Improvements in the Process of Triturating and Amalgamating Ores, and in Apparatus therefor.
Year: 1896

page_text: Improvements in the Process of Triturating and Amalgamating
Ores, and in Apparatus therefor.
A communication from JOHN THOMAS PENNY, of Percy Court, Mining Agent,
and WILLIAM HENRY RICHARDSON, Engineer, of Grenfell Street, both
Adelaide, South Australia.
1, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
This invention relates to processes and apparatus for triturating and amalga-
mating ores, particularly such as are auriferous or argentiferons, its object being to
recover float gold or other fine particles which, in the usual course of treatment,
are lost.
According to this invention, finely-divided ore in a continuous flow is subjected
to a series of triturating and amalgamating operations in which trituration is
alternated with amalgamation, and this series is preferably succeeded by a final,
process of concentration with amalgamation or separation, after which the gangue
or waste is discharged, the precious metal having been taken from it.
Important features of this invention are:-Trituration of the ore with such
rapidity as to evolve heat sufficient to act on the ore so that subsequent
amalgamation is facilitated; also the production of concussive action between
the finely-divided ore and the amalgamating surfaces so that float gold or other
metallic particles, however fine, will adhere to those surfaces, which moreover will
have less tendency to "sicken" than usual.
A convenient form of apparatus for effecting the operations above referred to is
as follows:-
A hopper is arranged to deliver wet ore in a continuous stream into a
chamber containing a series of triturating-plates arranged in pairs, with means
Surrounding
for revolving the plates of each pair in opposite directions.
each pair of plates is an annular pan having a raised wall, to catch the
material thrown from the plates. Each pan has an annular amalgamating
The ore
channel, and preferably is funnel-shaped and open at the bottom.
from the hopper above mentioned passes between the top pair of triturating
plates and is flung from them centrifugally against the amalgamating surfaces,
flowing thence down the funnel-shaped pan and out of it to the next pair of
triturating plates and their amalgamating-pan, and so on until the bottom of the
chamber is reached. At the bottom is an annular pan into which the material
from the lowermost triturating surfaces is delivered; in this pau are races or
channels, and rakes are provided to move the material in those races to the
discharge outlet. Conveniently, one set of triturating plates can be carried by a
central rotatable shaft, the other set being carried in a frame rotatable upon or
about that shaft; means may be provided for raising or lowering one set
relatively to the other. The form of such apparatus is such that if desired,
electricity may be conveniently applied therein to the treatment of certain
classes of refractory ores.

page_text: Above the aforesaid annular pan there may be a distributing plate having a
funnel-shaped central portion and a perforated outer wall, and an annular shield
surrounding the outer wall in the path of material thrown from the latter. The
settling pan may have zig-zag passages in it, and the rakes which are provided in
those passages may be carried by a rocking-bar.
Dated this 22nd day of February 1896.
BOULT & WADE,
Agents for the Applicant.
. Improvements in the Process of Triturating and Amalgamating
Ores, and in Apparatus therefor.
A communication from JOHN THOMAS PENNY, Mining Agent, and WILLIAM
HENRY RICHARDSON, Engineer, both of Grenfell Street, Adelaide, in the
Province of South Australia.
.I, ALFRED JULIUS BOULT formerly of 323 High Holborn, now of 111 Hatton
Garden, in the County of Middlesex, Chartered Patent Agent, 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:-
This invention relates to the treatment of gold and silver bearing ores which
have been reduced to the consistency of pulp or slimes. The gold or silver in such
ores being disseminated through them in an extremely finely-divided state, it has
hitherto been found practically impossible to effect, especially with certain classes
of ores, such as kaolin, a separation of the metal from the gangue.
It is proposed to accomplish this by repeated trituration, under such pressure,
and at such high rate of speed, as will develop.considerable heat by friction,
combining alternately with such trituration an amalgamation assisted by
percussion.
The object of this invention is to provide a machine in which the ore pulp can
be repeatedly triturated to extreme fineness between plates of iron, one or both of
which may be driven at a high speed under pressure; and to so arrange that,
between each triturating operation, the metallic contents are amalgamated by the
ore being thrown by centrifugal force from the triturating plates, against the sides
of the amalgamators.
Further a distributor and a seitling pan are provided in which final amalgamation
takes place before the discharge of the tailings or waste.
In the accompanying drawings illustrating the invention―
Fig. 1. is a sectional elevation of the apparatus complete.
Fig. II. a plan of the feeding hopper, with supply openings, showing radial arms
for support of same.
Fig. 111. plan of the carrier of the top triturating plate.
Fig. IV. top triturating plate.
Fig. V. plan of the carrier of bottom triturating plate.
Fig. VI. bottom triturating plate.
Fig. VII. plan of distributor.
Fig. VIII. sectional elevation of collar on central shaft.
Fig. IX. plan of the same.
Fig. X. plan of settling or final amalgamating pan.
Similar letters of reference indicate corresponding parts in all figures.

