Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1939-03-11

ANoEAAr duu nVANr HQFpAJAgAtL MA
terial. These ores carry free milling
ore at times with low grade sui
phides. and are hard to handle Ell
Their by concentration or amalga-
nation or eyandidation. The carbon
aceous and oxide matters are foul
ing cyanide or absorbed cyanide.
tried TO play with them.
l know others who had plenty OF
trouble with ore dressing OF the
Marysviile-Helena district and also
what about the ores on the Black
foot? This Is not very far removed
/ from Marysville, Is In fact part OF
| IT. what about White Horse mine
ores? But what Is the use OF going
into these. / think my experience is
plain enough The U. S. G. S. re-
ports mentioned carbonaceOus
shales and matters in the district
and in the ores. In the Marysville
/ district there are plenty Of re-
| fractory ores that won't cyanide.
without mentioning the base ore,
lead. silver and copper. lead. zine
ores and arsenopyrites. AS for high
grade ore Of SIS per ton. they are
few and far apart, / found by ex-
perience.
The dreams OF bonanza free gold,
easy to mill, get-rich-quick. belong
to the dark age of the SOS, but we
are in 1899 and we have progressed
through researches OF chemistry and
technicians. We have made II pos
sible to produce wealth from ma
terials and ores formerly consider
ed worthless.
Speaking OF materials worthless. /
you mention tailings. Yes. these
tailings probably could be handled /
with fair results because OF the OK
idation and decomposition OF car
bonaceous matters after a long per- /
iod of years. This could be possible I
and should help Substantially. Chem /
ical reaction and natural teaching 4
and reprecipitation, but this ap-
plies only to gold ores. 1t compli-
Gates flotation, oxidized sulphides,
soluble salts OF iron, lead, copper.
etc. So there we have problems OF
ore dressing again.
The high grade type ores are
getting less and less common
The simple easy bonana ores OF the
early days are a thing OF the past,
even in Marysyille as elsewhere. II
it was not for metallurgical re-
search on the other types of ores,
of which there are far greater guam
titles, where would we be by now?
1t is fortunate that we have such
organizations as the American Cy-
anide Co., which devotes part OF It's
revenue to unselfish research, and
make their findings available to the
industry.
AS for flotation OF the many types
of ores, much has been done. in
late years. The cyanidation of the
flotation concentrates is now a COM
mon practice, / wish to inform Mr..
Ropes, in many mills in Nevada,
Colorado, California, Canada, South
Africa, Mexico and Australia. I
could cite hundreds OF large mills
where this process is used At the
Wptwatersrand mill in the Trans
faal, South Africa, f1otation concen-
trate from slime Is cyanided with
The gravity concentrates from tables. .
The reason for this is that when the
pre- is finely ground, carbonaceous
matters are liberated and this Is re-
iuced to the minimum by this flow
sheet. Some OF the Marysville ores.
found, come under this classifi-
cation
Another important point the
economical feature in favor Of the
:yanidation of flotation concen-
rates is the reduction Of the bulk
If material to cyanide. This reduces
he size of the cyanide plant. Cy-
lnide equipment requires more
space. more building investment
md more heating in the winter. The
lotation equipment is simpler,
cheaper. The equipment required
o cyanide 100 tons of raw ore
md the size of the plant would cost
IS much as a plant with a capacity
# $50 tons of raw ore, using flo
alton and cyanide OF concentrate
ombined. I speak from experience.
For reference / would refer you
o the volume published by John
z. n. DOrr, "Cyanidation and Con-
entration of Gold and Silver Ores"
n 1886. You would find there
lenty interesting data from actual
perations OF plants all over the
Torld.
The American Cyanamid Co. has
ioneered many new ideas. not By
T.
aarches and operating tests in the
eld. You may criticize research
lemists, metallurgists and such or
anizations as the American Cyan
mid Co but what have you to
TIER that Is better? American Cy-
namid Co. has saved millions to
by their research and tech
icians' dreams, as you call them.
am myself registered MetalIur-
lcal Engineer and have done much
and test work on many
pes of ores all over the world.
nd therefore realize the value OF
he service OF such an organiza-
on as American Cyanamid. Com
my.
Yours very truly,
A. FRANCHIE