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GOLD AND SILVER.
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additions
to the tonnage of 1905 were Bisbee and Globe in Arizona, Butte in
Montana, Bingham in Utah, and Ducktown in Tennessee. Idaho recorded an
increase of Coeur d'Alene lead ores, while Colo-rado added to its tonnage from the siliceous ores of the Telluride districts
and from the mixed smelting ores of Leadville and Creede. Ores of lower
grade than in 1905 were mined in Butte and Leadville, so that in spite
of heavily increased tonnage the total quantities extracted fell off.
The slump in the price of copper in 1907 will result in a much lower
tonnage for that year in Butte and probably also in Arizona, while the
Bingham and Tintic districts, as well as the Colorado camps, will be
affected to a less extent.
The
average extracted value of the ores in gold and silver is lower in 1906
than in 1905 by 17 cents per ton, and now stands at $4.65. The average
value is higher in Arizona by 37 cents, in Idaho by 24 cents, and in
Utah by 10 cents. The unusually rich gold ores of Goldfield increased
the average value of Nevada ores by $9. On the other hand, Colorado
ores decreased 92 cents, Oregon ores 40 cents, California ores 31
cents, and Montana ores 39 cents in average value per ton. In spite of
the notable rise in values the ore production of Nevada for 1906 is
only greater by about 64,000 tons than it was in 1905. In tonnage the
important States, including Alaska, now rank as follows: Montana,
Arizona, Colorado, California, Utah, Idaho, South Dakota, Alaska. In
1905 California occupied the second place.
The
division of the tonnage shows that the copper ores and the siliceous
ores are most important with, respectively, about 10,500,000 and
9,200,000 tons. Gold and silver bearing lead ores amounted to only
about 2,300,000 tons, while the remaining divisions, zinc ores,
lead-zinc ores, and lead-copper ores, aggregated only about 1,250,000
tons. The greatest average extracted values in gold and silver are
shown by the siliceous ores, $7.87 per ton, and they vary from S31.64
per ton in Nevada to $15.43 per ton in Colorado, $12.29 per ton in
Idaho, $6.33 per ton in Arizona, $5.05 per ton in California, $2.40 per
ton in Alaska, and to the minimum $1.60 per ton in South Carolina.
The
copper ores are much poorer in gold and silver, the average extraction
value being only $1.55 per ton. They range from $12.82 in Colorado to
$3.38 in Utah, $1.58 in Montana, $0.79 in Arizona, and to only a
fraction of a cent in Tennessee and in the Lake Superior copper mines.
The
lead ores average $5.08 per ton, much of the value being in silver.
Utah lead ores and copper-lead ores, chiefly from Park City, Bingham,
and Tintic districts, contain from $10 to $15.20 in gold and silver.
Those from Colorado contain $8.75, while the Idaho lead ores, largely
from the Coeur d'Alene district, average only $3.34, of which all but a
small fraction is in silver.
The
zinc ores of Colorado average only $1.60 per ton, but it is to be noted
that in some of the ores included the silver is not extracted. The same
applies to New Mexico. The lead-zinc ores average higher—$3.07 per ton.
In many cases they are concentrates, and the richer lead ores are
separated from the poorer zinc blendes.
Tables
showing the extent of concentration will be found in many of the State
reports, but it is not yet possible to compute a general table
illustrating this for all of the Western States. 21650—m k 1906------9
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