The Salt Lake herald-Republican. [volume] (Salt Lake City, Utah) 1909-1918, 1910-11-06
o5WaUL15 PHI

The assays Of the drill core discloses
the value of the ore, and by comparing
the results from a number Of drill
holes extending across the face of the
vein. it is easy TO determine the gen
eral average of the value Of the lodges
With this important fact demonstrated,
it is an easy thing for the engineers
10 go ahead with the plans for the de-
velQpment of the great bodies of cop
per-bearing ore.
Shaft Mining Method.
The shaft-mining method is COM
PEELED wnen the ore bodies go down TO
great depth, as it is then impossible
10 work the deposits by glory holes
or tunnels. The shafts are from three
TO five compartments, with each of
these compartments of extra size 10
permit of the operation of immense
ore cars and the installation OF NAM
moth pumping plants and other ma
chinery The ore is mined by drifts
and crosscuts. very much in the same
manner in which gold mining Is car
rled on, with the exception that copper
mining Is conducted on a vastly aug
mented scale. Hundreds Of men are
employed N the underground work
ings Of every great copper company,
ore Is found in immense bodies Of sui
phide or oxidiZed rock. and after being
removed the old workings are permit
ted 20 cave. This saves the expense
Of timbering, one of the costly items
Of modern mining. When it is desired
10 keep the workings open, a portion
Of the ore body, termed a piller, is per-
mitted TO remain in order 70 support
the tremendous weight of the over
hanging ground. As the ore is broken
down it rests on a floor Of boards, pre-
viously laid to prevent the mingling
OF the ore with the waste rock.
In many of the copper mines the
water is so heeS>jly impregnated with
sulphur and other minerals that il be-
comes very valuable for chemical
purposes. and is carefully saved From
this is obtained material for sulphuric
acid and many other important COM
pounds. Gold and silver is also often
found with the copper, adding 10 the
value OF the ore and enabling the
company 70 disburse larger dividends.
Treatment of Ore.
After the ore is removed II must be
treated in order TO recover the copper
values from the other base contents,
such as iron, sulphur, lead and other
smelling in immense reduction works
provided for the purpose. A smelter
consists OF a number OF furnaces,
usually OF two kinds, reverberatory
and blast The blast furnace Is al
ways found in the smelter and treats
the principal quantity Of the ore. The
feVerberatOry furnace is mainly used
Tor the finer ore which would lose
much.of its value if discharged direct
ly into the blast furnace. The blast
furnace is provided with water jackets
and water acketed hoods. which pre-
vents the formation OF heavy crusts
OF metal in the interiors OF the fu1-
naces and assists the smelling of the
ore. Before the copper ore is loaded
into the furnace II is mixed with fiux,
consisting OF lime. silica and other
material Sometimes il is unneces-
sary 10 use much fiuXing material, as
the ore carries sufficient OF this for
the purpose desired, but usually it IS
imperative that a heavy percentage of
lux be added. In this work the pref
erence Is for gold bearing silicious
ores, as this Yields an excellent profit
TO the smelter company, as well as
saving the gold values for the owners
Of gold mines, besides meeting the
huxing requirements OF the copper
ore. Coke is added 10 the charge. the
whole ignited and a powerful air blast
turned on. To assist the draft the fur
naces are served by mammoth smoke
stacks. These are generally 20O feet
or over IN height, with a diameter of
about twenty feet, and are constructed
of self-sustaining steel
Stag Is Run Out.
After the charge OF ore and fux has
been in the furnace for several hours,
the copper forms into what is termed