Arizona Breccia Pipe Uranium Mineralization - History

History

The earliest breccia pipe mined for uranium was the Orphan, a mineralized pipe exposed on the southern wall of the Grand Canyon within the Grand Canyon National Park. During the late 70s, Energy Fuels Nuclear, Inc. (founder Bob Adams and successor Oren Benton) began a concerted effort to locate and then mine further examples of this previously neglected class of uranium deposit. With the exploration success of Energy Fuels and the ensuing development of the early Hack 1 and 2, Pigeon, and Kanab North mines, competing exploration and mining companies soon entered northern Arizona. During the 1970s and 1980s, relatively large companies such as Gulf Resources, Pathfinder Mines Corporation, Rocky Mountain Energy Company, and Uranerz all competed with Energy Fuels Nuclear, Inc., for mineral rights in the predominantly public lands of the Arizona Strip. By 1989, at least 13 uranium-ore-bearing breccia pipes had been identified by various companies. Nearly all northern Arizona uranium exploration had stopped by that year, however, due to the low uranium price.

Each of the ore-bearing breccia pipes mined during the 1980s was developed by Energy Fuels, which shipped ore northeast to its White Mesa Mill in Blanding, Utah. According to the United States Geological Survey, Energy Fuels Nuclear, Inc., produced in excess of 19 million pounds of U3O8 from seven mines through the 1980s.

The reason for uranium exploration and uranium mining in northern Arizona, during a period of low yellowcake price, was the high grade and compact nature of the uranium mineralization contained in some of the collapse breccia pipes in the region. In 1982, total production cost for breccia pipe uranium was about $10/lb U₃0₈ concentrate that then sold for approximately $40/lb. Later inflation-corrected cost data published by EFN in the Canyon Mine Environmental Impact Statement confirms the 1982 total cost quotation. In 2007 US dollar terms, the total cost to produce a pound of U₃0₈ from the average pipe was about $24. Average ore reserves for an individual mineralized pipe at that time were determined to be about 3.5 million pounds U₃0₈, with an average grade of about 0.6 percent U₃0₈, then giving the average economically mineralized pipe an approximate before-tax, undiscounted in-ground value of about $105 million (more than $225 million in 2007 US dollars). The breccia pipe mineral deposits range from 1000 to 1800 feet deep and have a vertical extent of up to 600 feet. The pipes typically have a 200-to-400-foot (61 to 120 m) diameter. A 1,000-to-1,600-foot-deep (300 to 490 m) shaft is usually required to access the deposits. In some cases where a mineralized pipe occurs near a deep canyon, a decline can be used instead of a shaft to access the ore during mining.