Salt Lake evening Democrat. [volume] (Salt Lake City, Utah) 1885-1887, 1886-01-28
CONCENTRATING LOW. GRADE ORE
Great success Reported on the Conn
stock-What Will Result From
the New Process.

u
The Golden Gate Concentrator set up
at the Brunswick mill, says the Virginia
Chronicle of the 26th, is said to be Civ
ing general satisfaction, and the manage
ment are about to order five more to take
the entire pulp resulting from the daily
crushing of the fifty-six stamps.
Last week the concentrates from l47
tons of ore were amalgamated in one pan
in twelve hours. Under the old process
it is necessary to run sixteen pans twenty
four hours to amalgamate that amount OF
unconcentrated ore crushings.
The bullion returns from the concen-
trates amalgamated are said to have ex-
ceeded the assay value of the ore 81 per
ton the ore from the assay samples show
ing an average value of SO per ton, while
the bullion assay returns gave value OF
$11.
This apparently phenomenal result can
readily be explained: The ore worked at
the Brunswick carries much larger per-
centage of gold than silver, and when
that metal predominates in quartz it is
well known fact that it is not so evenly
distributed as in ore where silver predom-
mates. 1t frequently occurs that in taking
samples for assay that the quantity taken
out of mass of crushings contains only a
small percentage of the yellow metal,
while the same amount taken from some
other part of the lot gives much greater
value.
If the statement OF the result obtained
from ore worked by the concentrating
process is not exaggerated, it will result
in the immediate introduction OF the pro-
cess in all the mills along the river, and
will lead to the overhauling and starting
up of old mills propelled by steam power
and the construction of new ones to
crush and concentrate the countless mil
lions of tons of low-grade quartz in the
Comstock lode.
Heretofore the wear and tear Of pan
castings and the pans themselves has
constituted the most expensive branch of
reducing ore to bullion.
The amalgamation of the concentrates,
according to the late experiment at the
Brunswick mill, demonstrates that the
wear and tear Of the pans and shoes alone
is reduced to less than one-sixteenth. A
| prominent mill man remarked that if the
tconcentrator does its work as well as re-
ported, there will be 10000 men en-
| ployed in the mines and mills on the
| Comstock in less than three years.
1t is rumored that in view of the sue
| cess of the experiment at the Brunswick,
| similar concentrators have been ordered
for the Eureka mill, to be used in work.
ing ore taken from above the 1850 level
of the Con. Cal. & Va. mine, which also
carries larger percentage of gold than
silver. Under the new milling contract
Senator Jones receives $6 per ton for
transforming into bullion the ore extract
ed from above that level Of the mine.
By the concentrating process it is claimed
that gold-bearing quartz can De crushed
and amalgamated for so cents per ton.
| This will allow the Senator a margin Of
$5. so per ton on all ore run through the
concentration. The shipments of ore from
above the 1850 level of the mine to the
Eureka mill average $50 tons per day.
This will give the mill owner clear
profit of over 81 900 per day.
In free milling ore where silver pre-
dominates, the concentrating process will
not prove so successful. If low grade,
ROlu-U6dTluS quartz Cdu Dc tletiloIolL LuCu
into bullion at a cost of only 30 cents per
ton or even $1.50, it would pay hand
somely to run cut at the base of Cedar
| hill, erect two or three one hundred-stamp
mills with concentrators on the floor of
the opening and rake the material pro-
miscuously into self-feeders, as the de-
composed matter which forms the hill
will assay over So per ton from base to
summit.
In like manner the entire belt OF low
grade quartz and mineralized decomposed
matter. assaying from 81 to $S per ton,
now being explored on the upper levels
of the north-end mines, which extends
in an almost unbroken line from the Utah
to the Silver Hill, a distance Of. over five
miles in length by several hundred feet
in width and depth, can be transformed
into bullion at profit, if the concentrate
ing process is adopted.