A New or Improved Process and Apparatus for, or connected with, the Amalgamation of Gold Ores, Tailings, and other Metals capable of · Amalgamation.
Year: 1899

page_text: Date of Application, 7th Mar., 1899
Complete Specification Left, 5th Dec., 1899-Aooepted, 6th Jan.,
1900
PROVISIONAL SPECIFICATION.
A New or Improved Process and Apparatus for, or connected with, the
Amalgamation of Gold Ores, Tailings, and other Metals capable of
· Amalgamation.
I, RICHARD FRANCIS ROUTHI, of 146, Fenchurch Street, in the City of London,
Commission Agent, do hereby declare the nature of this invention (a communica-
tion to me from abroad by Anatole Bargigli, of 9, Avenue de la Bourdonnais,
Paris, France, Engineer) to be as follows:
Many years of experiments and observations have established the facts, which
are well known by all miners, that the deficient results produced by the pro-
cesses of amalgamation as at present practised, are due to the following causes: -
1. To the production, by the repeated action of the stamps, of a fine impalpable
powder known as float gold or floating gold, which, being carried up to the
surface of the water, escapes the action of the amalgamating plates, and as it is
not deposited, becomes lost with the discharge of the water.
2. To the formation, by the same action of the stamps, of a fine mud known as
slimes, which, enclosing in its frothy substance a large proportion of the float
gold, passes over the amalgamating plates without allowing the mercury to come
in contact with the gold which it carries. These slimes have heretofore shewn
themselves refractory to all further treatment.
- :
In mining centres where cyanide processes are used for the treatment of the
tailings after the amalgamation, these two losses are estimated to be from 8 to 10
per cent. In Australia they are about 14 to 18 per cent.
3. To the presence of "rusty gold" which being covered with a thin film of
iron oxide is not attacked by the mercury and therefore escapes from the action
of the latter.
4. To the small particles of gold which being attached to the grains of quartz
and being carried along by them are not dissolved by the mercury.
5. To the fact that in order to avoid the formation of a too large quantity
of slimes, the grains of quartz are allowed to remain of a certain size which in
that case enclose in their mass a certain proportion of gold which gets lost, and
6. To the theft of amalgam which is always a factor of loss of a considerable
amount in spite of all precautions.
In consequence of these six main causes, the proportion of gold which is
extracted by amalgamation never exceeds 56 per cent. of the gold contained in
the ore treated. This is confirmed by the two following facts.
1. In mining centres such as those of South Africa, where the cyanide pro-
cesses are universally adopted, after having extracted by amalgamation a certain
quantity of gold, the tailings recovered by the cyanide operation, give a further
amount of about 50 per cent. of the gold already produced. Now, on deducting
only the 15 per cent. of the gold carried away by the water, the slimes and the
thefts of amalgam, the total extraction hardly reaches 85 per cent. This figure
has however certainly not been reached in any one case in 1898. This proves that
the amalgamation alone has not been able to produce more than 56 per cent.
TDi Q71

page_text: 2. At a conference which was held in January last at the Imperial Institute
in London, the Agent General for the Colony of Western Australia, Mr.
Wittenoon, said, (which was already a matter of knowledge), that the total pro-
duction of the Colony had reached in 1898 the enormous quantity of 1,052,000 ozs.
whilst the average amount of gold extracted per ton amounted to 27 dwt. The
third part of this production came from 3 to 4 large mines which employed
cyanide processes, and the general. average amount of the gold extracted per ton
treated did not exceed 20 dwts. or 1 oz. Now the water which is very dirty in these
mines, and in consequence of its great specific gravity carries away with it 15
to 20 per cent. of the float gold with the slimes; and as the tailings contained
from 12 to 18 dwts., and even 1 oz., it is evident that the amalgamation has not
been able to yield more than 55 per cent. The amalgamator constructed accord-
ing to this invention completely obviates these six causes of loss, by reason of
its special construction and its rational method of operation. In fact, all the.
crushed ore of the mill is carried along by the water that is compelled to pass
to its last drop through the apparatus; and the apparatus by means of its fluted
revolving plates triturates said ore so to speak against the mercury, (which
although liquid, has always a certain consistency), so that the whole of the gold
being brought into immediate contact with the mercury becomes dissolved by
the latter. As the apparatus is closed and thus renders any theft impossible, it
will be readily understood why the yield exceeds 90 per cent. This total amal-
gamator is thus a substitute of itself alone for all the complicated long and
expensive operations of the treatment of auriferous ores by the most improved
processes at present in use.
