Gilpin observer., 1909-07-15

means the salvation Of the camp
It is doubtful If too much can be
said on this very important PROPOSE.
tion. "A treatment system has never
been broaehed in the history Of the
camp that has created such wide.
spread interest or has oeeasioned
such general comment as that dis
covered by Messrs. Draper and Ala
dorf. From the tests made, which
have been most thorough and exact
ing, and In which Messrs. Draper and
AIsdorf had the assistance Of some
Of the best mining engineers in the
country, men who have had extern
sive experience in eyaniding ores, II
is certain beyond the peradventure
Of doubt that the problem Of pro-
fitably treating the low grade ores
Of this district has BEEN distinctly
solved.
Among the able mining engineers
who have acquainted themselves with
the tests made are Fred Mel. strout
and John Gross. Gross is connected
with the Maitland Mining company,
operating at Lead, s. D., and has
had long experience in designing
plants for the Colorado Iron Works
and has operated cyanide plants in
Old Mexico, South Dakota and mum
Der Of other places. He was an i'm
portant factor in the development Of
the Black Hills cyanide works, con-
sidered the best practice in the world.
strout and Gross are graduates Of
the School Of Mines and both have
had is years Of successful cyanide
practice. These gentlemen express
themselves in no uncertain terms AZ
to the feasibility and merit Of the
proposition Of building a cooperative
mill and in the design Of the con-
templated plant they have provided
for the latest proven and other metal
lurgieai practices, as they are adapt
ed for oiIpin county ores. Extracts
from their reports will be found most
interesting:
II is generally conceded that any
ore, having 4 fair commercial grade
Of the precious metals, can usually
be made to yield high extraction,
If the question is given sufficient
thought and attention by competent
engineers, who are allowed to design
a treatment plant embodyins all the
improvements, that bear on the char
aeter Of that particular ore.
From a technical standpoint, there
10 absolutely no reason why ores Of
Giipin county should not yield in
the same proportion as those Of other
camps II the latest methods of mill
designs are employed AZ elsewhere.
This is thoroughly proved by eIabo-
rate analytical data, complied by Mr..
AIsdorf, that the gold and silver val
ues in the ores follow the iron py.
rite almost totally, that Is to say,
the values that are not susceptible
to amaIoamation and which have
been considered to be more or less
refractory.
This fact has been generally known
and Il was for this reason that the
later concentration tables have been
substituted for the old GiIpln eoun-
ty Bump Table, SO familiar to the
early day milImen Of that locality,
to effect a closer saving Of the sui
phides which contain the main values
remaining after amaIoamation.
This was, Of course, a step in the
right direction but fortunately the
progress was not continued, and for
the past ten or twelve years has re.
nained stationary, while the average
grade Of ore has been steadily deelin'
Ing, exactly a. Il does In all mineral.
lied areas, with this distinction, that
Of all the western mining sections
yours stands out boldly az the only
one containing true fissure veins, In
a granite country rock, and having
high grade shoots more or less con-
tinuous to a great depth. This very
fact has been the main cause Of your
failure to advance the milling meth
ods, for the reason that you have
been able to depend on your shipping
ore to keep the district alive, ane
where such perjudIee exists as ts
the anenabiilty Of the ores to high
extraetions, and not being compelled
BY force Of necessity, you have al
lowed the matter to 90 from year e
year, trusting to your shipping ore'
to pull you through and hesitatin.
to srapp's with the milling problem
hAcAuaA Of lack of pnaans and fea