A Process and Apparatus for Extracting Precious Metals from Ores or Quartz.
Year: 1889

page_text: Date of Application, 23rd May, 1889
Complete Specification Left, 22nd Feb., 1890-Accepted, 22nd Mar., 1890
TROYINIONAL DI MULETUATION.
A Process and Apparatus for Extracting Precious Metals from Ores
or Quartz.
1, RICHARD LEWIS COUSENS of Johannisberg in the South African Republic,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the extraction of precious metals, such as gold and silver,
from ores or quartz, which I effect in the following manner. In the first place I
pulverise the ore or gold bearing quartz and pass the powder between or over
magnetised iron rollers so that the magnetic constituents such as iron and its
compounds are eliminated, these matters adhering to the rollers, and falling off or
being scraped off while the main body of the powder passes away from the rollers.
The ore or quartz powder thus freed from iron and its compounds, is then put into
a strong barrel made of wood or other non-conducting material with iron ends having
trunnions. A quantity of salt and lime is also put into the barrel and the whole is
moistened with water which may be acidulated. The inlet being closed, the barrel is
caused to revolve while a current of electricity is transmitted through the contents of
the barrel from the one end to the other. After a time, mercury is introduced into
the barrel and the revolution is continued for a short time.
-
The contents of the barrel are then run out into a receptacle where they may for
some time be agitated by revolving agitators. The mixture is then passed through
an electrolysing vessel arranged in the following manner. At the bottom is a plate of
copper or lead or it may be other conducting material, connected to the + electrode
of a battery or dynamo machine; this plate is imbedded in sand moistened with an
acid or alkaline solution; over this is a porous diaphragm on which there is a layer of
mercury connected to the electrode. In the middle of the vessel a partition
extends nearly down to the level of the mercury. The ore mixture is caused to pass
down the one side of this partition, over or through the mercury and up the other
side, the principal part of the precious metal amalgamating with the mercury. In
order to extract still more from the tailings, I cause them to flow over an inclined.
copper plate which is coated with mercury that is kept clean and bright by electrical
action; that is to say, the plate itself being connected to one electrical terminal,.
rubbers consisting of metal plates covered with felt or such like fabric are made to
reciprocate over the surface of the mercury plate, while these rubbers are themselves
connected to the other electrical terminal. Almost all the precious metal is thus
extracted, but, in order to prevent loss of mercury and any residue of precious metal,
the material or tailings, after passing the mercury coated plate, are caused to pass
through another electrolysing vessel or several of these and then to pass over a
blanket spread on a metal plate, between it and an upper plate, both these plates being
connected to opposite electrical terminals. The amalgam taken from the electrolysing
vessels, as well as that scraped from the mercury coated plate and that recovered from
the blanket, is then subjected to distillation in the usual way.
Dated this 23rd day of May 1889.
ABEL & IMKAY,
'Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
A. Process and Apparatus for Extracting Precious Metals from Ores
or Quartz.
I, RICHARD LEWIS COUSENS, of Johannisberg, in the South African Republic,
Electrical 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 :-
My Invention relates to the extraction of precious metals, such as gold and silver,
from ores or quartz, which I effect in the following manner. In the first place I
pulverise the ore or gold bearing quartz and pass the powder between or over
magnetised iron rollers so that the magnetic constituents such as iron and its
compounds are eliminated these matters adhering to the rollers, and falling off or
being scraped off while the main body of the powder passes away from the rollers.
The ore or quartz powder thus freed from iron and its compounds, is then put into a
strong barrel made of wood or other nonconducting material with iron ends having
trunnions. A quantity of salt and lime each about 20 to 30 lbs. per ton of ore is
also put into the barrel and the whole is moistened with water which may be
acidulated. The inlet being closed the barrel is caused to revolve while a current of
electricity is transmitted through the contents of the barrel from one end to the
other. After a time, mercury is introduced into the barrel and the revolution is
continued for a short time.
The contents of the barrel are then run out into a receptacle where they may for
some time be agitated by revolving agitators. The mixture is then passed through
an electrolysing vessel arranged in the following manner. At the bottom is a plate
of copper or lead or it may be other conducting material, connected to the + electrode
of a battery or dynamo machine; this plate is imbedded in sand moistened with an
acid or alkaline solution; over this is a porous diaphragm on which there is a layer
of mercury connected to the electrode. In the middle of the vessel a partition
extends nearly down to the level of the mercury. The ore mixture is caused to pass
down the one side of this partition, over or through the mercury and up the other
side, the principal part of the precious metal amalgamating with the mercury. In
order to extract still more from the tailings, I cause them to flow over an inclined
copper plate which is coated with mercury that is kept clean and bright by electrical
action; that is to say, the plate itself being connected to one electrical terminal,
rubbers consisting of metal plates covered with felt or such like fabric are made to
travel over the surface of the mercury plate, while these rubbers are themselves
connected to the other electrical terminal. Almost all the precious metal is thus
extracted, but, in order to prevent loss of mercury and any residue of precious
metal, the material or tailings, after passing the mercury coated plate, are caused to
pass through another electrolysing vessel or several of these and then to pass over a
blanket spread on a metal plate, between it and an upper plate, both these plates
being connected to opposite electrical terminals. The amalgam taken from the
electrolysing vessels, as well as that scraped from the mercury coated plate and that
recovered from the blanket, is then subjected to distillation in the usual way.
In carrying out this process I employ apparatus such as I shall describe referring
to the accompanying drawings.
Fig. 1 is a transverse section and Fig. 2 is a side elevation of a pair of magnetic
rolls for eliminating iron and its compounds from the pulverised ore or quartz.
Fig. 3 is a longitudinal section of a barrel in which amalgamation is effected under
electrical action.
Fig. 4 is a longitudinal section of the agitator, the electrolysing vessels and the
mercury coated plates and blankets.
Referring to Figs. 1 and 2 A A are two iron rolls having their shafts revolving in
iron bearings B at each end. Each bearing B is bolted on, or forms part of an iron
column which is coiled with insulated wire C. The two columns at each end of the

