The weekly tribune., 1893-06-09
At THE B, & N, SMEl1ER.
How the Copper is Taken From the
Rock, and Made Into Bright
Metal.
Interesting Details About the Process
of Concentrating. Smeiting
and Refining.

Did you ever visit the works oil the
Boston e Montana Consolidated Copper
and Silver Smelling company? rep
resentative Of The TRIBUNE had that
pleasure recently and will tell THE TRIB
UNE's less fortunate readers what is done
there.
The only ore now treated is from the
company's own mines, adjacent to the
famous Anaconda mines and carrying
similar minerals: it is brought from
Butte in the ore cars at the rate of be-
tween 500 and $50 tons per day, and Is
dumped into the bins beneath the Great
Northern's tracks, dt the upper end of
the concentrator. This crude ore con-
tans about per cent copper, and cop
per glance mostly associated with iron
pyrites.
From these bins it is run into the con-
centrator, and first, into rock-crushcrs
where it is SO prepared that it may be
conveniently handled
From the crushcrs it is run through
troughs, filed with II rapidly flowing
stream of water, into large Cornish
rolls, where it is again ground, and
thence into revolving screens of different
sizes. The ore that is not properly
crushed is again hoisted by elevators,
consisting of system Of buckets ar
ranged on belts. and back into the
crushers.
There is also provided steam stamp,
massive in every particular, which is Of
ten used instead of the Cornish rolls,
This stamp consists Of ii piston, fitting
into cylinder. and fitted with a heavy
head of steel, which fits into a large
mortar, resting on foundation about
ten feet in depth and extending to bed
rock This foundation is capped with
heavy, tapering oak beams, so arranged
as to offer springing resistance to the
tremendous blow.
From the screens, the ore is washed
through troughs, or "launders," over
"jigs." At one side Of each set Of Jigs,
there is arranged plate, upon which a
piston. with downward pressure, acts,
forming "plunger, and, at the bottom
of each Zig is a screen, SO that, when
the plungers fall, there are formed waves
in the jigs, suspending the ore particles
and allowing the valuable, heavy miner
ais to settle and the rest to pass on.
But the shines which have been wash
ed on are yet too valuable to run off. and
are re-crushed and re- jigged. There are
81 jigs arranged in rows, forming series
of several iigs each.
The fine shines, which do not settle on
the jigs, are run onto the double "round-
tables" IL in number, each consisting Of
two circular, sloping surfaces, about lG
feet in diameter, one above the other.
They are here run into boy, IN the
center of the table, which, overilowing,
washes them on to the table, where the
fine, worthless particles are swept off
first, by gentle stream, and, as the
table revolves, more powerful stream
washes off the richer portion, or"heads,"
to the 20 Frue vanners
The vanners are each made OF a wide
rubber belt about four feet in width,
running slowly over system of pulleys
and slightly inclined, the motion being
in an opposite direction to the inclina-
ton. lhe vanners have slight vibra
tory movement also, this suspending
and helping to concentrate the heads.
These motions cause the shines to be
carried off and the heavy heads to re,
main until washed oil in the water be-
meath the vanner belt.
From the yauners the particles 90 to a
series of boxes, shaped like an inverted
frustum OF square based pyramid,
each shallower than the preceding,
through which there is rapid stream
III I'll -
tied in the first, or even in the last, and
they go TO the settling tables, where
there is a gentle stream. and nearly all
particles are settled. The taiings from
the concentratpr carry from to ] = per
cent copper and are carried off by the
waste water into the river.
The concentrates are removed by cars
from the boxes and tanks and taken to
the smeltcr bins, from which they are
changed to the lirueckner roasters to be
partly cleared of the sulphur which they
contain, which averages about 10 per
cent. These rOasters, twenty-four in
number, each takes sixteen tons per
twenty-four hours. They are great re-
volving cylinders with fire-boX at one
end. This process reduces the sulphur
to about per cent. The roasted con-
centrates, the sulphur being supplanted
by oxygen, are termed ''calcines" and
weigh but GG per ceIt Of the concen-
trates.
The calcines are next put into the fur
naces, which are heated by gas produced
from Sand Coulee coal by seventeen
Wellman and fourteen Taylor producers.
The gas and air are carried through sep
arate brick ''checker-work" or bricks
loosely piled, into chamber at one end
of the furnaces, where they are heated
by hot friedrich, whence they are blown
toward the furnace, and, uniting at the
exit, burn and produce white heat in
the furnace, but cannot melt the cast