IMPROVEMENTS IN AMALGAMATING MACHINES
Year: 1884

page_text: I, MONCRIEFF PARRY GOSSET, of Old Broad Street, in the City of London,
Mining Engineer and Fellow of the Chemical Society do hereby declare
the nature of said invention for "IMPROVEMENTS IN AMALGAMATING MACHINES,"
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
The said invention consists in providing a vibratory amalgamating-pan with an
inwardly curved end of a peculiar construction, whereby in the longitudinal
reciprocating movement of the said pan the mercury or amalgam contained therein
is, at each stroke of the pan caused to curl or lap over after the manner of a wave,
and to thereby inclose and amalgamate particles of gold floating on the surface of
the water and ore.
It further consists in providing the said vibratory pan with a reciprocating
mixer, which moves in practically the same plane as the amalgamating-pan, but at
an increased speed, to keep the reduced ore and water in a state of agitation, and
thereby prevent the ore becoming packed into a solid body.
It further consists in certain details of construction of the apparatus, looking to
its efficient operation as hereinafter fully described.
In the accompanying drawings, forming a part hereof, Figure 1 is an exterior
side view of the improved amalgamator, and Figure 2 an end view of the same.
Figures 3, 4, and 5 are respectively a longitudinal section, a plan view, and a
transverse section of the amalgamating-pan and mixer, the whole being represented
on an enlarged scale.
Similar letters of reference indicate similar parts in all the views.
A represents a portion of the frame from which the amalgamating-pan B and
mixer C depend. The amalgamating-pan is here shown as consisting of a wooden
trough, a, with its bottom and sides covered with iron plates b, and one end
provided with the wave plate c.
By reference to Figures 3 of the drawings it will be seen that the upper edge of
the waveplate c extends beyond a central vertical line, and approaches the surface
of the mercury or amalgam. Consequently in a rapid longitudinal reciprocating
movement of the pan the mercury or amalgam is not only carried up the bollow

page_text: surface of the wave-plate, but introverted and brought back in a solid sheet, which
envelops the float gold on the surface of the water.
The amalgamating-pan may be made entirely of iron, if desired. As the wave-
plate c does not necessarily extend to the upper edge of the pan B, it is provided
with an extension, d, which may be either inclined, as shown in the drawings, or
vertical The inner curved surface of the wave-plate c is accurately bored or faced,
and its lower end rabbeted in order that a tight joint may be formed with the
bottom plate b. The said plate b is inclined downward toward the wave-plate c,
so that a body of mercury is maintained in the pan. In order to obtain the
desired inclination of the bottom of the pan B without increasing the depth of
mercury contained therein, the said bottom is formed, in two sections, with an
offset where they are connected. This offset, which is represented by e, is curved
in a manner similar to the wave-plate; but it is not absolutely necessary to the
proper operation of the invention that the offset should occur, or that it should be
curved as shown.
C is the mixer, consisting of a frame, f, preferably of wood, having projections g
on its under side. These projections have a V cross-section, and they are arranged
so that one transverse row is opposite the spaces in the row immediately behind it.
By this means, in the reciprocal movement of the mixer, the portion of the
contents of the pan upon which it acts is driven in small streams through the
apertures between the projections g toward the back end of the pan, and it flows
back to the front end by the force of gravity.
The pan B is suspended by means of rods h from the frame A. and it will be seen
that these rods, which are spread at their upper ends to give rigidity to the
apparatus, are adjustable in length for obvious purposes. The mixer is also
suspended from the frame A by means of rods i, corresponding, practically, with
the ones h.
By reference to the drawings it will be seen that when the pan is at rest its
contents (amalgam, ore, and water) will occupy the space below the dotted
line yy, and that the projections g of the mixer extend below the surface of the
contents of the pan, but do not touch the plates b. The pan and mixer receive
their reciprocating movements from eccentrics, cranks, or other similar devices,
which are connected to them by means of the rods and l.
It is designed to give the amalgamating-pan about eighty double strokes per
minute, and the mixer about one hundred and sixty; but the speed of either
device may be increased or diminished as desired.
The pulverized ore from the stamps and water are introduced to the pan B
through the trough or chute D, and the overflow from the pan is through a similar
chute, E.
In the operation of the invention the mercury or amalgam at each stroke of the
pan impinges against the wave-plate c, and, following its curved surface, is
introverted in the form of a wave, as herein before described, and in this movement
incloses a portion of the ore and water, which to escape from its enclosure has to
pass through a body of mercury, and the free gold therein is thus amalgamated.
In the continued operation of the apparatus which includes the mixer, the whole
of the ore and water is thus made to pass through a solid body of mercury, as
described. The value of this wave action of the mercury will be apparent when
it is understood that in all ground ore a large proportion of the gold contained
therein is in such a minute state of comminution that it will float on the surface of
water, and this extreme levity of the particles of gold renders the ordinary
amalgamating process exceedingly wasteful. In this amalgamator the floating
gold is forced within an inclosure of mercury and cannot escape therefrom without
amalgamation.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that I am
aware that amalgamating-pans have been made with a curved inwardly-projecting
end; but in all such pans the curved surface has either been less than a semicircle,

page_text: or, if projecting beyond a vertical line extending through the centre from the curve,
as described, has had an ascending inclination. In both these constructions there
is nothing to guide the mercury in a curved wave toward the surface of the water
and amalgam and the mercury consequently falls, in separated particles, which
cannot be considered as an imperforate envelope, as is found when this construction
is employed.
I do not claim, broadly, an amalgamating-pan with an inwardly-curved end;
but what I claim is:-
In an amalgamator, a longitudinally-reciprocating amalgamating-pan having at
one end thereof an inwardly curved wave-plate, the free end of which extends
downward or toward the surface of the amalgam in the said pan, substantially as
specified.