The Iron Mountain, Missouri. [Volume: 8, Issue: 1, 1888, pp. 36-45]

42

UNITED STATES ASSOCIATION OF

[VOL. 8,

for several miles passes through the Iron Mountain Mining Company's property before entering the lands of others; for the estate
immediately connected with the Iron Mountain embraces about
twenty-five thousand acres.
ORE SEPARATORS.
There are three concentrating works or separators at the Iron
Mountain, two of which were in operation at the time of our
visit. Each of these has its own steam boilers and engine, and,
although differing somewhat in detail of construction, may be
described as follows:
The leaner ore from the mining operations, or the material
which has been hydraulicked, is brought by carts or tram-cars
to two wrought-iron washers, of conical form, with interior
blades. Into these the material passes to revolving screens, made
of cast-iron, in which there are holes one inch in diameter. All
that passes through these screens is elevated by a system of chain
buckets to the upper portion of the separator, and the remainder
drops from the screens on to cars, where, if necessary, it is picked
over. This large sized material is recognized as "cone ore."
The finer ore, after being raised by the elevator buckets, passes
through four revolving screens with holes, three-fourths, onehalf, one-fourth and one-eighth inch in diameter respectively,
the material of each size going to different jigs. The material
which passes through the three-fourths, one-half and one-fourth
inch screens is treated in six eccentric-tray jigs, two for each
size; that which passes through the one-eighth inch screens goes
to two crank-arm double-tray plunger jigs.
Elevator buckets remove the ore and tailings from each pair
of jigs and deposit them in separate hopper bins, from which
they are drawn into cars and carried to stock-piles or wastedumps.
The product of one,of these separating works is fifteen to
twenty-five tons of dressed ore per hour, and the services of nine
men are required after the ore is delivered at the washer. These
are distributed as follows: Two men at washer; four men at
jigs; two men removing finished products and tailings; one engineer. If working night and day, this force would be duplicated.