An Improved Process and Apparatus for the Amalgamation of Gold and Silver Contained in their Ores.
Year: 1889

page_text: Date of Application, 24th June, 1889
Complete Specification Left, 11th Apr., 1390-Accepted, 17th May, 1890
PROVISIONAL SPECIFICATION.
An Improved Process and Apparatus for the Amalgamation of Gold
and Silver Contained in their Ores.
I HERBERT CAVE of 21 Half Moon Street, Piccadilly, London, W. Gentleman,
do hereby declare the nature of this invention to be as follows:-
This improved process of amalgamating gold and silver for the purpose of
extracting the same from their ores comprises two distinct stages or operations.
The first operation consists in subjecting the ore in a finely pulverized and dry
condition to the direct action of mercurial vapors or fumes whereby much of the gold
and silver is amalgamated or prepared for analgamation in the subsequent operation
constituting the second part of the process. This preliminary operation is performed
by placing the finely crushed ore along with some mercury in a suitable vessel which
is heated until the mercury has been vaporised and diffused through the mass of ore
which is easily and quickly penetrated by the mercurial vapors. In this manner the
gold and silver contained in the ore are much more readily attacked than if liquid
mercury were employed. The vessel is provided with means of intercepting any
uncondensed vapors that may escape so that loss of mercury is prevented.
The second stage of the operation is performed by placing the mercurialized
charge along with some mercury in a rocking vessel or pan preferably in the form
of a boat mounted to oscillate on a transverse axis. The charge of ore is mixed with
sufficient water to bring it to the best conditions for the collection of the mercury
diffused through the charge and for the amalgamation of any gold and silver that
may have escaped the action of the mercurial vapors. A small quantity of mineral
acid is added to the water. A result may however be obtained with water only. By
the rocking of the vessel, the mercury and slime are caused to flow backwards and
forwards so as to facilitate the gravitation of the precious metals and minute mercury
globules through the charge to the bottom of the vessel where they are picked up by
the mercury as it flows backwards and forwards.
When the operation is complete, the slime is run off from the surface of the
mercury and another charge of ore, prepared according to the first stage of the
process, is introduced and the operation repeated, and so on until the mercury
becomes thick with the amalgam. The mercury is then washed out and squeezed in
the usual way, the liquid mercury which is expressed being returned to the amalga-
mating vessel, for use again.
The second part of the process may be employed alone, that is to say powdered ore
which has not been previously charged with mercurial vapors may be amalgamated
directly in the rocking vessel above described.
Dated this 24th day of June 1889.
COMPLETE SPECIFICATION.
An Improved Process and Apparatus for the Amalgamation of Gold
and Silver Contained in their Ores.
I, HERBERT CAVE of 21, Half Moon Street, Piccadilly, London, W. Gentleman,
do hereby declare the nature of this invention and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the following
tatement:-
This improved process of amalgamating gold and silver for the purpose of
extracting the same from their ores, comprises two distinct stages or operations.
The first operation consists in subjecting the ore in a finely pulverised and dry
condition to the direct action of mercurial vapors or fumes whereby much of the
gold and silver is amalgamated or prepared for amalgamation in the subsequent
operation constituting the second part of the process. This preliminary operation
may be performed by placing the finely crushed ore along with some mercury in
a suitable vessel which is heated until the mercury becomes vaporised and diffused
through the mass of ore which is easily and quickly penetrated by the mercurial
vapors. In this manner the gold and silver contained in the ore are much more
readily attacked than would be possible by liquid mercury alone. The vessel is
provided with means of intercepting any uncondensed vapors that may escape so
that loss of mercury is prevented.
The second stage of the operation is performed by placing the mercurialised
charge of ore along with some mercury in a rocking vessel or pan preferably in
the form of a boat mounted to oscillate on a transverse axis. The charge of ore
is mixed with sufficient water to bring it to the best conditions for the collection
of the mercury diffused through the charge and for the amalgamation of any gold
and silver that may have escaped the action of the mercurial vapors. A small
quantity of mineral acid is added to the water. A result may, however, be
obtained with water only. By the rocking of the vessel, the mercury and slime
are caused to flow backwards and forwards so as to facilitate the gravitation of the
precious metals and minute mercury globules through the charge to the bottom of
the vessel where they are picked up by the mercury as it flows backwards and
forwards.
When the operation is complete, the slime is run off from the surface of the
mercury and another charge of ore, prepared according to the first stage of the
process, is introduced and the operation repeated and so on until the mercury
becomes thick with the amalgam. The mercury is then washed out and squeezed in
the usual way, the liquid mercury which is expressed being returned to the amalga-
mating vessel for use again.
The second part of the process may be employed alone, that is to say powdered
ore which has not been previously charged with mercurial vapors may be amalga-
mated directly in the rocking vessel above described.
This rocking vessel is illustrated in the accompanying drawings, forming part of
this specification, wherein figure 1 is a side elevation, figure 2 a plan, and figure 3
a transverse section, of the said vessel.
A is an iron pan of the form shewn mounted to oscillate on gudgeons a a in
bearings in the frame B, the oscillating motion being imparted thereto from a crank c
on a shaft C coupled to the pan by a connecting rod D. E is a central transverse
partition dividing the upper part of the pan to prevent the bodily shifting of the
charge of ore from one end of the pan to the other, the said partition not descending
to the bottom of the pan but leaving an opening to allow the mercury to flow to and
fro through the charge of ore. F is a plug closing an opening in the bottom of the
pan at which the slime is run off from the surface of the mercury.
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
chuim is ;
1. In the process of amalgamating gold and silver contained in their ores, the
operation of subjecting the ore in a finely crushed and dry condition to the direct
action of vapors of mercury, as and for the purpose specified,

page_text: 2. The herein described process of amalgamating gold and silver contained in
their ores, said process consisting in first subjecting the ore in a finely crushed and
dry condition to the action of mercurial vapors and then to the action of liquid
mercury in a rocking vessel, substantially as herein specified.
3. The herein described rocking pan constructed substantially of the form herein
specified.
Dated this 11th day of April 1890.
H. CAVE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.