COPPER ORES.
The
production of gold from copper ores was $5,424,047 in 1912, against
$5,450,079 in 1911. Increases in gold output from these ores were noted
in 1912 for Alaska, Arizona, Montana, Nevada, and New Mexico, and
decreases for California and Utah, caused in the former State mainly by
smelter litigation, in the latter by labor troubles. The States
producing over $1,000,000 in gold from copper ores in 1912 were Utah
and Arizona, followed by those with less than $1,000,000, Montana,
Nevada, and California, all in the order named, which was the same
ranking as in 1911. The gold is recovered from these ores by
electrolytic refining of blister copper obtained in smelting crude ores
and concentrates.
LEAD ORES.
The
output of gold from lead ores in 1912 was $1,348,087, against
$1,201,606 from this source in 1911. The Utah lead ores ranked first in
yield of gold from this source, followed by those of Colorado, as in
1911. The remainder of the gold from lead ores is chiefly from Nevada,
Arizona, Idaho, and Montana, in the order named. Increases for 1912 are
noted for Colorado, Idaho, and Nevada, and decreases from the other
important States.
LEAD-ZINC, ZINC, AND MIXED ORES.
Production
of gold from lead-zinc ores was $258,177 in 1912, against $357,455 in
1911. The output was mainly from Colorado and Utah. From zinc ores the
gold production was $100,898 in 1912, against $43,624 in 1911, chiefly
from Arizona and Montana. From mixed copper-lead and copper-lead-zinc
ores the gold output was $47,538 in 1912, against $23,221, chiefly from
Colorado, Utah, and Montana.
DISTRIBUTION OF SILVER PRODUCTION OF 1912, BY SOURCES.
The
mine production of silver from dry or siliceous ores, copper ores, and
lead ores combined in 1912 was 93.47 per cent of the total output,
against 94.21 per cent in 1911. The production from dry or siliceous
ores decreased from 41.25 per cent of the total silver output in 1911
to 39.88 per cent in 1912, and the output from lead ores decreased from
25.53 to 25.20 per cent, but the output from copper ores increased from
27.43 to 28.39 per cent. The yield from lead-zinc ores also increased
from 4.01 to 4.26 per cent, and that from mixed copper-lead and
copper-lead-zinc ores from 0.47 to 1.01
E
per cent. The small outputs from zinc ores and from placers showed little change.
The following table shows the source of silver production of the United States by classes of ores, by States:
