Gold Hill daily news. [volume] (Gold Hill, N.T. [Nev.]) 1863-1882, 1877-11-12

In the New lork 4ui"i"J hec"'o VI
November lat, we find tho following well
written and carefully prepared commune
cation from It's special correspondent at
Virginia City. DIR. James Delavan' which
will DO read with interest by our fellow
Coms,ockers. as giving . largo amount Of
information on the subject Of which 1t
treat:
Under tho present system Of milling ores
nm the Comstock, though surely the most
economical and successful yet devised,
there IL a loss Of thirty-hve per cent. to
The mine ownes-the mills working up to
but sixty.ive per cent. Of the assay value
Of the ore. To more fully illustrate how
this loss occurs. We will suppose Q ton OF ore
10 ASSAY one hundred dollars, half OF which
will be gold. weighing but little over three
ounces troy. and the other half silver.
weighing but forty 10 forty-four ounces troy.
Thus We have but forty-seven troy ounces
In q mass Of two thousand pounds avoir-
dupois. Nor Ia this precious mass In .
metallic state. but transfused throughout
this large bulk Of ore eighteen cubic feet
a. sulphurets. chlorides, aud other chemi.
cal conditions. To extract these very
small fractions from the bulk, salt, sui
phato Of copper sulphAte Of iron. etc.,
are used, which change them chemically
and prepare them for the bettor action OF
tho quicksilver In amalgamAting. II will
then be no surprise 10 ovon those who are
not familiar with milling. that many OF
these very minute particles should escape
from tho action OF the quicksilver In %
large q mass. The quicksilver itself, Of
which there Ia . loss OF from AZ TO 3t
pounds 10 the ton Of ore worked, carries
or some Of this value In the shape OF
smalgam. The value Of all tho ores hero
ON tho Comstock 10 such that In the pro-
cess Of milling there Is . very hno slime
which floats or with the water, 70 DO set
tied In large reservoirs and dried further
n The percentage thus lostis calculated
TO 30 about 10 per cent. OF the Gro value.
Thus In milling one ton Of 500 ore, the
mine secures but Sos. Ten dollars 10 car
ried of with tho slime and S25 with ~
or 81 pounds Of quicksilver In the tall
ings.
Now II must not DO supposed that this
vast wealth Is lost 10 the world !; on the
contrary, this waste has built up an In
dustry which employs In its utilization .
largo number OF men consumes large
sums In the way Of fuel. chemicals, and
other materials, giving employment to
u best machinists and inventors, and rc-
turning many hundreds Of thousands OF
dollars for tho money and brains en-
ploysd.
Each Of the three large milling COM
panics-thc Lyon, the Pacific and the
Union-have their failing mills" for
tho purpose Of working these same shines
and taiilngs, and each Of these companies
have their own method Of treating and
working them.
The Union Milling Company uses tho
Parke process, which In considered the
beat, having tho greatest capacity for the
the power used the percentage saved Ia
also greater. and II can DO worked on tall.
ings OF q lower grade; while the cost OF
milling il less than by the other processes.
Tho Pacific Mill and Mining Company
uses the Woodbury. process, which 10 also
very successful. This company has tho
finest mills IN tho State, under charge OF
their inventor.
The mills at Dayton tho Lyon Compa.
ny-arc Of great capacity, and Tho most
complete in their details OF any ON tho
coast. All Of these companies use their
own and other inventors slime dryers.
sluiccs. concentrators, pans, etc., with
some Of their wi reflneries for refining
bullion.
Ira \. Parko, Esq, superintendent OF
the Railroad and Express mills. and tho
inventor Of the pans, mullers and process
bearing his name. Mr.. Woodbury.. the Su-
perintcndent Of tho Mariposa and Omega
mills. working with his process, Mr. Con.
rad wicgand-the inventor OF the method
Of refining the amalgam before being ro-
torted with bullion. thus occurring bullion OF
extra fineness-areAl all old ~well.known Com.
stockers connected with and q part OF all
methods OF working tailings. At the same
time In many cases, concentrating u Q
separate branch OF tho business. The
method In common use, is tho old Style OF
blanket %sluices. yet some very excellent
machines have OF late been introduced.
and ~ they arc the inventions Of Comstock-
ers. wo will speak Of them In their order.
"Tho Tool Tables" arc q fiat platform
about forty feet long. and twelve 10 fifteen
feet wide. covered with canvas or canton
flannel. Tho table has 4 slight inclination,
and running lengthwise on the higher
side Is q trough which distributes the
water containing the tailings evenly over
the table; likewise. running tho length OF
the table. Is an iron pipe perforated with
small holes OH the principle OF asprinkler.
The tailings having been allowed to run
over tho table until tho cloth cover 10 well
coated with sulphurets, the water 10 then
sbnt oT aud the ~sulDhureta washed from