Gilpin observer., 1909-07-08
CYANIDE TALK

Gilpin county, the home OF the sui
phide-copper belt, where Marshal ID.
Draper, NJ E., and Percy r. Alsdorf,
after experimenting since January
20, 1909, have produced their first
bullion for the mint. The button
weighs 1875 ounces, is about 900 fine
and shows what can be done with the
average run of sulphides. After the
plates in the modern ama,gamation
plant shall have extracted fair per-
centage of the gold the plan in brief
is for cyanide to do the rest The
concentrate waste, with the gold and
silver extracted by amalgamation ana
cyanide, will be shipped to the West
ern Chemical works in this city or to
similar plants elsewhere to have the
sulphuric acid extracted, which can
be accomplished cheaper and more ex
peditiously than when the gold-silver
values are yet present.
Draper is graduate of the Colo
RADIO School of Mines, class of 1894,
while Alsdorf has had several years
useful experience in the Gilpin county
field as a chemist and assayer. Their
present plan. based upon the assured
success of their cyanide experiments,
involves the expenditure Of 100000
for the erection of an up-to-date com
posite mill, on the terrace plan, equal
to handling 800 tons per day of the
pttn ns mi " ore
The cooperative plan is proposed,
which shuts out the middle man and
promoter. In other words, the mine
owners of Gilpin will subscribe for
the mill shares-raise the $4,000
This assures two things: First
a steady supply of ores for the plant.
Second-the distribution of ore treat
ment profit back among the mines,
thus feeding the latter with the life
blood of activity-the capital needed
in original development and that
which should be expended in meas
uring the life of the mine. The latter
is factor too often overlooked or
neglected in Colorado camps.
Draper's report on the feasibility
of the proposed plant contains much
interesting and valuable data. 1t cred
its Gilpin county with the production
up to date of S150,0o0,000 mainly in
gold, the silver. copper and lead val
ues being largely incidental. AS a
rule the mines are not large and only
four of the many properties have
their own mills.
This suggests the necessity for
cooperation, as the best plant in the
world partially supplied with ore will
not prove a success. AS superintend-
ent of the Fifty Gold Mines treat
ment plant. Draper has already test
ed the cooperative plan. Instead OF
relying entirely upon ores from the
mines of his company, he has taken
ores from other producers on the
custom basis, and thus developed the
deposits $4,000 gold bricks at the bank
with the regularity of sunrise.
Diapers cyanide tests and results
have been checked up by other cy-
OF attention to this method of home
treatment in the gold camps of Amer
ica and Mexico.
Their reports are all favorable
based upon the present output of the
Giipin county mines. about 400 tons
per day at all seasons of the year.
The Nevadaville mines, soon TO be
relieved of surplus water by the ex
tension of the Newhouse tunnel. can
easily double this supply. This means
-hc enlargement of the proposed
plant. Heavy charges on the treat
mcnt of concentrates at the smelters
and freight rates on the same from
5he concentrating plants to the valley
will be avoided by the home treat
iGent plan. which, in turn, will en-
y courage production, making 1t feast
ble and profitable where it is not so
at present.
Smelter charges on Gilpin county
concentrates range from IS to S12
per ton-about all the traffic will
bear. On similar material in the Grip
pie Creek district, where home treat
ment plants are in competition, the
smelling charge has dropped TO $3.50
TO 81 per ton.
AS applied to Gilpin county ores
the term free milling is misleading.
and has been since 1864. when the
rebellious elements in those ores so
far defeated the stamp mills that
Professor n. p. Hill was called in,
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