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MINERAL RESOURCES.
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announced
and advocated for the extraction of gold from low-grade or difficult
ores, and although some of these are of great merit and mark signal
advances in the art as demonstrated in actual practice in mining camps
where their usefulness and applicability are undoubtÂedly proved, some
of them are mainly advertised in regions where money is always to be
had for "get-rich-quick" schemes and where personal knowledge of mining
and metallurgy are so rare that frauds readily flourish.
The
total production of gold by amalgamation in 1911 was 1,120,344 fine
ounces, of which California, Nevada, South Dakota, Colorado, and Alaska
mills furnished the greatest supply, in the order named. The total
output of silver by amalgamation was 941,155 fine ounces, of which
Texas, Nevada, California, and Colorado furnished the bulk, in the
order given. The Texas recoveries are by pan amalgamation of silver
ores, the other recoveries being mainly with the gold of gold-silver
ores.
The
total production of gold by cyanidation in 1911 was 1,259,400 fine
ounces, the bulk of the output coming from Nevada, Colorado, South
Dakota, Alaska, and Arizona, rapidly descending in the order named. The
total output of silver by cyanidation was 8,781,552 ounces in 1911, of
which Nevada alone supplied nearly 7,000,000 ounces, followed by New
Mexico, Colorado, Idaho, Utah, Montana, and South Dakota, in the order
given.
In
addition to these recoveries by amalgamation and cyanidation the
rapidly disappearing chlorination process yielded 181,206 fine ounces
of gold in 1911, of which 160,937 ounces were recovered in Colorado,
20,006 ounces in California, and 263 ounces in South Carolina.
According
to the percentages of the total output from all sources of gold and
silver, it appears that amalgamation yielded 23.9 per cent of the gold
and 1.54 per cent of the silver; that cyanidation supplied 26.1 per
cent of the gold production and 14.1 per cent of the silver; and that
chlorination produced 3.8 per cent of the gold output in 1911. In the
various States interesting relative differences arc shown by the table
giving percentages of total output by amalgamation and cyanidation. In
South Dakota 61.5 per cent of the gold was recovÂered by amalgamation
and 36.8 per cent by cyanidation, leaving but 1.7 per cent recovered by
placering and smelting combined. In Wyoming, California, Oregon, and
Nevada percentages of gold above the average are recovered by
amalgamation, and in Nevada, Arizona, New Mexico, the Appalachian
States, South Dakota, Colorado, and Idaho percentages above the average
by cyanidation. In silver recoveries Texas led with 98.5 per cent of
the State output, yielded by amalgamation, followed by South Dakota
with 33 per cent. The production of silver in 1911 by cyanidation was
56.8 per cent of the State output in New Mexico, 53.2 per cent in
Nevada, and 51.7 per cent in South Dakota. As shown in a preceding
table the bulk of the silver output of the United States is not from
milling but from smelting ores.
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