The Goldfield news and weekly tribune. [volume] (Goldfield, Nev.) 1911-1947, 1915-08-14
NEvAOA-OOUGLAS
ISSUES REPORT
NEW Teaching PLANT WILL UI.
PLACED in OPERATION
SOON

According to a statement thai has
just been issued on the Nevada Doug
las Copper company, the new leach
ing plant will be ready for operation
about the middle of this month. After
four years of experimental work the
management now believes that it can
handle the sulphides and oxides, al
though each will be treated by a diff
ferent process. Not only the copper
will be made marketable, but the
ron and sulphur will be used as we'll.
The treatment of fifty tons of sui
phides, it is declared, will produce
sufficient sulphuric acid to treat 200
tons of oxides. In brief the process
is described as follows by Supt.
Archie J. Orem:
The sulphide ores are submitted to
an acid treatment under pressure in a
closed receptacle, in which operation
the sulphides of copper and iron are
converted into the the sulphates of
the metal and taken into solution.
This solution is then decanted off
and passed through e%lectrolytic cells
or owe scrap iron, where the copper
is removed. The remaining iron
sulphate solution is then carried to
an evaporating tower, where the
water is ~evaporated off and the fer
rOus and ferric sulphuric crystals
are allowed to crystalize out. These
iron sulphate crystals are then intro
duced into a dryer and submitted to
a temperature sufficiently high to
drive off all the water of ~crystaliza-
ton, after which the dried sulphates
are submitted to a roast in the wedge
muffle furnaces, sufficient heat be-
ing applied to decOmpose the sui
pilates. The gerater portion of the
gases coming off in the form of sui
phur triOXide, which is collected in
the absorption towers and made into
sulphuric acid to be used in the leach
ing of oxidized ores.
The remaining residue of ferric
oxide is then drawn off and prepared
for market.
The teaching of the oxidized ores
is carried on in Pachuca tanks.
where the ore is agitated with air
and leached with the sulphuric acid
obtained from the preceding sulphate
roast. The solution is then decanted
and passed through e~lectrolytic cells,
where the copper is taken out, after
which the water is evaporated off
and the sulphide crystals dried and
roasted in the muffle furnace as be-
fore outlined.
1t will readily be seen from the pre-
ced1ng that there is new any sui
phuric acid loss except that which is
consumed by the limestone and that
portion of the sulphur which goes to
form sulphur dioxide in the fur
naces.
The total est per ton for mining
and treating sulphide ores is $5.1S.
AS the general average of the ore
to be treated is a little above 8 per
cent in copper, the ore will hav,
gross valuation of $12 per ton in
copper and will sell at a net profit
OF 1852, exclusive of the VIOLATION
OF the iron and sulphuric acid.
The total cost of producing a ton
of iron and sulphuric acid by this
method should not exceed 50, and
with sulphuric acid at this price,
oxidized ore running as low as /
per cent in copper can be treated at
a profit.
Officials of the company declare
that there is blocked out at the
mine $4,000 tons of ore averaging
better than 8 e Cent in copper.
During the next few months it is