page_text: machine are bolted on an iron base D and these two bases are carried on a wood or
other suitable framing E. Above the gap of the rolls A is a hopper F carried on
two columns G and having at its mouth an adjustable sluice H. Below the rolls A
are fixed plates I inclined downwards at each side, with an opening between their
upper edges, and in the base framing is situated a trough J. The pulverised ore or
quartz being fed into the hopper F runs down in a thin stream between the rolls A. A
which are caused to revolve in the direction of the arrows while a current of
electricity is transmitted through the coils C. The two rolls A A are thus magnetised
presenting their principal magnetic force at the parts of their peripheries which are
Dearest, the currents in the coils being so directed that the rolls have opposite
polarities. A powerful magnetic influence is thus transmitted through the stream of
mineral passing between the rolls, causing such iron or compounds of iron as may be
in the mineral to adhere to the rolls while the non magnetic mineral descends freely
into the trough J. As the rolls revolve carrying with them the adhering magnetic
substances, the magnetic influence becomes less and less at the parts of the periphery
which recede from each other, and consequently the adhering particles drop off the
rolls on to the inclined plates I and slide away at each side. The rolls generally
thus clear themselves sufficiently of the adhering matter, but scrapes may be applied
to them in the usual way.
The barrel K shown in Fig. 3 is of wool hoopel with iron or steel and is strong
enough to withstand considerable pressure. It has iron ends L L' with shafts
projecting from the mounted in pedestal bearings. The one iron end L is secured
by bolts to one of the hoops M near the farther end of the barrel, and the other end L'
is in like manner secured to a hoop M¹ by bolts intermediate to those which secure L,
so that there is no metallic connection of the two ends of the barrel; thus when the
pedestal bearings are connected respectively to the terminals of a dynamo electric
machine or other source of electricity, the electric current can only pass from the one
end of the barrel to the other through the contents of the barrel. The barrel is
charged through a manhole k (of which there are preferably two diametrically
opposite) with the cleansed pulverised material taken from the trough J and with
salt and lime each in quantity about 20 or 30 lbs. per ton of ore and the contents are
moistened with water which may be acidulated. The manhole being then closed the
barrel is caused to revolve for some time while the contents are subjected to the
electrical current. The barrel being then stopped, mercury is introduced through a
charging vessel arranged with double stop cocks like a lubricator, without relieving
the pressure within the barrel. After introducing the mercury the barrel is again
made to revolve for a time, and then the contents are run out. In some cases, instead
of employing salt, which in decomposing gives off chlorine, substances may be used
that give off iodine or bromine.
After treatment in the barrel K the contents are fed into the circular receptacle N
Fig. 4 in which a rake O is made to revolve. From an outlet with adjustable sluice n
the material flows into the electrolysing vessel P shewn to an enlarged scale in Fig. 5
which is arranged in the following manner. The vessel being made of wood or other
non-conducting material has at its bottom a plate p of copper lead or other conducting
material connected to the + terminal of a dynamo or other source of electricity.
On the plate p is a layer p' of sand or other porous material moistened with acid or
with an alkaline or salt solution and covered by a porous diaphragm p², which may be
of felt or like material. On the diaphragm p³ is a layer p³ of mercury which is
connected to the terminal of the electric generator. A partition p* extends down
nearly to the mercury, so that the material entering from the agitating receptacle N
has to pass down on the one side of the partition, over or partly through the mercury
and up on the other side of the partition. From P the material flows over a sheet Q
of copper which is coated with mercury and is fixed on an inclined bed of wood.
The length of this incline may conveniently be about 6 feet. At each end of it are
mounted chain wheels R carrying chains from some of the links of which hang iron
rubbers faced with flannel. By the revolution of the wheels R these rubbers are
caused to travel along the face of the copper Q in the direction of the arrow.
-
The

page_text: plate being connected to one terminal of an electric generator while the chains
and rubbers are connected to the other, the mercurial face of the plate Q is kept
bright and ready to take up by amalgamation such of the precious metal as passes
with the tailings over the surface of the plate Q. After leaving the plate the
tailings pass through two or more electrolysing vessels P like that above described,
and then over a woollen or felt blanket S which extends about 6 feet in length on an
inclination between a lead plate below it and a copper plate above it, these plates
being connected to opposite electrical terminals. The tailings that flow from the
blanket may be passed through a final electrolysing vessel P or through several of
these in succession. The amalgam collected from the vessels P the plate Q and the
blanket S is distilled in the usual way.
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 ore or quartz
by crushing the material, clearing the pulverised material of the magnetic constituents
by passing it between magnetic rolls, effecting amalgamation under electric action in
a revolving barrel, and passing the material through electrolysing vessels, over
amalgamating surfaces electrically cleansed, and through a blanket subject to electric
action.
2. The magnetic rolls constructed and operating substantially as described with
reference to Figs. 1 and 2.
3. The amalgamating barrel K constructed and operating substantially as described
with reference to Fig. 3.
4. The construction and arrangement of the electrolysing vessel P substantially as
described.
5. The combination of the agitating vessel N, the mercury coated plate Q with its
rubbers r, the blanket S with its enclosing plates, and several electrolysing vessels P
constructed and arranged substantially as described with reference to Fig. 4.
Dated this 22nd day of February 1890.
LARLY
0 TUDY
ABEL & IMRA
Agents for the Applicant.