884 MINERAL RESOURCES, 1913----PART I.
The
tonnages treated in gold and silver mills, with increase and decrease
for 1913, have been noted in connection with a preceding table.
The
total yield of gold by amalgamation in the United States in 1913 was
927,572 fine ounces, valued at $19,174,615, against 1,003,470 ounces,
valued at $20,743,266, in 1912, and against 1,120,344 ounces, valued at
$23,159,566, in 1911. The principal decreases for 1913 compared with
1912 were from 141,470 to 136,122 ounces in Alaska, from 391,421 to
360,102 ounces in California, from 93,283 to 85,022 ounces in Colorado,
from 88,979 to 64,283 ounces in Nevada, and from 241,502 to 224,649
ounces in South Dakota. The principal increase was from 7,953 ounces in
1912 to 27,726 ounces in 1913 in Oregon. California, South Dakota, and
Alaska continued the greatest producers of gold by amalgamation in the
order named. The total yield of silver by amalgamation was 428,844 fine
ounces, against 795,755 ounces in 1912. The production is largely from
Texas (where pan amalgamation has been used), followed by Colorado,
California, and South Dakota, and the decreases were marked in Texas
and California. The recovery in Colorado, California, and South Dakota
is mainly incidental to the extraction of gold.
The
total output of gold by cyanidation in 1913 was 1,348 fine ounces,
valued at $27,872,289, against 1,386,526 ounces, valued at
'$28,662,036, in 1912, and against 1,259,400 ounces, valued al
$26,034,108, in 1911. The bulk of the output was In Colorado. Nevada,
South Dakota, Arizona, and Alaska in order named. The increases were
chiefly in Arizona (from 90,812 to 97,123 ounces), in California (from
51,423 to 62,372 ounces), in Colorado (from 158,591 to 462,483 ounces),
in New Mexico (from 18,561 to 22,467 ounces) and in Oregon (from 2,525
to 12,140 ounces). The main decreases were in Alaska (from 97,369 to
91,531 ounces), in Montana (from 40,957 to 36,684 ounces), in Nevada
(from 444,633 to 403,267 ounces) in South Dakota (from 132,669 to
124,589 ounces), and in Utah (from 21,148 to 12,756 ounces). The total
output of silver by cyanidation was 14,090,407 fine ounces in 1913,
against 11,728,730 ounces in 1912 and 8,781,552 ounces in 1911. The
principal increases for 1913 as compared with 1912 were from 42,738 to
69,140 ounces in Arizona, from 72,715 to 77,788 ounces in California,
from 355,462 to 365,965 ounces in Colorado, from 61,201 to S4.S55
ounces in Montana, from 9,941,876 to 11,890,016 ounces in Nevada, from
841,575 to 1,024,063 ounces in New Mexico, and from nothing to 255,141
ounces in Texas (where pan amalgamation is now being largely supplanted
by cyanidation).
in
addition to these recoveries by amalgamation and cyanidation the
rapidly declining chlorination process yielded $236,188 in gold in 1913
against $339,432 in 1912. The output was $86,998 from Colorado and
$149,190 from California in 1913.
According
to the percentages of the total output from all sources of gold and
silver amalgamation yielded 21.5 per cent of the gold and 0.6 per cent
of the silver in 1913 against 22.3 per cent of the gold and 1.2 per
cent of the silver in 1912. Cyanidation yielded 31 per cent of the gold
and 19.7 per cent of the silver in 1913 against 30.9 per cent of the
gold and 17.8 per cent of the silver in 1912. The decrease in relative
output by amalgamation is therefore pretty well offset by the increase
by cyanidation. Amalgamation in 1913 pro-
