A Method of Extracting Gold from Auriferous Ores by an Improved Process of Amalgamation, and Apparatus therefor.
Year: 1890

page_text: Date of Application, 9th June, 1890
Complete Specification Left, 9th Mar., 1891-Accepted, 11th Apr., 1891
PROVISIONAL SPECIFICATION.
A Method of Extracting Gold from Auriferous Ores by an Improved
Process of Amalgamation, and Apparatus therefor.
I, JAMES WRIGHT MACFARLANE, of 16, Queen's Crescent, Cathcart, in the
County of Renfrew, Engineer, do hereby declare the nature of this invention to be
as follows:-
My invention relates to a method of extracting gold from auriferous ores by an
improved process of amalgamation and apparatus therefor. In which process I
employ one or other of two distinct types of continuous-acting high speed centrifugal
machines.
In the first type the centrifugal machine is provided with a drum made of iron
steel or other suitable material and preferably of a cylindrical shape, the axis of
which coincides with the axis of revolution. Into this drum which has no per-
forations on its cylindrical surface I place a quantity of mercury which when under
the influence of centrifugal force spreads itself symetrically round the internal
surface of the drum. One end of the cylindrical drum is closed and is made to fit
on to a conical part on the revolving spindle. The other end of the drum is left
open but is provided with an internal lip of such depth as is required to hold a
given quantity of mercury, so that the inner surface of the mercury may be
almost or flush with the inner edge of the lip, as the mercury would increase
somewhat in bulk on amalgamation and also as the pressure of the ore on its
internal cylindrical surface would displace the mercury to a certain extent,
to prevent the excess mercury from flowing over the top along with the ore, I
provide a small concentric chamber on the other side of the closed end with
holes connecting the two parts of the drum. The lip of this chamber being
the same or slightly larger in diameter than the other lip of the drum permits of
the excess mercury flowing over it into the casing from where it can be collected
instead of allowing it to pass over with the ore where would in all likelihood be
lost. The ore after being ground in the usual way is poured in a continuous stream
into the drum of the centrifugal machine at or near the axis of revolution. When
the ore meets the bottom or closed end of the drum, the centrifugal force propels
it outwards against the face of the approximately cylindrical wall of mercury, but
as the ore if projected outwards in a plane at right angles to the surface of the
mercury would gradually accumulate in a circular heap and ultimately flow over
the top without meeting with the mercury. I employ the following devices for
causing the ore to flow in a thin film continuously over the face of the mercury,
and which devices I may employ together or separately as I may consider is best
suited for the kind of ore to be treated and the circumstances of the case
determine. In the first place I form the closed end of the drum in a dished or
cupped shape, the inner surface of which is provided with radial grooves, or grooves
parallel to radii, so that the ore instead of being thrown outwards in a plane at
right angles to the axis is constrained gradually to change its motion from an out-
ward direction to a direction which, with the velocity imparted to it by the grooved
dished end would cause it to move across the face of the mercury approximately
parallel with the axis of revolution. The gold particles of the ore being of a
higher specific gravity than the mercury and moreover being under the influence
of a very intense centrifugal force would immediately sink into the mercury while
the lighter portion of the ore would roll or slide over the surface of the mercury
until it passed over the lip of the drum. In the second place, I employ a liquid
which I change into the drum either with the ore or separately and which liquid I
employ in quantity sufficient to sweep the ore along with it across the face of the
mercury and over the lip of the drum the liquid being either pure water or any

page_text: suitable chemical solution. In the third place I employ various mechanical con-
trivances to which I give the general name of "plough and which are made to
act upon the surface of the mercury in such manner that the ore floating on the
surface is compelled to move in the desired direction, and as the plough may be
made in different ways to effect the same object I simply mention two kinds of them
here, as follows viz.
1st. A stationary plough composed of one or more blades made of iron steel or
other suitable material, the cutting edge of which blades dip into or only touch the
surface of the mercury and at an inclination such that at each revolution of the
drum the ore is pushed across the face of the mercury any desired distance.
2nd. A revolving plough turning on an axis parallel with the axis of revolution
or more or less inclined thereto or in the same straight line with it. The plough
may be made to revolve by its periphery being in contact with the mercury in the
drum or it may be made to revolve independently by suitably arranged gearing.
