Miami Mine

Description: Miami includes an open-pit copper mine, a smelter and a rod mill.

Location: 90 miles east of Phoenix, in the heart of Arizona’s historic Globe-Miami mining district.

Did you know? The Miami mine historically had been the major copper producer in the Globe-Miami mining area, one of America’s premier copper mining districts.

Ores: The Miami mine is a porphyry copper deposit that has leachable oxide and secondary sulfide mineralization. The predominant oxide copper minerals are chrysocolla, copper-bearing clays, malachite and azurite. Chalcocite and covellite are the most important secondary copper sulfide minerals.

Processes and facilities: Since about 1915, the Miami mining operation had processed copper ore using both flotation and leaching technologies. The design capacity of the SX/EW plant is 200 million pounds of copper per year. During 2015, Miami’s operating plans were revised to suspend mining operations and produce copper through leaching material already placed on stockpiles. 

Background: The first prospecting expeditions visited the area in the 1860s. Copper was mined underground until after World War II, when the first open-pit mining began. Miami was among the first to employ “vat leaching” (1926) and precipitation plants to recover oxide minerals. It did this in conjunction with its flotation concentrator, which processed sulfide minerals. The plant’s smelter was modernized in 1974 to meet Clean Air Act standards and further modernized and expanded in 1992. The success of an SX/EW plant commissioned in 1979 led to the demise of vat leaching by the mid-1980s and ultimately the concentrator in 1986. The rod mill was commissioned in 1966 and the refinery in 1993 (the refinery was permanently closed in 2005).

Ownership: 100%.


Type: IsaSmelt™ technology (primary furnace) and ELKEM electric furnace (secondary); four Hoboken style converters, two oxygen plants; and an acid plant treating all process gases.

Did you know? The Miami smelter processes copper concentrate primarily from FCX's Arizona copper mines. In addition, because sulphuric acid is a by-product of smelting concentrates, the Miami smelter is also the most significant source of sulphuric acid for FCX's North America leaching operations. Miami is the only smelter in the United States to achieve International Organization for Standardization (ISO) 9001:2000 certification. In addition to copper concentrates, the smelter also recycles inorganic metal-bearing waste typically produced by high technology industries, extending the useful life of valuable metals and reducing disposal of metal-bearing waste in landfills. Copper and other precious metals are extracted during this process.

Ownership: 100%.

Rod Mill

Product: Continuous-cast copper rod.

Did you know? Completed in 1969 and the first of its kind to be located at a mine site. The plant uses the Southwire design casting system with Morgan mills to produce 7,500-pound and 15,000-pound copper rod coils.

Production: The Miami rod mill treats cathodes from the Miami mine and our other North America copper mines.

Ownership: 100%.