The Elk Mountain pilot., 1882-06-22
REDUCTION and SEPARATION OF GOLD,
SILVER LEAD AND COPPER
By pr. ionseln.

] "a w. XSh0Sbe8-
We are accustomed to laugh at the
ancients for trying 10 separate gold
and silver by fusing the alloy with
sulphur aud strewing litharge on the
fused mass, or, as told Of the Persians,
the argentiferous silver was fused three
times with copper and three times
with sulphur. Yet on closer consid-
Grafton we are astonished at how
clever they were in these methods,
and how thoroughly they made use Of
the few aids which they.had then. In
fact these processes furnish the key to
whole series of metallurgical opera
tons, and timely changes In those
principles may perhaps cause many
more revolutions IN metallurgical pro-
cesses.
The first :nducement to return to
the Old methods was the difficulties
presented by the present me;hods in
treating copper alloys which may
contain considerable gold, without
too much expense. Upon the ground
of observations made in the Frankfort
assay Office, with the aid of l.. Opi6-
clus, new and improved process i;
likely to be perfected which promises
to be Of importance not in assay works
merely, but also in lead and copper
works.
1t has been found that 4 mixed alloy
containing gold, silver and corrercan
be divided into two portions, one con-
tanning all the gold and most of the
silver, and the other Of copper with
greater or smaller residue of silver
but no gold IN it. The manner of
doing this is by the use Of sulphur,
which is melted with the alloy in such
excess that it combines with all the
copper and silver. Then by blowing
air through the melted sulphurets
portion Of the sulphur burns. This
precipitates all the gold, which, in
the presence OF SO much sulphur, was
taken up by the sulph'irets in large
Quantities then most Of the silver is
thrown down, and rich alloy is OBJ
tanned which can be separated from
the sulphuret Of copper above i,
which is free from gold. The blow
ing OF air through it here acts like the
litharge did witt, the ancients, but
more energeticaliy and More ration
ally. With them, too, the sulphur
was burned by the oxygen in the
li,harge and the metal separated as
regulus. If the blust is turned off
just at the right moment, the regulus
will consist almost entirely Of gold.
FIRST Of all this process was only used
as a preparation for the separation
with sulphuric acid. SO that all the
gold and the greater part Of the silver
were thrown down, while the rest of
the silver is found along with the COZ
per, and free from gold, in the sui
nhurets above, which are afterwards
reduced in another crucible to metal
by blowing air through it.
In the Frankfort ASSAY Office 66o
pounds of su!phide is melted al once
in graphite crucibles. The air can be
introduced into the fused mass by
pumps or cylinder blast, or, if the
fusion takes place in a closed space,
koerllIng's steam injector can be
used with an absorption vessel, in
which the sulphurous acid is convert
ed into sulphuric acid and the part,-
cles of .::stal that are carried slonc
settle there.
The principles mentioned above
seem to be Of great importance to
lead and copper smelters, to VII
the following points present them
selves: The removal Of the gold from
the copper matte, and silver matte, as
we'll as the removal of gold and silver
from MATES containing both lead and
copper, and the production OF lead
su,tabl.. for assay on the one hand.
and Of a copper matte free from gold
and silver on the other. Well con-
structed closed crucible furnaces
offer special advantages. particularly
in removing or utilizing the sulphur.
Gus acid for sulphuric acid, which