The periphery of the plough may be made cylindrical or otherwise and with
helical circular and or longitudinal grooves cut into its cylindrical surface and with
any suitable section of thread, or the periphery of the plough may be made of bars
laid longitudinally or in a helical or circular manner.
In the second type the centrifugal machine is provided with a drum made of
iron, steel or other suitable material and preferably of a conical shape the axis of
which coincides with the axis of revolution, the narrow end being closed and
formed so as to fit on to the revolving spindle of the machine. The drum which
is not perforated has the interior conical surface cut into a series of concentric
grooves increasing in diameter as their distance from the closed end increases. The
mercury and ore are poured into the drum at or near the axis continuously, with
or without liquid as the case may be and either together or separately. When they
touch the closed end of the drum the centrifugal force propels them outwards into
the smallest concentric groove of the series which the mercury fills up and overflows
into the next along with the ore floating on it. In this manner a series of circular
cascades are formed by which the mercury and ore are churned together, the
mercury and ore finally flowing over the top of the largest concentric groove and
are discharged together into the case of the machine, the mercury being collected
in the usual way and returned to the drum of the machine by means of a pump or
otherwise to go through the same operation again until it is sufficiently saturated
or amalgamated with the gold to require changing. In another form of the drum
I collect the mercury in the last groove of the series and instead of allowing it to
How over the lip along with the ore I discharge it by itself through a small hole
or pipe into a separate chamber of the casing of the machine, from which chamber
it is returned to the drum either by pumping or as I prefer it by a skimming tube
attached to the outside of the drum which collects it from the chamber referred to
and discharges it into the closed end of the drum. In a third form of the drum
instead of discharging the mercury into a chamber of the casing 1 form another
concentric groove or chamber on the drum beyond the lip over which the ore is
discharged, and which circular chamber is connected to the drum by a number of
bridges which also act as tubes for conveying the mercury from the drum to the
chamber leaving sufficient space between the bridges for the ore to pass after
escaping over the lip. This chamber being attached to the drum revolves along
with it so that the mercury collects in it and I withdraw it from the chamber
while the machine is in motion by means of a stationary skimming tube and
discharge it again into the closed end of the drum, continuously, to go through
the same operation until it is sufficiently saturated with the. gold. As soon as
there has been sufficient mercury poured into the drum to fill up all the grooves
with a quantity over and above so that the circulation may be established, no
more mercury is required until the time comes for changing it. Or I may change
the mercury continuously by pouring in a relatively small quantity continuously
and allowing it to flow over by a lip, tube or otherwise when it reaches a certain
level in the drum. To save the power required to drive the machine as far as

page_text: possible I may employ a cylinder preferably stationary and concentric with the
drum and made smooth on the inside, into which cylinder the mercury is dis-
charged after collection by the skimming tube, this smooth cylinder premits the
mercury to rotate within it until it is again discharged into the drum with a velocity
very nearly the same as that of the drum. Before the mercury and ore pass into
the drum I may make them both together pass into a concentric chamber in the
drum having perforations all round the periphery, the object being to mix and
distribute the mercury and ore evenly and with practically the same velocity as the
drum. It is obvious that I might also employ a cylindrical drum similar to that
mentioned for the first type of machine instead of the conical drum on the second
type of machine, and in the same manner that is by causing the mercury to flow
through it along with the ore instead of the mercury remaining practically
stationary in the drum and allowing the ore to pass over the face of it the mercury
being circulated by pumps, skimming tubes &c. with or without collecting chambers
all as detailed for the second type machine. In the same manner I may also employ
the conical drum on the first type machine, by allowing the mercury to remain
practically stationary in it and causing the ore to flow across the face of it by some
of the devices already mentioned for the first type machine.
In the treatment of some kinds of ores, where I consider it would be advantageous
propose to use in conjunction with the centrifugal machines before mentioned,
for the purpose of assisting the amalgamation, a dilute solution of calomel (HgCl)
in "Aqua Regia" (HNO, +3HCI) which solution may either be charged into
the drum of the centrifugal machine together or separately from the ore or it may
preferably in some cases be charged into the battery from whence it would pass to
the centrifugal machine along with the ground ore.