page_text: A is the circular casing in which the working parts are contained, and which is
supported upon a solid bed or base A. Ba central vertical shaft, the middle
upper portion of which is squared for the purpose hereinafter described. The
centre shaft B is driven by means of gear wheels B1 B2, the latter being keyed to
a main driving shaft B³ revolving in suitable bearings and provided with fast and
loose pulleys B B, and with a fly-wheel B. The vertical shaft B is supported
on a suitable end bearing C arranged in a bar C' hinged to the base A The
bar C¹ is provided with a suitable screw attachment C2, by means of which it can
be raised or lowered as required, and the shaft B correspondingly affected. The
upper end of the shaft B revolves in a suitable bearing D fixed in the centre of
cross pieces D. The cross pieces D' are supported by converging angle or east-
iron frames D2 arranged at opposite sides outside the casing A, and having their
lower ends bolted to the base A'. The casing is provided with a circular feed
hopper E, having preferably three feed openings E. The hopper E is supported
by a cast piece having three radial arms E2 (Fig. 11.). Through the shoots E' the
pulp or slimes are delivered into the machine in a continuous stream in preferably
regulated quantities, the hopper E being fed from any suitable source of supply.
Through the end of each of the radial arms E2 a vertical bar F is passed. These
vertical bars F are provided with a series of collars F' for the purpose hereinafter
more particularly described, and upon back nuts, screwed upon each upper end is
placed the respective radial arm E2, the whole being securely held together by
means of screw nuts F2 placed at the top and bottom of the bars F.
As before described, the upper middle portion of the vertical shaft B is squared
in order that there may be built upon it a series of collars (Fig. VIII.), together
with the carriers of the lower triturating plates (Fig. V.). A shoulder B is
formed upon the shaft B, and above it the shaft is squared as before described.
On this shoulder is placed a circular bottom plate G, and upon it a collar H
(Fig. VIII.) provided with a lower flange H'. The collars H are square shaped,
and are provided with a square opening as shown in Fig. IX., of such size as to fit
the square of the central shaft B. Over the collar H which rests on the plate G
is placed a second flanged collar H. This second flanged collar is provided with
an indiarubber block or other spring H2 extending upwards about half of the height
of the collar. Over the collar H, and upon the indiarubber or other spring H, is
placed the carrier I of the lower triturating plate, as shown more particularly in
Fig. V. This carrier I is provided with a squared central opening fitting over
the square of the collar H, and the body of the plate is bent or otherwise cast in
the form as shown more particularly in section in Fig. 1. The carrier plate I is
provided with three or more holes 1', into which drop similar projections, cast or
otherwise formed on the bottom of the lower triturating plate. The lower triturating
plate 12, as shown more particularly in plan in Fig. VI., is provided with a central
circular opening 13, and with three or more deep recesses I radiating therefrom. The
plate 12 is provided with pins or studs I cast on its lower surface in such position and
of such size as to intimately engage the openings I' in the lower carrier 1. Upon the
upper surface of this lower triturating plate, and having its lower surface in
intimate connection with it, is placed the upper triturating plate K of the form as
shown more particularly in plan in Fig. IV. The upper triturating plate K has
also a central opening K', and is provided with recesses K² somewhat shallower
than the recesses in the lower triturating plate 1. The upper triturating
plate K is also provided with suitable studs or projections K³ cast on its upper surface
for the purpose of engaging similar openings in its carrier. This carrier L is of
the form as shown more particularly in plan in Fig. III. It is provided with a
circular opening L' of similar size to the circular openings in the upper and lower
triturating plates K and 12, and with suitable holes L for the purpose of engaging
studs K2 in the upper triturating plate K as before described. To the carrier L
are bolted or otherwise secured three arms L. These are bent upwards and
outwards in the form as shown more particularly in Fig. I., and each outer end is

