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

/ read with interest the article
by Mr.. Ropes In your issue of Feb.
is, last, in your Mail Bag column.
concerning the new reagents Just
put out by the American Cyanamid
Co. These reagents are carbonoEa-
ceous depressers. in other words,
cleaning reagents for concentrate.
to remove or depress 'carbonaceous
shines.
am quite surprised at Mr.. Ropes
statement regarding the ores OF the
Marysyille district. My experience
has been that practically all the
ores / had to work on were in the
shale OF a carbonaceous character,
containing much carbonaceous col
lOidal material and some Of these
carbonaceOus matters we're of or
ganic origin. metomorphosed vege-
table and animal matters. / would
take only two particular instances.
One was a gold ore in a carbona-
ceous oxidized shale OF the North
Gould mine. ! used everything I
could think of to clean the concen-
trates. (flotation concentrate) from
carbonaceous colloids. which would
not let the concentrate settle. max
ing a very dirty product. Besides
I the plates were coated by Shiny
matter which was holding water Inn
purites. as mine water was used
These impurities were iron carbon
ates and lime and iron sulphates as
well as impure lime carbonates,
which precipitate on the amalgama-
4 ton plates, making them useless.
The plates we're replaced by Jig
and traps to catch free gold part
of which was oxidied or furnished.
Now here is what I used in this
case: AS we had stamps I used hy- |
droxide and wood ashes. These were |
partial success on the plates but |
not permanent I added at times |
a little weak cyanide solution. This. |
however, was little detrimental |
to sulphide, but helped the oxidixed
gold.
The use of potassium hydroxide,
sodium silica and copper sulphate in
right proportion and at the right
plate helped to clean the concen-
trate, to depress the carbonaceous
slime and reactivate the sulphides.
Sodium chloride helped to settle
in combination with sodium and a
little sulphuric acid.
These reagents were used. at var
ious times and placed in the mill
until a fair result was obtained.
However, none of these reagents
were used in the mill before tests
were made. If you think this was a
technician's dream well you may
try it and see for yourself, Mr..
Ropes. This was an operators prob
lem, to get it or not to get it.
got 1t but not as good as I wanted.
This was one case / worked on,
but the nearby mill of the Jay
Gould mine has similar trouble in
the flotation section and some In
the cyanide section. The Seven-up-
Pete mill had much trouble The
General Engineering tested the ore
and built the mill and then troubles
in the mill developed to such an ex-
tent that the mine shut down. An
other neighbor mine and mill was
up against 1t, the little mill of the
Bachelor mine. Neither of the last
two named could get clean high Z
grade concentrate for the very reas-
on that the carbonaceous colloidal ,
slime crowds out the value and di-
iutes the concentrates and these ,
ores have no graphatic substance in !
1t either. So don't you think re-
search is not needed on the Marys- !
vile ores, Mr.. Ropes. Marysville Z
is not the exception. All the dis !
tricts present plenty of problems ;
for the metallurgical chemist
The next typical case was an ore a
silver, gold, lead and lead O
carbonate in a black gray blue {
shale, from the Lawlor Brothers of G
The mine is six miles
from town and not far from the f
Penobscot and other well known Y
mines in the district. think they q
called it the Silver Queen They il
nave an organization and Mr.. Julius D
Hall of Wallace, Idaho, is the engi- o
leer. This investigation was made "
or my own personal satisfaction.
/ tried the ore and ii forms a n
rery dirty Shiny concentrate. Car 2
'naceous matters are present in s,
arge quantity. The gangue is ii
ioapy. like soapstone or serpentine 81
md indications Of possible graph e
ltic matters are present. Sodium | a
ilica did no good to depress coll o.
ODDS in suspension. A mixture Of al
NaOH and Si02 and a little copper OF
ulphate helped to settle the concen- n.
rate. A small amount of milk OF /
ime still helped further and the e
water with the slime *
ould be decanted, but there is a u
title loss from colloidal slime. al
The microscope tells the story II
Without assays. but assays checked III
he microscope finds. %
The ores l examined and worked
n, beside these two instances. from
he Marysville district are from the
fcKay mine or Bear Gulch and