Gilpin observer., 1911-02-16

bearings of the big crusher in the
new mill of the Frontenac Consoli-
dated Mining company, was overcome
Tuesday afternoon and the mill was
put in operation. Since that time
every section Of the huge plant has
worked in a very satisfactory man
Eer. This evening a night shift will
be put on and from now on the mill
will be in steady operation, with
three eight-hour shifts, with four
men to the shift. One feature of the
proposition which savors of economy
is that the need of large force of
men has been minimized in the auto
matte system Of handling ores and
the use of electric power.
A heavy supply of ore from the
Frontenac and Aduddell mines, con-
sisting of 50 tram cars, were on the
track at the mill awaiting the COM
to this the bins were full to their
capacity of $50 tons each.
The mill has capacity of $50 tons
every "a hours. The big crusher will
handle this amount of ore in eight
hours, and therefore will only be. in
operation one-third of the time. The
storage bin for the crushed ore, when
once filled, will supply dirt enough
to run the mill "a hours.
The plant will be run exclusively
on Frontenac and Adduddell ores, OF
which there is vast reserve. Twenty
thousand tons Of fresh dirt is broken
in the Slopes. saying nothing of the
thousands of tons of old stope fill
ings. In addition to this there are
900 tons OF dump stuff which aver
ages $3.50 to the ton in the cars. The
vast profit to be made in handling
this product is readily discernible
when it is known that the ore (that
which is broken and in the Dump
can be handled at the low cost Of
s1.S5 a ton. This includes tram haul,
milling. freight charges and smelter
treatment.
Much speculation is rife as to the
success of the now plant. All anxiety
along this line may be dispelled when
it is stated that this is by no means
ap experiment in any sense. 1t is
but counterpart of the Iron City
mill, which has been successfully
treating the Frontenac and Topeka
OF es the past two years. The only
hat hn fu- "
cepting some modern improvements
and the increased capacity, is that
in the Iron City stamps are used
to grind the ore, where in the new
mill rolls are used. The experimental
stage was passed when the process
of treating the Frontenac and Adud-
dell ores was adopted, after the most
rigid tests of the various equipment
Of numerous mills in the state had
been made on the particular ores that
will be handled.
The ore is hauled via the tram
right into the mill, and dumped into
the bins. 1t is conveyed to the crush
er through an automatic shaking
feeder. 13x24 inches in size. The
crushed ore is carried by elevator No.
to $50 ton storage bin for crush
cd ore and from here is fed by an
automatic feeder to the first set Of
1896 inch coarse rolls. then to ele-
vator No. 2 to double line revolving
screens, 4Sx72 inches, three screens
in each series. The oversize from the
coarse screen goes back to the rolls
for regrinding; oversize from second
screen to two double coarse jigs;
oversize from third screen to five
jigs, same size and style. All Jig tail
ings go back to finishing rolls, Of
ches. and are reground and returned
to same screens above.
In this way the pulp is handled
through rolls. screens. jigs and back
again until all coarse mineral Is sep
arated and the entire feed is put
through the third or fine screen Of
10 mesh. II Is then passed on to the
first series of seven Card tables and
re-concentrated. All fine concentrates
are taken out and the waste from
these seven tables then goes to the
tube mills-2 mills feet diameter
by 12 feet long-and is reground to
40 mesh, thus liberating all fine par
ticlos from the coarse sands.
The discharge from the tube mills
is elevated and by a series Of class.
ifiers is divided into four different
sizes Of pulp and is distributed over
the second series OF 10 Card tables.
All mineral Is separated and the
middlings. or richer part Of the tails
from the above tables. pass to tho
lower series Of three Card tables
which take out all available mineral