Advantages of the total amalgamator:-
1. Great economy in its installation; because the apparatus costing only some
few hundreds of pounds, is available for even the smallest mines.
2. Great economy of treatment: because the apparatus only requires an outlay
equal to one fourth of that which is necessitated at the present time for the same
work,
3. Rapidity of installation and of operation because the apparatus can be
erected and set in operation in one day.
4. Theft is suppressed, because the apparatus is entirely closed and in-
accessible.
5. All the floating gold which is carried away by the water is placed in intimate.
contact with the mercury and is kept back by the apparatus.
6. The slimes which are at present refractory to all treatment are triturated
by the revolving plates so that they give up all the gold which they contain.
7. A minimum yield of 90 per cent., thereby allowing of the working at a
profit of low grade quartz, which cannot be treated at the present time, and the
abandonment of the tailings as being practically exhausted.
S. The capability of mounting the apparatus either upon wheels in order to
transport it from one place to another for the treatment of the tailings, or in a
boat for the purpose of treating the gold bearing sands of rivers by pumping
the said sands direct into the apparatus without any other hand labour.
9. The capability of simplifying the numerous tools and apparatus of mines
and of doing away with the considerable labour which is necessary at present
for treating gold bearing and other ores.
10. The capability of crushing the ores to a great fineness in order to extract
the whole of the gold because in this case the more slimes there are the better
is the yield.
Description of the amalgamator constructed according to this invention.
The apparatus consists:-
1. Of a cylindrical support forming the base of the apparatus.
2. Of a cylindrical distributor forming the lower part of the apparatus..
3. Of superposed cylinders forming the body of the annanatua

page_text: 8. Of an inlet pipe for water and mineral.
9. Of the driving mechanism.
The cylindrical support terminates at its upper part by a plate which forms
the base of the whole apparatus. In the middle of this plate there is formed a
spherical cavity which serves to collect the amalgam which having a density
greater than the mercury which becomes lodged in this cavity sheltered from the
water currents. At the bottom of this cavity there is a delivery pipe and a tap
for the extraction of the amalgam. This cavity is closed at its upper part by
a cover plate which is formed with holes, through which the amalgam passes.
This plate also serves as a support for the vertical shaft.
The cylindrical distributor forming the lower part of the apparatus is one of
the most important parts of the apparatus. It carries on its lower circumference
an annular channel or crown where the water and mineral circulate before passing
into the apparatus by holes, arranged in circles at the base of the cylinder and
near the bottom.
Three cylinders form the body of the apparatus. The latter carries a mercury
gauge which enables the action of the apparatus to be regulated.
The top cylinder forming the cover of the apparatus and as aforesaid of smaller
diameter than the others allows the water and residue which have already passed
through the apparatus, to rise to a certain height above the level of the mercury,
to allow the particles of mercury to deposit which would have to be extracted
before this water and the residue are discharged by an opening. This cylinder
is also provided with a tube for the introduction of mercury into the apparatus.
Closed at the upper part, it carries at its top a stuffing box to keep the shaft in
its vertical position. A bracket fixed on this cylinder supports the pieces which
by a pulley and an endless screw communicates motion to gearing and the shaft.
An opening allows the apparatus to be examined. The shaft passing through
the whole length of the apparatus carries between its flanged end and nut the
triturating plates, and causes them to revolve. This shaft rests on a plate and
is supported by a series of balls. At the top of the shaft a centre screw is pro-
vided for keeping it in place, on its lower pivot.
The shaft with its triturating plates in consequence of its less density floats
in the mercury.
The distributor is simply a circular plate bored in a special manner.
Bored
at first on its edge with a certain number of holes the total section or area of
which is only one and a half to twice that of the pipe. The distributor has at
its centre a large aperture, the object of which will be hereafter explained. This
plate is fixed to the base plate of the apparatus by 8 screws. The triturating
plates are an essential feature of the apparatus. All their projecting lower parts
are provided with small projections or ribs while their upper parts are smooth.
