Idaho County free press. [volume] (Grangeville, Idaho Territory) 1886-current, 1890-04-04
Raw Ore Smelling at the Mines.


yer ores, especially of those containing
small quantities of copper and lead, for
the purpose of profitable concentration
of the valuable metals in rather low
grade matte: from which they could be
recovered by subsequent treatment.
And, believing this subject to be one of
great Importance, / have for several
months had in mind the idea of prepar-
ing for publication brief expose OF my
ideas upon the matter. From this /
have. until now, been deferred by vari-
Gus causes. And now, in the En9in.er-
ing and Mining Journal of Feb. s, Just at
hand. Mr.. T. Il. Bartlett, the well-known
maker of the Bartlett Water-jacket Fur
naces comes forward with some "Notes"
npon this same subiect-'tho under a
slightly different heading-whch con-
tains much of the substance of what
wished to say. The disappointment
from being forestalled is ,however, equal
ed by the pleasure feel from the fact
that my independent conclusions are so
well backed up, not only by the opn-
ion of 80 eminently successful metal
urgist. but also by the practical results
of Mr.. Bartlett's experiments.
still have something to say, however,
for ! am deeply impressed with the idea
that matters can be proftably carried
much farther than has been proposed.
Like Mr.. Bartlett "H has al,cdys been n,y
belief that not enough attention has been
paid to the smelling of argentiferous
ores in blast furnaces without the use of
lead" and that american smelters
have not, as rule. appreciated the idea
that silver and gold can be concentrated
and saved by the use Of sulphur, iron and
copper as well as by the use of lead.
tThe italics are mine.) But, as l have
said, / would 90 farther, and see no
reason for excluding lead entirely, as
not of use in small quantities. nor for
limiting ourselves in all cases to the use
of blast furnaces.
Briefly. my ideas are that we should
certainly be able TO concentrate pracli-
cally the whole of the silver in poor
ores, as well as in rich, by smelling with
enough OF SldDhur and iron with copper
or lead or mixture of those metals TO
produce a matte of six to ten per cent.
of the weight of ore used.
Practically the presence of copper or
of lead in small quantities is necessary
for the production of q clean Stag with a
matte rich in silver; because these met
ais form with great facility combina-
ton of the nature of double sulphide
with sulphur and silver and those dou-
BILE sulphides are dissolved eagerly by
the bath of iron sulphide, while the sui
phide Of silver alone has much less af.
finity of solution. Copper sulphide is Of
much the greater benefit in this way
but it is my belief that lead will be
found practically successful. The law
in this matter appears to be that we
should have at least enough, with some
excess, of copper or of lead, or of both
together, to form those double sulphides
with all the silver present, otherwise,
we should expect very nearly the same
results ms though no copper or lead
were used.
Practically, then, there should be al
least as much of these metals as there il
of the silver; possibly, with lead alone,
two or three times as much. Mr.. Bart.
let's experiments are conclusive, | be.
iieve, as 10 the power CT copper in sucl
small quantities. Mr.. Bartlett also
shows that the loss of silver in the slaf
need not be more than / ounce per ton
and, quoting Mr.. Lang's report of the
performance of the smelter at Mineral
City, Idaho, shows that the practical
loss there is only u ounces per ton o
Stag when smelling 20 to "a tons of ore
into one of matte; or about double the
degree Of concentration that have ad.
vocated. With charge made up with
more pyrites, which may undoubtedly
be had by going deeper. SO as to make q
ton of matte for 10 or IL tons Of ore, the
loss would he decreased to one half this
amount. For, with an equally fluid Stag
The Toes will in all cases be inversely as
the amount of matte made; since the
Stag will retain practically uniform
quantity of matte, the silver and copper
contents of which will be, of course
proportionate to it's richness.
If MessIs. Lang x Biddle would smell
for ten to one concentrate, instead o
20 to ! and then thoroughly roast this
concentrate and resmelt, with suitable
additions of acid ores for f,ux, TO make .
go TO 20 per cent. matte, returning the
resulting slags to the ore charge, they
would save half their present waste Of
silver; 40 per cent. of the freight bills on
matte and would increase, also, the
smelling capacity of their furnace by
means of the fluxing Stag.
Won't it pay?
have given to this article the title oil
Raw Smelling" because it is of ores
comparatively poor in lead and cope,
that am speaking, ores which are to
be worked for silver. mainly, and which
do not, as whole. contain enough OF
sulphurized material to make more than
the requisite per centage weight OF
matte. Where the ores available foi