Gilpin observer., 1899-11-09
ORE REDUCING MACHINERY.
Progress Being Made In Devising Effective
PrOceRAeR.

Progress Being Made In DevIsing Effective
Processes.
Machinery for the reduction of ores
has bothered the minds of men ever
since it was known that gold and silver
We're infinitely combined in n hard mat
rix, but 1t Is only within the past fifty
years that the greatest progress has
been achieved by way of successful
designs, and here it is safe to say that
more advancement has been made in
the past fifty years than in the preced-
ing 2,5OO.
Stamps were used fifty or more years
ago, but the stamps of the past We're
crude, cumbersome and really unme-
chanical as compared with those of
the present day. Gradually, and as the
Americans began to handle them, they
evolved into a more effective machine,
and to-day the stamp batter of the min
ing world is as unlike the battery of
fifty years ago as it is possible to con-
ceive, and to Californians largely be-
longs the credit of this great advance.
AS time passes progress in all things
comes with it. Time has perfected the
stamp battery to such degree that it
seems nothing more can be added.
With all this has come also advance
ment in interchangeable manipulation
iiu eNtIictloH VI TIE pTeclOuS IletdlS.
With the stamp battery and its ac-
companying machinery for the eXtrac-
tion of the precious metals not over Go
per cent. on the average, has been the
yield. while with the advance of the
solution processes from So per cent. to
% per cent. under suitable conditions,
is rs readily and more economically OBJ
tained. The stamp battery performs
its crushing part completely, where
simply crushing is required, yet for
the solution system it produces too
much Shiny material, which increases
the expense per ton of manipulation as
well as reduction. What is demanded
for gold and silver ores, and more es-
pecially gold. is a plant that produces
uniform product free from shines,
and by which more perfect and
speedy percolatiOn can be had.
In the effort to gain this higher per-
centage obtainable by solution process
es new and economical questions arise,
which begin to show that as II protita-
ble machine the stamp battery has
reached its eliminating point of use
fulneSS for ores containing gold and
silver, and especially for gold, and that
new method of reduction must be
adopted for economically gaining the
high percentage Obtainable which all
up-to-date mill men know can be had.
The progress of the times in metal
lurgy demands that at least 80 per cent
of the gold values and so per cent. If
not 50 per cent. of the silver values
should be extracted on an economical
basis. and this edict is relegating the
stamp battery for ores of the precious
metals to the past. and upon the simple
proposition that it is inapplicable to the
economical working of advanced solu-
tion systems. to say nSthing of the
cheapening of machinery and expense
of reduction by this method.
The cyanide processes. of which the
= Macarthur Forrest is the original. are
the advance steps in metallurgy of the
present period. and great advance 1t
Is. when we consider the imperfect eX-
traction of gold of even twenty years
ago.
The question that calls for con-
sideration in the change of machinery
for the extraction of gold is. shall we
hold to the stamp or shall we break in
to the operations of the past and OBJ
tain. as we can. n higher percentage of
gold values at less expense?
In some sections, notably Australia.
this idea of change is largely acted
upon, and has proved acceptable by
proving profitable.
When we give our thoughts for criti-
cally considering the stamp battery we
see cumbersome collection of heavy
material. requiring large space for
buildings. heavy expense for eXcavat-
ing. erection, etc. above what II should
he for the amount of work to be exc
cuted.
The coming system not only gives n
higlas percentage of the metals at n
less expense. but the machinery for
doing it, where freight, time. excava-
tions. buildings. ETC., are considered
will in the majority of instances cost
all of One-third. If not one-half. less.
This coming system for reduction of
gold and silver ores Is the use of crush
ers. rolls and barrels. or. as they are
more properly termed. ball mills. All
of this class of machinery has been in
use separately. as every mill man
knows. and they have proved in their
separate operations practical and eff
fective.
The newer feature Is the combination
of the more perfected machinery of
this special kind. To make more clear.
will say:
First-Will be n suitable crusher for
reducing the ore down to say inch
in size.
Second-The use of steel rolls for re-
ceiVlng tnlS Linen ore ana bringing 1t
down to say A-inch or coarser. as may
be desired. and agreeable to rock being
reduced.
Third-The ball mill. for receiving
the ore from the rolls and reducing It
= to any desired fineness. say from 30
mesh 900 wire to SOmesh (G4OO). all
OF uniform grain and free of any
amount of slimy material.
This system of reduction is dircctly
In line-in fact, is the most desirable
where base gold or silver ores require
the use Of furnaces or where furnace
work may he required to better the
percentage for any of the solution pro-
lussns