I also propose to use in conjunction with both types of the centrifugal machine
before mentioned, amalgamated copper plates where such would be advantageous,
placed in such manner in the case of the machine that the ore which is discharged
in a continuous thin stream from the drum all round will strike against and roll
down them the plates being preferably made in the form of cones down the
inclined sides of which the ore would roll.
In cases where the mercury is charged into the battery, the before mentioned
centrifugal machines may be used for collecting the mercury and amalgam, and any
particles of gold which may have escaped amalgamation in the battery.
Dated this 7th day of June 1890.
JAMES WRIGHT MACFARLANE.
A Method of Extracting Gold from Auriferous Ores by an Improved
Process of Amalgamation, and Apparatus therefor.
I, JAMES WRIGHT MACFARLANE, of 16, Queen's Crescent, Cathcart, in the
County of Renfrew, Engineer, do hereby declare the nature of my invention, and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement in writing, reference being had to the
accompanying drawings, that is to say :-
My invention relates to a method of extracting gold from auriferous ores by an
improved process of amalgamation and apparatus therefor. In my process I.
employ one or other of two distinct types of continuous acting high speed
centrifugal machines, that is, one type in which the mercury remains practically
stationary, and in the other it flows through.
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereunto
appended four explanatory sheets of drawings in which the same. reference letters
are used to indicate corresponding parts in all the figures where shown.

page_text: Figure 1, Sheet 1, is a sectional elevation of a continuous acting high speed
centrifugal amalgamating machine complete, with an approximately cylindrical
form of revolving drum A, mounted on the upper end of its driving spindle B,
carried in suitable footstep and neck bush bearings at B', B2, fitted in the basement
and upper parts of the hollow column standard frame C, supporting the whole, the
spindle B being driven by the band and band pulley B3, B4, below, these latter
being shown in elevation as their details and lubricating arrangements may be of
any ordinary construction. Figure 2, on Sheet 2, shows a half sectional elevation
and Figure 3 a corresponding quarter horizontal section taken on the lines 2-2 in
Figure 2 of the drum part A, and improved fittings connected therewith of the
cylindrical form of continuous acting amalgamator shown in Figure 1, but slightly
modified therefrom. Figures 4, 5, and 6, 7 and 8, 9 show sectional elevations and
horizontal sections of the drum part A. and improved fittings of a cylindrical
amalgamator all slightly modified from that shown in Figures 1 to 3. Figure 10,
on Sheet 3, is a complete sectional elevation of a continuous acting amalgamator
corresponding to Figure 1, Sheet 1, but having an inverted conoidal form of
drum A with annular grooves a round its interior periphery as constructed in
accordance with my improvements. Figure 11, on Sheet 4, shows a sectional
elevation, and Figure 12, a horizontal section taken on the lines 11-11 of
Figure 11 of the drum A and upper part of the inverted conoidal drum form of
amalgamator shown in Figure 10, with slightly modified arrangements of the
improved fittings. Figures 13, 14, and 15, 16, and 17, 18, show sectional
elevations and horizontal sections respectively of the drum part A. and improved
fittings of the inverted conoidal form of amalgamator all slightly modified from
that shown in Figure 10.