page_text: provided with a suitable opening L fitting over the vertical bar F as before
described.
As shown in Fig. I., it will be seen that the pairs of triturating plates are
built up in series one over the other until a sufficient number have been placed upon
the vertical shaft to extend upwards sufficiently near the top of the machine.
This building is effected by placing one above the other as before described with
collar H and spring H2 upon collar and spring until the whole is complete. The
screw-nuts F2 at the top and bottom of the vertical bars F are then tightened, and
the whole of the radial arms L3 of the upper carriers L become rigidly fixed. The
central shaft B is then raised by means of a screw attachment C2 and the hinged
bar C, until the lower triturating plates 12 are in intimate connection with the
upper triturating plates K. By means of the same screw attachment the pressure
of the lower upon the upper triturating plates can be adjusted according to the
class and character of ore under treatinent, and whether greater or less friction is
required for its successful trituration.
The ore as fed from the supply hopper passes through the feed openings E', and
falls into a central shoot M. This, as shown in section in Fig. 1., is cone-shaped
and is securely fixed to and rotated by the uppermost carrier L of the series. The
central shoot M is provided with a circular opening of similar size to the central
openings L1, 1, and K'; its outer edges are carried upwards sufficiently high to
prevent the ore contents from splashing over during its revolution. The ore
directed by this feed shoot M fills the circular openings in the triturating plates,
and by means of the recesses I and K2 flows between them. The plates 12 and K
are in the meantime driven in opposite directious by the devices hereinafter
described at a high rate of speed, the ore being finally discharged in a continuous
stream from their outer edge. The trituration may be carried on by a single or
double action of the plates. In a single action the lower triturating plate I only
revolves, the upper triturating plate K and the amalgamators being stationary.
In a double action the bottom plate is revolved at a high rate of speed, and the
upper plate K and amalgamators in the opposite direction at a lower rate.
For combining amalgamation with percussion with this rapid trituration a series
of circular amalgamating pans are placed between the series of triturating devices.
These amalgamating pans N are preferably formed as shown in section in Fig. I.
They are constructed with a central opening of similar dimensions to that Lof
the upper carrier I, and being securely fixed upon it towards its centre, rotate
with it when in double action.
It will be seen by reference to Fig. I. that these amalgamating pans N are
cone shaped towards their base, and that the upper portion is dished at N', so as
to form a riffle in which mercury can be placed. The pan is then bent upwards
and turned inwards upon itself, in order to prevent the ore from being splashed
over when forcibly thrown into it from between the triturating plates. In this
way the ore passing through the first triturator is thrown with force against the
curved upper portion of the amalgamating pan N. The percussion causes a portion
of the metal to be amalgamated, and to gradually move down with a certain
amount of attrition into the riffle N'. The ore is carried over, down the cone-
shaped base into the circular opening in next triturator of the series, to be dis-
charged from it in a similar manner into a similar amalgamating pan, and so on
alternately triturating and amalgamating with percussion until the lowest series of
the amalgamating pans is reached.
It is found in actual practice that the greater portion of the metallic contents
of the ore is caught in its passage over the series of amalgamating pans as before
described; but in order to extract any traces of metal which may be left, the ore
is discharged from the lowest amalgamating pan N into the centre of a circular
distributor O made of copper, in the form as shown more particularly in Fig. VII.
The centre of this distributor O is prolonged upwards in the form of a cone O'
as shown in section in Fig. I. The outer wall of the distributor O is formed of

page_text: a series of upwardly projecting plates 0%, the corners being left open, as shown
in Fig. VII, in order to allow of the passage of the stuff. The distributor O
being placed upon the plate G, is revolved at a high rate of speed, so that the ore
pulp is discharged by centrifugal force through the opening as provided. It is
thrown against a circular amalgamated copper shield Pi, provided with a riffle and
fixed to the lowest projecting arm L³ of the series. From the shield P¹ the pulp is
discharged by a circular plate P into a settling-pan, where it is finally amalgamated,
and the tailings and refuse discharged in a continuous stream, as hereinafter
described.
The triturating plates may be provided with a single, but preferably with a double,
action as before described. The revolution of the series of lower triturating plates
is accomplished as before described, by the squared openings in the lower carriers [
fitting over the squared collar H, which itself is fitted upon the shaft B. The
shaft B being driven by gear wheels B1 and B2 from the main shaft B³. The base
plate G and the distributor O being driven in the same direction. The upper
triturating plates and amalgamating pans when in double action are driven in the
opposite direction by the lower ends of the rods F being passed through the radial
arms Q cast upon a crown gear-wheel Q driven by a bevelled wheel Q² secured to
the main driving shaft B³.
After passing through the machine, the ore pulp is delivered from the discharge
plate P into a circular settling pan or race R. formed of copper and having vertical
divisions R', as shown in plan in Fig. X. and in section in Fig. I. The walls R'
formed in the race R by the vertical divisions R' are amalgamated, and the
bottom of the wells supplied with mercury. The ore pulp, being discharged into
the innermost well R2, is caused to travel in the direction of the arrows as shown,
and to be finally discharged from the discharge shoot R³ by means of a series of
vibrating rakes S. The settling pan or race R is supported in any suitable manner
from the base A', and is intended to be stationary. The series of rakes S are
suspended from a frame S', the ends of which are bolted to a circular plate S³,
which sits loosely upon collar Q placed upon the central shaft B. Motion is
imparted to the rakes S by a crank attachment S³ loosely attached by means of
a screwbolt to a toothed wheel S. The toothed wheel S is driven by a small
toothed wheel S, secured to the main driving shaft B³. By means of this vibrating
motion of the rakes S the ore is slowly impelled forward in the settling pan or
race R in the direction of the arrows as before described, the heavier particles
being allowed to settle and any metal contained therein being finally amalgamated.
The concentrates and amalgam are drawn from an outlet provided for the purpose,
the light stuff or tailings being carried over the discharge.
In the treatment of certain classes of ore it may be necessary to add certain
chemicals in order to assist in the extraction of the metallic contents. This should
be done prior to the ore being introduced into the machine for trituration, but such
addition forms no part of our invention.
My correspondents are aware that the trituration and subsequent amalgamation
of finely divided ores is not new, such treatment being the object of their former
invention, for which they have obtained Letters Patent No. -19,759 of 1889. Also
that ore has been previously ground between circular mullers and discharged into
an outer annular amalgamating well or pan, but their invention, as before described,
differs essentially from these former inventions, both in purpose and construction,
in the following respects:-
The purpose of such grinding is a further reduction of coarse ore. The machine
receives the ore after such further reduction, for a trituration to impalpable fine-
ness, involving a considerable amount of friction, and consequently, increase of
temperature. Such trituration is caused to alternate with an amalgamation with
percussion. The ore pulp is triturated and amalgamated under percussion in
a rotating amalgamator, alternately again and again, until it has passed through
the machine. Such amalgamation is accompanied by sharp percussion of the ore

