The Black range. (Robinson, Socorro County, N.M.) 1882-1897, 1884-01-11

one having tw~enty-three years expert
ence among all classes of ores a be
relied upon.
A few general statements rs to the
principles of concentrating ore will be
Of service to mine Owners The prin-
ciple underlying the whole subject of
concentration Is the difference in the
specific gravity of the mineral and the
gangue containing the same. A sim-
pie test is seen, and a good illustration
Of the principle, In taking a piece o
galena ore and a piece of quartz of
equal size and dropping both into
water, the greater rapidity of fall of the
galena ore shows its greater specific
gravity. The principle upon which
a concentration is built is similar, viz:
"0f sizing the ore and gangue from an
eighth of an inch in diameter down to
an impalpible powder, precipitating
both in water. and by an ingenious ar
raugement of the machinery catching
the mineral by itself and the gangue
by itself" Applying this principle to
the different classes of ores in this dis
trict we find that the concentration will
practically treat them all with but very
few exceptions. A pure galena or boz
mite ore cannot be concentrated as
nature has already concentrated them.
The same minerals mixed with gangue
rock in large or small quantities can be
concentrated, the number of tons
being put into one depending upon the
amount of gangue rock contained in
the ore. A good illustration is seen in
the Silver Monument and Colossal ores,
The irst-class ores running from $500
to $500 per ton cannot be concentrated
to any advantage as the process would
simply size the ore, and save it all,
there being practically no gangue rock
to wash out. The second-class ores
running from $50 to $12O per ton will
pay to concentrate and from three to
six tons can be concentrated into one.
These two mines are mentioned as be-
ing best developed and best known.
Other properties carrying similar ore
will pay to concentrate in like manner.
AS will have been noticed by all miners,
the minerals themselves vary in their
specific gravity. AS a rule those miner
ais whose specific gravity is greatest
are the most easily concentrated and
with the least percentage Of loss. The
concentration now in process of cree.
ton will treat the following classes
of ores the degree of saving varying
with the specific gravity of the ores,
viz galena, iron, bornite, free gold; the
sulphides and oxides, horn silver OF
chlorides, silver glance, copper glance,
ruby silver and gray copper, The blue
and green carbonates are difficult to save
and a preliminary test should be made
upon these ores before expanding any
great amount on such properties. Also
minerals so thoroughly decomposed as
to be soluble in water cannot be con-
centrated. In no case can %concentra-
tion separate minerals chemically uni
ted, for example, the silver and galena,
or silver and copper or gold and iron
cannot be separated by concentration.
1t then may be asked "Of what use is
the process if the bullion cannot be ex-
tracted." A simple example will show
the use and profit of concentrating:
Surprising the Silver Monument has
eight tons of ore worth by assay value
$45 per ton, shipment Of the ore to
Argo would cost as follows: From
the mine to Engle, 500; from Engle to
Denver. $40; cost Of treatment, $40.
Making a total of $40 per ton. Ore.
then worth by assay value at the Sill
yer Monument dump $45 per ton is
worthless. 1t won't pay to handle.
Surprising the ore is brought to the
concentration and we have the follow
ing result:
Cost of freight from mine to Chloride
per .Yt.UO
Cost of concentrating. .................. 800
Waste IN concentrating. 90
Fr't on | ton concentrates, to Engle. $40
" " Engle to Denver. u
Cost OF treatment OF concentrates. .. II
S4
One eighth of 81 81 %
-
Total cost per ton $l6.25