Referring to Figures 1 to 9 on Sheets 1 and 2:-The centrifugal machine here
shown is provided with a drum A made of iron, steel or other suitable material, of
nearly a cylindrical shape the axis of which coincides with the axis b, b, of the
spindle B. Into this drum A which has no perforations proper through its
cylindrical surface, I place or feed in the mercury and ground ore to be treated as
hereinafter described which when under the influence of the centrifugal force
spreads itself symmetrically round the internal surface of the drum A, as indicated
at a. One end of the cylindrical drum A is closed, that is, the lower end A¹ in all
these arrangements; and is made to fit by a deep central boss A" on to a conical
part at the top of the revolving spindle B. The other or upper end A² of the
drum A is left open, but is provided with an internal lip a¹ of such depth as is
required to hold a given quantity of mercury, so that the inner surface of the
mercury at a may be flush with or any desired distance within the inner edge of
the lip a. As the mercury would increase somewhat in bulk on amalgamation,
and also as the pressure of the ore fed in on its internal cylindrical surface would
displace the mercury to a certain extent; to prevent the excess mercury from
flowing over the top along with the ore, I provide a small concentric chamber A
on the other or outer side of the closed end with a hole or holes a² connecting the
two parts A, A³, of the drum A, through which the mercury would flow by the
pressure due to the centrifugal force. The chamber A³ has a lip a" which is
the same or larger in diameter than the other lip at of the drum A. and which permits
of the excess mercury flowing over it into the ch mber C of the casing C¹, C
formed and mounted at the top C' of the column C from where it can be collected
and drawn off by a branch at C³ to be returned, or not as the case may be, by a
pump or otherwise regularly or intermittently as required to the drum A, instead
of allowing it to pass over the lip a' and top A² with the ore where it might be
lost or require to be recovered. The ore after being ground in the usual way is
poured or fed preferably along with the mercury in a continuous stream by a
hopper H at one side of the centre boss A, as shown in Figure 1, or it might be
over the centre, as shown in the other figures, into the drum A of the centrifugal
machine, as hereinafter described. When the ore meets the bottom or closed
end A' of the drum A. the centrifugal force propels it outwards against the face of

page_text: $
21
the approximately cylindrical wall of mercury, but as the ore if projected outwards
in a plane at right angles to the surface of the mercury would probably accumulate
in a circular heap and ultimately flow over the top without meeting with the
mercury, I employ the following devices for causing the ore to flow in a thin film
continuously over the face of the mercury and which devices I may employ
together or separately as I may consider is best suited for the kind of ore to be
treated, and the circumstances of the case determine. In the first place I form
the closed end A' of the drum A. in a dished or cupped shape, the inner surface of
which is provided with radial grooves or projections at a³, or parallel to radii, some
distance out from the centre, and which may be continued parallel up the inner
cylindrical surface of the drum A, so that the ore instead of being thrown outwards
in, a plane at right angles to the axis is constrained gradually to change its motion
from an outward direction to a direction, which with the velocity imparted to it by
the grooves a³ on the dished end would cause it to move across the face of the
mercury approximately parallel with the axis of revolution. The auriferous
particles of the ore being of a higher specific gravity than the mercury and
moreover, being under the influence of a very intense centrifugal force, would
immediately sink into the mercury, while the lighter portion of the ore would roll
or slide over the surface of the mercury until it passed over the lip a' of the
drum A. In the second place I may employ a liquid, which I charge into the
drum, either with the ore or separately, and which liquid I employ in quantity
sufficient to sweep the ore along with it across the face of the mercury, and over
the lip a of the drum A, the liquid being either pure water or any suitable
chemical solution. In the third place I employ various mechanical contrivances to
which I give the general name of "Plough and which are made to act upon the
surface of the mercury in such manner that the ore floating on the surface is
compelled to move upwards or in the desired direction to pass over the lip a', and as
the ploughmay be made in different ways to effect the same object, I simply
mention two kinds of them here as follows:-namely, first, a stationary plough,"
shown in Figure 2, composed of one or more blades d made of iron, steel, or other
suitable material secured on a fixed bracket D, bolted at D' to the upper stationary
frame H' to which the hopper H is mounted, the cutting edge of which blades
dip into or only touch the surface of the mercury and at an inclination such
that at each revolution of the drum A, the ore is pushed across the face of the
mercury any desired distance towards the delivery lip a. Second, as shown in
Figure 1, a revolving "plough" D turning on an axle D" parallel with the axis
of revolution or more or less inclined thereto, or in the same straight line with it,
and carried in a stationary bearing bracket D bolted at D' to the frame H'. The
plough may be made to revolve by its periphery being in contact with the
mercury in the drum A; or it may be made to revolve independently by suitable
arranged gearing. The periphery of the "plough " D2 may be made cylindrical
or otherwise, and with helical circular or longitudinal grooves and projections d'
cut into its cylinder surface, and with any suitable section of thread; or the
periphery of the "plough instead of being helical, as shown in Figure 1, may
be made of bars laid longitudinally or in a helical or circular manner.
