The White Pine news. [volume] (Ely, Nev.) 1906-1910, 1908-09-01

fumes emitted. the United states
company employed Mr.. Sprague III
January, 1907. 10 carry on series oil
experiments with view TO discover
ing if he could find any means by
which the fumes and gases from the
rooster furnaces could be filtered
: through the baghouses, which had
previously proved successful on th2
: blast furnace gases.
At first determinations were made
! of the velocities volumes and Temper
atures of the gases. also of the guam
/ tity and quality of the solid matter
held in suspension in gases. 1t con
+ tanned. besides this. various sui
pilates. The composition of the gases
was also determined particularly
with respect To the sulphur dioXide.
Filtration experiments We're under
/ taken first on the copper furnace
gases. The gases were forced through
/ bags of some fabric by means of 4
! fan and the filtration was entirely
successful so long as the bags lasted:
but these invariably We're destroyed
in a day or two. Various kinds OF
bags were used-cotton. linen. wool
flannel and burlap-all with the same
result. 1t was thought that their
failure might be due to the gases
not being at the right temperature,
and experiments were undertaken in
which they were maintained at vari-
Gus definite temperatures. Although
it was found that the degree of heat
had some effect on the life of the
bags in all these tests they We're de
stroyed in greater or less time. nsh-
ally a few days. II was also found
that the presence of moisture was
detrimental However, examination
of the destroyed bags showed the
presence of minute quantities of sui
phuric acid. and it was found that
destruction was due to this sulphurie
acid
A series of tests was undertaken
to determine the amount of sulphurie
acid in all the various gases. There
was none whatever in the lead blast
furnace gases, a very minute quanti-
ty in the copper furnace gases and
comparatively large quantity in the
roaster gases. 1t was found that the
fumes as well as the sulphurie acid
were highly destructive TO yegets-
ton. and that the values in the fumes
amounted to serious loss to the
smelter.
1t was. therefore. doubly important
that this fume be filtered out of the
gases Filtration experiments were
also undertaken on the blast furnace
gases. Their filtration was entirely
successful. All the solid matter IN
suspension was distracted and the
bags were not destroyed Suisse
quently, the present bag house was
put into commission. A large amount
of lead was recovered. as well as ar
senic. which would have passed out
into the air. Attempts were also
made to filter the rooster gases. but
the bags were destroyed practically
at once by the sulphuric acid con-
tanned in the gases. The sulphuric
acid in the rooster gases amounts TO
a production of about three or four
tons daily, when roasting 200 tons
of sulphide ores.
The amount of sulphuric acid was
found TO be extremely small, in all
the gases except those of the rooster
plant At last zinc oxide was tried.
and results We're successful from the
tirely neutralized, with formation of
zinc sulphate; the sulphur dioxide
was not attacked by the neutralizer,
the bags were preserved and the fl
tration of the gases were perfectly
An experimental playhouse
was put into use on the copper plant. /
and ran with the same bags. for
The rate of filtration was
six times that practiced on the large
scale, so that this test was practically
equal TO one of a year After the /
termination of this experiment the /
bags were torn into strips and the /
tensile strenSth of the threads test
ed. The fabric was found not to have
deteriorted in the least. test was
now made on a large scale. a portion |
of the copper furnace gases was car
ried over to a section of the playhouse j
taking lead furnace gases This test
lasted three months. About -
pounds OF zine oxide were used daily .
for the naturalization of gases. This +
experiment was also altogether sat /
isfactory