The Pioche weekly record. [volume] (Pioche, Nev.) 1877-1900, 1885-05-30
REPORTING AMALGAM.
rs. I. Scientific Press ]

BY the ordinary system OF retorting
amalgam the quicksilver is distilled by
heat only, and the quicksilver fumes are
forced cut Of the retort by their own
pressure. The condensation is effected
by Liebig cooler. The disadvantages
of the system are, first, that at the end
Of the retorting the retort must remain
filled with the quicksilver fumes; sec-
ond, that it takes a high temperature
and long time to remove all the quick
silver from the bullion; third, the con-
densed quicksilver contains large per-
centage of black Stun, which is merely
quicksilver in a finely divided state. Mr..
c. A. Stedefeldt, the well.knowu metal.
urgist, formerly of this city, but now
resident OF New York, has devised new
system Of retorting amalgam, which con.
sists in forcing the quicksilver fumes out
Of the retort by means of steam blast,
condensing steam and quicksilver to.
gether, and constantly circulating
stream OF air through the retort and con-
denser. The effect is that at the end of
the retorting no quicksilver fumes are
left in the retort; the retorting is done
at lower temperature and in less time,
and the condensed quicksilver does not
contain trace of the black slum men,
toned above.
To carry out this method Of retorting
cast,iron retort Of the usual form is set
into a fireplace of the customary con-
struction. The retort connects by means
of pipe with condenser. This latter
is box made of boiler iron, which is
perforated by numerous tubes like
tubular boiler, or surface condenser, in
order to give the condenser larger cool
ing surface. The condenser is divided
into numerous compartments by parti-
lions which have alternate openings at
top and bottom, one reaching from top
nearly to bottom, and the next from bot.
tom nearly to top.
At suitable point in the pipe con-
Meeting the retort and condenser steam
blast is introduced, which creates a
vacuum or suction in the retort. In
consequence Of this suction the quick
silver fumes and air from the retort are
rapidly drawn into the condenser. Here
the quicksilver and steam from the steam
blast, condensed is passing up and down
over and under the partitions and the
air leaves the condenser through pipe.
The same pipe leads back to the front or
cover of the retort again; hence the same
air which was originally in the retort and
condenser keeps in constant circulation.
The base metal in the amalgam, as soon
as the retort gets ed.hot, absorbs the
oxygen of the air, and finally leave only
nitrogen atmosphere, by which pos
sible oxidation Of the quicksilver is pre-.
vented. The quicksilver and condensed
water accumulate in the condenser each
one up to certain level and then run
out in a continuous stream through suit
able outlets which are provided.
The air pump which carries the air
from the condenser back to the retort is
connected by means of T connection
with another pipe. The object of this
latter pipe is to equalize the pressure
caused by the expansion of the air inside
of the retort at the beginning of the
operation, and the falling off Of quick.
silver fumes in the retort at the end Of
the operation. The condenser is sur
rounded by box which is supplied with
cold water, arranged so the cold water
will circulate through the condenser
tubes, and the warm water run Off
The operation is as follows: The re-
tort is charged with amalgam and closed
by the cover in the usual way; then the
pipe connected with the condenser i.
connected with the retort through ar
opening in the cover. The fire is started
and as soon as the retort gets warm the
steam blast is turned on. As soon a.
the quicksilver commences to run" the
fire is kept very low, the distillation
going on very rapidly. When the quick
silver runs light the heat is increased
After the quicksilver ceases to run tn,
steam blast is kept in operation for hal
an hour logger, in order to draw from
the retort every trace of quicksilve
, fumes. The cover of the retort can thel
, be removed, without the slightest risk
while the retort is still hot.