The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1896-03-04
BUSINESS, MINING AND STOCKS

built on scientific lines; yet. withal
| IT is 50 simple in its construction and
workings that any thinking man can
easily handle it.
Mr.. Mitchell, the inventor of this gold
saver, in spe aking of the merits of the
! amalgamator, says: 1.-The object of
| the machine is to amalgamate all of
the gold that is free from rust, oil or
any other substances that would rem
| der it unresponsive to the action OF
| quicksilver; also to save the flour gold,
which. prior to the invention Of this
machine, it has been most difficult to
accomplish for the following reasons,
! viz: One of the greatest difficulties
has been that where sufficient water
has been used to handle the gravel,
! the current holds the gold in suspen-
/ sion. thereby carrying 1T off with the
! tailings. Second, when the water sup
| ply would be brought down to the ex-
| tent that the gold could find the bot
! tom of the sluice or rifles, the black
| sand that is so common in placer de-
! posts, particularly in flour gold plac-
ers, would first find its way to the bot
! tom and bake on the surface of the
/ Sluice, burlap or rifles. and would soon
! cover and fill the receptacle intended
| to entrap the fine colorS of the precious
metal; hence another failure recorded.
| Third, where quicksilver has been used
| in different devices, other than the
| Acme amalgamator, it has been found
that either there has been a great loss of
quicksilver, due to the inability of the
devices to hold 1T in a solid body, and
to keep it from Touring. at best, or
passing off in globules with the sand.
This particular form of loss is more
APT to result when the gravel is forced
through a body of quicksilver, as the
many small cavities in each small
grain of sand, (Which can easily be
seen by using a strong glass;. which,
as a natural consequence will fill with
quicksilver. and finally be deposited
with the tailings and waste.
Sometimes we are asked what we do
when gold is so light that it viii not
settle, even in a bottle of water, with
out agitation. In that case we do no
thing with it by our treatment, as our
method is mechanical and not chemi-
CAL But gold that has a specific gray
ity over that of still water, we can and
do save to the extent of 80 per cent.
I'm the treatment of -four gold by our
Acme amalgamator, we use a grizzly
or screen with one-eighth slots provid-
ed with two patent sprays which throw
an unbroken sheet of water on the
gravel as it is thrown into the machine,
which prevents the escape of the pay
dirt without being first thoroughly torn
and disintegrated. The finer parts then
pass with the water through the screen
onto a conVeyor, which carries it to the
head end of the rifles. from which
point it first meets with the quicksil-
yer in motion at the rate of 220 vibra-
tions a minute. as it is carried through
a series of rifles charged with 200
pounds of quicksilver, which are set at
certain pitch at right angles. The
oscillation Of the screen and rifles
causes the gravel to run back and forth
in each rifle, and as there are fifty-fiVe
of them, the material is brought into
contact with the quicksilver at least
500 times before it reaches the extreme
end Of the rifles, thereby exposing the
-four gold to the quicksilver, as well as
the heavier particles of the yellow
metal The pitch of the rifles and the
small amount of water used regulates
the flow of current so as to prevent
the fine gold from flowing off before it
is forced many times in contact with
the quicksilver; hence it can be readily
understood that the escape of single
color is practically impossible, and that
the great body of quicksilver is at no
time separated, thus giving it no occa-
sion or chance to flow. while the pecu-
liar shape of the rifles prevents the
escape of any globules of quicksilver.
The rapid oscillation of the rifles also
prevents the black sand from baking.
as it is always ON the upper surface of
the quicksilver"
Since coming to this city Mr.. Mitch
ell has sold an interest in his invention
to Messrs. w. H. Irvine and Fred
Walker, and it is the intention to man.
ufacture the machine in Salt Lake City
for the mining trade
Besides the adaptability of this ma
chine in the saving of placer gold, it
is also invaluable as a saver of gold
in tailings and Shines and the amalga-
mator now ON exhibition at the Atlas
block is to be placed behind the plates
at a mill in Arizona, and it is expected
that it will save its own cost within
three months.