Arizona citizen. [volume] (Tucson, Pima County, A.T. [i.e. Ariz.]) 1870-1880, 1876-08-12
The LixiVIatIOn Process for the Re-
ductiOD of Silver Ores.

ough anu cheap working OF gold and
silver ores, is of interest to our Arizona
readers. The Lixiviation process has
been heretofore described in The
CITIZEN, and the Ostrich Mill Compa-
ny has successfully treated Old Mine
ore by it, yet the following from the
San Francisco Bulletin will be read
with interest by our silver miners:
EDITOR BULLETIN: The reduction
of rebelliOus silver ores by llxiviation,
instead of by amalgamation, is now
almost in universal use in Sonora, Mex
leo, and Lower California, and is rap
idly gaining favor in SinalOa and the
interior. 1t is not, as many suppose, a
new discovery, but merely a mOdifica-
ton of an old and well-known process,
with cheaper chemicals than those for
merly in use.
THE METHOD AT PRESENT ADOPTED,
Is TO crush dry through No. Is or 20
screen, then treat in reverberating fur
naces with salt in the same way as for
amalgamation. The ore should be
more carefully chloridized, if possible,
than for treatment with quicksilver.
When thus prepared the ore is placed
in large tubes or watts with false bot
toms covered with canvas or burlaps.
The watts hold about six or seven tons.
The ore; is then leached or liXiviated
with water for few hours to dissolve
and carry off the soluble salts of the
base metals. The salts of silver not
being soluble in water are not affected
by this process. After the base metals
are thus eliminated the ore is leached
with solution of hvposulphite of soda,
in which the silver is soluble. This
liXiviation takes from six to ten hours,
or even more. according to the richness
of the ore and the strength of the solu-
ton. This solution is carried to large
vat 1t is transparent, and scarcely dis
tinguished from common water, except
by its taste. The silver thus obtained
in solution is precipitated by polysul-
phide of lime which is prepared by
boiling sulphur and lime, proportional
according to the metals under treat
ment. THIS solution can be boiled
either by fire or steam. 4 portion OF
the sulphur and lime solution Is then
added 10 the hyposulphite OF soda SO
luton when the silver is at once pre-
cipitated as black powder, which Is
sulphide of silver 5. A. G.. After
straining, this sulphide is roasted in a
reverberatory furnace to expel the sui
phur, during which process 1t grand
lates, assuming much the appearance
and color of blasting powder. In this
IconditiOn il will assay from five to SIX
hundred fine 1t is then refined in the
refining furnace, or in the crucible, &C
cording to the quantity under treatment.
ITS ECONOMY
| Is very great. A skilful operator will
work up to nineIy-five per cent of the
assay. The ordinary average loss 10y
amalGamation is at least fifteen per cent.
making a gain of ten per cent. All
the wear and tear, as well as the orig
inal outlay for pans or barrels Is avoid
ed. and no power whatever Is requisite.
The watts can be built fo7 mere tritie,
and will last an indefinite length OF
time. Hyposulphite of soda is worth
in this market from five to six cents a
pound, sulphur from four to five cents,
while lime is abundant in nearly every
mining district In the hacienda man.
aged by the undersigned, producing,
say, sixty thousand dollars a month,
the following saving is effected:
Eight per cent. say, add'al product, $500;
two per cent. less duties. The silver
being $40 fine instead Of 150..-.-......Sl, 2JO
-Four cords OF wood less per diem, at 80
s. 80 per wv
Saving In the use OF quicksilver......... l,O9Q
Saving in 20
Wear and tear of machinery ......--..-- 5Oy
Additional gold saved, at leash, l,5Os
Makinga direct saving per month OF slO.l2C
But in addition to this we use a
number 20 screen instead of number
10. as in the amalgamation process
thus more than doubling the power OF
the battery. Experience proves that
! crushing with an Is OF 20 screen eXpe
dites the lixiviatiOn process, without
producing any additional loss. In ad
dition to all these items, the first cost
of building q mill Is greatly reduced
ORES SUITABLE FOR TREATMENT BY
LIMITATION.
All rebellious ores not containing
free gold can be advantageOusly treat
led. 1t has been urged as an objection
even by parties acquainted with the
process, that the proportion of gold
/ frequently found in. silver ores cannot
be saved by lixiviation. Our experience
| is decidedly to the contrary. 1t is true
our ores have but very little gold, vary
| ing from a trace only TO FIVE or six
dollars a ton. BY the process Of ANAL
gamation this yielded in bar of fit-
teen hundred ounces, only about twenty
dollars gold. BY lixiviation we obtain
hundred dollars and upward in each
bar
It's the opinion of those having the
greatest practical experience, as well
as scientific knowledge, that there are
no ores so base, no combinations so
stubborn, but they can be treated sue
Icessfullv-say to within ninety per
cent of the assay by limitation. OF
course there is much to learn in a pro-
cess new at least in Its application to
the economical treatment of ore in
! large quantities; but | have not as yet
heard OF any failure where ordinary
intelligence has not been wanting
while on the other hand the use OF
Quicksilver has been almost entirely il
! not entirely abolished in Sonora. !
should add that the process IS now
used frequently without even the use
of soda, with sulphur and lime only
BY this method the treatment is some
what slower. and is said not to save
the gold, nj least not to an equal extent
/ but il is even more economical. Al
though the process appears so simple
| should strongly recommend any per
/ son without experience to employ 6
sklllful man. They are plenty IN So
nora.
/ OTHER QUESTIONS To BE CONSIDERED.