It
has not been possible to obtain a complete report showing the total
consumption of potassium cyanide and sodium cyanide used in the
recovery of gold and silver in the United States in 1919. If the
quantity used in California, Alaska, and Oregon is added to the
2,210,844 pounds reported to have been used in other Western States,
the estimated total consumption was probably about 3,000,000 pounds.
The
quantity of cyanide used per ton of ore or tailings treated and the
quantity of gold and silver recovered per pound of cyanide show
considerable variations. These variations are doubtless due in part to
greater efficiency in large milling plants in some of the States,but
are caused mainly by differences in the character and the metal
content of the ores treated.
ACKNOWLEDGMENTS.
To
those engaged in the mining and metallurgic industries, to merchants,
bankers, and transportation officials of the United States and Alaska,
to the Bureau of the Mint, the Post Office Department, and the Bureau
of Foreign and Domestic Commerce of the Department of Commerce, and to
other officials, public and private, who have cooperated with the
United States Geological Survey by furnishing information on the
production of gold and silver, acknowledgment is gratefully made. To
the authors of the Survey mines reports on the production of gold,
silver, copper, lead, and zinc in the Eastern, Central, and Western
States and in Alaska, Messrs. C. N. Gerry, V. C. Heikes, Charles W.
Henderson, G. C. Martin, and Charles G. Yale, the writer is especially
indebted.
