102 
MINERALS YEARBOOK, 1967 
 
treated at the Lavender open pit concentrator, and all of the concentrate
produced was smelted at Douglas. 
 Although underground exploration was continued during the year, no important
discoveries were made. The tonnage of new ore developed was somewhat less
than the tonnage mined. The company expected a sharp decline in the output
of Copper Queen underground and Lavender pit ores during the early 1970's.
To replace these operations, Phelps Dodge planned to start developing another
ore body with the completion of the Tyrone project in New Mexico in late
1969 or in 1970. 
 The Douglas smelter, 40 miles east of the Copper Queen Branch operations
at Bisbee, treated ores from the underground mines at Bisbee, concentrates
from the Lavender-pit concentrator, and copper precipitates from Lavender
pit leach material. Also treated at the smelter were copper scrap and other
copper-hearing materials on a custom or toll basis. 
 Production of copper from the New Cornelia Branch, Ajo mine, was 40,118
tons, representing 26 percent of company output. The ratio of waste to ore
mined in the Ajo open pit was 1.58 to 1, the lowest stripping ratio of the
three properties operated by the company. Installation of a short-head cone
crusher and of automatic ball mill controls were among the major developments
at this property during the year. 
 Phelps Dodge Corp. and Tidewater Oil Co., in a joint venture, were the successful
bidders on one of two tracts of land on the San Xavier Indian Reservation.
The bonus offer was $501,938 for 24,935 acres in the central and western
part of the reservation. Under terms of the mineral prospecting permit, with
option to lease, Phelps Dodge and Tidewater were to have 2 years to evaluate
the property and determine its potential. Prospecting may be conducted for
all minerals, other than gas or oil or other hydrocarbons, sand and gravel,
and building stone. The successful bid was to be approved by the landowners
before the permits were to be issued. 
 Ray Mines Division, Kennecott Copper Corp., replaced the old jaw crusher
located at the Ray pit with a new 54-inch primary gyratory crushing plant.
The old jaw crusher and other usable equipment was te be installed in the
silicate-ore leaching plant under construction. 
 Ore treatment capacity at the concentrator operated by Inspiration Consolidated
Copper Co., at Inspiration, was limited by loss of the new leaching-plant
excavator, which failed during tests in 1966. Available highest grade ores
were mined; production was at the maximum with the old equipment. Ore treatment
at Inspiration involved segregation and treatment of three kinds of ore—oxide,
oxide-sulfide, and sulfide ores. Oxide ore with negligible sulfide content
was discarded after leaching. After leaching, mixed oxide-sulfide ores were
sent to the concentrator for milling to recover the sulfide content. Selectively
mined ores, high in sulfide and low in oxide, were sent directly to the concentrator.

 The Live Oak and Thornton open-pit mines were operated continuously until
closed by the strike. Before the shutdown, preproduction stripping of the
Thornton West extension was completed and ore production begun. Preliminary
development of the Red Hill pit was completed. The division mined and milled
4.0 million tons of ore at an average rate of 20,270 tons per day. The ratio
of waste to ore was slightly lower, 1:28 in 1967 compared with 1:30 in 1966.
In 1967, 1,739 tons, 6 percent of the total output by Inspiration Division,
was produced by waste dump and in-place leaching. Vat leaching, a similar
process, was also used as the first step in the processing of ore-grade material.
Leach solutions from vat leaching were stripped of their copper content by
electrowinning, which produced a refined copper cathode, and by precipitation
of copper in the off-solution in the form of cement copper. Leached ores
were retreated by grinding and flotation concentration to liberate and recover
the sulfide copper. The tank leach-concentrator process recovered 50.8 million
pounds of copper, 94 percent of the Inspiration output. 
 Operated by Christmas Division, Inspiration Consolidated Copper Co., the
Christmas underground mine, 10 miles north of Hayden, was closed from October
10, 1966, to July 15, 1967, and was successfully replaced by an open-pit
operation. in the early stages of development, some difficulties were encountered
becaure the pit was small, cramped, and lacked the preproduction stripping
needed for full production. Accelerated waste stripping, extensive drilling,
and assembling and train-