The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1896-01-26

South Africa and New Zealand, West
Australia, Cripple Creek. Siberia, al
most all the gold fields in the world
offer striking examples. Perhaps South
Africa, with it's tremendous yield, af-
fords the most conspicuous instance
The ores of the TransVaal are for the
most part of low grade. That is to say,
they carry less than half an ounce OF
gold to the ton of mineralized rock
Few save those actually engaged in
gold mining, understand how small a
proportion this is. If in ton of gold
bearing ore there is an ounce of gold,
that is still, by weight, but one twenty
four thousandth part of the whole And
IN South Africa the proportion is less
than half this. In other words, out of
As 600 bits of mineral bearing rock, but
one single portion is gold. And it is
difficult, almost absurdly difficult, to
extract even this.
SCIENTIFIC GOLD EXTRACTION.
The ordinary method of gold extrac-
ton. as almost every one knows is to
crush the ore to a fine powder and run
this over amalgam plates OF quicksil-
yer. The gold is precipitated upon the
plates and afterwards scraped off. But
by this means, even by the best de-
vices, only about half the gold values
are saved. The rest goes off in a kind
of slime which is known as "taiings."
In South Africa the amount lost by this
method is almost exactly one-half In
other words, if the ore runs SIS or $40
to the ton, only 81 or SIS of gold is
gained. 1t is here that cyanide comes
into play. The 'tailings" are gathered
UP and deposited in huge watts contain
ing a weak solution of cyanide of po-
tassium. This chemical has a peculiar
fnV ND Tol inc
as water dissolves sugar or salt. The
gold is held in solution. When this
teaching process, as it is known, is
complete, when all the gold has been
dissolved out, the gold-laden liquid is
run through a kind Of filter made Of
bright zinc shavings cut very fine. This
precipitates the metal, and afterwards
when the solution of cyanide has been
run off, these zinc shavings are put in
clear water and thoroughly shaken, with
the result that the gold falls off and
is deposited in the bottom of the tub
Here it is gathered up and put through
the refinery and come out, sometimes
almost pure, and sometimes in a coarse
bullion.
Where ores are of low grade they are
not put through the stamp mills at all.
but are crushed to a fine granulation
and treated directly by the cyanide.
This is the case WIN the Cripple Greek
ores of low grade, as with the ores of
New Zealand and many other coun-
tries In New Zealand so or 80 per
cent of the gold values is obtained by
this means; in South Africa between 80
and 40. In the latter case this saving
affords not only the entire profit there
is in working the mines, but even much
more SO that It Is fair to say that
without cyanide there practically would
be no South African gold fields.
But the new process has not always
been successful. In California. for in
stance, it has so far been found Of lit
tie value. Then, too, there is among
mining men, or was until very recently.
decided prejudice against the new
method When it was first brought out
FIVE or six years ago it was hailed as a
panacea for every i'll that gold mining
knew It was to treat every sort of
rock. and all with equal success. And
In so many instances it signally failed
that many experienced men concluded
that II was not worth much of anything
at ali. The truth lay between the two
extremes.
GOLD PRODUCTION OF THE