Arizona state miner., 1919-10-03
HOW FLOTAT|ON PROCESS CAME ABOUT
Meeting of Western Governors Merely Scheme to Divert
Attention From Packers to Retailers.

AIlCAAt1OAA 1Ol1I
"Wonder what causes that iron to
float?"
Well might this industrious Colo
RADIO wife, washing her miner hus-
bands oily overalls, marvel. Shining
particles of iron were floating on the
surface of the water in her tub.
A woman's curiosity thus aroused
led to more and more discussion of
the way metallic minerals were ap-
parently upsetting the well-known
law of gravity formulated by Isaac
Newton shortly after an apple falling
from tree started him thinking.
Thus was born the germ of an
epoch-making invention for separat-
ing precious metals from worthless
rock.
For the now celebrated oil flota-
tion process is based on the fact that
when a small amount of oil is mixed
with pulverized ore and oil attaches
itself to particles with metallic lus-
ter, which, when agitated in water
have film of air surrounding them
and are buoyed up-float on the
froth-and can then be skinned
from the surface while the refuse re-
mains at the bottom.
But that is the most recent in a
long series Of strides the precious
metal mining industry has made
since mining on a grand scale was
started in California and Nevada
more than fifty years ago.
The United States Geological Sur
vey places $774,034, 900 as the value
of the 1913 output of gold, silver,
copper, lead, and zinc 1t is estim-
ated that but for the great advances
made since 1850 in the precious
metal mining industry that less than
25 per cent of the above output
would have been possible at profit.
Vast Industry
Just what are the amazing strides
this "most human" of all industries
has made?
Mining has become vast industry
based on quantity output, modern
borsaving devices and every aid
science could give in discovering,
mining, and extracting the ore.
First, in the field of discovery. By
diamond drilling (Which can take a
core 1 u inches in diameter out of
the mineralized earth to a depth of
ed and the geological structure
studied; or by "churn" drilling,
which bores hole six inches in
diameter and 5000 feet in depth,
enabling the pulverized material to
assayed and valued at the various
depths.
Snoo1,I
mountains of copper ore can be at
tackled by the modern steam shovel
and thus economically handled, as
shown in the illustrations.
Or where it is necessary (as is
generally the easel, to go below the
earth's surface, shafts and tunnels
are made by high explosives after
holes have been drilled by com
pressed air. Then sometimes when
conditions are right an ore body the
size of skyscraper down in the
bowels of the earth is undermined
and allowed to sink down and break
up and electric trans are then run
along side and the ore removed.
Modern pumps and ventilating sys-
TENS, too, play an important role in
keeping the mines clear of foul air
ana water.
Modern Extraction
Third, the field of metal extrac-
ton. After the ore is brought to the
surface the metal must be separated
from the worthless rock. In all cases
it is put through a grinding or
stamping mill and pulverized.
In olden times various and expen-
sive and laborious processes were
used to recover gold and silver, but
when the Mother Lode of California
opened up the first great free gold
deposit in the world the first big
step in extraction was taken-amal-
gamation. The fact that mercury
(quicksilver) attracts gold and silver
was generally known, but it was first
applied on a vast scale in the Cali
fornia stamp mills. Then the famous
gold fields of Africa-the Rand-a
process was devised for "cyaniding"
the gold and silver ore. This 'cyan-
iding" is based on the fact that a
solution of potassium cyanide will dis
solve the gold (but not the waste
material surrounding it), and then
by adding zinc to the solution the
gold is freed again.
Less Cost
Concentrating consists in forcing
the pulverized ore over a series of
rifles The heaviest and smallest
tand most metallic) parts meeting
least resistance as they are shot
through the water go farthest and
are thus separated from the lighter