Durango semi-weekly herald., 1902-01-13
MILLS OF SAN JUAN.
Written for Mines and Minerals. by
Frank HartmanD

/ hS 6iSoI hC6iou hhoN II as
the San Juan country. embracing the
counties of San Juan. San Miguel.
Ouray. Hinsdale. Dolores, La Plata,
and Archuleta, has made wonderful
progress during the past Eve years,
particularly during the past year. and
| this is due in the main to the pro-
gress of economic milling. In 1893,
when the price of silver was cut in
I two. or reduced nearly one-half many
of the low-grade products were
closed. but about all of these have
resumed operation, and many more
new producers of like character have
the operators of the silver mines were
confronted with a situation which
seemed to preclude further effort, Il
G. Stoiber, then proprietor of the
Silver Lake plunged into the problem
with more than a million to lose IL
he failed, but emerged successfully,
after employing every close value
saving appliance which the charac-
ter of his low-grade lead-silver ores
suggested. He saved the values 50
well that his concentrates of 81 ores
enabled him to continue mining
profitably. When this had been done
| other owners of low-grade mines
proceeded to the building or alteration
of mills which would enable them to
operate, and all along the line.
throughout the entire San Juan re-
| gion, there has been marked ad
vancement in the economy and bet
ter value saving OF mill enterprises
| Processes and methods which have
been regarded as unsuited to this
or that condition have been proven
| here and there, by closer attention
to detail, to be adapted to the sue
cessful treatment of certain ores
1t was not the fault SO much of
| the table or other appliance as IL
was a failure of the mill man to un-
| derstand how to adapt the ore to the
machine or method.
A study of the various processes Of
concentration in this country. differ
| ing in one or more details, as one
passes from one mill to another, il
most interesting and instructive
The Gold King mill on Cement Creek.
s miles from Silverton, employs so
stamps, $50 pounds each, finch drop,
9S drops each per minute, and 13
4-foot and 25 6-foot vanners. There
are 16 amalgamating plates over
which all the pulp first passes. The
| ores from the mine are carried over
an aerial tramway nearly l mile, and
are crushed before entering the auto
matte stamp feeding bins, being dis
tributed along the feed line by a
travelling belt. The ore is chiefly a
heavy sulphide of iron. containing
gold, silver and copper A centrifu-
gal pump is employed at each battery
for elevating the product passing
from the amalgam plates, s to Ia
feet, over the vanners. w. Y. Kin
terprise to it's success, has expert
enced little difficulty in milling his
ores. and has not found it necessary
to change any of the machinery or
appliances which he first selected.
| The Hercules Consolidated Mining
Co.. operating properties at the south
edge OF Silverton, runs its ores over
a gravity skip line of 1000 feet tu
the mill, where they are first crush
ed and passed through rolls. From
the rolls the product is elevated to
revolving screens. Hydraulic sizers
are employed and four products OF
concentrates are made, the first one
at the tgs. All that passes the jigs
goes to stamps and passes over
amalgamating plates. The finish is
made on Whitley tables. This plant
is operated by waterpower obtained
from Mineral Creek. The Gold King
Co employs steam. owing to difficulty
of securing sufficient water during
| winter months. The Hercules peo
pie use water as initial power fol
generating electric power. and also
to light their mine and mill with elec
tricity.
The Sunnyside Mill at Eureka,
miles north of Silverton, on the Ami
mas River, employs 20 1,00O-pound
stamps. finch drop, 80 drops pei
minute. All pulp passes through
40-mesh screens before going to the
amalgamating plates and passing OF
to Bartlett tables. From here the
material is conveyed to Wiley tables
the tailings finishing on large ares
of canvas tables. Each stamp crushei
from 2R to tons of ore daily
Each ton of concentrates represent.
5 tons of crude ore. A mill of l!
stamps has been operated at thu
mine, 3A miles distant by aeria
tramway. for several years, but tn,
lower mill is being enlarged for hand
ling the entire product, at least dur
ing winter months, and steam powe
was recently put in at the lower mil
for winter use. Judge ]. H. Terr,
and sons, Joe and Will, own the Sun
nyside enterprise, and they are pro
ceeding methodically for deeper min
ing and greater milling. An elec
tric plant of $50 horsepower has bee
installed at the lower mill. whicl
will be operated by water in sun
mer and steam in winter.
The Silver Lake has two mills, on
at the mine and one at the Anima
River, at the track side of the 81