1960 1961 1962 1963 1964 1965 966 1967 
70 
 
 
 
~ 60 
C 
0 
 
 
0 
 
~ 50 
C 
0 
U) 
 
0 
 
*- 40 
 
w 
a. 
0~ 
0 
030 
 
 
 
 
0 
THE MINERAL INDUSTRY OF ARIZONA 
 
 
 
 
Figure 2.—Mine production of copper in Arizona, by months, in terms
of 
recoverable metal. 
97 
 
 
Lavender, Bagdad, and Christmas mines. About 35.3 percent of the waste and
leach material was removed from the Twin Buttes property. .The ratio of waste
to leach material at 11 of the larger open-pit mines was 1.2 to 1. 
 Selective mining ceased to be a major copper source in Arizona. More than
92 percent of the underground ores was mined by block caving; only 660,000
tons was mined selectively. The copper content of the 8.5 million tons of
ore from three large underground mines ranged from 0.758 percent copper developed
by block caving at San Manuel ' to 4.77 percent. The higher analysis represented
the copper in ores mined selectively at Magma. The Copper Queen underground
mine at Bisbee, in continuous operation since 1871, yielded both mill and
highgrade direct-shipping ores. 
 From three open pits and one underground mine, Phelps Dodge Corp., the largest
producer in the State, accounted for about 31 percent of the total output.
The company mines at Morenci and Ajo were operated at capacity until July
15, 
when operations ceased because of the strike. The Lavender open pit and Copper
Queen underground mine were operated at capacity until July 2, when the regular
vacation shutdown began; operations were not resumed because of the strike.
Until closed by the strike, the open-pit mines were worked 188 days, the
equivalent of a 6.5-day week; the underground mines were worked 174 days,
equivalent to a 6-day week. 
 Designed to recover part of the nonsulfide copper content of the Morenci
ores, operation of the leach-precipitationflotation plant (LPF) system was
reported to have improved, although it had not reached designed annual capacity
of 10,000 tons. Further improvement was expected in 1968. During the year
modification was begun on the sulfuric acid plant built in 1965 to provide
acid for the LPF system and for outside customers. 
 The Morenci open-pit mine operated 
by Phelps Dodge Corp. was the State's 
leading copper producer, mining 29.2 
million tons of material, of which 11