Blackfoot news. (Blackfoot, Idaho) 1891-1902, 1898-08-20
A GREAT COPPER MINE.
The Calumet and Beclz of Michigan I'm
pioys 5000 Men.

Tho Calumet and Hecl2 of Michigan Km
pioys 5000 Men.
The Calumet and Hecla Copper Min
Ing Company employs 5000 men. The
monthly pay roll is 100000. Its an
nual receipts average $14,OO0.000,
from which dividends at the rate Of
$40 per share are annually declared.
The total dividends paid by the com.
pany since its reorganization in 1867
amount to over $52,0OO,OO0. The total
receipts of the company to date
amount to more than $3S5.OO0,000
Overlying the vein is a cupriferous
amygdaloid rock; its floor or footwaI
is composed Of trap rock. The first ac-
tive mining by the present company
was begun in 1861, in which year the
initial shipment of 76S tons of copper
was made. From that year the prod
net kept increasing, till now the an
nual shipment has renched 96,000,O00
pounds of copper.
The formation in northern Michigan,
extending from Portage lake north
westerly TO Keweenaw point, and
thence across Lake Superior to Onto
nagon. is a conglomeration of pebbles
in solid form with an intermixture of
pure native copper.
The method employed in mining this
vein is as follows: The shafts proper
which reach to the bottom of the mine
are timbered from bottom to collar,
pine timber being used clear through.
Levels are uniformly 90 feet apart,
which affords access to the different
parts of the mine. Through these lev
| els the copper rock is brought to the
main shaft by tram cars that switch
/ 20 and fro from the different openings
I At the intersection of each level the
ore is dumped into the skip, which
runs up and down the main shaft at
/ a speed of 600 feet per minute. At the
summit the skip rises to the top of the
rock house, where the ore is automat-
/ ically dumped into the ore crushers,
thence into the ore cars, whence it is
carried TO the mills for treatment. The
vein is punctured by diamond drills,
the average depth of each hole being
five feet.
In the Calumet and Hecla mine sew
enty-fiye drills are operating, and they
blast twice day. During the forty
years OF mining on the conglomerate
the bed, which averages twelve feet
has never lost its width, while the
thickness ranges from fifteen TO TWEEN
ty-five feet. The width and thickness
of the nmygdaloid vein are uncertain
Sometimes they are found TO meas
ure twenty-five feet across. while al
other times but a few inches. Tn,
conglomerate is a dull red in color, th'
amygdaloid is a dirty gray.
The character of both lodes is sucl
that the most economical way TO min'
them is by Slopes, inclining toward thu
vein and under it near the footwall
and working obliquely around it.
The Calumet and Hecla stamp mil
is situated at Lake Linden. There ar
practically two mills in one. of clever
ball heads each, and having a capacit.
of 6.oo0 tons conglomerate per day
The metal is found deposited in tn
rock in all possible forms. The separa
ton of the copper from the rock i
effected by passing the stamped rocl
over a system of iigs, whereby til
sand, by its less specific gravity, !
fioated of into a steady current o
water. and the copper. being tn
heavier. settle and falls through tn
sleeves. One line of jigs succeeds an
other. over which in succession tn
copper which has Just passed through
a previous set of sleeves is made {
pass. and the sand which is containe-
in the water is carried away by tn
, current OF water to the lake 10y sys
tenn of sand wheels and launders. Tn
number of iigs and the velocity of tn
current are so regulated as TO secur
the desired separation, with very littl
loss OF copper.
The head current of water comm
from the stamp heads. in which fioa
the light material and fine dirt,
turned from the main launder into la
eral ducts. which convey it to tn
large slime tables over whose conica
shaped. slow moving surface it is mad
TO pass.