Description: Morenci is a porphyry copper open-pit mine and processing facility.

Did you know? Morenci is one of North America’s largest producer of copper and one of the largest open-pit mines in the world. It is one of the world’s largest producers of copper cathode from SX/EW. Its operations pioneered the use of Global Positioning Satellite system technology and computer-controlled dispatching in its haul trucks, shovels and other heavy equipment.

Location: Southeast Arizona, about 50 miles northeast of Safford.

Ores: 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: Crush and convey systems, agglomerating facility, stacker/conveyor, concentrator, and four solution-extraction (SX) plants , three electrowinning tank houses (EW) and a copper concentrate leaching facility.  Due to the production curtailments implemented in early 2009, the concentrator and concentrate leaching facility are being held on a care and maintenance status.

History: Phelps Dodge & Company invested $50,000 in the property in 1881, marking the New York mercantile’s first venture into mining. Through acquisition, Phelps Dodge consolidated all mining operations in the district by 1921. Initially underground, Morenci transitioned to open-pit mining beginning in 1937. The operation nearly doubled its production capacity during World War II at the urging of the U.S. government to meet wartime needs. Morenci’s first SX/EW plant was commissioned in 1987. Once home to two smelters, the last smelter ceased operation in 1984. Both have been demolished and reclaimed. A merger in 2007 brought the Morenci mine into the Freeport-McMoRan family.

Ownership: 85% Freeport-McMoRan Copper & Gold. 15% affiliates of Sumitomo Corp.

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