Mohave County miner., 1917-03-10
NEW GRAVITY.
FLOW To
REDUCE
COST

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Steffy custom mill is begin
ming to take definite form.
The work of excavating the
benches that are to provide
the fall for the ore from the
time it enters the mill until
it leaves as concentrates or
tailings, has been completed,
and the work Of construc-
ton is swinging along
smoothly and rapidly.
Teams and men are building a good
road to the head of the mill, while Mr..
E. NJ. Bind of the Emerson has men
employed in making road from that
property to connect with the one be-
ing built by F. E. Steffy. Negotia-
tons are on with the Santa Fe rail-
way for the construction of a spur
that is to be run from a point on the
railroad at the lower end of Silver
Hill to the new mill. All is industry
and of businesslike appearance, Civ
ing property owners more encourage
ment than anything that has happen
ed since the present movement began
here.
Mr.. Sicily states that the concen-
tration plant he is installing consists
of practical apparatus that has had
years of trial and that has demon
strated its usefulness in the largest
plants in this country. No expert
ments are to be attempted. There
will be no fangles. The result is GER
tain to be a process that will yield
results as good as are obtained else
where, with a reasonable certainty of
its being a step in advance of many
others, especially as far as the mat
ter of costs is concerned. The gravity
feature will practically eliminate over
head expense, and is expected to re-
duce the treatment charges approx
mately II per cent.
K. ard K. FlotatiOn
The application of the K. and K. flo
tation process, one of the most mod
ern in use, win insure the handling Of
a large daily tonnage, which in re-
turn will tend to further reduce treat
ment costs.
The following is a brief description
of the fow-sheet: At the head of the
mill there are five 125-ton capacity
ore bins, ore from which is conveyed
to a central point where it is auto
matically fed into a 9x15 Blake crush
er, from whence, by gravity, it is
passed to a 14x30 Allis Reliance roll.
1t then falls onto a 19-foot Hancock
jig, of Mr.. Steffy's own design. At
this point about go per cent of the
mineral content is extracted, a very
close separation of the lead and zinc
being effected. All gangue matter
from this jig goes by gravity to a
secondary 14x30 Oils Reliance roll,
the product from these rolls passing
downward to two Sicily hydraulic
screen classifiers, where shines are
thrown off. Pigot discharge from
these classifiers gravitates to five
No. Whitley concentrating tables,
where the first tailings are made,
which are expected to be very low,
and where about 60 per cent of the
gangue matter will be thrown off.
Middlings from these tailings go to a
Marcy ball-mill, where it is ground
to an S0-mesh. This product in turn
goes to five No. Whitley finishing
tables, where a second failing is made,
the middlings dropping to a K. and K.
flotation machine of 100 tons capacity.
At this point a junction is formed be-
tween the middlings from the finish
ing table and the shines from the n.y.
draulic classifier.
All concentrates, from those made
by the Hancock jig on down to the
flotation product, go as unit to the
concentrate bins and are drawn off
into trucks at the lower end Of the
mill, ready for transporting to the
railroad.
No Manual Labor
A study of this flow-sheet reveals
the complete elimination of all manual
labor in connection with its operation
other than such as may be required
to attend to mechanical adjustment.
The flow is controlled entirely by
gravity, doing away with elevator
costs. The system is the result Of Mr..
Steffy's lifelong study to simplify con-
centration and to eliminate overhead
costs wherever possible.