Arizona’s unrefined copper concentrate exports are soaring at the same time two foreign-owned, multinational mining companies are planning to construct the Rosemont and Resolution copper mines. The mines would be among the largest in the country, raising questions of whether most, if not all, of the copper would be exported.
Arizona has long been the nation’s leading copper-producing state. And for decades most of the copper concentrate extracted from sulfide ore bodies such as those found at the proposed Rosemont and Resolution mines was processed at giant furnaces called smelters. The smelters transformed copper concentrate into metal that could be further refined into products such as wire and tubing.
The smelters also were notorious for emitting high levels of air pollution and heavy metals including arsenic and lead. One by one, the smelters closed leaving the state today with only two located in the communities of Hayden and Miami.
At the same time, foreign investment in Arizona copper mines sharply increased with Grupo Mexico taking control of three Arizona mines through its Asarco subsidiary and the Japanese conglomerate Sumitomo Corp. purchasing a 28 percent share in Phoenix-based Freeport McMoRan’s Morenci mine, the largest copper mine in the United States.
