The Black Hills union and western stock review. [volume] (Rapid City, S.D.) 1904-19??, 1906-02-23

values as Indue Dy Cno numerous dLldlSd-
mating schemes devised to meet the vary
ing physical occurrence Of values in gan
que matter; to chemical treatments and re-
duced cost Of handling,
The COLONIZATION and cyanide methods
have stood the test of practice and come
into general use within the last eighteen
years. Each Of them has it's own peculiar adj
vantage OF disadvantage; neither Of them are
adapted to every kind Of ore. COLONIZATION
is comparatively cheap and simple and is
we'll adapted to ores not containing large
percentage Of silver or copper or not having
a lime gangue. One great advantage is
that the precipitated gold is clean and free
from other metals and requires but little
after manipulation. The great dsadvan-
tage is that the ore requires a dead roast
and any silver is lost unless recovered by
some subsequent treatment.
The Cyanidation Of ores is not well
adapted to heavy sulphides. Ores contain
ing Arsenic Anthony, Copper or Tellur-
ium in appreciate quantities cannot
the Cyanide process. An extraction is
seldom obtained over 20 per. cent of the
assay value. Nevertheless, the method has
many advantages and has been used with
much success. Where number of years
ago large values went to waste in the tails
from amalgamation, to-day are saved by
cyanidatlon. The change in amalgamation
is marked by larger plate area and in
side amalgamation. The initial cost of the
increased plate area is greater, but is we'll
repaid by the saving it makes
There has been many Improvements in
hydraulicking for gold over the old STYLE
By the use Of the hydraulic ''giants'' and
other schemes given amount Of water will
do much greater work than formerly. The
gold dredges are strictly modern and are
now widely used.
LEAD AND SILVER: AS these metals are
usually associated in nature and are jointly
separated from the gangue, we may consider
them together. Fewer changes have been
made in the treatment of these than in most
other metals. The reason probably being
that there is nothing simpler than blast
furnace smelling for their reduction. Where
they do not occur together, the missing one
is brought from some other source and
mixed at the furnace. The improvements
in this line are very marked, especially in
the line Of rapid and thorough means for
roasting and chloridizing the ores to be
afterwards amalgamated or treated by some
method of lxivation. The process during
the last few years in the smelling Of lead
and silver ores has been mainly, as in the
iron furnace, an improvement in the me.
chanical handling of ore and product, con-
struction of furnace, also better knowledge
OF the chemical requirements, better
choice Of fuel and better system for the
collection and handling Of fue products,
COPPER: Regarding the smelling and
refining Of copper, we find that as in the
metallurgy of gold, progress has been great.
Mines that were abandoned twenty years ago
are today working and yielding handsome
profits to their owners. Instead of mining
rich ore streaks, it is more profitable to
mine the whole vein, even though the
average yield Of copper is very low, from
for this is found in the refined methods for
reduction, cheap haulage and large scale
OF operation. For instance, in the Lake
Superior district where the copper is found
in the metallic state, the problem.of cheap
production is mechanical one, that is,
handling Of large quantities Of ore with the
Least possible cost, improved facilities for
crushing and concentration. The steam
stamp is used in crushing these ores, In
the copper regions Of Montana and Arizona
the same problems together with others due
to the complex and refractory character Of
the ore have been met and successfully over
come. The mechanical roasting furnaces are
used to great extent, affecting great saw
ing, of labor and time as, in the smelling Of
lead and silver ores, the influence of technical
training and mechanical ingenuity is MOTTO
able, The mating Of these complex ores IS
nov an established practice and the refining
Of the matte and extraction of the precious
metals by smelling Cor copper bottom is
fully warranted by the unfailing results
Among the other inventions and improves
ments that have come into general use
within the last decade sre the Bessemeriz-
ing Of cooper matte and deposition Of the
copper by electrolysis.