in
Alaska, 25,234 ounces in Colorado, and 22,076 ounces in Nevada. There
was no appreciable increase shown in any State, though there were large
decreases in 1918 in California, South Dakota, Idaho, Oregon, and
Washington.
The
total yield of silver by amalgamation in 1918 was only 216,670 fine
ounces, valued at $216,670, against 288,791 ounces, valued at $237,976,
in 1917. The output came mainly from California, South Dakota, Alaska,
Oregon, Colorado, and Nevada, in the order given, and consisted chiefly
of silver alloyed with gold.
The
total output of gold by cyanidation in 1918 was 1,047,186 fine ounces,
valued at $21,647,256, against 1,169,478 fine ounces, valued at
$24,175,256, in 1917, and 1,260,172 ounces, valued at $26,050,067, in
1916. The output was 430,042 ounces in Colorado, 215,500 ounces in
Nevada, 140,193 ounces in Arizona, 115,234 ounces in South Dakota,
46,290 ounces in California, 43,749 ounces in Montana, 28,205 ounces in
Oregon, and 22,127 ounces in Alaska, in 1918. The only important
increases in 1918 were that of Arizona, amounting to 21,431 ounces, and
that of California, 23,640 ounces. The principal decreases were in
Alaska, 25,688 ounces: Colorado, 94,405 ounces; Montana, 20,313 ounces;
Nevada, 10,817 ounces; South Dakota, 12,326 ounces.
The
total yield of silver by cyanidation in 1918 was 9,736,605 fine ounces,
valued at $9,736,605, against 11,535,747 fine ounces, valued at
$9,505,455 in 1917, and 14,432,378 ounces, valued at $9,496,505, in
1916. Nevada led, with the bulk of the output (8,078,689 ounces), and
was followed by Texas with 569,565 ounces, Colorado with 327,726
ounces, and New Mexico with 262,114 ounces. The most notable losses
were in Arizona, 94,627 ounces; Nevada, 1,141,663 ounces; New Mexico,
393,067 ounces; Colorado, 52,926 ounces; Montana, 118,724 ounces.
The
quantity of gold recovered from ore treated by amalgamation decreased
about 150,300 ounces in 1918, and that recovered from ores cyanided
decreased about 122,300 ounces.
Of
the gold-producing States, whose chief output is from milling ores,
Alaska, California, New Mexico, and South Dakota still yield more gold
by amalgamation than by cyanidation, whereas the latter process
produces more gold than amalgamation in Arizona, Colorado, Montana,
Nevada, and Oregon, and it produces much more silver in Arizona,
Colorado, Montana, Nevada, New Mexico, Oregon, South Dakota, and Texas.
Alaska, California, and Idaho were the only States in which the
recovery of silver by amalgamation exceeded that by cyanidation.
Altogether amalgamation produced gold and silver valued at $14,239,595
from milling ores in 1918, against $31,383,861 produced by cyanidation
from such ores in that year.
Of
the total output of gold from all sources in 1918, amalgamation
produced 25.4 per cent in Alaska, 35.5 per cent in California, 36.7 per
cent in New Mexico, and 63.7 per cent in South Dakota; and cyanidation
produced 53.3 per cent in Arizona, 69.5 per cent in Colorado, 29.1 per
cent in Montana, 67.3 per cent in Nevada, 15 per cent in New Mexico,
and 36.2 per cent in South Dakota.
Of
the total output of silver from all sources in 1918, amalgamation
produced 35.1 per cent in South Dakota and 16.8 per cent in Oregon, and
cyanidation produced 80.8 per cent in Nevada, 33.5 per cent in New
Mexico, 53.5 per cent in Oregon, 61.5 per cent in South Dakota, and
98.8 per cent in Texas.
