AN IMPROVED AMALGAMATING AND CONCENTRATING MACHINE FOR THE TREATMENT OF METALLIC ORES AND FOR SIMILAR PURPOSES
Year: 1876

page_text: LETTERS PATENT to Charles Wright, of Gresham House, in the City of London,
for the Invention of "AN IMPROVED AMALGAMATING AND CONCENTRATING
MACHINE FOR THE TREATMENT OF METALLIC ORES AND FOR SIMILAR
PURPOSES."
Sealed the 20th June 1876, and dated the 16th February 1876.
PROVISIONAL SPECIFICATION left by the said Charles Wright at the Office
of the Commissioners of Patents on the 16th February 1876.
CHARLES WRIGHT, of Gresham House, in the City of London. "AN IMPROVED
AMALGAMATING AND CONCENTRATING MACHINE FOR THE TREATMENT OF METALLIC
ORES AND FOR SIMILAR PURPOSES."
My improved machine is constructed with a bed and casing similar to those of
ordinary iron rotating pans, geared and driven from underneath by a pulley on
a horizontal shaft. The bed is level from the centre to a ridge on the edge of
an outside groove or channel, and retains all material treated of greater specific
gravity than 2 or thereabouts. When this accumulation of concentrated matter
rises to the height of the said ridge, the machine must be stopped and cleaned up,
an operation readily performed in about 10 minutes.
The frequency of the "cleaning up" is dependent upon the per-centage of
sulphurets contained in the ores treated.
When the machine is used solely for gold amalgamation it does not absolutely
need cleaning oftener than once a week, and may in the meantime be locked up
as no attention is needed for its interior nor can any amalgam escape so long as
the machine is kept in proper motion.
The vertical driving shaft passes up through a long boss in the centre of the bed,
and upon the top of this shaft is fitted a hub to which arms are attached. These
arms have two series of carriers adjusted to their lower side; those of one series
graze the bed and are curved and set to give a drawing motion towards the
centre of the machine to all particles of ore which gravitate near the bed of the
said machine. The carriers of the other series are curved and set reversely, and
have precisely the opposite effect upon all lighter material in suspension, as these
last-named carriers do not touch the bed of the machine. By this arrangement
of the carriers therefore a double current of the particles is produced, the upper one
carrying off the slimes towards the curb, and the lower one drawing heavy and

page_text: solid particles from the curb inward; in this respect therefore the carriers serve
as self-clearing riffle bars.
A
The discharge openings for slimes are so arranged below the surface of the
water as to permit all "float" gold to remain undisturbed by the discharging
streams, and to allow of the employment of various expedients to secure it.
spray of clear water playing upon the surface will throw down the greater portion
after a time; and if sodium amalgam is judiciously used just before drawing off
the contents to clean up, little, if any, need be lost.
•
This improved machine concentrates closely and rapidly in water without a
current, and is designed to effect the saving of "float" gold, a saving at present
only possible by the employment of sluices extending for iniles and extensive slime
pits.
In addition to the convenience and security of having the mill tailings exhausted
within the building, it is to be remembered that the further the particles of gold
are carried the finer and more difficult to save they become, while the first cost
of long series of sluices, slime pits, and the like, and the necessary repairing and
attendance, greatly detract from the value of tailings, which are but imperfectly
treated at last.
The groove or channel at the circumference of my machine has openings into
hoppers below, and is traversed by scrapers to clear it of coarse light material, such
as unground quartz, which finds its way over the ridge and is consequently collected
and reground in any suitable pulverizer.
The slimes from the upper discharging points will not be of any value and are
allowed to go to waste.
In treating gold ores, gold amalgam and sulphurets will be found ranged upon
the bed of the machine at the centre and at relative distances therefrom in the
exact order of their various specific gravities.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Wright in the Great Seal Patent Office on the 15th August
1876.
"AN IMPROVED
CHARLES WRIGHT, of Gresham House, in the City of London.
AMALGAMATING AND CONCENTRATING MACHINE FOR THE TREATMENT OF METALLIC
ORES AND FOR SIMILAR PURPOSES."
The said Invention relates to a machine which I call an improved amalgamator
and concentrator for treating metallic ores and for similar purposes, as hercin-after
described and as illustrated in the accompanying Drawings, in which Figure 1 is a
plan or top view showing one-half of my improved machine; Figure 2 is a vertical
central section of the same.
Like letters indicate the same parts throughout the Drawings.
My improved machine is constructed with a bed a and casing b similar to those
of ordinary iron rotating pans, and it has arms c and carriers d, d, geared and
driven from underneath by a pulley e on a horizontal shaft f; a* is a hopper
whereby the ore is fed into the machine below the water on the bed a.
The bed a
is nearly level from the centre to the ridge or rim a¹ on the edge of the outside
groove or channel a², and retains all material treated of greater specific gravity
than 2.5 or thereabouts. When this accumulation of concentrated inatter rises to
the height of the said ridge or rim a¹, the machine must be stopped and cleaned up,
an operation readily and quickly performed. The vertical driving shaft f1 passes up
through a long boss or bushing g in the centre of the bed a, and upon the top of this
shaft is fitted a hub c¹ to which the arms c are attached, these arms have two series
of carriers & and d¹ fitted and adjusted to their lower side, the carriers of the series
d graze the bed a and are curved and set to give a drawing motion towards the
centre of the machine to all particles of ore which gravitate to the bed. The

