The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1918-05-02
FLOTATION In COEUR D'ALENES

ners, this fine silver mineral Is caught
in the flotation machines. and as
the flotation concentrates
are enriched, and the table and vanner
impoverished. in silver as
to their lead content.
With silver at present prices, the in
extraction of silver obtained
by flotation is important and justifies
the use of the process in treating
Occur d'Alene ores. Fine grinding Of
table middlings will also increase in
importance throughout the district. In
this field and in the treatment of the
lead zinc ores, flotation. following
gravity concentration of the pulp. will
become the established practice.
Fiotation May Become Of Primary
Importance.
In the event of a notable decline in
lead and zinc prices, the future of sew
eral of the Occur dAlene properties
will depend upon the successful appli-
cation of the flotation process. This
is especially true of properties pro-
ducing ores in which the valuable
minerals occur finely disseminated.
For example, flotation has increased
the recovery of the Gold Hunter mill
20 per cent as compared to what 1t
was with gravity concentration. Flo
tation has made it possible to profit
ably treat the fine grained lead-zinc
ore that now forms the bulk of the
Morning mines output 1t was the
great difficulty of treating the fine
grained lead-zinc ores from the last
mentioned property that caused flota-
/ ton to be first tried in the district
First Use of Flotation in the Occur
d'Alenes.
Flotation in the Occur d'Alenes be-
gan with the adoption of the Macquis-
ten tube for separating blende from
siderite in the granular table feed al
the Morning mill. This was the first
commercially successful flotation plan
in the United States, although frotf
flotation had at that time been prac'
ticed in Australia for a number o
years in the treatment of lead-zint
and copper ores. The Macquister
tube had been used several years ear
Ilier in a small way in Nevada, and i
was the description of that installation
in the Journal of October rs, 1907
under the title of Concentration Up
side Down. which first caused the of
ficers of the Federal company to thinl
Of using the Macquisten tube A
that time the Macquisten tube was o
such a crude design mechanically tina
Its efficiency in operation was sucl
as to preclude the possibility of usini
1t successfully on a commercial scale
At the Morning mill, where 1t was in
troduced in 1910. the Macquisten tub
was developed into successful ap
pliance.
But the device will treat efficientl
only a granular feed, and upon size
smaller than 150-mesh it is not salts
factory, even when the sulphide par
ticles are granular. Thus, while tn
adoption of the Macquisten tube mad
1t possible for the Federal company t
separate the greater part of its gran
ular blende from the sderite in tn
middlings obtained from the table
In the gravity treatment of the ore,
much blende was still being lost, an
1T was the necessity of finding som
method of satisfactorily treating thi
part of the ore that led the compan
to investigate froth flotation, and fin
ally caused other companies in tn
district to appreciate it's possbilitie
in the treatment Of the shines fror
the lead ores.
Between 1911 and 1913, the Fedora
company tried out several froth-flota
ton methods upon the Morning mil
shines The Potter Delprat process
or one almost Identical with it, unde
the name of the Wyman process, wa
first tried, but 1t did not succeed, be
cause of the large acid consumption
caused by the siderite gangue. TIL
method was finally discarded, and tn
company then experimental with tn
froth -flotation process. In the expert
ments encouraging results were OBJ
tanned, but the work was finally stop
ped. Early in 1914. at the invitation
Of II. A. Guess, T. M. Owen, who wa
one of the early workers in differ
entail flotation. and had had exper
fence with flotation in Australia, Wis
tied the Morning mill and conducted
experiments upon the Morning ore
He showed that the slime portions
could be treated by differential flota
ton and that the lead and zinc con
centrates recovered were of market
able grade. In April 1914, the ap
plication of differential flotation wa
undertaken by Mr.. Guess.
Invention of the Callow Cell.
At the time the mill at the Nationa
mine near by was being built, ant
Callow pneumatic cells were being in
stalled, J. M. Callow had found tha
excellent results could be obtained OF