Figures 4 and 11 the ground ore, or ground ore and mercury are fed in through
the hopper H over the upper close centre of the drum A, preferably closed in by
the stationary feed tube open at its lower end to lead the ore and mercury
down the annular channel H between the boss A" and case F and under the rim
disc or annular channel H", secured by screws or otherwise to projections at H!!!
on the bottom A' of the drum A, into the lower part of the drum, which would
preferably be formed with a large annular groove ax, with a lip projecting rather
further in than the end of the ring and channel disc H" and lipa at the top to
cause the ore to mix with the mercury in passing up out of the channel H during
its centrifugal action. Or as seen in Figure 6, this disc H which revolves
with the drum A, may extend up annularly at H' near the boss A" to
*
"
CC
In

page_text: near the hopper H, and so conduct the ground ore down the revolving
channel to the lower part, and annular layer of mercury, all as indicated by
the arrows in these figures.
in the amalgamator, shown in Figures 10 to 18, the centrifugal machine is
provided with a drum A made of iron, steel, or other suitable material, and of a
hollow inverted conoidal shape, the axis of which coincides with the axis b of
revolution, the narrow or lower end A being closed and formed with a boss A",
to fit on to the revolving spindle of the machine. The drum A. which is not
perforated, has the interior conical surface cut into a series of concentric grooves
at a which may be of various sections, but increasing in diameter as their distance
from the closed end A¹ increases towards the open end A². The mercury and ore
are poured or fed into the drum A by the hopper H either together or separately
at or near the axis continuously, with or without liquid as the case may be.
When they touch the closed end A' of the drum A, the centrifugal force propels
them outwards into the lower concentric groove a* at the bottom of the series,
which the mercury fills up and overflows into the next groove along with the ore
floating on it. In this manner a series of circular cascades are formed by which
the mercury and ore are churned together, and finally flow over the lip a of the
highest concentric groove a*, as shown in Figure 11, and discharged together into
the outer chamber E' and case E of the machine mounted on the top C' of the
column frame C and the ore and mercury drawn off by a branch or branches
at E³, and separated by any of the means at present in use the mercury may then
be returned to the drum A. of the machine by means of a pump or otherwise, to go
through the same operation again until it is sufficiently saturated or amalgamated
with the gold to require changing. In this figure the outer case E carries the fixed
frame plate H' of the feeding in hopper H direct on it; but in all the other
figures, it is carried from this, by an intermediate annular top E" and ring
plate E
Iu
By another improvement shown in Figures 4, 6, 8, 10, 13, and 15, I collect the
mercury in the last or upper large groove a* of the series and instead of allowing
it to flow over the lip of the upper end A of the drum A along with the ore, as
shown in Figure 11, or drawing it off by the lower holes a² and groove lip A³ at
the bottom, I discharge it by itself through a small sealed trap, hole or holes a or
a pipe below the lip into the separate chamber C², C", of the casing of the
machine, from which chamber it is or may be drawn off by the branch C³ and be
returned to the drum A, by pumping as before stated. Or instead of discharging
the mercury through small orifices a little below the level of the circumference
of the lip A, as shown in Figures 4, 6, 8, 10, 13, and 15 I may, as shown in
Figure 2, fix a nipple or nipples near the top of the drum A, rather shorter
than the lip a and fit a cap over its inner end, thus forming a small trap or traps
to conduct off the excess of mercury from the inner surface of the drum A.
another form of the drum A, shown in Figure 17, instead of discharging the
mercury into the said chamber C, C¹¹, in the casing, 1 form or mount another
concentric internal ring groove or chamber A on the drum A. beyond the ordinary
upper edge A2 over which the ore is discharged, and which circular chamber A³ is
connected to the drum A by a number of bridges b', which also act as tubes or
have tubes formed in them, for conveying the mercury from the drum A. under the
lip a to the ring chamber A leaving sufficient space between the bridges & upper
edge A2 and the ring A³ for the treated ore to pass into the chamber E E' after
escaping over the lip a". This chamber A' being attached to the drum A revolves
along with it, so that the mercury collects in it and I withdraw it from the
chamber A5 while the machine is in motion by means of a stationary skimming
tube and discharge it again into the upper closed end of a stationary feeding
tube or cylinder continuously, to go through the same operation, until it is
sufficiently saturated with the gold. As soon as there has been sufficient mercury
poured or fed into the drum A to fill up all the grooves a* with a quantity over
and above this so that the circulation may be established over the lips of these

page_text: grooves a from the lowest to the highest; no more mercury is required until the
time comes for changing or renewing it. Or I may change the mercury continuously
by pouring or feeding in a relatively small quantity continuously with the ore and
withdrawing it by itself through sealed holes or traps a, a, such as have already
been described when the mercury has reached a certain level in the upper
groove a*.
