The Providence news. (Providence [R.I.]) 1891-1906, 1897-09-30

is still in use in Mexico and at mines
in the United States, was that of hand
picking. The improvements in sampling
ores have been even more striking.
Great improvements have also been
made in ore crushing. For the bowlder
crusher OF Bolivia and Mexico have been
substituted the battery of stamps and
the rolls. A large amount of labor has
been saved by the manner Of construc-
ton Of the smelling works. All refining
works are now built in terrace form and
are so arranged that the base bullion,
which has necessarily to be handled
while being unloaded, sampled and
charged into the softening furnace, shall
run from one furnace to another and
not be lifted again until it is loaded.
"In the smelling proper improve
ment has been even more active than III
the preliminary operations.
I'm the treatment of dry silver ores,
which are amalgamated with quick
silver and retorted, the chief improve
ment of recent years has been in the
saving of quicksilver.
"The methods Of extraction of high
grade silver in vogue in the Unite1
States and in the best mills throughout
the world may be summarized as fol-
lows: The ore is hauled TO the mill, Ia
sifted and sorted by machinery, crushed
by heavy stamping batteries or by the
rolls, after which it is carried directly
TO the amalgamating pans, in which 1T
is kept constantly in motion by ma
chinery, passing through the eight pans
in four hours From these the pulp
passes into settlers, which clean up the
charge of 1000 pounds in four hours
more. The mass is then retorted. The
average cost of an average mill in Ari-
zona was from So. IL TO $4.90 per ton
Of ore
1.-THE improvements in lead silver ex-
traction have been perhaps more nota-
bic than any others. Prior to 1874 these
ores were reduced by amalgamation as
ordinary dry ores About that time it
was discovered that this silver could be
far more easily extracted by process
of smelling Following this discovery
came the great development of Lead
Vile and Pueblo in the early eighties.
The essentials of this method of extrac-
tion are: CD The smelling of the ore in
an ordinary blast furnace; (2) the con-
centration of the silver into much
smaller quantity Of lead; (8) the sopa-
ration of tie silver in cupcling fur
mace. The blast furnace has been great
ly improved during the last 25 years.
can important feature of the general
Improvement in the silver industry has
been the rapid introduction Of electric
ity into mining operations. The use Of
tho electric light has greatly facilitated
all processes carried on within the
mine Electric power is also employed
in hoisting ore and i'll pumping. with
the very best results both Us regards
cost and convenience. Electricity can
be transmitted long distances with only
small loss of power, and il is thus
possible TO use power at such distance
from its source as would render il other
wise unavailable. The importance Of
this improvement can be better realized
when we consider that one of the
greatest obstacles which mining, espe-
cially in Mexico, has 10 encounter is
the difficulty of obtaining fuel for pow
pr, owing both TO the lack Of transpor-
tation facilities and, where these exist.
20 the high charges for hauling coal
from the United States Where water
power Exists within radius Of so miles
IL can be used for the transmission Of
electric power TO a silver mine. The
economy Of power is very remarkable.
At one set Of mines in Mexico, those
operated by the Real Del Monte works,
electric power is obtained from ReRla
falls and transmitted from 3 to 25 miles
60 work pumps, hoists, stamp mills,
crushors ard vontilators
"It is obvious that the results Of this
long series Of improvements in silver
mining and silver smelling have been
greatly to lower the cost Of producing
silver. These improvements have doubt
less 20 some extent been accelerated
by the falling price Of silver. which they
have also tended 10 produce. IL was not
90 bc expected that the great advances
which have characterized every other
department Of industry would not affect
the production OF silver and IL should
be remembered that there is no reason
70 believe that this march Of improve