DENVER & RIO GRANDE WESTERN ROUTE, 
257 
help tear down the mountain. Locomotives with long lines of ore 
cars shuttle back and forth across the face of the mountain, at times 
directly above the spectator, then again far below. It seems to be 
pandemonium let loose, but out of it comes the ore in a steady stream 
that makes the spectator wonder. 
metallic copper. This ore occurs as 
grains of a crane disseminated 
ina Hp ass of m ite 
Fro ade to 1909 ee Boston Con- 
cd Mining Co., which operated 
on part of this ground, used steam 
produced over 438,000,000 
The ore averaged 
1.65 per cent copper, or only 33 pounds 
loss in milling reduced this figure to 23 
pounds actually recovered. 
In e Utah ins Co. built 
creased in size until it could treat 900 
tons of ore a day. same time 
genie development was proceed- 
906 it amounted to nearly 
ie miles. The plan was to extract ore 
by the caving system, but when some 
idea was gained of the extent of the 
ore b 
be required to make a sufficient ton- 
nage of commercial concentrate, steam 
work. The 
partly to load ores on cars for milling 
and partly to remove the top or cap of 
the deposit, a brown oxidized material 
from which part of the copper has been 
removed by natural leaching. <A photo- 
906 show 
capping. Trees s grew 
on the hillside. where apparently slight 
change had been made on the surface. 
the property of the Boston 
Co. was consolidated with that of the 
could be successfully treat 
d the amount that would 
XCVI, A), 15 miles 
notth of Bingham, was constructed, 
section by section, until its eapacity 
was 4,000 tons of material a day. 
The ore was concentrated at the ratio 
of 20 tons of ore containing less than 
2 per cent to 1 ton of concentrate con- 
pein about 25 per cent copper, leav- 
5 per cent of the original win tesla’ 
es be discarded as tailing. 
velopment proceeded so ra 
the company was reorga 
times. In ae it wa 
$4,500,000, in 1910 
talization Benge $25,000,000, To in- 
Magna mill (PI. 
uled mmense tonnage, 
ae ene rae Copper Co. constructed 
a railroad from Bingham to Garfield, 
a distance of 20 miles, in order to meet 
After the property of the Boston 
Consolidated Co. was taken over the 
Magna plant was shut down in Feb- 
treated 
tin 
sized plant, but these mills require 12 
trains a day hauling 40 cars of 50 
tons of ore each. The Magna plant 
alone covers 20 acres, and the com- 
pany owns an immense acreage for the 
disposal of the tailings. most 
ESAT DOS ae 
