In
output of silver from copper ores Montana continued to lead with
10,521,219 ounces in 1918, against 8,911,389 ounces in 1917 and
11,226,034 ounces in 1916; Arizona followed with 5,347,618 ounces in
1918, against 5,214,411 ounces in 1917; Utah ranked third with
1,445,559 ounces in 1918, against 2,225,119 ounces in 1917; and
California produced 669,711 ounces in 1918, against 882,480 ounces in
1917. The production of Montana is mainly from Butte, that of Arizona
has been chiefly from Bisbee and Jerome, that of Utah from Tintic and
Bingham, and that of California from Shasta and Calaveras counties. Of
these districts Bisbee well represents the disseminated type; Bingham
produces from both lode and disseminated deposits; and the remainder
produce silver chiefly from copper ore mined from deep lodes.
LEAD ORES.
The
mine production of silver from argentiferous lead ores in 1918 was
18,291,243 fine ounces, against 19,096,474 fine ounces in 1917 and
19,216,586 ounces in 1916. The output from Idaho decreased from
8,063,768 ounces in 1917 to 8,036,861 ounces in 1917, that of Utah
decreased from 7,490,650 ounces to 6,672,725 ounces, and that of
Colorado increased 288,856 ounces. The yield in Idaho is mainly from
the silver-lead ores of the Coeur d'Alene, that in Utah is chiefly from
the Park City and Tintic districts, and that in Colorado from Aspen and
Leadville. There was a decrease in the production of silver from lead
ores in California from 726,174 ounces in 1917 to 448,547 ounces in
1918. There were also decreases in both Nevada and Arizona, but these
decreases were more than balanced by an increase of about 320,000
ounces in Montana. Most of the output is from the desilverization of
lead bullion from smelting of western ores and concentrates.
ZINC, LEAD-ZINC, AND MIXED ORES.
Argentiferous
zinc ores produced 135,676 ounces of silver in 1918, against 549,656
ounces in 1917, mainly as refinery by-products from the smelting of
zinc concentrates from Colorado, California, and Nevada.
Lead-zinc
ores produced 7,290,380 fine ounces of silver in 1918, against
8,645,038 ounces in 1917, chiefly from concentrates from the Coeur
d'Alene in Idaho, the Butte district in Montana, and the Park City
region in Utah. The output from Idaho decreased from 3,619,535 ounces
in 1917 to 794,449 ounces in 1918. The production of silver from
lead-zinc ores in Montana increased from 2,386,824 ounces in 1917 to
4,532,034 ounces in 1918.
Copper-lead
and copper-lead-zinc ores produced 224,580 ounces of silver in 1918,
against 448,042 ounces in 1917. The output was mainly from Utah, New
Mexico, Colorado, Arizona, and California.
