Ajo aerial view
Aerial view of Ajo, Ajo smelter and tailings. The Phelps Dodge Mining Company's Ajo Incorporated (PDAI) copper smelter was built in 1950 near the mining town of Ajo, Pima County, Arizona. It was used by Phelps Dodge to test innovative smelting technologies in the 1970s and 1980s, and finally closed in 1985. The smelter was dismantled by 1996.