Year: 1874

As New Mexico is greatly interested in
the mining and working of precious
metals. a few words upon one of the
many processes OF beneiciating ores
NAV not bs entirely unwelcome. We
wish TO call attention to the process
known as lixiviation for the extraction of
silver. This is comparatively unknown
and not employed in the United States.
For many years experiments have been
made by different chemists and metal
nroists in endeavoring to perfect this
process sufficiently to give it u command
over the present modes of working ore;
vet it is but lately, within the last two or
three years, that its practical working
has been such as to commend it as the
most profitable. In Sonora it was first
developed into its present high standing;
and such is the estimate placed upon 1t
there that most Of the mills are adopt
ing it; and all acknowledge Its superior
ity in working ores for silver alone.
Where gold is found in the ore it is ex-
tracted by the old methods. Llxiviatiop
steps in and takes the place Of quick.
silver; otherwise the milling, etc.. is
lust the same. Pans and settlers are
done away with, and with them quick
silver. For rough outline Of this
method We have the following: The ore
is dry crushed by battery and roasted
in q triple furnace. The roasted ore is
placed in wooden boxes (about four feet
wide, two feet high and eight
feet long) which have false bot.
toms or frame of latis work
covered with canvass in order to re-
tain the ore while filtration takes place.
Roasting is necessary in order to obtain
soluble metalc salts in the ore. Water
is now run upon the ore in the boxes;
the flow of water received being equal to
full. The salts of the base metals be-
ing slouble in water, we find that they
are decomposed and carried off by this
flow OF water. leaving behind the silver.
After four or i've hours test is made to
know whether all the base salts passed
off. The test is either made by sulphate
Of lime or by tasting--the water being
very sweet when bearing silver. Next
the flow of water is turned off and the
ore allowed time to become drained
occupying about an hour. Then solu-
ton of blue and salt or chloride OF cop
per is run on, which carries off the silver,
Is received in large tanks (wooden)
where the sulphate of silver is precipi-
tated by solution of sulphate OF cal
cum. About one part of lime to two of
sulphur is used in making the latter
solution. The clear liquor in the pre-
clpitatipg tanks is now run off and
pumped into the reservoirs or tanks from
which it originally came--to be used
again. The precipitated silver is taken
and placed in canvass drains, and
washed with water to remove the hy-
posulphate OF lime. 1t is then pressed
and dried in furnace (reverberatory)
the sulphur being disengaged by the
heat. From the furnace the silver is
placed in crucibles with proper fuxes.
Some suppose this process to be not ap-
plicable to refractory ores; yet SO and SO
per cent. silver are obtained from ore
which has considerable galena, zinc
bIende, some antiDony, arsenic, iron
pyrtes, etc. About one day is
necessary In this process. The
number OF boxes or tanks used
should be regulated by the capacity Of
the mill. The cheapness of the method
is notable; merely lumber for the boxes,
some lime and sulpber; no expense in
pans, entirely avoiding the monstrous
expense of quicksilver. This subject is
well worthy the attention of mill men
and miners, as it greatly reduces the cost
Of beneticiating silver ores.


:. The foregoing is from the Santa Fe
New Mexican. All we can add is that
Mr. Hitchcock, of Big Bug, in this coun-
ty long ago witnessed the trial of this
process upon some of his ores, by Mr..
hustel of San Francisco, when it work
ed like charm. II Arizona Miner.