page_text: against the walls of the amalgamating pan, causing the metals to be automatically
separated from the gangue, and the amalgamation to be materially assisted. The
alternate trituration and amalgamation is combined with the final amalgamation
with percussion by means of a distributor, and a further amalgamation in a settling
pan before final discharge of the tailings.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondents and in what manner
the same is to be performed, I declare that what I claim is :-
First. In machines for the extraction of gold and silver from their ores, a machine
provided with devices arranged in series for alternate rapid trituration and
amalgamation with percussion and attrition, substantially as herein described.
Second. In machines for the extraction of gold and silver from their ores,
a machine provided with devices arranged in series for alternate trituration and
amalgamation with percussion and attrition, combined with a final distribution
and amalgamation with percussion, and a subsequent amalgamation in a stationary
settling pan.
Third. In machines for the extraction of gold and silver from their ores,
a triturating contrivance arranged in series, consisting essentially of a lower
triturating plate (such as 12), a lower triturating plate carrier (such as I), an upper
triturating plate (such as K), and an upper triturating plate carrier (such as L),
a collar (such as H), and an indiarubber er other spring (such as H2), substantially
as herein described and shown in Figs. I., III., 1V., V., VI., and VIII.
Fourth. In machines for the extraction of gold and silver from their ores
provided with devices arranged in series for alternate trituration and amalgamation,
the combination with a flanged collar (such as H) of an indiarubber or other
spring (such as H2), substantially as herein described and for the purpose
indicated.
Fifth. In machines for the extraction of gold and silver from their ores, in the
construction of the carriers of the upper triturating plates, a series of radial
arms (such as L³), extending upwards to the vertical bar F, substantially as herein
described.
Sixth. In machines for the extraction of gold and silver from their ores, the
combination with a series of radial arms (such as L³), fixed to the carriers of the
upper triturating plates, of a series of collars (such as F) and bars (such as F),
the whole being rigidly attached together, substantially as herein described.
Seventh. lu machines for the extraction of gold and silver from their ores,
the combination with a triturating device of a circular amalgamating pan (such
as N), provided with high outer walls, against which the ore pulp is thrown with
percussion, and a lower riffle (such as N¹), into which it flows from such outer
wall, substantially as herein described.
Eighth. In machines for the extraction of gold and silver from their ores, in
which the metal is preferably separated from the ore pulp by alternative trituration
and amalgamation with percussion, a distributor (such as O), provided with
upwardly projecting walls (such as 02), substantially as herein described.
Ninth. In machines for the extraction of gold and silver from their ores, the
combination with a distributor (such as O) of a circular wall (such as P¹) provided
with a riffle, against which wall the ore pulp is thrown with percussion, substantially
as herein described.
Tenth. In machines for the extraction of gold and silver from their ores, the
combination with devices by which the metal is separated from the ore pulp by
alternative trituration and amalgamation with percussion, of a settling and
amalgamating pan or race (such as R), substantially as herein described.
Eleventh. In machines for the extraction of gold and silver from their ores,
in which the metal is separated from its ore by alternative trituration and
amalgamation with percussion, the combination with a settling and amalgamating

page_text: pan or race (such as R), of a series of rakes (such as S), to which a vibrating
motion is imparted.
Twelfth. In machines for the extraction of gold and silver from their ores, by
trituration, a device by means of which the lower and upper triturating plates can
be driven in opposite directions and at different rates of speed.
Dated this 18th day of November 1896.
BOULT & WADE,
Agents for the Applicant.