LEAD ORES.
The
mine production of silver from argentiferous lead ores increased
considerably in 1920 but did not equal that of 1918 (18,291,243
ounces). The output from Idaho increased 1,334,149 ounces, that of Utah
increased 1,230,788 ounces, and that of Colorado decreased 226,577
ounces. The yield in Idaho is derived mainly from the silver-lead ores
of the Coeur d'Alene district, that in Utah chiefly from the Park City
and Tintic districts, and that in Colorado from Aspen and Leadville.
The production of silver from lead ores increased also in Nevada,
California, Arizona, Montana, and Missouri. Most of the output is
obtained from the desilverization of lead bullion from smelting of
western ores and concentrates.
ZINC, LEAD-ZINC, AND MIXED ORES.
Silver
from argentiferous zinc ores increased greatly in 1920. It was mainly
refinery by-product from the smelting of zinc concentrates from
Montana.
Silver
from lead-zinc ores decreased. It came chiefly from Colorado, from
concentrates from the Coeur d'Alene region in Idaho, the Butte district
in Montana, and the Park City region in Utah. The output from Idaho
increased from 493,027 ounces in 1919 to 862,435 ounces in 1920, that
in Montana decreased from 3,678,353 ounces to 2,531,685 ounces, and
that in Utah decreased from 714,480 ounces to 630,875 ounces.
The output of silver from copper-lead and copper-lead-zinc ores came mainly from Idaho, Utah, Nevada, and Arizona.
