installed
which is claimed to have given good results with the exceptionally
fine gold on Snake River. The machine consists of a wooden box with a
trough at the bottom. A jig impulse is given to water in one side of
the box, with the effect of keeping sand agitated in the other half, so
that platinum and gold fall to the bottom. Some tons of concentrates
have been collected. Experiments are still being conducted as to the
most efficient method of cleaning up these concentrates.
Three
miles south of Crescent City, Cal., a large concentrator has been
erected on a tract of 135 acres of beach protected by sand dunes from
the ocean. The sand is lifted by a hydraulic injector to riffles made
of a patented alloy. The concentrates are cleaned up on similar
riffles, which are subjected to an alternating current.
It
is interesting to note that while the proportion of platinum to gold,
where it occurs in the beach sands, varies from one-twentieth to
one-half, and occasionally is even greater, the larger part of the
platinum product came from dredge mining on Feather and Yuba rivers,
Cal. On Feather River the dredges did not yield more than 1 part of
platinum to 1,000 parts of gold, and on the Yuba the proportion of
platinum is far less—certainly not more than 1 part of platinum to
3,000 of gold, and probably less. This speaks well for the efficiency
of the methods of cleaning up in dredge work.
REFINED PLATINUM.
The
United States supply comes chiefly from the unmanufactured and
manufactured platinum imported indirectly from Russia. In addition,
45,280 ounces of platinum sand were imported into the United States,
which, by the usual estimate of 80 per cent fine metal, would yield
36,224 ounces of refined platinum. It is estimated that the fine metal
in the platinum sand produced in the United States would be 70 per
cent, or 505 ounces. In all 36,729 ounces of fine platinum would
probably be the contribution from foreign and domestic platinum sand.
Another considerable source of platinum supply in the United States
comes from the refining of imported and domestic gold and copper
bullion, and from this source 1,300 ounces of platinum were obtained in
1912. It is not possible to determine the proportion of this platinum
which came from domestic sources, but it probably was not more than 500
ounces. In all, the refined platinum produced in domestic refineries
amounted to approximately 38,029 fine ounces, valued at $1,732,221, as
compared with 29,140 fine ounces similarly obtained in 1911.
Much
of the platinum obtained from copper bullion originated in the mines at
Sudbury, in Ontario, Canada, but during 1912 materials classed as
copper-platinum-palladium concentrates continued to be shipped from the
New Rambler mine in Wyoming. The concentration plant established at
that point makes it probable that this region will become a small but
regular contributor. This mine and the platinum localities in general
in the United States were described in the report of this series for
1911 by Waldemar Lindgren.
In
the foothills of the Whitepine Mountains, Nev., near Illipah, in T. 17
N., R. 59 E, Mount Diablo meridian, 30 miles northwest of Ely, is a
deposit of black sand from 500 to 1,000 feet in width and extending
southwest from Illipah for 4 or 5 miles. Samples of the sand and
