing I have shewn in diagrammatic form, a convenient
arrangement of apparatus for carrying out my invention; thus A is a blower,
B is a bromine jar, C a cyanide jar, 1 the extractor, having a false bottom, and
E a condenser, all connected together by suitable pipes, which are provided with
taps or cocks. The working of this apparatus will be clearly understood without
further description.
When the ore is moistened with cyanide solution, the cyanide jar C will be
cut out, and the bromine mixture will be carried direct to the extractor.
The apparatus used may however be the same as that now used for the bromine
or chlorine processes, and the operations will be of much the same character.

page_text: 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:―
1. The process for extracting precious metals from their ores, consisting in
treating moistened crushed ore with cyanogen in a concentrated state in combina-
tion with a gaseous mixture of bromine and oxygen.
2. The process for extracting precious metals from their ores, consisting in
moistening the crushed ore to such an extent that it will "ball" in the hand, with
a concentrated solution of cyanide; placing the moistened ore in a gas-tight vessel;
subjecting the same to the action of a gaseous mixture of bromine and oxygen,
whereby the precious metals are converted into soluble salts of the same; obtain-
ing the precious metals in solution by washing the ore; and, finally, recovering
the metals from the solution by precipitation or electrolysis, in the usual manner,
all as herein described.
3. The process for extracting precious metals from their ores, consisting in
moistening the crushed ore with water to such an extent that it will "ball" in
the hand; placing the moistened ore in a gas-tight vessel; subjecting the same
to the action of a gaseous mixture of bromine, cyanogen and oxygen, whereby
the precious metals are converted into soluble salts of the same; obtaining the
precious metals in solution by washing the ore; and, finally, recovering the metals
from the solution in any well known manner, all as herein described.
4. In the process for extracting precious metals from their ores, the employ-
ment of bromine and cyanogen in a gaseous form as herein set forth.
5. In the process for extracting precious metals from their ores, the employ-
ment of a concentrated solution of cyanide, as and for the purpose herein set forth.
6. In the process for extracting precious metals from their ores, the employ-
ment of oxygen in combination with a concentrated cyanide solution, as set forth.
7. In the process for extracting precious metals from their ores, the employ-
ment of oxygen in combination with bromine, as set forth.
8. In the process for extracting precious metals from their ores, the employ-
ment of a concentrated solution of cyanide in combination with bromine and
oxygen in a gaseous form, as herein set forth.
9. In the process for extracting precious metals from their ores, the employ-
ment of a gaseous mixture of bromine, cyanogen, and oxygen, as set forth.
Dated this 11th day of July 1899.
NEWTON & SON,
Agents for the Applicant.