To save the power required to drive the machine as far as possible,
I may employ the feeding cylinder or conoidal duct F, which may be stationary
and secured to the plate H, as shown in Figures 4, 11, and 17, concentric with
the drum A and either made smooth on the inside, as shown in these figures,
or made with helical grooves at F1, as shown in Figure 10, and preferably made
of copper and amalgamated on the interior surface, into which cylinder F F¹
the mercury is fed and then discharged at its lower open end into the
bottom A of the drum A, with a velocity very nearly the same as that of the
drum. Before the mercury and ore pass into the drum A, I may make them
both together pass from the hopper H into a concentric chamber H2 mounted
or formed on the boss A" of the drum A, having perforations & all round the
periphery, and which revolves with the drum, the object being to mix and distribute.
the mercury and ore within the cylinders F, F, evenly and with practically the
same velocity as the drum A. The mercury and ore passing down through these
holes from the rotating chamber H2 may pass down an annular channel formed
by a rotating shell or wall H³ screwed or otherwise secured at H, to the outer
shell of the chamber H this shell H³, as shown in Figures 8, 13, and 15, and in
the stationary form at F, Figure 4, curving outwards to meet the mercury in the.
lowest groove a* of the drum A, and so cause the ground ore to mix with and pass.
through the mercury; and this web H³ may be made of an annular U or V like
form at H", and have slight projections or corrugations on its outer periphery
opposite each groove a* on the inner periphery of the drum A, as shown in
Figures 8 and 15, to cause the ground ore to pass into the mercury in every groove
on its passage to the top lip a'.
Although I prefer to have the cylindrical form of drum adapted to the type of
machine in which the mercury remains practically stationary and the conical drum
adapted to the type of machine in which the mercury flows through it, it is obvious
that the two kinds of drums can be made to fit either type of machine although
they may not be equally satisfactory, for the purpose intended. It is also obvious.
that in a high speed centrifugal machine the effect of gravity is of no moment what-
ever consequently the centrifugal machines described may be made to work equally
as well horizontally as vertically or in any way inclined, by a slight rearrangement.
of the hoppers and fittings.
In the treatment of some kinds of ores where I consider it would be advantageous;
1 propose to use in conjunction with the centrifugal machines before mentioned, for
the purpose of assisting the amalgamation, a diluted solution of calomel (HgCL)
in aqua regia (HNO, +3HCL) which solution may either be charged into the drum
Or it may
of the centrifugal machine together with or separately from the ore.
preferably in some cases be charged into the battery or pulveriser from whence it
would pass to the centrifugal machine along with the ground ore.
I also propose
to use in conjunction with both types of centrifugal machines, amalgamated copper
plates G where such would be advantageons, placed in such manner at an angle in
the outer chamber E¹ of the machine, that the ore or ore and mercury which is
discharged in a continuous thin stream from the drum A. all round will strike
against and roll down these plates G, on its way to the bottom of the chamber C';
the plates being preferably made in the form of angled cones, down the inclined
sides of which the ore would roll, as shown in Figures 1 and 11 and all as indicated
by the arrows.
In cases where the mercury is charged into the battery or pulverising machine,
the before mentioned centrifugal machines may be used for separating and collecting
the mercury and amalgam, and any particles of gold which may have escaped
amalgamation in the battery.

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 :-
First. The herein described method and apparatus for extracting gold from
auriferous ores by an improved process of amalgamation, consisting in feeding the
ore and mercury into the cylindrical or inverted conoidal revolving drum of a
continuous acting high speed centrifugal amalgamating machine, with annular
chamber in casing to receive and recover the mercury, and separate treated ore
outer annular discharge outlet chamber substantially as herein described, in reference
to and by way of application shown under various modifications in the accompanying
drawings.
