IMPROVEMENTS IN EXTRACTING GOLD FROM THE ORE
Year: 1854

page_text: PROVISIONAL SPECIFICATION left by Richard Archibald Brooman at the
Office of the Commissioners of Patents, with his Petition, on the 11th
January 1854. A communication.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN EXTRACTING GOLD FROM THE ORE," (communicated to me
from a foreigner,) to be as follows:-
These improvements embrace, first, the employment of electricity; and,
second, the construction of an improved amalgamating machine; and by these
a larger amount of gold is obtained from a given quantity of gold bearing
quartz, or gold sand, than from the old processes, as well also a saving of time
for forming the amalgam is effected. And, first, as to the employment of
electricity. The Inventor has found that by keeping the mercury constantly
charged with galvanic or other electricity, the deposit of gold, or the formation
of the amalgam, is far more rapid than without it, and also that the product
is largely increased. The means by which the Inventor accomplishes this is by
connecting the poles of a galvanic battery with a plate of gold situated in the
bottom of the amalgamating vessel, by proper conducting wires. And in
order to insure the most perfect action or effect, the gold ore is so discharged
that it shall be minutely diffused throughout the mass of quicksilver, which is
a feature wanting in the old machines.

page_text: The amalgamating vessel consists of a cylindrical cistern set upon a firm
basis, as shewn at A. A spout or overflow pipe is cut into or secured at the
top, as seen at B. At C is shown a hollow spindle, set vertically, stepped in
the centre of the cistern A, and kept in position by a proper frame, having a
box to receive the journal of the said spindle in which it may revolve. There
is a funnel on the top of the spindle, into which the gold ore is discharged.
The lower part of the spindle terminates in two branching arms D, likewise
hollow, but stopped at their ends, as shewn, having, however, a narrow longi-
tudinal slit cut on the under side for a discharge place, as seen at E, Figure II.
These arms are brought down so as to discharge the gold ore near the bottom,
and immediately over the gold plate or surface before mentioned. By this
means the ore is sure to be well diffused through the mercury, obtaining
thereby the greatest effect from the action of the latter upon the gold. At F
is seen the plate of gold on which the amalgam is deposited as fast as formed.
This plate is in the form of a broad flat ring, and may be secured by any
cement insoluble in the materials thrown in, pitch or resin being a good sub-
stance for that purpose. Should the miner find it inconvenient to provide a
plate of gold, a gold surface may be formed by sifting gold dust on a bed of
pitch or other proper cement. At G is shewn the wires for conducting the
electrical current from a galvanic or other battery. These wires terminate in
contact with the gold plate or surface at the bottom of the cistern, as repre-
sented. Finally there are plugs for discharging the contents of the cistern
through the bottom, when desired.
The operation is as follows:-The cistern having been charged with mer
cury to the required depth, rotary motion is given to the spindle C, and the
gold ore, in the condition as discharged from the pulverizing mills, is received
into the funnel at the top of the spindle, whence it descends. and is passed out
in a finely divided stream through the slits E into the midst of the mercury.
through which it is constantly being diffused in the best manner to insure that
the action of that shall form the amalgam, the water and all dirt of less'
specific gravity passing out at the spout. As now operating, the machine forms
an amalgamator of superior quality to the old modes. by which the ores 'are
precipitated and agitated on the surface of the mercury. Shortening the time
of forming the amalgam, and also increasing the product, are ellects due to
the application of electricity; therefore, the Inventor keeps the gold depositing
plate, and also the mercury, constantly charged by means of a galvanic or
other battery through the connecting wire G as shown. The amalgamated
gold is by this means precipitated upon the gold surface, and adheres to it.

page_text: When the operation has proceeded far enough, the plate is severed from the
bed of the cistern, and removed, when the amalgam adhering to its surface is
to be taken off, and the gold separated in the usual way. The plate is then to
be replaced, or another put in the cistern, to be recharged with a fresh supply
of mercury, and thus the operation may be kept up.