A number of holes are formed at the centre and extend towards the edge for
allowing water charged with mineral to pass. The total section or area of these
holes varies, between 15 to 20 times that of the supply pipe. All the other parts
are too well known to require description here. The apparatus now described
is calculated to work with a mill of 5 crushing stamps of 20 to 25 tons of mineral
in 24 hours.
The apparatus according to this invention may however be constructed of
greater dimensions, except the height which does not vary, and be adapted to
work with 2, 3 and 4 batteries.
Operation of the amalgamator:-
The apparatus being arranged as above indicated, operates as follows:-
A small air valve on the supply pipe is first opened and the water is slowly
admitted with the mineral, either from a conical upper reservoir placed at a
proper height, or from a pump direct. Air escapes by the said air valve and as

page_text: soon as the water appears the valve is closed and water is allowed to come to
a suitable level, the mercury ascending in the gauge. As soon as the latter is
at its normal height that will indicate that the water has filled the annular
channel and is escaping by the lateral holes or passages, the apparatus is charged.
At this point the shaft carrying the triturating plates is set in motion and all
the water and mineral that the supply pipe can contain is admitted.
As soon as the water issues by the lateral holes, it comes in contact with the
distributing plate, the holes of which although of a total area greater than that
of the supply pipe do not allow the passage of all the water which constantly
arrives, and the water is carried towards the central opening, that is to say, the
centre of the apparatus, from there passing from one triturating plate to another,
by the apertures therein, sometimes ascending vertically, sometimes being drawn
circularly by the plates and finishes by arriving at the top of the apparatus, and
after having left the precious metal, the water and residues escape by an opening.
Theory of the operation:
:-
In industrial practice the pump would only have to raise the water mixed with
the mineral to a reservoir, placed at such a height that the pressure of the
column of water just exceeds that of the column of mercury to establish through
the mercury a natural flow, without almost any bubblings. Whatever may be
the method of re-supplying the water drawing the mineral, the theoretic prin-
ciple on which the apparatus is based is the following. The pipe will bring into
the apparatus four very different elements, riz:-water, the earthy part of
mineral, precious metal in fine powder, or in small grains as well as a certain
quantity of air. If we take the water as a term of comparison and that we admit
that it weighs 1, that of the air will be part, that of the earthy material of
the mineral 2 times more, and that of the precious metal 19 times more.
All these elements move in a liquid metal the weight of which is 13 times
that of the same water. As soon as all these materials go through the holes
into the apparatus the air by reason of its very little density escapes immediately
towards the top of the apparatus followed more slowly by the water, and then by
the earthy materials. The free gold of a density very much greater than the
mercury naturally remains at the bottom of the apparatus and amalgamates.
But a great part of the gild although free is often attached in extremely fine
particles to the small grains of quartz and being drawn by the water. Their
ascending movement being very slow these grains of quartz are caught by the
flutings of the turning plates and are triturated against the mercury which,
.although liquid, has always a certain amount of consistence. It will be easily
understood that this trituration is repeated 70 times and each time on a length
of from 2 to 4 inches all the gold attached to their surface is dissolved. More-
over in the processes of ordinary amalgamation the great loss by the slimes
prove this, that the gold reduced into powder extremely fine is held at the surface
of the water by the microscopic globules of air, runs with the water, without
coming in contact with the mercury. In this amalgamator this cannot take
place. In fact the globules of air and water identically as the grains of quartz
are disengaged by the action of the flutings of the revolving plates, and however
fine the reduction of the precious metal may be, it amalgamates with the mer-
cury.
More slimes there are, better is the result. The gold being amalgamated is
deposited in little globules at the top of the revolving plates sheltered from the
currents however weak they may be, the circular movement of the plates causing
these little globules to move slowly until they meet with one of the holes to fall
on the plate immediately below and so on to the bottom of the cavity. During
the operation of the apparatus the gauge allows of its regular movement being
controlled, and stops any drawing away of the mercury.
Dated this 7th day of March 1899.

page_text: A New or Improved Process and Apparatus for, or connected with, the
Amalgamation of Gold Ores, Tailings, and other Metals capable of
Amalgamation.
