Arizona citizen. [volume] (Tucson, Pima County, A.T. [i.e. Ariz.]) 1870-1880, 1876-08-26
The LixIvIatiOn Process.

space to it, and believing it the one
which will be eventually and generally
lapplied in Arizona, as well as in Sono.
ra and elsewhere, we will continue to
give more or less of such matter as
comes within our observation. The
following appeared in the San Francis
co Bulletin of August 10, without any
signature:
! EDITOR BULLETIN: In your issue OF
the 9TH, | notice a communication I'M
der the head of " LixiviatIon for Rebel.
liOus Ores" in which are some errors
in the history of the introduction of this
process in Sonora, Mexico, which l
wish to correct For several years
prior to 1868, had been working ores
in Sonora by amalgamation and smelt-
ing, but owing to the very rebellious
character OF the ores, it was found i'm
possible to treat them with a profit by
any of the then used methods of reduc-
ton, viz, amalgamatiOn and smelling.
Reading about that time an article in
the Scientific Press on the Kuestel &
Hoffman process of COLONIZATION and
Lixiviation, came 10 San Francisco
expressly to examine the process,
bringing with me some 1000 pounds of
my ore, to test its adaptability TO those
ores. The result of these tests were
such as TO induce me to employ Mr..
Hoffman to go to Sonora with me, to
Introduce their process at my hacien-
da. The process of Messrs. Kuestel &
Hoffman was, briefly, the partial de-
sulphurization of the ore by roasting,
and then placing it in closely-sealed
tanks, and filling these tanks with
chlorine gas. The gas was generated
from sulphuric acid, salt and peroxide
of manganese, mixed in certain proper
tions. The teaching was had with a
solution of hypersulphite of soda, and
the silver in solution was precipitated
! by solution of sulphide of soda.
After the introduction of the process
there were found so many obstacles in
the way, such as arose from unskilled
labor, difficulty and expense of procur-
ing the necessary chemicals so far
from the sources of supply, that it Sc
riously affected the utility of the pro-
cess. Finally, our gas generator gave
out and stopped all operations. Mr..
Hoffman, upon my recommendation,
was employed He introduced this
process in the hacienda of La Trini-
dad.
In this dilemma, while considering
what must be done, against the earnest
protest of Mr. Hoffman, commenced
experimenting on simply roasting the
ore in a reverbatory furnace, and
teaching. | soon found that by care
full roasting l obtained as good results
as we had before obtained by the form
er process. From this moment our
success was assured. We commenced
at once to improve our mechanical ap-
pliances, altering our doors so as to eff
feet great economy of fuel and more
through determination of the ores.
One of the most important changes
made was the substitution of sulphide
of lime IN place of sulphide Of soda.
The extreme difficulty of the manufac-
ture of the sulphide of sodium or its
/ importation from San Francisco, in
consequence of its liability to spontan-
eous combustion, suggested to I. C..
Mills, who was IN my employ, and
who was quite an amateur chemist, the
/ idea of the use of the sulphides of
lime or potash. The formula for max
/ ing these compounds he found in some
medical work in his possession. 1t
was found upon experiment that the
sulphide of lime was the most easily
made, and the material the most readi-
ly at hand.
At La Trinidad, after expanding sew
thousand dollars on Mr.. Hoffman's
mode of working, the process was aban-
doned, and ours was adopted and is still
in use. One after another of the mills
in Sonora adopted the process, until
for several years past no other mode of
working silver ores has been in use in
that State. Later the system has been
introduced in the Homigueria Compa-
nv's works in Lower California, with
what results Mr. Brooks has told your
readers in his letter Of the 9th of July.
The process, as now practiced in So
nora, Sinaloa and Lower California,
had its origin, or at least lis first prac-
teal application and adaptation to Pc
cific coast wants, at my hacienda and
under my direction. All the essential
mechanical appliances row in use were
first used and perfected at the same
place, aud greater variety of rebel
lious ores have been treated there sue
cessfully, and by this process, than any
other place on the continent. So
much for the truth of history"
As remarked by Mr.. Brooks, the es-
senlial point in the treatment of ores
by this process is the roasting. l have
consequently given this matter espe-
cial attention particularly in reference
to mechanical furnaces. | put up two
of the :. RrncknerN furnaces as early h