The Morenci mine is a porphyry copper deposit that has oxide, secondary sulfide and primary sulfide mineralization. The predominant oxide copper mineral is chrysocolla. Chalcocite is the most important secondary copper sulfide mineral, with chalcopyrite as the dominant primary copper sulfide.

Morenci is an open-pit copper mining complex that has been in continuous operation since 1939 and previously was mined through underground workings.

Morenci’s available mining fleet consists of one hundred and fifty-four 236-metric-ton haul trucks loaded by 13 electric shovels with bucket sizes ranging from 47 to 57 cubic meters. Morenci’s mining fleet is capable of moving an average of 815,000 metric tons of material per day.

The Morenci operation consists of two concentrators with a milling design capacity of 132,000 metric tons of ore per day, which produce copper and molybdenum concentrate; a 72,500 metric ton-per-day, crushed-ore leach pad and stacking system; a low-grade run-of-mine (ROM) leaching system; four SX plants; and three EW tank houses that produce copper cathode. Total EW tank house capacity is approximately 900 million pounds of copper per year.