page_text: carriers of the other series are curved and set reversely to the carriers d, and
have precisely the opposite effect upon all lighter material in suspension, as these
carriers do not touch the bed a. By this arrangement of the carriers therefore a
double current of the particles is produced, the upper current carrying off the slimes
towards the curb, and the lower one drawing heavy and solid particles from the
curb inward; in this respect therefore the carriers d, d', serve as self-acting riffle
bars.
The groove or channel a² at the circumference of my machine has openings a³ into
hoppers below, and is traversed by scrapers on the ends of the arms i to clear
it of coarse light material, such as unground quartz, which finds its way over the
ridge and is consequently collected and reground in any suitable pulverizer.
The discharge openings j for the slimes are so arranged below the surface of the
water as to permit all "float" gold to remain undisturbed by the discharging
streams, and to allow of the employment of various expedients to secure it. A
spray of clear water playing upon the surface will throw down the greater portion
after a time, and if sodium amalgam is judiciously used just before drawing off the
contents to clean up, little, if any, need be lost.
Considering that in actual milling the best authorities estimate the unavoidable
loss of "float," "flour," and impalpably "fine" gold at present to be fully one-third
(and often two-thirds) of the assay of the ores treated, it is of the greatest
importance to mining companies to stop this enormous waste. In some instances
the native gold is so extremely fine that the slightest breath is sufficient to blow it
away, its excessive lamination giving its minutest particles so much surface to be
exposed, that it has been found impossible with the best amalgamating con-
trivances hitherto known (using a current of water) to pay the expenses of working
sands, which by assay should have yielded enormous profits.
My improved machine concentrates closely and rapidly in water without a
current, and is especially designed to effect the saving of "float" gold, a saving at
present only possible by the employment of sluices extending a great distance and
extensive slime pits. Convenience and security are obtained by having the mill
tailings exhausted within the building, and there is also great economy in this
arrangement, as the further the particles of gold are carried the finer and more
difficult to save they become, while the first cost of long series of sluices, slime pits,
and other appliances, and the necessary repairing and attendance, greatly detract
from the value of tailings which are but imperfectly treated at last.
The frequency of the "cleaning up" is dependent upon the per-centage of
sulphurets or other heavy substances contained in the ores treated. When the
machine is used solely for gold concentration or amalgamation, it does not
absolutely need cleaning more frequently than once a week, and may in the mean-
time be locked as no attention is needed to its interior, nor can any amalgam
escape so long as the machine is kept in proper motion.
The slimes from the upper discharging points being of no value are discharged as
waste.
In treating gold ores, gold amalgam and sulphurets will be found ranged upon
the bed of the machine at the centre and relative distances therefrom in the exact
order of their various specific gravities.
I do not confine myself to admitting the feed in the centre of the apparatus as
shown in the Drawings; I propose sometimes to feed at various distances from the
centre according to the nature of the material to be treated. For this purpose I
make the arms c with channels or pipes for the feed, and by means of holes in the
same I regulate the distance from the centre at which I wish to admit the feed.
I also in some cases propose to carry off the concentrated ore by a pipe or pipos
near the centre. Through the said pipe or pipes I propose to admit a stream of
water, either continuous or intermittent, and at such speed that the heavy particles
will descend against it, while the lighter particles are floated upward.
Having thus fully described the said Invention and the manner of performing
the same, I wish it understood that I claim,--
•

page_text: First. In a machine for treating metallic ores and for similar purposes, the two
sets or series of carriers mounted upon arms or bars, which extend from a central
vertical shaft or axis, and so curved and set and arranged in combination with the
bed of the said machine, that the two sets or series of the said carriers produce
currents in opposite directions on the said bed, as above set forth and for the
purposes specified.
Second. In the said machine the combination of the said series or sets of carriers,
the arms fixed on the vertical shaft, the bed constructed with the circular channel,
and rim or ridge around its periphery, the scrapers working in the said channel, and
the other parts of the said machine, as shewn in the accompanying Drawings and
operating as above set forth.
In witness whereof, I, the said Charles Wright, have hereunto set my hand
and seal, this Eighth day of August, in the year of our Lord One thousand
eight hundred and seventy-six.
CHARLES WRIGHT. (L.S.)