Idaho County free press. [volume] (Grangeville, Idaho Territory) 1886-current, 1890-05-30
beneath, and the charge slowly sinks in

as liquid by the cooler ore above
From this ore it will, in part, be reds.
titled as the heat increases, to pass ur
through the fu ell above, and on through
the next ore charge; being thus con-
tinually condensed, absorbed and re-
vaporized, as the successive charges
pass downward through the furnace:
the sulphur, during continued opera
tons, remain ing always in the same
locality, being continuously wasted by
quantities CARRIED off in the upward
current OF escaping gases, and continu-
ally replenish ed by freshly liberated
snlphides from the pyritous portions OF
the successive charges of ore.
Whatever portions of sulphur remain
to pass up Il Trough the fuel after the
latter has acqu red red heat will be
converted, in part, into the bisulphlde
OF carbon; and this, il it be not decom-
posed by carbon doxide, will not be re-
condensed, but will remain as n yapor.
This Is the mo st powerful of reducing
and sulphurizihg agents, but can only
act momentarily, as 1t were, during its
exit In the upward current of ping
gases, and befo re leaving the hot region.
This bisulphidt, if present, will be very
certain to reduce and sulphurize some
iron from portion OF the oxides.
Returning to our ore charge-Du
the vaporization of a part of the sulphur
absorbed by the oxidized Ores any por-
tons OF metals present in the metallic
slate, ana any oxides las of copper, lead
and silver VIII ich are reducible by sui
phur Will be attacked, chemically, by
the latter, prod ucing the respective sui
phides OF those metals; or, in presence
of the red oxide of iron, or the black
oxide of manga nese, and silica, without
excess of su phur, producing the
sulphdtes. Sin &c these reactions occur
at temperature below that ofthe active
reduction OF metals by the furnace
gases, and too rapidly for the latter to
act in any case, il seems necessary to
have enough pyrites for the liberation
of sulphur to effect the complete deoxi-
dation and sulphuration of all these
metals: for it is to be borne in mind
that the metals left unsul phurized, if
any, will be the precious ones. Gold is,
indeed, not to he sulphurized, directly,
in this way, but will be dissolved. as a
double-sulphide. by the iron or other
metals oflhe matte.
Copper, lead and silver oxides NAV
by substitution" be directly reduced,
with simultaneous sulphuration of the
metals, by the mono-sulphide of iron,
without free sulphur; but silver and
lead in the metallic state are unaffected
thereby. And this last precludes the
possibility of depending upon this re-
action in the reducing atmosphere of
the blast furnace when the saving of
email quantity Of silver is to be effected
for the copper and the lead must both
be sulphurlzed before the silver can be.
and this substitution reaction does not
take place until the fusion of the iron
sulphide; when all the free sulphur has
been driven Of u, and any farther SUI
phuration of these metallic particles
can not be accomplished. 1t is true
that metallic silver may be somewha
soluble in the al atte, but so it is also in
basic slak; and, except in MATES rich
In copper or lead, we can not expect a
satisfactory collection of silver without
sulphuration.
Any portions of sulphates of copper.
lead or silver v hich may be found, or
which were originally present, in the
ores, will be reduced later by the fur
mace gases, or by contact with the
molten iron sulnhide, forming sulphides
by loss of oxyge IN.
AS the charke continues to sink in
the furnace fusion of the mass begins
and progresses; first, the sulphide from
the lower portion runs out; then, as
'Huxing" or formation OF Stag. begins in
the mass above, the upper layer of sui
phides fuses, and the elquated "metap
runs down through the charge and the
fuel below to the bottom of the furnace;
mixing, on its way, with the Stag or
melted rock, and collecting to itself all
the sulphurized particles of metal that
may be present. And when the top |
layer of our charge has given up nearly
all of its sulphides, the fusion of the
bottom of the next charge above will |
begin. and the iron sulphide from this |
will come down through the fuel to con-
tinue the leachllg process: and so. as
long as the operation of the furnace is
kept up from char to charge this pro-
cess will be cont nued.
The reasons 70 making up the charge
in the manner stated will now be appa-
rent.
The use of fine ore in the blsst-fur.
mace decreases its smelling capacity at
the rate OF about one per cent. for each
per cent. of fines used; and for this rea.
son the direct use of large quantities of
fines is not practicable.
And here, since writing my notes for
the above and what is to follow here
after, there came to me new thought,
which after two weeks of contemplation
still seems to off ar practical solution,
At once, of all these sulphuraiion diff