The Owyhee nugget. ([Silver City], Idaho) 1905-1984, 1908-03-13

mill that treats about 40 tons of ore a day,
of an average grade of something like
$500 per ton, of which about one-fourth
is gold and three-fourths silver. The
method Of treatment is by straight con-
centration on frue vanners and Wiley
tables, which recover about three-fourths
of the value in the form of high grade
concentrates consisting principally of fine
grained chalcopyrite and argentite. The
tailings are treated in pans and settlers
without further grinding, but with the
addition of little steam heat and small
doses of salt and blue stone total recov-
cry of 80 to 93 per cent Of the values are
made at a total milling cost of So. 80.
The mining costs are high, which is due
to the fact that the pay streals, while
rich, are usually narrow and their ex-
traction often involves lot of tedious
sorting work The ore occurs as hard
chalcedonic white quartz in nearly YER
tical fissure vein that traverses the granite
formation OF Florida Mountain, and two
dome shaped caps of basalt and rhyolite
and the main vein is constantly accom-
panied by narrow dixie of black basalt
often reduced to a soft slippery clay
gangue, which makes close timbering and
filling necessary, and often involves the
mining of space from to 10 feet wide
| to get foot or SO of high grade ore In
other places, of course, the pay is wider,
but it is doubtful if the actual profitable
ore exceeds foot in width on the aver
age. If it could be mined cleanly to this
width, its value, of course, would be
much higher than the mill feed now used,
which itself is considerable.
Parallel with this main vein, at a short
distance to the south, small vein in
tight hard granite walls of nearly clean
white quartz with crustifed lines of rich
argentite along its frozen wall margins,
has been mined through several levels in
shoots ranging from 80 to 200 feet in
length, carrying from to 8 inches of pay
and involving the necessity of breaking
21S or 8 feet of hard granite and accom-
panying barren white quartz to get the
creamy borders.
The mine has total of 1872, 900 lineal
feet of development, of which $500 feet
were run during the past year, This
means an extensive amount of tramming
and underground handling. The main
opening is the Florida Mountain tunnel,
connecting with the mill, IL 900 feet long,
and still going. This connects with the
extensive intermediate levels, nearly all
of which are operated at some point
through to within a short distance of the
crest of the vein, 1,7O0 feet above, and it
is a. wonder that the mining costs are
held down as low as they are under such
conditions. The motive power all thrc.agh
is by electricity from the compalIy's own
plant from Swan Falls, without which il
would be practically impossible to operate
the mine at profit. AS it is, with close
capable management, margin of about
20 per cent profit is obtained from the
operation. The lowest level has not beer
as productive as some of the middle hori
IONS of the mine, but some shoots of tbs
characteristic rich ore of the upper level
have been encountered in the Florid,
Mountain tunnel, which affords a new
drainage level to sink from, and the man
agement is hopeful of the remineralizatiol
of the fissure below that level, as lon,
shoots of rich ore is being found at nearl.
the same horizon in the formation on
similar fissure at the Potosi mine near by
The men are well housed and every pre-
caution is taken underground to insur
their safety. Miners are paid 1926 day
trammers, $500; cagers, 1925; timber
men, 1915; motormen, $3.50; surface
! laborers, So. 100; hoisting engineers, So. 70