I, RICHARD FRANCIS ROUTI, of 146, Fenchurch Street, in the City of London,
Commission Agent, do hereby declare the nature of this invention (a communica-
tion to me from abroad by Anatole Bargigli, of 9, Avenue de la Bourdonnais,
Paris, France, Engineer), and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement:--
The object of my invention is to provide an improved apparatus, for the amal-
gamation of gold and other ores, by causing the water charged with the crushed
mineral and earthy matters, hereinafter termed "pulp" to be passed upwards
through a body of mercury in divided streams, and at the same time to cause
the pulp" to be acted upon, during its said upward passage by the serrated
under surfaces of a series of superposed revolving plates, each plate being per-
forated so that the particles after being so acted upon and triturated against the
mercury, by the lowest triturating plate, passes upwards through the perforations
in the latter plate, to be again acted upon by the under surface of the next
triturating plate, and so on until the uppermost plate is reached, while the gold
which becomes amalgamated is free to descend to the base of the apparatus, from
whence it is withdrawn by a pipe or conduit controlled by a tap, while the residue
passes off at the top of the apparatus.
My invention will be readily understood by the following description having
reference to the accompanying drawings, whereon Fig. 1 is a vertical section of
my, new or improved amalgamating apparatus. Fig. 2 being a plan view of the
same.
Fig. 3 is a vertical section similar to Fig. 1 but shewing the lower part of the
apparatus only, and drawn to a larger scale than the previous figures.
Fig. 4 is a half plan view of a fixed pierced plate, hereafter described as the
distributing plate, and Fig. 5 is a vertical section of same.
Fig. 6 is a half plan view, of one of several revolving plates, employed in
the apparatus, and hereafter described as the triturating plates, the left hand
part of the view, Fig. 6, shewing the under side of the plate and the right hand
part shewing the upper side of the said plate. Fig. 7 is a vertical section of
the same plate.
By employing this apparatus the gold is brought into intimate contact with
the mercury, and becomes dissolved by the latter.
Referring to Figs. 1 and 3, the base A of the apparatus conveniently consists
of a hollow frame or cylindrical casing, the upper horizontal casing A forming
a bed plate. Centrally in the bed plate A there is formed a cavity B, preferably
hemispherical, and from the lower part of same there extends a downwardly in-
clined passage or pipe B', terminating on the exterior of the base casing A in
a tap B, by which the delivery of amalgam can be controlled from the said
cavity, within which it collects, as hereafter described. The cavity B is closed
at its upper part by a cover plate B³, perforated with. holes, through which the
amalgam passes to the said cavity.
The body C of the apparatus is cylindrical, stands vertically upon the bed
plate A of the base casing A, and is conveniently formed of several cylindrical
rings, connected one to the other, until the structure is of the required height.
At the base of the cylindrical body C adjacent to the bed plate A¹, there is
formed, within an enlargement of the wall of the lower cylinder, an annular

page_text: channel 1, from which there extends externally, a tubular passage D', connected
to a pipe E, serving as the supply pipe by which the water charged with the
mineral to be amalgamated is delivered under pressure to the annular channel D.
From the said annular channel D there extends a considerable number of
relatively small radial passages F', in the base of the lower cylinder of the body C,
such passages F, opening into the interior of the apparatus at the base thereof,
above the base plate A¹.
At a short distance above the base plate, and above the exit ends of the radial
passages F, in the interior of the apparatus, there is fixed a horizontal plate G
which I term the distributing plate: this plate G is vertically perforated with a
series of holes G1, best seen at Figs. 4 and 5, the total area of the said holes G¹
being one and a half to twice the area of the delivery pipe E, while centrally
of the plate G there is a larger circular aperture G2 hereafter mentioned, and the
"pulp," delivered under pressure by the supply pipe E, enters in divided streams
through the radial passages F, from the annular channel D, and percolates up-
wards through the perforations of the fixed distributing plate.
Upon the top of the vertical cylindrical body C of the apparatus there is a
cylindrical cap C₁ of smaller diameter than the body C, centrally upon the closed
top of which there is a stuffing box (2, and I provide a central vertical shaft H,
which extends from the base plate A, up through the interior of the body C,
and projects through the stuffing box (before mentioned.
