The semi-weekly miner. [volume] (Butte, Mont.) 1882-1886, 1882-05-10

DRY GOLD PlAAO1R9.
The Method OF WORKING them By
OoutEifaGal Force.
The following extracts from the Mn
ina Record describes device for obtain
ing the precious metal by centrifugal
force without the agency Of water, from
sands containing gold:
At an iron foundry on West Twenty
seventh street, machine was exhibited
yesterday which, it II claimed. will at .
cheap rate separate gold dust from sand
without the agency Of water. The de-
vice 10 intended to meet the require
ments Of the placer region of the West,
Mexico and Central America, where
vast tracts Of gold-bearing sand are
found miles distant from any source Of
water supply. To illustrate the work.
ing Of the new l. ventiOn, the exhibitor
scattered an ounce or 80 Of gold in .
granular state through q busIel ofcoarse
sand, which was placed in vessel,
shaped like the hopper Of mill. From
the taper end Of this it was then allowed
to pour between two curved copper
plates, situated horizontally and revolv-
Ell ut q speed of from sixty-five TO eighty
revolutions minute. Passing between
these plates the sand Is driven by CEN
trifugal force against "wall" Of mercu-
~, which is also maintained through
the action of centrifugal force. Sur
rounding the copper plates Is nm iron
casting like an iron stew pan with the
greater part Of the bottom cut out, 80
that its half section resembles letter l..
Thi. IL connected with an axis by four
hollow arms, each Of which il made to
contain ab'ut tifty pounds Of mercury.
The whole arrangement il revOlve<l in u
direct on contrary to that Of the plates,
and by rotary force the mercury runs
from the arms through grooves provid-
ed. and climts along the upright sur
face, corresponding with the upright
stroke of the l., thus forming \ perfect
wall. Every particle Of gold as 1t Is
thrown instantly anna ganiates with 1t
while the sand is partly thrown "tt' by
its own rebound and partly blown away
by series Of pipes attached I" a blower
used in connection with the machine.
peratOr chooses II passed through, the
machine is stopped. the mercury is with
drawn Nv a trap from the arms, into
which it falls the instant the rotation
ces,ytx. 1t Is then strained through tick
ing in the way well known to all miners,
and the gold ia finally cleared Of It.
through the agency of heat in the COM
mon way. The experiment resulted
i'm the recovery Of the gold originally
mixed with the sand, without sensible
diminutioh, and the advantages claim
ed by the plan are: First that 1t ex-
tracts every particle Of gold from the
matter PASSED through it, and, second,
that It does so without any serious loss
Of mercury. 1t is claimed that 1t will
oper up vast stores of the precious met
al not ct present available, and will
even render It possible to work over
again with profit: the ''tailings'' Of
mines operated under old systems. The
outside diameter Of the machine shown
was five feet, and It was claimed that
with it ore or sand could Ike worked at
the rate Of q ton I'm less than twenty
minutes. Among those who witnessed
the trial were several representatives OF
Western and Southern America min.
ing interests.
For long time past the utilization Of
dry gold placers has l,ecn desitieratum,
but a. yet no instance Is known in
viii oh any rational attempt command
ing the proper kind Of technical advice,
rs well as the financial means required,
has been made in this direction. The
San Pedro and Canon del Agna cOnins-
ny of Boston preferred tn unnecessarily
apply in New Mexico where there is no
water the methods of California, where
there IL no water, ut an expense Of u
quarter million Of dollars, rather than
tn spend u few thousand dollars in an in
vestigation as to the possibility of work.
ing their placers without water.
Very errOneOusly it has been assumed
that the successful working Of dry gold
placcrs depend on the invention Of u
machine Tor the separation of the gold
from the sand. Such preparations can
he perfected in several well known
ways with the aid Of several gOOd apla-
ratilses, either patented, ar free for use
by all, and there IL certainly no difficult
ty in effecting such selmrntion.
In other words the difficulty il not
solely technical one, and the technical
part, as far ~ the separation Of gold and
sand IL concerned, have been solved
practically in an absolutely satisfactory
way, but what remains to do is the sue
cessfnl handling of large amounts of ma
terial without the aid of water for so low
expense rs will not materially surlnsas
the expense of handling the material
with the help of water, say ut not more
than five or ten cents per ton OF 2,OOO
pounds.
1t is important to know that ninety
nine tons in one hundred may lie hand
led and all the gold may Ike collected in
one without the use of any special sepa-
rator, on account of the difference in
size of gold from the size of the land and
gravel occurring In the same bed with
the gold.
The success of working dry placers Is
therefore dependent on general engin:
eering skill In moving ut low cost dry
gravel, and on special skill in treating
ores 30 AZ to retain the gold within =
small part Of the total mass and ultf-
tely on treating the retained small part
for separation proper. 1t Is in this
sense 0nl that the foregoing from to-
days Herald deserves attention.