The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1913-06-26

which must float or must contain one
layer only. The actual amount of zinc
concentrates that can be floated dur
Ing a period Of "a hours Is from l75 to
200 pounds. containing 4S per cent Of
zinc. In lead flotation, the amount of
concentrates. by weight. would be con-
siderably greater.
The range of size Of the particles
amenable to flotation is from 2O-mesh
(hole LAO inches square) down to the
impalpable shines is usually from As
to 30 per cent Of the material passing
through a 200-mesh screen (hole 0.Oc3
inches square).
The extraction of which the tubes
are capable, depends on the character
of the ore. the fneness to which the
ore has to be ground to free the min
eral, etc. The efficiency ranges, Y BY
actual tests, from so up to IS per cent.
Deslimins Tube Feed.
In preparing the feed for the tubes,
It rs first destined; that is, all the Inn
palpable shines are removed, leaving
nothing but granular material as tube
feed. The principal reason is not that
the fine shines can not be floated, but
that they are difficult to settle, since
both mineral and gangue in this finely
divided state will all float, not only on
the surface but under the surface as
we'll remaining in suspension in the
water This tends to produce low
grade, sometimes unmarketable, ship
ping product. "A second reason is the
enormous surface area which small
amount of the finely divided sulphides
will occupy. floating as they do, like
the coarser material, only In thin
film. AS an illustration, let us take
30-mesh particle. which is about 1850
inch in diameter. and occupies cor
responding area. If this 30-mesh par
ticle were crushed to pass 500-mesh
screen (were such screen to be had)
we would have particles of about O.O01
inch in size and about 1890 pieces,
which would require approximately
II times as much surface as one 30
mesh particle. disregarding the space
between the particles.
The feed after being destined, is
passed through a dilute sulphuric acid
bath of from 005 to 0.5 per cent
strength, which has tendency to
clean the particles and also to assist
in rendering the gangue particles re-
sistant to flotation. After the feed has
reached the tubes a small quantity
of dilute Of soap and oil Is added
at the feed end of each tube for the
purpose of increasing the surface flow
the mineral particles through
the tube
Low Cost.
The cost of treatment, based on a
of 100 tons per "a hours in
Guiding cost of acid. oil. power, at
.endance, repairs and supplies, is APP
40 cents per ton, using
our tubes In series. The cost per ton
'ased on 200 tons capacity. using four
ubes in series will not exceed 80 cents /
Ter ton of ore treated. The actual
'ost for sulphuric acid. soap and oil /
lsed in the solution at the Morning
liant is less than cent per ton Of ore
reated.
Who're Used
The first installation of tubes was
made at the Adelaide mine of the Glas- I.
'ow & Western Exploration company
t Golconda, New. The separation /,
1ade was between chalcopyrite rather
nelly disseminated and quartzose
angue. containing both spinel and
arnet
The second and most important in
tallation was made at the Morning
line Of the Federal Mining and Smelt-
~ company at Mullan, Idaho. The Il
lateral treated is Whitley table tall
lgs and the separation made is be-