CYAN IJIATION
For the Small Operator
SAND TltEATMENT
This article is written for the
small operator who lias a stamp
mill and who plates and concentrates
his ore. It is our purpose to point
cut how cheaply a small cyanide
plant can be erected as an adjunct
t‘» an existing mill and how easily
and cheaply it ran he operated wMi
out much technical knowledge.
If you have free milling ore and
your tailings will average as low as
$1-50 per toD, you can make aa ad
ditional profit by cyanldlng. If th°
profits run much higher, you will
of course, do much better, as It
does not cost any more to treat
$3.00 or $4.00 tailings than $1.50
tailings.
The method recommended is the
time honored, so-called, "percolat
ing process" that has been in uso
for more than thirty years. In 99
cases out of 100 the battery tailings
are quite lino enough for cynniding,
*o don't think you have to put in
expensive machinery for regriuding.
All you need are leaching tanks
placed below the mill, precipitation
boxes and one solution tank. Most
text books will tell you that you
need sump tanks for weak and
strong solutions and that the ore has
to be treated first with weak solu
tion. But all these are unnecessary
complications which the small oper
ator does not need. All he needs i3
the sump tank placed below the pre
cipitation box in which the cyanide
solution is collected and from which
It Is pumped back into the leaching
tanks.
If you operate, for Instance, a
hvo-stamp mill and crush 20 tons
of ore 24 hours, about one half of
your rock will he sand of different
degrees of fineness and one half will
be sliznes. By the percolating pro
cess you can treat all your sands
and about half your slimes in the
battery. Tua other half of the
slimes cn about 25 per cent of the
.total rock you crush will consl.it of
extremely Are sllmeii which have
heuu treated by another method
v/liieh we will describe In another
article.
The leaching tanks are equipped
with a Altering medium in the bot
tom and the tailings run by gravity
from the batten' Into these tanks.
In order to spread them out evenly
over the whole surface a so-called
distributor is used. When the tank
is full you pump cyanide solution
from your sump tank directly onto
these tailings, and let the solution
disolve It.
Coming back to the small opera
tor who crushes 20 tons per day, he
would need three leaching tanks T8
feet in the diameter and about 6
feet high. Each of these tanks will
hold about fifty tons of tailings so
that it would take about three days
to fill the tauk, allowing for 15 tons
or slimes to be impounded for fu
ture treatment. It v/ill take six
ouys to fill the other two tanks. It
will, therefore, bo six days before
you need the first tank again, which
will be sufficient time to give you
good extraction.
Leaching tanka coat about $260
complete in Sun Francisco, or a
total of $7S0 for the set of three.
A precipitation box of ample ca
pacity will cost about $135 and a
sump tank costs $125. In addition
you need a small centriflcal pump
(about 1 inch) driven by a 3 H.
P. motor or gas engine. The total
cost of the tanks and machinery
lor the plant would run about
S1200. To convey the solution from
leaching tanks to zinc boxes, from
zinc boxes t^ sump tank and from
sump tank through the pump and
buck to the leaching tanks will re
quire pipe and fittings. One inch
pipe Is quite largo enough for this
purpose.
To commence operations you
need about 150 pounds of zinc shav
ings and about 200 pounds of
cyanide.
The cleanup Is a very simple mat
ter. It requires no machinery of
any kind. All that Is needed Is a
couple of galvanized tubs, a whis
broom, and a scoop. A. molting
furnace can be made on tlie ground
-f an old oil drum and all that you
need to buy Is a gasoline burner
aud pressure tank, which will cost
approximately $25. ,
As far as operation is concerned,
.til that you need to know la how
to test your solution. This is done
by a simple chemical process which
any assayer can teach you in a few
minutes. The entire equipment re
quired for this purpose will not ex
ceed $5.00.
The simplest method of discharg
ing tanks is to sluice themt out af
ter treatment. This, of course, re
quires a good deal of water. If
70 u do not have an abundance or
water the tanks will have to be
mucked out into cars and the tail
ings put over a dump. i
There is no secret about the cya
nidation process. A man of aver
age intelligence can learn enough
about it to operate such a small
plant successfully and can cot 'as
good results a a trained mining en
gineer operating an expensive plant.
As stated before, the first cost
will be in the neighborhood of
£1200. To this sum must be added
freight from the shipping point,
cost of timber for foundations (you
ran use logs if there Ib timber on
your ground).
If you sluice out your tailings,
no extra labor is required to operate
this plant as the battery man bus
ample time to attend to the few
things that need looking after. If
you have to muck out the tanks It
will of course, require extra help.
This process applies chiefly to
free milling ores, but base ores can
also be treated by first removing
the base metals by concentration.—
The “Underground,'* San Francisco..
HAD TO EXAMINE HER NOTES
What was the name of the hotel
you stopped at in Denver, dear?
Oh! I can't remember the name.
Just a second and IT1 look ahrough
my towels.