The top cylindrical cap C, forming the cover of the apparatus, is or may be
of smaller diameter than the body, and allows the water and residue which have
already passed through the apparatus, to rise to a certain height above the level
of the mercury, to allow the particles of mercury to deposit, which would have
to be extracted before this water and the residue are discharged by the opening C³
in the side of the cap.
The lower end H₁ of the shaft H aforesaid, enters a bearing in the cover
plate B3 of the central cavity B of the case, above which there is a collar H on
the shaft. Between the cover plate 333 and the collar H², I provide a ring of
antifriction bearing balls.
Upon the top of the cylindrical cap C₁ of the body there is a fixed yoke J
carrying a centre pin J, which bears upon the upper end of the shaft H, and
maintains the position of the shaft vertically.
Fixed upon the shaft N and within the body of the apparatus, I provide a series
of super-posed triturating plates K, such series of superposed plates K forming
a perforate cylindrical body fitting the body of the casing C; these plates K
extend from near the distributing plate G to near the lower part of the cylin-
drical cap C aforesaid. Two only of such plates K are shewn in section at Fig. 1,
similar plates being superposed one upon another, as indicated by the dotted
lines. The triturating plates K are of a circular disc formation, and form an
important feature of the device, the detailed construction of same being clearly
shewn at Figs. 6 and 7. Each plate K is formed with upper and lower concen-
tric projecting ribs K1, K2, the faces of the lower ribs K being serrated radially,
as indicated by the inverted quarter plan at Fig. 6, while between the ribs there
are a number of perforations K³ through the plates K of somewhat sector or
segmental formation, for allowing the "pulp to percolate through same; the
total area of these perforations K³ in each plate varies between 15 to 20 times
that of the supply pipe E.
The vertical shaft II carrying the triturating plates K is revolved by gearing
such for example as by a worm wheel L fixed on the upper end of the shaft H
operated by a worm Li Fig. 2, carried in bearings on the cross head J and driven
by any convenient means, such as by a pulley L. In some cases instead of all
the triturating plates being fixed to the vertical shaft and revolving therewith,
may so fix only every alternate plate to the shaft, the remaining plates being
loose on the shaft and being prevented from revolving therewith by a projection
or the like, on the plates, entering a groove in the inner wall of the chamber,
I

page_text: Thus a series of triturating plates revolve with the shaft while the alternate
plates are stationary.
The body C of the apparatus is filled with mercury to the level of the upper
triturating plate at K*, and a gauge glass M is provided by which the level of
the mercury can be observed. Also the cylindrical cap C is fitted with a pipe N
by which mercury can be inserted.
The frictional resistance to be overcome in rotating the triturating shaft H is
but small, as the shaft H and triturating plates K, being constructed of material
of less density than mercury, become floated in the latter, and do not therefore
exert pressure on the lower bearing.
The operation of the amalgamator constructed as described is as follows:-
The body of the apparatus being charged with the required mercury, by means
of the pipe N, the "pulp" to be treated is admitted by the supply pipe E under
artificial pressure, or pressure obtained by reason of the supply pipe E extending
upwards to a tank (not shewn) at a sufficient height.
The mercury will then assume its proper level, that is, it will rise to or about
the uppermost triturating plate, and the level will be shewn by the gauge M.
The vertical shaft H carrying the triturating plates K is then set in motion.
As soon as the "pulp" issues by the radial passages F, it comes in contact
with the under surface of the distributing plate G. The pulp is then forced
upwards through the perforations of the distributing plate G and is thereby
divided into a number of vertical streams, but although the perforations G¹ are
of a total area greater than that of the supply pipe E, vet these perforations may
not allow the passage of all the "pulp" which constantly arrives, and the said
"pulp" is therefore carried towards the central opening C, that is to say, the
centre of the apparatus, from there passing upwards along with the numerous
divided streams from one triturating plate K to another, by the apertures therein,
sometimes ascending vertically sometimes being drawn circularly by the plates
and finishes by arriving at the top of the apparatus, and after having left the
precious metal behind, the water and residue escape by the opening C³ in the
cylindrical cap C₁ at the upper part of the apparatus.
