AN IMPROVED MODE OF AND APPARATUS, FOR TREATING ORES FOR THE EXTRAC- TION OF METALS THEREFROM
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by Evan Hopkins at the Office of
the Commissioners of Patents, with his Petition, on the 1st November
1862.
I, EVAN HOPKINS, of Clarendon Gardens, Maida Hill, in the County of
Middlesex, Civil Engineer, do hereby declare the nature of the said Invention
for "AN IMPROVED MODE OF AND APPARATUS, FOR TREATING ORES FOR THE EXTRAC-
TION OF METALS THEREFROM," to be as follows:-
The chief object of this Invention is to effect by an economical mechanical
process the separation of gold from its ores to such an extent that when the
ore is submitted to furnace heat (to complete the separation of the gold) it
will be presented in the form of a rich auriferous powder.
In carrying out my Invention I first crush the ore by means of stampers or
other suitable apparatus, and then discharge it by the aid of a stream of water
on to a separating or assorting apparatus. This apparatus consists of a grating or
sieve, which is placed over the upper end of an inclined bed or table. This bed
I cover with blankets, and on the blankets place a series of boards, so as to cover
to a certain extent the blankets, which form a kind of lining. These boards I
groove transversely and in such manner that in end view the divisions between
the grooves will take the form of hooked saw teeth inclining upwards towards
the grating or sieve. The object of these grooves is to form receptacles for the
retention of the rich granules as they are washed down over the inclined plane.
When the operation of flooding the table has continued sufficiently long to

page_text: charge the grooves with the auriferous product, I remove the grooved boards
and carefully wash them, and I next submit the product to a similar operation
in a second assorting machine, discharging the pulverized material through a
hopper on to a bevilled grooved board and down an inclined table provided with
a covering of blankets, by which means the bulk of the ore will be still further
reduced and the richness greatly enhanced. The blankets or lining I also
wash daily, adding the product obtained to that under operation. The rich
and highly concentrated products retained in the second assorting apparatus I
next collect and convey to rotary washing pans of novel construction, and the
product discharged by the water from the apparatus I regrind and further
treat if found of sufficient value. The washing pans (a series of which will
be required), I make of wood and of a shallow conical form, ribbing the part
near the lip after the manner of the grooved boards, and for the like purpose.
The pans I mount on inclined shafts, which I drive by bevil gearing. In or
near the centre of the pan I make an opening (which is closed by a plug
during the washing operation) for discharging the gold product from the pan.
The auriferous product obtained from the inclined table may be discharged
continuously by shutes into the pans, and at the same time water is also caused
to flow into the pans, which, by their rotation, keep the auriferous product in
constant agitation; the lighter particles will therefore flow over the lower
part of the rim of the pan together with the water, and be caught by a series
of boxes placed to receive it, while the more weighty and valuable particles
collect at the bottom of the pan. When a sufficient quantity has been
collected, the pans are tapped, and the resulting gold product is ready for
smelting. The product collected in the boxes may, if it prove sufficiently rich
to warrant the expenditure, be subjected to a second grinding, and treated as
before in the assorting and washing apparatus.
This process is also applicable to the extraction of tin, platinum, and other
heavy metals from their ores.