production of gold from refining lead bullion from lead ores sold or
treated in 1915, chiefly from Utah and Colorado, was $1,745,709,
against $1,540,348 in 1914, or 1.8 per cent of the total domestic
output of gold in each year.
LEAD-ZINC, ZINC, AND OTHER ORES.
production of gold from lead-zinc ores was $611,870 in 1915, against
$360,746 in 1914; from zinc ores $102,832 in 1915, against $39,548 in
1914; and from copper-lead and copper-lead-zinc ores $51,603 in 1915,
against $11,323 in 1914.
DISTRIBUTION OF MINE PRODUCTION OF SILVER IN 1915, BY
mine production of silver from the three most important sources of
silver—dry or siliceous ores, copper ores, and lead ores—was 89 per
cent of the total output in both 1914 and 1915. The output from dry and
siliceous ores decreased 4.5 per cent in 1915, that from lead ores
decreased 0.3 per cent, and that from lead-zinc ores more than 1 per
cent, but that from copper ores increased 4.6 per cent. The combined
output from placers, zinc ores, copper-lead, and copper-lead-zinc ores,
was a little more than 2 per cent of the total production of silver.