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 1918. If the
quantity used in California, Alaska, and Oregon is added to the
3,316,835 pounds reported to have been used in other Western States,
the estimated total consumption was probably about 1,900 tons.
The
figures given indicate the elimination of the use of potassium cyanide
in the recovery of gold and silver, for only about 700 pounds were used
in 1918, and this was probably from old stocks at mines. The growing
scarcity of potassium cyanide necessarily increased the use of sodium
cyanide. The domestic supply of sodium cyanide was sufficient to supply
the domestic consumption. As the quantity of bullion recovered was less
in 1918 than in 1917, however, the quantities of quicksilver and of
cyanide used were less. 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 mainly caused by the difference in the
character and the varying 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. B. S. Butler, C. N. Gerry, V. C. Heikes,
Charles W. Henderson, James M. Hill, G. C. Martin, and Charles G. Yale,
the writer is especially indebted.
