The Anaconda standard. [volume] (Anaconda, Mont.) 1889-1970, 1899-04-24
AN ORE MILLING PROCESS
It Promises to Revolutionize
Quartz Mining Everywhere.
REDUCES COST OF APLANT
Also Reduces to Minimum the Precious
Metals Wasted During the Mill
ing Process-Mining Men
Already Interested.

metals from refractory ores which is
likely to revelutionize quartz mining
that was recently invented is said to
be an improvement on the old cyanide
process, and it brings the cost down
so that men of moderate means can
engage in quartz mining, which they
cannot do under the old systems. Not
only that, but it enlarges the margin
of profit on low grade ores.
The new process is said to be the
only one that will recover from the
ores as by-products other valuable ma
terials in addition to the gold or sill
ver There is absolutely no waste in
the tailings under this system, as every
particle of pulp that is likely to con-
tain valuable elements is sent back
through the process again, and when
it is finally discharged the valuable
minerals that are left will not be
worth much. Technically, the systems
object Is to provide means whereby
gold and silver can be rapidly dissolV-
ed as they exist in silicious ores, earth,
ETC., by applying hot alkaline and cy
anide of potassium solutions under
pressure and recovering the equivalent
of the metals from the solutions by
the same energy without the use OIL
zinc or other precipitating agencies.
All other processes depend upon pre-
cipitating agencies to solidify the prec-
iouS metals.
One great advantage in this system is
the preliminary treatment. In Other
systems expensive machinery is requr-
ed to get the ores to the necessary
shape, and the roasting process In
wolves a cost alone of $1.15 to $1.5O per
ton This is dispensed with altogether
in this system. In the roasting process
some refractory ores depreciate in value
through volatilism, and by avoiding
the roasting these valuable elements
are saved and are recovered as by
products. In the old processes uni
form size of the ore pulp is required
for good success, and dust is great
interfering element. Thus expensive
machinery is required to crush the
pulp to a uniform size and clean IT,
figure as the solutions do not perco-
late through the pulp and thus more
expensive machinery is not required.
The advantages of these innovations
are apparent when the cost of mill
of 100 stamps is considered. Under
any of the old processes it would cost
nearly 100000 while under this pro
II Pio'ooo
because of the expensive machinery
the use of which is done away with.
The cost of milling is so low that it
is reckoned that with the exception or
the cost of mining all above 81 per
ton is profit whereas the old systems
cannot mill less than twice that. An
other advantage is that cold weather
interferes with the old processes and
cuts no figure with this. A lower grade
of ores can be worked with this sys-
tenn than with any other and a much
higher profit made.
In operation the system. while com
plicated to an outsider, is simplicity
itself compared with other processes,
and much less labor is required upon
it, The ore is first reduced to pulp
that will pass a 4-mesh sieve. then
three tons of the pulp are placed in
each of four operating tanks on cars.
One ton of cyanide solution is discharg-
ed into each tank and then the mass
is boiled and kept moving by ag1tat-
ing apparatus for three hours. by
that time the evaporation nearly equals
the amount of the solution added to
the tanks.
AS the evaporation takes place in
the tanks, so it does on the boilers to
an equal amount and the escape and
replacement is equal. The metals are
recovered by evaporation to dryness.
The cars are ddetached, pushed forward,
where the contents are dumped into
a failing bin. There the solution is
drawn off from the pulp and returns
| to a receiving tank. After settling ii
| is pumped up to settling tank over
| a series of boilers. and after settling
| there it is returned to the boilers.
The solutions then contain the gold
silver and other elements sought after
| Water is added, the discharging gate
is closed, and the pulp, or failing, is
subjected to a washing treatment. This
lasts six hours, after which the solu-
ton is drawn off into a tank and wash
water added. The water is then drawn
off into another tank, as it contains
gold and silver for failing treatment
1t is pumped unfiltered to a solution
tank above the operating tanks
strengthened by cyanide, and then ad-
| ded to fresh ore.
The first solution contains the prec-
| ious metals. 1t is drawn off to some
| boilers, where after constant evapor.
| alton it becomes thick. 1t is Their
drawn off into auxiliary evaporatins
| boilers, where it is evaporated to com
! plete dryness. The residium is pulver'
lied. turned into crucible, % pounds
of it at a time When the finishing
| pot is reached another % pounds is ad-
ded and fused. and the process is con-
| tinued until the crucible is three
| fourths full The crucible is then taker
| from the furnace and allowed to cool
| Cold water is added. and shortly the
mass of precious metal in a porous
state is the result CT all this work. Il
| at any stage of the proceedings there
| is solution taken away which ma!
contain something of value. it is sen
through again and there is no waste.
!