The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1916-10-05
CONTINUED from last issue.)
A. Stanley Elmor

vi
and the year 1904. l have done thi
nurposely because l wish to deal wit
his inventions of later date and thei
development separately; but for tn
purpose of keeping the record in or
der | wish to turn back on our hig
road of flotation to the year 1901
when my own minor contribution wa
made in the form of the discover,
that slight acidulation of the mobil
mixture of ore, water and oil great,
enhanced in some cases the selectiv,
action of the OIL l wish to state her
also that during the progress of tn,
development of the Frank Gilmore in
yention, most exhaustive trials were
made with various kinds of oil ant
mixtures of oils, vegetal. animal ant
mineral, of all degrees of viscositA
from solid or semi solid wakes to the
lighter spirits such as turpentine, ben
zol etc, etc. Nor were the investi-
cations confined to oils alone; expert
ments were made with many sub
stances which for the purposes of this
process acted in similar manner to
oils.
The effect of various degrees of
temperature was studied and much at
tention was given to the question of
the degree of agitation as affecting
the results obtainable on different
kinds of ores. Many forms of mixers
were designed and employed, giving
degrees of agitation or mixing from
the most violent turbulence down to a
mere gentle stirring. 1t is worthy of
note here that in the London testing
works in the year 1902 a Gabbett
mixer Ga vortex mixer giving a violent
agitation with the incorporation of
large quantities of air) was employed
at the suggestion of Mr.. McDermott
in an elaborate series of tests carried
out on telluride of gold ore from the
Lake View mine in Western Australia.
All the end of 1902 a working plant
was sent to that mine in which the
ore, water and oil passed through high
speed centrifugal pumps used with the
object of securing the most violent
agitation of the oil with the particles
or mineral and rock freely suspended
in the large quantity of water en-
ployed.
At these London testing works and
in the various mine installations OBJ
Sarva tiop wac oonctantly mazda of thn
various forms of float which were
obtained. 1t was noted for instance,
that the varying proportions of the
mineral would be buoyed up or float
ed to the surface or maintained on
the more or less quiescent surface of
the water by Q) a large excess of
oil, ca mixture of oil and air, CD
individual oil coated particles floating
by surface tension ca a froth of
oil coated mineral particles and air,
60 individual oil coated particles or
aggregations of oil coated particles at
tached to separate air bells.
Sometimes all of these phenomena
could be seen in different parts of the
same apparatus. 1t was also remarked
that with certain proportions of some
kinds of oil some minerals would form
aggregations which would sink. But
it is to be remembered that in all such
phenomena were auxiliary subsequent
to and dependent upon the differentia-
ton of the mineral and rock particles
resulting from the previous selective
action of the oil employed.
Various proportions of oil were tried
the Investigations were even carried
so far as to prompt trials with ground
cork, chopped straw and similar buoy
ant materials which had been pre-
viously coated with oil or grease. 1t
was found that by mixing such mater
ials with a mobile mixture of ore and
water and quite good extraction
could be obtained in some cases
each little ship floating with it's cargo
Of mineral, or being grouped together
with air bubbles making a froth.
1t is probably true to say that up to
1904 all commercial working plants
had been operated with a large guam
tity of oil. That is, instead of buoy
ing up the previously creased mineral
particles by means of air bubbles in
the form of froth, as he did in his
later patents, Frank Gilmore up to, say,
1904 preferred to employ an excess OF
oil with which was Incorporated
large quantity of air for this purpose.
In the interests of historical ac-
curacy cannot too strongly insist
upon the basic fact that the flotation
process consists essentially of two
steps: first, the differentiation of the
two sets Of particles by causing one
set to be wet with oil and the other
set to be wet with water in the pre-
sence of large quantity of water,
so that the oil has the best possible
opportunity of exercising its free
choice; second, the subsequent separa-
ton of the differentiated particles.
1t is perfectly obvious that the first
step-the differentiation-is the all
important one because the second step,
the separation, cannot be made COM
mercially unless a practical way OF
securing the requisite differentiation
has first been devised and applied.