Morning appeal. [volume] (Carson City, Nev.) 1877-1906, 1877-08-08
DRY ORE CONCENTRATION AT THE
MANHATTAN SILVER MILL.

this subject, by Mr. A. Trippel, Mining En-
ginecr, 1t is intended for DR.. r. W. Ray
mond's forthcoming report on the Mineral
Resources Of the Rocky Mountains. We
make few extracts as the article is too
! lengthy to give it entire in these columns
Tho peculiar character and great richness
of the Reese River District ores worked in
this mill are well known and need no new
description. It may be well to call attention
to the fact that the fuel used for the Stete-
! feldt furnace in this mill is wood and charcoal
combined. Of the whole wood and charcoal
| consumed about nine cords of wood are used
! daily for the motive power, and small guam
tity of charcoal for the melting furnace and
assay room the remainder is used for the
roasting of ores. It should also be mentioned
that the cord of wood costs S12, and charcoal
| 30 cents bushel, while labor is generally
| paid 81 per shift.
AT the present time the expenses of milling
the ore must be less, as the company now has
its Own iron foundry on the spot, and an ex-
tenaige, well-appointed repair shop. With re-
gard to the percentage of silver produced,
there is no doubt that the Manhattan is ahead
OF any other mill in Nevada, and its working
results may therefore, be the more interesting.
The most important feature in Reese River
| District was the introduction Of /" krom S >"
dry separation or concentration of ore at the
Manhattan Mills. 1t has already been stated
! in last years report that previous tests with
Lander Hill ores in Krorns establishment at
the Sheba Mine, near Unionville, had given
satisfactory results, and it was expected that
equal results would be obtained at Austin
with the same ore These Iesults (of which
give the details in the appended table, were
a total product of concentrations, including
dust, equaling about SO per cent. of the assay
value Of the worked ora. The ore which was
used on that occasion was q mixture from the
principle mines then worked by the Manhat-
tan Company, having mean assay value of
$40 per ton OF this mixture a little over
five tons were treated. The mineral in the
ore consisted Of sulphurets of iron, copper,
lead, fahl-ore, antimonial silver, and ruby sill
yer, finely distributed through the quartz, yet
the most PARTICLES were easily visible, and
could be well distinguished from each other.
The results being as favorable as could be eX
pected, it was decided TO construct works with
q capacity to treat fifty tons of ore per day,
and during the winter the machinery, or most
of it was constructed in New York, and erected
the following summer in the building formerly
known as the - Boston Mill, and expressly
purchased for that purpose by the Manhattan
Company The main part of this building Is
a massive structure ll6 by Al feet, with a
large extention on the east side, and spacious
rooms for steam engine and boilers. The
motive power was furnished by two engines,
one of so horsepower for the crushing and
another of Is horse power for the concentra-
tors proper. The first was partly rebuilt by
Booth & Co. of San Francisco from the en-
CINE on hand in the mill building, and was
provided with the best modern improvements; |
the smaller one was ordinary engine. The |
arrangements for feeding the boilers were ex-
ceedingly well made, and everything done to |
economist fuel, which at Austin is very eI-
pensive The machinery for crushing and |
was distributed mainly on two |
floors of the main building, with loft and |
screen tower, with bins for ore and tailings, !
and the main portion of the screening and siz-
ing arrangements. The building being on a
hillside, it was arranged that the ore be
dumped high up on platform in the rear of
the same, and delivered through chutes on
the second floor next to the ore breaker-one
of Blake's largest size.
Cost of milling labor IS 68; Fuel SO IS;
Supplies 81 90; Quicksilver So 03; Salt s. sc;
Office labor 50 90; Castings 50 So; Hauling
50 80; Total S31 y.
A most interesting comparative test with
wet concentration was made side by side with
the dry process. A well-constructed auto
matte working triple jig was used; the water,
being scarce, was continually pumped back in
the reservoir, and as the ore was compare
lively free from dust, no difficulty was exper-
fenced in doing so. The general result was,
hat the product was equal to that made III
hree of Krom's separators; the average tail
ngs were trifle poorer, but the concentra-
ions were by far lower in value than in
Arom's machines, and my impression is that
he work done by the latter is preferable for I
hat class of ore.
Another interesting yeatuse for mill men {
las been we'll proven by this trial; it is the
of the exhaust fan in the place of !
he finer sort of screens. Not that this idea S
S new but, | think, it has never commanded 6
he attention it deserves from mill men
Screening through fine screens is, at best, a '
cry imperfect and troublesome operation, l
nd expensive at that, while | am fully salts c
led myself that proper application OF the t
Exhaust fan would produce a uniformly sized '
ulp with far less dust and at much less d
ost. 1
''She Just Too Sweet to Live, is the lat l
st crime in musical compositions; Maybe t
he is, my friend, but let us take practical k
lew Of the awkward situation. Is she fat t
nough to killl-and if killed in this warm f
leather, would she keep As rule, you i
now, the most saccharine young woman 7
rows devilishly disagreeabIe, even to the d
ose of affection, in very brief period, when a
aughtered in August. Sometimes the sweet W
ess will be clean gone out of her before one t.