Improvements in Extracting Precious Metals from Ores or Minerals containing them, and Apparatus therefor.
Year: 1890

page_text: Date of Application, 22nd Sept., 1890
Complete Specification Left, 20th June, 1891-Accepted, 22nd Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in Extracting Precious Metals from Ores or Minerals
containing them, and Apparatus therefor.
I, JAMES BALLANTYNE HANNAY, of Cove Castle, Loch Long, in the County
of Dumbarton, Chemical Engineer, do hereby declare the nature of this invention
to be as follows:
In my Specification No. 14,061 of 1886 I described a process for obtaining
gold from refractory ores, or other auriferous substances by subjecting the materials
to the action of chlorine and electricity aided by admixture of a cyanide. I have
since discovered that by electrical action and agitation in presence of a cyanide,
applied by suitable apparatus, the chlorine may be entirely dispensed with, and thus
not only gold, but also silver may be obtained from ores or minerals containing
them. I reduce the material to be treated to a fine powder and mix this with
water and a solution of potassium cyanide to the consistence of a fluent sludge. I
place this sludge in a vertical vessel, which may be cylindrical, and which is
provided with agitating apparatus so arranged as to cause an active circulation of
the sludge from below upwards and from above downwards. At the upper part
of the vessel I provide a compartment, which may be of annular form separated
from the body of the vessel by a partition of porous material such as asbestos
fabric, and in this compartment I place a metallic or carbon electrode immersed in
solution of cyanide such as potassium cyanide. Also at the upper part of the
vessel I fix another electrode, preferably carbon, which may be in the form of a
grating through which the circulating sludge has to pass.
The electrodes being suitably connected to the poles of a voltaic battery or to
the terminals of a dynamo machine, the metal is to a large extent extracted from
the sludge and is deposited upon the cathode within the porous compartment.
After continuing the process for some time, the sludge run off and filter pressed,
and the expressed liquid containing cyanide of the metals in solution is charged
again into the operating vessel with addition of ore which is operated on as
before.
Dated this 22nd day of September 1890.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Extracting Precious Metals from Ores or Minerals
containing them, and Apparatus therefor.
I, JAMES BALLANTYNE HANNAY, of Cove Castle, Loch Long, in the County
of Dumbarton, Chemical Engineer, 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 :-
In my Specification No. 14061 of 1886, I described a process for obtaining gold
from refractory ores, or other auriferous substances by subjecting the materials to
the action of chlorine and electricity aided by admixture of a cyanide. I have
since discovered that by electrical action and agitation in presence of a cyanide
applied by suitable apparatus, the chlorine may be entirely dispensed with, and
thus not only gold but also silver may be obtained from ores or minerals containing
them. I reduce the material to be treated to a fine powder and mix this with
water having in solution not more than two per cent. of potassium cyanide to the
consistence of a fluent sludge.

page_text: I place this sludge in a vertical vessel which may be cylindrical, and which is
provided with agitating apparatus so arranged as to cause an active circulation of
At the upper part
the sludge from below upwards and, from above, downwards.
of the vessel I provide a compartment, which may be of annular form separated
from the body of the vessel by a partition of porous material such as asbestos
fabric, and in this compartment I place a metallic or carbon electrode immersed in
solution of cyanide such as potassium cyanide. Also at the upper part of the
vessel I fix another electrode, preferably carbon, which may be in the form of a
grating through which the circulating sludge has to pass.
The electrodes being suitably connected to the poles of a voltaic battery or to
the terminals of a dynamo machine, the metal is to a large extent extracted
from the sludge and is deposited upon the cathode within the porous compartment.
After continuing the process for some time the sludge is run off and filter
pressed, and the expressed liquid containing cyanide of the metals in solution is
charged again into the operating vessel with addition of ore which is operated
on as before.
The accompanying drawing is a vertica! section of apparatus whereby the process
above set forth may be conveniently carried on. A is a vessel preferably cylindrical
with its bottom filled in with brick or other structure to give it a rounded form.
B is a shaft carrying a propeller C a short distance above the bottom, and under
a block D made of carbon or of carbon pieces held together in a framing of wood
or ceramic material. E is a porous diaphragm, which may be porous fabric
supported on a wooden framing, parting off a compartment containing, a conducting
plate or plates F connected to the negative, terminal of a dynamo machine or other
source of electricity to the other terminal of which the carbon D'is connected.
G is a run off pipe with valve opening inwards.
Although I have in the above description mentioned potassium cyanide as the
salt employed, other cyanides may be employed, the re-action being chiefly due to
the cyanogen.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
I claim is
1. The herein described process for extracting precious metals from ores or
minerals containing them by subjecting the finely pulverised mineral mixed with
solution of potassium or other cyanide to electrical action and agitation.
2. For operating in the manner above referred to apparatus substantially as
described with reference to the accompanying drawing.
Dated this 20th day of June 1891.
ABEL & IMRAY,
Agents for the Applicant.