Gold.—The
yield from siliceous ores decreased from $3,818,226 in 1921 to
$3,012,211 in 1922, and that from" copper ores decreased from $27,471
to $15,064; the placer output increased from $4,226,000 to $4,395,000.
Twenty-three dredges produced $1,767,753 of the placer gold, which was
$185,233 more than the dredge output in 1921.
The
2,513,455 tons of siliceous ores treated in 1922 yielded an average of
$1.23 in gold and silver a ton, and the 581,384 tons of copper ore
contained $1.10 in gold and silver a ton.
About
41 per cent of the total output of gold in Alaska came from gold lode
mines in 1922, against 47 per cent in 1921, 53 per cent in 1920, 47 per
cent in 1919, 37 per cent in 1918, 31 per cent in 1917, and 29 per cent
in 1912. The 627 placers operated in 1922 yielded 5,226,000 cubic yards
of auriferous gravel, of which the dredges handled 3,186,343 cubic
yards and made an average recovery of 55 cents a cubic yard in 1922,
against 57 cents in 1921, 69 cents in 1920, 77 cents in 1919, and 57
cents in 1918. The estimated total recovery of gold by dredging for the
period 1903-1922 is $24,875,205.
No important new placer-bearing areas were operated in 1922.
Silver.—The
mine production of silver in Alaska in. 1922 was 729,945 fine ounces,
against 761,085 ounces in 1921. The copper mines produced 623,518
ounces, an increase of 78,289 ounces; the siliceous ores 71,346 ounces,
against 99,515 ounces in 1921; and the placers 26,369 ounces, against
22,565 ounces. Lead ores yielded 8,712 ounces in 1922 and 93,776 ounces
in 1921.
ARIZONA.
Gold.—The
mine production of gold in Arizona in 1922 was $3,524,134, or $593,831
more than in 1921. Placers contributed only $11,981. The deep mines
produced $3,512,153, of which 64 per cent came from dry and siliceous
ores mined chiefly in Mohave, Cochise, and Yavapai counties, and 34 per
cent was contained in copper ores mined chiefly in Cochise and Yavapai
counties. Mohave County had a gold output of $2,100,728, Cochise County
of $755,733, and Yavapai County of $464,101. The gold recovered from
ores treated at gold and silver mills represented about 60 per cent of
the total deep-mine output, against 80 per cent in 1921, and crude ores
shipped to smelters contained about 36 per cent. The crude copper ores
mined and smelted directly (without previous concentration) contained
an average gold output of about 73 cents a ton.
Silver.—The
mine production of silver in Arizona increased from 2,469,394 fine
ounces in 1921 to 4,531,864 ounces in 1922. Of this output 2,766,277
ounces came from copper ores, 1,012,558 ounces from dry and siliceous
ores, 744,559 ounces from lead ores, and 8,357 ounces from copper-lead
ores. Cochise County produced 2,655,673 ounces in 1922, of which
1,324,294 ounces came from copper ores and 786,890 ounces from
siliceous ores; and Yavapai County produced 949,331 ounces, derived
mainly from copper ores. Bullion recovered from gold and silver ores,
almost all by cyanidation, contained 152,128 ounces of silver,
concentrates 478,339 ounces, and crude ore shipped to smelters
3,883,494 ounces.
