Idaho semi-weekly world. [volume] (Idaho City, Idaho Territory) 1875-1908, 1892-12-13
4 NEW, CHsAP PROCESS
Asw Gold 1, Extracted IN Rarss ef
Australia where Water 10 Scarce.

trlcts where water 10 . scarce COM
modify has lately been completed for
= mine in South Australia, says the
Sydney Journal. BY its use gold sx-
traction snd ore dressing can be con-
Quoted with machinery that will not
cost nearly AS much rs that now in
use. The plant for treating finely
crushed material, such as iailings,
consists OF series Of four endless re-
volving canvas belt shaking tables
for roughly concentrating, and two
tables Of similar construction, but
with india rubber belt, for finishing. I
The material to be treated is first
classified by the air current into as
many classes IS there are tables in
the series, and each class is fed onto
its respective table These tables are |
SO adjusted as to allow no valuable
material to pass away at the lower
end, and AS little as possible of the
vaIueless material to pass over at the
upper end. The roughly concentra-
ted material falls over the heads or
upper ends of the tables, and from
there is carried onto the first finish
ing table, which is also adjusted to
save only clean ore or gold, an! the
tailings from it are again passed
through the whole process. The set
Of tables is estimated to separate the
free gold and pyrites from two or
three tons per hour of tailings or
crushed quartz at total cost of about
Is. per ton. The system is equally
well adapted to the treatment of tin
or silver ore. The material has, of
course, to be dry; but ore and sand
driving appliances are common, both
in Europe and America, and the cost
of drying automatically is never more
than few pence per ton. All thai
is new in the process has been thor.
oughly tested and proved by the in
ventor by an exhaustive series of ex
periments extended over severa
wears. Successful experiments have
been made with pyrites, showing tina
the coating and impurities that ren
: der pvritous gold refractory" to treat
). ment by chlorine or mercury are NJ
obstacles to this separation when sub
, iected to this process. The materla
heing all fine, No classifying appar
atus is required, the work being don
with one table and a small pair c
&C rolls. The table has hopper divid
IL ed into two compartments set owe
- 1t. The hopper has an opening |
the bottom that allows the content
10 to pass through 1t in about two hour
10 The days work of say ton OF pyr
be ties is placed in one compartment an
the table set in motion, the pyr't'
- is allowed to run into it, and as
falls off at the tail of the table
i, passes through the crushing rolls al
h, is again lifted by elevators into Il
hv other compartment of the hopper.
=. this wav the operation is repeat
20 until the pyrites is thoroughly p'
~ verizcd and the gold separated. a
ter each time that the contents of t
.oa hopper has passed through, the &c
will be found collected at the head
the table, and may be taken off
=. about pound of sand, the only
-. tendance required being to pl;
-. the days work in the hopper,
~ the end of every two hours to tt
the gold with a little sand
the head of the table. The ton
pyrjtcs is thus reduced to
pounds, and afterwards merely
ouires to be melted, which may
- accomplished with less than hal
horse power. Oil engines are G
sidered to be well adapted to driv
dry crushing plants in districts VT
the small quantity of water neces'
~ for a boiler is obtainable. They
=, sumo one pound of mineral oil
horse power per hour. This at !
per pound-about the usual po'r
most Australian ports-with t2o
Ne ton added for carriage, will make
cost of fuel in remote regions a
,.;u IS. for each ton of quartz crus
.s n The extra cost on any payable
~. is. however, more than compens
for in the increased yield obtaine
the dry process as compared will
wit ordinary process of working.
" The Ketchum smelter will sta
on the Goth of January.
give a
10 ON BERT Prey left yesterday for