Weekly expositor. (Brockway Centre, Mich.) 1882-1894, 1890-10-17
FIRST 1lN.MILL IN The U. s.
IL u Now In Successful Operation In the
Black Hills.

The mill of the Glendale Tin-Miuing
company is the first tin-mill established
in the United States, and from which
is now being put out the first fruits of
the Dakota tin mines. The mill Is
located on Iron Creek abont twenty
two miles southwest of Rapid City, at
the foot of the mountain in which the
mines are situated The mill proper
measured so feet in width by 100 feet
in depth aud is divided into three
stories. it is unique in plan. compact
and convenient well built in all partic-
ulars. and protected from all danger Of
fire. by system of water-pipes and by
having roofs, ETC., covered by a thick
asbestos coating.
Either steam or water power may be
used for running the machinery. The
steam equipment consists of two 100
horse power boilers and 100-horso
power high speed engine. The water
power equipment consists of a,nume 20
by inches in section, bringing the water
from dam on Iron Greek, one and
one-quarter miles distant from the
mill, giving head of 100 feet pressure
at the wheel. About 500 miners inches
wheel, which was manufactured by
Craig, Ridgeway q Co. of Coatsville.
Pa. The water-poweg will be used
except during the cold snaps in the
winter, the engines being placed in the
mill rs reserve power in the case of
accidents.
The ore is hoisted from the main
shaft and dumped first into an ore bin
OF 200 tons capacity. located high up
the mountain over the mill. From this
bin it is conveyed to the mill by wire
rope bucket tramway, the loads going
down the hill to the mill hauling the
empty buckets back to the mine. The
ere buckets mechanically deliver their
contents into 175-ton ore bin above
and back of the mill. The large Jumps
OF ore are crushed, first by a Gates
crusher, then passed through drier
to set of Gates improved Cornish
rolls; thence elevated to {, set of rotary
sizing sleeves. From the sleeves the finer
sizes are conveyed TO n set of Paradox
concentrating tables. and the coarser
sizes to common Hartz jigs. The
screens jigs, and concentrators separate
completely all the mica. quartz, and
feldspar, leaving clean concentrates of
cassiterite. or oxide of tin. ready to be
smelted into tin bar. The concen-
trates are for the present being shipped
to Chicago to be smelted, but it is the
intention of the company to erect Mt
once smelling plant in the hills. The
first shipment of concentrates to
Chicago yielded Go per cent of metallic
tin, and the second shipment 60 per
cent; and it is expected that with more
practice they will yield over 40 per cent.
The main vein measures from TWEEN.
ty-eight TO thirty-two feet i'm width at
the outcrOp and over forty feet in the
lower working. There is no doubt as
to the true fissure character of the vein,
rs it cuts the states at nearly right
angles, and has well-de6ned polished
walls with thick clay gangue or
csrvage. The vein stuff is principally
alDte (white feldspar), with here and
there white, CLASSY quartz. The black
crystals of tin oxide are disseminated
ali through the vein material. varying
in size from crystals weighing an
ounce or more to those rs fine as grains
of pepper. Assays and tests from the
different workings give an average of
over per cent metallic tin, while
picked or specimen rock is often BLAST
ell that will yield over 80 per cent of
the while metal. With these largo
bodies of ore, and the excellent facili-
ties for mining cheaply. there is no
question but that the present mill, with
capacity of crushing and concentrat-
ing 100 tons of ore per day of twenty
four hours, will soon be supplemented
by u still larger mill.-Rapid city Re-
publican. 9