Year: 1887

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, 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 mercury amalgamators, chiefly designed for the extraction
of gold from crushed quartz, and it comprises various improvements hereinafter set
forth.
The said invention is illustrated in the accompanying drawing, in which
Figure 1 is a plan, and
Figure 2 a vertical central section of the improved amalgamator.
Like letters indicate corresponding parts throughout the drawing.
A is a conical pan, which is firmly secured to a flange B' at the upper end of a
vertical shaft B supported in a step or bearing C on the base-plate C, and in a
bearing D' formed in a bracket or standard D. The shaft B is connected, by means
of bevel-wheels E, E', with a shaft F supported in bearings F and provided with a
pulley F whereby it is to be connected with a suitable motor for rotating the shaft B
and pan A. Any other suitable means may, however, be provided for rotating the
said pan.
The central part of the bottom of the pan A is provided with a perforated plate or
grating a, which, at its circumference, is riveted to the pan A; the said pan is to be
filled with mercury to the height of a few centimeters above the said perforated plate
or grating. In the centre of the grating a terminates a pipe G which is provided at
its upper end with a funnel G¹.

page_text: A conical plate b is fixed in the pan A, a space being left between the said plate
and pan; and a cone c is tightly fitted to the said conical plate b for the purpose
hereinafter explained. A box or receptacle d of wood or other suitable material is
fitted in the shaft B beneath the centre of the pan A to collect the amalgam. This
box or receptacle is provided with a cock e for drawing off the amalgam.
His a trough or channel which is supported upon a frame H and which surrounds
the pan A. This trough or channel is designed to receive the quartz-slime which
flows over the edge of the pan A, and the said trough or channel is provided with a
pipe I for conducting away the said slime.
The finely pulverized quartz is to be mixed with water and introduced into the
pan A through the funnel G¹ and pipe G. In its passage through the layer of
mercury, the quartz-slime must be divided into fine streams in order to pass through
the holes of the grating a. When the pan A is rotated, the mercury is thrown by
centrifugal force towards the periphery of the said, pan and covers the bottom
thereof with a thin layer having a large surface, which, by reason of the constant
motion, materially promotes the amalgamation.
An important advantage of the improved amalgamator in comparison with other
amalgamators is that the motion of the mercury is not caused by friction like that
produced by mill-stones, which, as is known, promotes sickening to a great extent.
The quartz-slime, after liaving passed through the grating a, has a tendency to
move towards the periphery of the pan, but cannot arrive there otherwise than
through the small space between the pan A and the conical plate b; it is therefore
kept continually in contact with the layer of mercury in the said pan. The cone c
serves to prevent the escape of the slime except under the cone b. The said quartz-
slime has, moreover, by reason of the centrifugal force, a constant tendency to
penetrate into the layer of mercury. The slime passes over the edge of the pan A
into the channel H whence it is conducted away through the pipe I.
The repeated passage of the quartz-slime through, or in contact with the layer of
mercury causes a thorough amalgamation of the small particles of gold contained
therein with the mercury. When the machine is stopped, the amalgam collects in
the wooden box d; it may therefore, be drawn. off from time to time through the
cock e.
Whilst the rapid rotation of the pan A on the one hand ensures a thorough
amalgamation, it causes on the other hand (like any kind of motion) liability, to
sickening of the mercury.
This defect is obviated, according to the present invention, by conducting permanent
electric currents through the layer of mercury. These currents, as experience proves,
also improve the amalgamating affinity between gold and mercury; they are generated
by the apparatus itself, that is to say, by the aid of one or more horse-shoe magnets K
and a copper ring secured to the underside of the pan. The current is produced by
the rapid rotation of the ring f over the positive and negative poles of the magnets,
and the said current passes directly through, the pan, into, the mercury, the decom-
position of which it prevents or limits materially, while it promotes the amalgamation.
The number of magnets required may be determined by experiment:
Between the pan A and the shaft B.is an insulating layer g of felt or other suitable
material. The pan A is secured to the flange B¹ by means of wooden wedges or
keys which are held by means of thumb-screws . The mercury is insulated from
the shaft B by the box d which is made of non-conducting material.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed as communicated to me by my
foreign correspondent I wish it understood that I claim :-
First. A centrifugal amalgamator comprising a pan A by the rotation whereof a
large surface of mercury is obtained (which is in continual agitation and is therefore
automatically kept free from any layer injurious to the amalgamation) and wherein
the amalgamation is effected without friction such as that produced by mill-stones, as
above specified.

page_text: Second. The employment of the cones b, c which compel the quartz-slime to pass in
close contact over a large surface of constantly agitated mercury, substantially as
set forth.
Third. The utilization of the rotation of the pan for the production of electric
currents by means of magnets and a copper ring substantially as described, for the
purpose of preventing sickening of the mercury and to promote amalgamation.
Dated this 30th day of November 1987
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.