Second. In an amalgamating process for extracting gold from auriferous ores, the
construction or general arrangement and combination of the parts of a continuous
acting high speed centrifugal amalgamating machine, with a cylindrical, or an
inverted conoidal revolving drum, with separate mercury receiving and recovery
chamber, and treated ore discharge chamber, and amalgamating and circulating
fittings, substantially as herein described in reference to and shown under various
applications in the accompanying drawings.
Third. In a drum form of continuous acting high speed centrifugal amalgamating
machine, the forming of an internal discharge lip in drum to hold the mercury, with
overflow outlet for mercury into recovering chamber below the ore discharge outlet
or lip substantially as herein described in reference to and by way of application
shown in the accompanying drawings.
Fourth. In a drum form of continuous acting high speed centrifugal amalgamating
machine, the forming of an annular concentric chamber or duct over the closel end
of drum with outlet holes or apertures for the ore and mercury to pass to acting
surface of drun, substantially as herein described in reference to and by way of
application shown in the accompanying drawings.
Fifth. In a drum form of continuous acting high speed centrifugal amalgamating
machine, the forming of a separate chamber in casing for receiving and recovering
the mercury, substantially as herein described in reference to and by way of
application shown in the accompanying drawings.
Sixth. In a drun form of continuous acting high speed centrifugal amalgamating
machine, the forming of a separate chamber in drum beyond the lip, with bridges
and tubes to receive the mercury, (below the lip for discharging the treated ore)
and feeding it back to drum, substantially as herein described in reference to and by
way of application shown in the accompanying drawings.
Seventh. In a drum form of continuous acting high speed centrifugal amalgama-
ting machine, the fitting of a stationary "plough" in drum composed of one or more
blades for assisting the motion of travel of the ore on the surface of the mercury,
substantially as herein described, in reference to and by way of application shown
in the accompanying drawings.
Eighth. In a drum form of continuous acting high speed centrifugal amalgamating
machine, the construction and arrangement of a rotating "plough "for agitating and
assisting the motion of the ore on the surface of the mercury, substantially as herein
described, in reference to and shown in the accompanying drawings.
Ninth. In a drum form of continuous acting high speed centrifugal amalgamating
machine, the fitting of amalgamated copper, or other plates or cones in the stationary
outer case for the ore discharged from the drum to act against, substantially as
herein described in reference to and by way of application shown in the accom-
panying drawings.
Tenth. In a drum form of continuous acting high speed centrifugal amalgamating
machine the forming of the internal acting surface of the drum with a series of
concentric grooves or channels, substantially as herein described in reference to and
by way of application shown in the accompanying drawings.
Eleventh. In a drum form of continuous acting high speed centrifugal

page_text: amalgamating machine, the constructing of the closed end of a dish shape, and with
a series of outward diverging grooves or their equivalent on the internal surface for
assisting the radial outward motion of the travel of the auriferous ore and or
mercury, substantially as herein described in reference to and by way of application
shown in the accompanying drawings.
Twelfth. In a drum form of continuous acting high speed centrifugal amalgama-
ting machine, the forming or fitting of a mercury and ore mixing perforated
concentric hollow top or chamber in drum, in combination with a stationary or
rotating inverted vertical cup cylinder or chamber for discharging the mercury and
ore with considerable velocity into the close end of drum, substantially as herein
described in reference to and by way of application shown in the accompanying
drawings.
Thirteenth. In a drum form of continuous acting high speed centrifugal amalgama-
ting machine, the forming or fitting of a vertical cup cylinder or chamber within
the drum for leading or discharging the mercury, or mercury and ore into the close
end of drum, substantially as herein described in reference to and by way of
application shown in the accompanying drawings.
Fourteenth. In a drum form of continuous acting high speed centrifugal
amalgamating machine, the combination and use of a solution of calomel in aqua-
regia for treating the ore, or which may have treated the ore previous to being
placed therein, substantially as described.
Fifteenth. The use of a drum form of continuous acting high speed centrifugal
amalgamating machine, for separating and collecting the mercury, amalgam, and
gold, previously treated or amalgamated in a battery or ore pulverising machine
substantially as described.
1001
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.