The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1909-04-26
MUCH POWER IS
USED AT BINGHAM
Great LOW-Grade Producers
Break Down Vast Tonnage
Each Shot.
HOW BOSTON CON.
MINES IT'S P0RPHYRY
Gazing and Steam Shovel Work
Both Used to Disturb the
the Resources.

The Boston Consolidated owns forty
nine acres OF imprcgnated monzouitc car
ryinG 1.5 per cent copper, from which
an estimated production OF 56. O00.0 900 tons
Of ore can be derived. In addition TO this
there arc l01 acres Of l per cent ore
which may constitute a valuable asset in
the future, Tor although immense cop
per deposits are being developed in many
parts OF the world. the exhaustion OF
ore that can be now profilably worked
with copper selling at II cents per pound
is proceeding so fast that the revea
tlon OF fresh resources by development
has no tendency TO depress the price
Whatever may be the fluctuations in
copper quotations within the next few
years, the future, counted In decades,
must call for the utilization of ores OF
lower copper-content than can be mined
today. lhis Will neccssitate q higher
average price for the metal, unless mod
crn improvements In mining and metal J.
lurgy reduce tho cost of trea atment equal
ly with the average diminution In grade.
Whllc the average opper-content of
the ore body dceVopcd by the Boston
Consolidated is placed at l.o per cent,
much or" of higher tenor exists, which
is characterized OF the more highly fraC-
turcd portions Of monzontc. FOR exam
pie, the moO2Onitc area extends east
wardlY INTO the ground OF the Ohio Cop
per company. where tho SiliCification has
neen sun more complete, resulting In
greater Irregularities in the distribution
OF the metal; that is, there are zones of
higher concentration, IL may be observed
i'll passing that the moro highly siliclous
ores are claimed 10 yield a larger per-
ccntage OF extraction by concentration.
The low-gradc ores of the Boston Con-
solidatcd contain .025 ounces silver and
O.NO3 gold per ton. on the basis OF u
cents copper and - per cent net recovery
upon copper aud % per cent on gold
aud silver these ores would yield gross
return of $G.cI per ton, and ii IS safe
TO say that the total cost OF operation
will fall below 81 per ton.
The conditions presented by the mon
zoniic ore body in the territory OF the
Boston Consolidated have leo TO a min
ing practice at variance with that adopt
cd by It's ncishhor Both Gazing and
fundamental differences. The open-cast
work is conducted in benches of mod
crate height, fifty feet being the clcva-
ton of bank aimed at; this. however, is
subject TO Consderabi variation arising
from surface Irregularities, The rock is
shattered by blasts in deep holes bored
by Keystone drill, The No. drill is
used, and the holes are cased with six
inch we'll casing. The holes arc drilled
twenty five feet from The edge OF the
bank, SO that with each blast q. cube
of material approximately twenty-five by
twenty live by fifty feet. 1873 cubic
yards, is shaken, The bottom OF the
hole is first sprung that is. cham
hercd. with a charge OF fifty pounds Of
dynamite. large charge Of Trojan pow
der, consisting OF 900 to 500 pounds is
then introduced and exploded electrically
with OK caps. The Trojan poyder is said
to be particularly well adapted to this
work; II is quite insensible to ordinary
shock, does not freeze. and is unaffected
by moisture The 80 per cont grade OF
powder is employed for bank blasting,
The cost Of drilling the holes is said
10 fall below 90 cents per foot. including
necessary renewals of casing. most OF
TN" casing. however. being recovered un-
damaged after each blast, At one time
an experiment made with II hole
l20 feet deep; il was blasted, with n
charge Of four tons of - per cont dvna-
mite, The method OF blasting a lower
bank. however. is considered more salts
factory. The excavation is done by Mar
ion and Vulcan steam shovcls OF the
nincty-fivc-ton type with five cubic yard
diDpcrs. The company owns four OF these
machines. The usual crew 0f engine
men, cranomon. fremen and four Ditmcu
is employed. The ore is loaded upon
cars on narrow gauge track, and con
Ncyed around the spur of the mountain
To the mine bin on a gradient OF about
per cent. The cost OF tho ore mined
and delivered TO the bin is said to aver
age 1S4 cents per ton. The use OF mar
row gauge service railway offers some
advantages over the standard gauge en-
ployed i'm Bingham canyon. 1t neccssitatcs
less cutting for the track. and Is much
more flcXibe.-Mining and Scientific
Press.