In practice, the "pulp would only have to be supplied from a reservoir,
placed at such a height, that the pressure of the column of water just exceeds
that of the column of mercury, to establish through the mercury a natural flow
almost without any bubbling. Whatever may be the method of supplying the
"pulp" at a proper pressure, the action is the same, that is to say: The supply
pipe will deliver the "pulp" into the apparatus, the "pulp" consisting of four
principal constituents, i.:--water, the earthy part of mineral, precious metal
in fine powder, or in small grains, as well as a certain quantity of air. Now all
these elements move in a liquid metal the weight of which is about 13 times
that of water.
As soon as all these materials go through the perforations of the distributing
plate G, into the apparatus, they become separated, the air by reason of its very
little density, escapes immediately through the mercury towards the top of the
apparatus, followed more slowly by the water, and then by the earthy materials.
The absolutely free gold, being of a density very much greater than the mercury,
naturally remains at the bottom of the apparatus and amalgamates. But a' great
part of the gold, although free, is often attached in extremely fine particles to
The small grains of quartz, and their ascending movement being very slow, these
grains of quartz are caught by the serrations of the first triturating plate K, and
are triturated against the mercury which although liquid, has always a certain
amount of consistence; the particles escaping upwards through the apertures K³
of the first plate K, and are then acted upon by the second plate K, and so on.
It will thus be easily understood that this trituration is repeated numerous times,
and each time by a length of surface of the plates K, and that by this continuous
action, all the gold incident in the particles becomes dissolved.

page_text: The gold becomes amalgamated during the upwards travel of the "pulp," and
is deposited in small globules at all points of its travel upon the top of the re-
volving plates K where guided by the smooth inclined concentric ribs, and being
sheltered from the currents, however weak they may be, the circular movement
of the plates causes these little globules to move slowly until they meet with
one of the holes E3 by which they fall on the plate immediately below and so
on to the bottom of the cavity B. During the operation of the apparatus the
gauge M allows of its regular movement being controlled, and any drawing away
of the mercury may be observed.
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. In apparatus for amalgamating gold and other ores, the combination with a
vertical cylindrical casing containing mercury, passages to the interior of the
base of the casing, and means for supplying the "pulp" to be treated to the
passages at a greater pressure than that of the column of mercury, a cavity at
the base of the casing to receive the amalgam and an exit, above the level of the
mercury, to take off the water and residue of the pulp; of a central vertically
arranged rotatable shaft, a series of superposed circular plates fixed on the shaft,
each plate having upper and lower concentrically ribbed surfaces, the ribs on the
lower surfaces being serrated, and a series of segmental perforations through
each plate for the passage of the "pulp" and amalgam-such series of superposed
plates forming a perforate cylindrical body fitting the body of the casing capable
of rotation, and through which the pulp and amalgam percolate in a vertical
direction therein, substantially a's set forth.
2. In apparatus for amalgamating gold and other ores, the combination of a
vertical cylindrical casing to contain mercury, an annular channel at the base
thereof, a tubular passage and a pipe to conduct the "pulp" to be treated to the
annular channel, a number of radial horizontal passages from the channel to
conduct the "pulp" to the base of the interior of the casing, a perforated dis-
tributing plate, having a central, circular aperture fixed horizontally a short
distance above the base of the casing, a central spherical cavity in the base of
the casing to collect the amalgam, an inclining pipe and tap to draw off the
amalgam, a perforated cover plate, for the cavity, and a bearing in the cover
plate, a cylindrical cap above the cylindrical casing, a central stuffing box in the
top of the cylindrical cap, a yoke provided with a central pin and carried by the
cylindrical cap, a shaft passing through the stuffing box supported at its base in
the bearing in the cover plate, and at the top by the centre pin in the yoke, and
mechanism to revolve the shaft, a number of superposed circular plates fixed on
the shaft, each plate having upper and lower concentrically ribbed surfaces, the
ribs on the lower surfaces being serrated, and a series of segmental perforations
through each plate for the passage of the "pulp" and amalgam, a space in the
cylindrical cap, a pipe to conduct the water and residue away, a gauge glass on
the casing to enable the level of the mercury to be observed, and a pipe for the
insertion of the mercury, substantially as set forth.
3. The combination and arrangement of parts composing the herein described
apparatus for amalgamating gold and other ores, constructed and acting sub-
stantially as described with reference to the accompanying drawings.
BREWER & SON,
London & Leeds, Agents for the Applicant.