An Improved Process and Apparatus for Extracting Gold from Minerals containing it.
Year: 1890

page_text: Date of Application, 25th Nov., 1890
Complete Specification Left, 20th June, 1891-Accepted, 24th Dec., 1891
PROVISIONAL SPECIFICATION.
An Improved Process and Apparatus for Extracting Gold from
Minerals containing it.
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. 14061 of 1886 I described a process for obtaining
gold from auriferous minerals by treating the material under electrical action with
chlorine and a cyanide. I have found that the chlorine may be entirely dispensed
with when the mineral is subjected to electrical action and agitation in the presence
of a cyanide, and in the presence of mercury by which the larger fragments of free
gold are amalgamated, while the smaller or combined particles are dissolved by
the cyanogen. My present invention relates to a process for thus extracting gold
and to apparatus suitable for effecting it.
For this purpose, I provide a vessel, preferably cylindrical, with a bottom of
basin shape containing mercury, which I connect with the negative terminal of a
battery or other source of electricity.
At some distance above the mercury I support a cylindrical block of carbon
having through it a conical hole so wide at the top that only an edge of carbon is
presented on the upper side of the block. I connect this block to the positive
terminal. Between the mercury and the lower side of the carbon block I mount on
a vertical shaft a fan or propeller. I reduce the mineral to be treated to a powder
sufficiently fine to make a fluent sludge with a solution of potassium cyanide, and I
charge the vessel with this sludge to a level above the carbon block. The fan or
propeller being made to revolve causes the sludge to flow against the surface of the
mercury, upwards outside the carbon block, and down again through the central
hole, thus keeping it in active circulation subject to the electric action in presence
of the cyanide by which the small particles of gold are dissolved and in presence of
the mercury, which is kept superficially clean, and takes up in amalgam the larger
fragments of gold as well as gold electrolysed from the cyanide solution.
Dated this 25th day of November 1890.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Process and Apparatus for Extracting Gold from
Minerals containing it.
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 auriferous minerals by treating the material under electrical action with
chlorine and a cyanide. I have found that the chlorine may be entirely dispensed
with when the mineral is subjected to electrical action and agitation in the presence
of a cyanide, and in the presence of mercury by which the larger fragments of free
gold are amalgamated, while the smaller or combined particles are dissolved by the
cyanogen. My present invention relates to a process for thus extracting gold and
to apparatus suitable for effecting it.

page_text: For this purpose, I provide a vessel, preferably cylindrical, with a bottom of
basin shape containing mercury, which I connect with the negative terminal of a
battery or other source of electricity.
At some distance above the mercury I support a cylindrical block of carbon
having through it a conical hole so wide at the top that only an edge of carbon is
presented on the upper side of the block, I connect this block to the positive
terminal. Between the mercury and the lower side of the carbon block I mount
on a vertical shaft a fan or propeller. I reduce the mineral to be treated to a
powder sufficiently fine to make a fluent sludge with a solution of potassium
cyanide, and I charge the vessel with this sludge to a level above the carbon
block.
The fan or propeller being made to revolve causes the sludge to flow against the
surface of the mercury, upwards outside the carbon block, and down again through
the central hole, thus keeping it in active circulation subject to the electric action
in presence of the cyanide by which the small particles of gold are dissolved, and
in presence of the mercury, which is kept superficially clean, and takes up in
amalgam the larger fragments of gold as well as gold electrolysed from the cyanide
solution.
The accompanying drawing is a vertical section of apparatus suitable for operating
in the manner above set forth.
A is a vessel having its bottom lined with copper C preferably corrugated as
shewn, the hollows of the corrugation being charged with mercury.
On a central
shaft B is fixed a propeller D, which revolves above the mercury and below a
block E made of carbon or of pieces of carbon held in a wooden or ceramic
framing. The copper C is connected to the negative terminal of a dynamo machine
or other source of electricity and the carbon E is connected to the other terminal.
F is a run off pipe with valve opening inwards.
Although I have mentioned potassium cyanide as the salt employed, other
cyanides may obviously be used the reaction depending chiefly on the presence of
cyanogen.
Having now particularly described and ascertained the nature of my said 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 gold from minerals containing it
by subjecting the finely pulverised mineral mixed with solution of cyanide to electric
action and agitation in the presence of mercury.
2. For operating in the manner above set forth, apparatus substantially as
described with reference to the accompanying drawing.
Dated this 20th day of June 1891.
ABEL & IMRAY,
Agents for the Applicant.