Overview
Miami includes an open-pit copper mine, an operating smelter and a rod mill.
The Miami Mine historically has been the major copper producer in the Globe-Miami mining area, one of America's premier copper mining districts. Miami is now conducting an extensive, award-winning reclamation program and is in partnership with other mining companies from the area to remediate contaminated ground water downstream of the historic production sites.
Location
Miami mine located 90 miles east of Phoenix in the heart of Arizona's historic Globe-Miami mining district.
Geology and 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.
Copper mineralization occurs as disseminations in a Tertiary age porphyry. The deposit that has leachable oxide and secondary sulfide mineralization.
Mining Operation
The Miami mining operation has been on care-and-maintenance status since 2002, but has historically processed copper ore using both flotation and leaching technologies since about 1915. Since 2002, residual leaching of stockpiles has continued with copper recovered (from solution) by the SX/EW process. The design capacity of the SX/EW plant is 200 million pounds per year. The Miami smelter processes concentrates primarily from Bagdad, Sierrita, Morenci and Chino, and has been in production for over 80 years. The smelter has been upgraded during that period to implement new technologies, to improve production and to comply with current air quality standards. During 2006 and 2005, approximately 675,000 and 750,000 tons of concentrate, respectively, were processed through the smelter. The Miami smelter is the most significant source of sulfuric acid for the various PD domestic leaching operations. The sulfuric acid is a by-product as sulfur released during the smelting of concentrates is captured. The rod plant produces about 316 million pounds of 5/16 inch diameter ISO9001 rod per year. An electro-refinery at the site has been permanently closed.
Processing
Ores Processes and facilities:
SX/EW plant, smelter and rod mill. In October 2009, FCX announced initiatives to resume limited mining activities at the Miami mine.
Smelter
IsaSmelt technology (primary furnace) and ELKEM electric furnace (secondary); four Hoboken style converters, two oxygen plants; and an acid plant treating all process gases.
The smelter is the only one 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. In addition, the smelter produces by-product sulfuric acid.
