The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1921-04-14
LOCAL LEADING ORES
BY FLOTATION PROCESS
BULLETIN GIVES RESULTS OF
EXPERIMENTS AT MOS
COW STATION.

The chief metals produced from the
ores of the Occur d'Alene region are
lead and zinc with minor amounts of
copper, silver and anthony. In
much of the ore the lead and zinc
minerals are so finely disseminated
that the making of clean lead and
zinc products by the usual methods is
impossible At most of the mills a
good percentage of both lead and zinc
is recovered in the concentrates from
the jigs. but fine grinding is essential
to effect a reasonably clean separa-
ton of either mineral when finely
disseminated; in fact. in an ore
crushed to 200 mesh some of the lead
and zinc particles are still mechanic
ally combined.
Purpose of Experiments.
The United States bureau of mines
in cooperation with the University of
Idaho, the Idaho state bureau of
mines and geology and certain min
ing companies of the Occur d'Alene
region has done much experimenting
in order to find some method by
which better commercial separation
might be effected. On account of the
character of the ores and in order to
avoid any radical changes in the pres
ent methods or equipment in the mills
it was thought best to try to effect a
better separation of the lead and zinc
by differential flotation with
whatever changes in the present
treatment this might necessitate
should it prove successful. That is
the object is not to evolve a differen-
tial flOtation process which would re-
place the present methods of gravity
but rather one that
could be applied to the relatively fine
mills and which are not being sue
cessfully treated by gravity methods
Or by flotation From a large num-
Der of tests run to date on different
pres some encouraging results have
been obtained. Although they are
not to be considered as final they in
iicate that the separating of lead and
zinc sulphides by differential frota-
ion may be practicable in the treat
nent of certain ores. A report on the !
results of these tests has recently |
been issued as bulletin POS of the
United States bureau of mines The |
'eport also contains a chapter deal
ng with flotation tests of a few cop
'er and silver ores.
Method of Test.
In conducting the experiments with
ead-zinc ores the principal object has
'een to determine the flotation mix
ure that would effect the best differ
initial separation from a commercial
tandpoint. The actual testing of
ny ore was preceded by preliminary
hysical examination of the ore screen |
nalysis after crushing to y inch size
T. less and examination under the mi
roscope of the finer sizes to ascertain j
he fineness of crushing necessary to /
berate most of the mineral particles. 5
)llowed by chemical analysis of the {
re and of the products obtained from 7
ne screen analysis The more i'm /
ortant points brought out by this r
N''AAiAAe'i9 tAeiiAAudllOIs CONSIDERED II
18th references to subsequent flota- y
on testing. are the necessary de- il
rec of fneness in grinding. and the t
imposition of the ore as to the min t
ais sought and the gangue constit i.
-nts present C
In actual flotation tests. expert
ents We're made on each ore using
herent oils and chemicals alone. to
termine the relative value of each E
to its flotative properties. Next
rious combinations of oils and
emicals were tried, followed by G
SITS using different quantities of the te
agents. Besides oils and chemicals. tN
any of the derivatives of both min o.
al and vegetable oils, such as phe- e1
l. anthracene, engenol and guaia- re
l. were tried. Some of the oil de- te
'atives gave good results. gt
Hlotation tests of Idaho ores. by c. re
Wright J. G. Parmalee and J. T sh
rton A copy of this bulletin NAV re
obtained by writing the director ed
the bureau of mines Washington. SC
c. tn