Gilpin observer., 1915-05-13
PROCESS

w. F. Gray, manager of the Couer
d. Alene mine, is conducting some
very interesting tests with the flo
tation process of extracting mineral
values from shines, with an apparatus
at the Stroehle boiler shops in Black
Hawk. This system of slime treat
ment has been attracting the atten-
tion of mining men of late, although
the process can not be said to be a
new one, the scheme of separating
the matallics from the silica or waste
having been evolved some years ago.
Flotation is practiced in the treat
ment OF ores in many mining Sec
tons in this country and in various
mining districts in Europe John Gun
dy, who is connected with big min
ing concern opel ating in Korea, but
who is now home on a vacation, was
present yesterday afternoon at the
Stroehle boiler works s in Black Hawk,
when Mr.. Gray was experimenting
with the flotation process Mr.. Gun
dy says that tie mills of the COM
pany in Korea are equipped with
this process for the extraction OF ore
values from the shines and that the
results are stonis, ing Thousands
OF dollars are saved annually that
prior to the adoptio of the flotat.on
system, were lot. Mr. Gundy says
in Korea. $50 of the values in the
shines are recovered
The apparatus in Black Hawk does
not permit Of a very reliable test
from the fact that tie device is not
one in practical operation, but nev-
ertheless good idea is given of the
feasibility CT T. e process on the
shines of Gilp'n county ores. A test
made last week ty Mr.. Gray result
ed in a saving of Sc ozs.- gold, S.95
ozs. silver and 80 c-pper from heads
that ran .0s ozs. gold. This was on
shines from Couer d. Alene ore.
: The principle of the fotation pro-
cess is very simple. easy of compre-
mill. Where tie sys tenn is in prac-
tical use, as Mr.. Gundy explained, re-
ferring to the plant in Korea, there
are six boxes in a row, the shines
passing from one to the other There
are two compartme nts to each box,
the shines enterirg the receiving re-
ceptacle in which there is an agita-
tor that revolves at a speed of
around 1,200 revolt tons minute. Ee-
tween the receivi' box, which stands
upright and the horizontal compart-
ment. there is a small opening, per-
mitting the shines to pass from tie
agitator box to the box where the
discharge of the separated product
is carried off in bubbles These bub-
bles are created ty mixing a solu-
tion of pine oil and sulphuric acid in
the shines, which are constantly sgi-
tated. The bubbles arise and car
ry the fine particles of metal with
them, the silica settling to the bot
tom Of the boxes. IN practical work.
the bubbles of tie first two boxes are
saved and <he shines that pass
through the other boxes are reground
to a fineness of from $50 to 200 mesh
and again subjected to the flotation
process. The exper Sc of treating
shines with this process is very low
as only a pound Of pine on and a
pound of sulphur'c acid are required
to each ton of shines.
From what is known of the flota-
tion process. Il ere is no question
but that tins sys EN- of separation
can be used on the shines of the ma
jority of tie ores of Gilp'n county,
and make a recovery of tie values
that have heretofore been lost that
will enable the oountless mines of
the district conta aiming low grade ores
to pay a handsome profit. All that
has been needed to make the low
grade mines of this district pay has
been the discovery and adoption of
some system that would make high
er percentage CT saving than any
now in use. And flo alton seems to
be the long-needed process.
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