NORTH AMERICA

SIERRITA

Description

Morenci is an open-pit copper mining complex.

Did you know? We have expanded our mining and milling capacity at Morenci to process additional sulfide ore identified through exploratory drilling. The project targets average incremental annual copper production of approximately 225 million pounds through increases in milling rates to 115,000 metric tons per day (mtd).

Location

Southeast Arizona, about 50 miles northeast of Safford.

Ores

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

Processes and facilities

The Morenci operation consists of two concentrators capable of milling 115,000 mtd, which produce copper and molybdenum concentrates; a 68,000 mtd crushed-ore leach pad and stacking system; a low-grade run-of-mine (ROM) leaching system; four solution extract (SX) plants; and three electrowinning (EW) tank houses that produce copper cathode. Total EW tank house capacity is approximately 900 million pounds of copper per year. During second quarter of 2015, Morenci’s concentrate leach, direct-electrowinning facility, which was placed on care-and-maintenance status in early 2009, resumed operations.