Mining history 1930-1975
Mining history 1930 - 1975
The“Great Depression” brought the merger of the Calumet and Arizona with Phelps Dodge. Yet with these difficult times came investments in more mechanization and modernization of the mines to make them as efficient as possible in the face of low copper prices. Only the Junction and Campbell mines were operating, as PD leased the Czar, Holbrook and Southwest mines. The Shattuck was leased out and the Denn closed for maintenance.
Fortunately, for Bisbee, gold and silver prices were raised to unprecedented levels, so ores high in gold and/or silver ores were preferentially mined. Nevertheless, Bisbee was ready to fully contribute to the all-important war effort when needed. However, the post-war years were difficult for copper, as so much war scarp was on the market. Bisbee turned to mining lead and zinc to survive until 1950. By now the low-grade ores left by the early Sacramento Pit were attractive and when combined with the deeper Southeast orebody, a new open pit mine was possible. Thus began the Lavender Pit, which gave Bisbee and additional 25 years of life by twice expanding the original mine plan.
It is doubtful that the high-cost underground mines alone could have carried the necessary overhead and too, processing much of the underground sulfide ores in the new concentrator saved on smelting cost by removing much of the associated waste rock. Certainly the continued improvements in mining techniques, notably backfilling and blasting brought important cost savings, but underground mining is labor intensive. In the end, high labor costs, low metal prices coupled with new and onerous regulations brought an end to mining at Bisbee 95 years after it began.
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