Durango semi-weekly herald., 1902-01-13

depth OF 30 feet and advised further
development This property in the
prospect stage, produced S25. 900 in
so days, being drowned out during Is
days OF the time, during the present
season. Amalgamation and concen-
tration are employed and the tables
are saving about 40 per cent of the
product that leaves the plates. The
operators will put in cyanide plant
having determined that the tailings
can be treated successfully by this
process.
Other mills In the La Plata district
are to be remodeled to suit the vari-
GUS characters of the ores. Most of
them were built ill-advisedly on reck-
less statements that the ores were
free milling, but the fallacy or un-
truth of this having been learned at
great expense. practical men are pro
ceeding on practical lines.
While there are in the San Juan
country idle mills, it is noteworthy
fact that all that are operating are do
ing SO profitably. For the reduction
of the ores generally to pulp, few
mistakes have been made in the EN-
ployment of the modern stamps, but
many errors have been made on the
theory or presumption that the ore
was free milling. Progress has been
made in the study of the peculiar char
acter of ores and the adaptability of
methods and appliances for their sue
cessful treatment. AS an instance
in the result we do not find two con
centrating or two cyanidation plants
in the entire country conducted upon
the same detail, Each one has been
adjusted to the requirements of spe-
cial conditions. While every mill ap-
pears to be making close savings
there is not a mill operator in the
country who is not studying closer
savings.
Within the area of the San Juan
country nearly every appliance known
to the concentration of ore is employ
ed in some place or in some manner.
Tables are made to do jig work.
Screens are abandoned in one place
and a tinr mesh is sought in another.
Crusher and rolls in one place and
stamps without either in another.
Hydraulic or ordinary water
classification does not appear to have
reached stage of perfection any
where. Regrinding has not been
avoided with any special degree of
success. No two sets of tables are
which has given the San Juan country
more than two.thirds of its produc.
ton during the past five years
Many new milling enterprises are pro
jected for the near future, and there
will be several new mills built dur.
ing the coming year. Alterations
changes and notifications Will be go
ing on all the time as the mine own
ers of the San Juan are determined to
save their values.
All forms of power are employed
here. but the tendency is to water
as initial power and electricity. tc
| save coal in a country where coal IL
| cheaper than elsewhere in mining
sections.
During the past two years there
has been a flood of capital seeking
| tlllHe iuNcStHltIt III llt Dan Judl
country, and every opportunity offer
ed has required mill treatment. There
are few mines in the San Juan ship
ping their entire product In the crude
state, and those that are doing so
have mill products which ultimatel!
must have mills.
| Among the sections most needing
mills at present are the La Plata ant
Needle mountains. The former need.
amalgamation, concentration and cy
andation, with pyritic treatment tt
concentrates and crude product. Th'
Needles need concentration an,
mating Determinations have beeI
made which will result II
one of the largest combinatio'
mills in the world being bull
on the East Mancos of La Plata group
and the work of construction, 1t Il
understood, will be begun during th'
coming year.