Uranium mining in the United States: Difference between revisions
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In Utah, uranium is found mostly in penecordant deposits in sandstones of the Cutler Formation ([[Permian]]), Chinle Formation ([[Triassic]]), and [[Morrison Formation]] ([[Jurassic]]). It is often associated with organic material in the normally oxidized sandstones. Common uranium ore minerals are [[carnotite]], [[tyuyamunite]], [[uraninite]], and [[coffinite]]. |
In Utah, uranium is found mostly in penecordant deposits in sandstones of the Cutler Formation ([[Permian]]), Chinle Formation ([[Triassic]]), and [[Morrison Formation]] ([[Jurassic]]). It is often associated with organic material in the normally oxidized sandstones. Common uranium ore minerals are [[carnotite]], [[tyuyamunite]], [[uraninite]], and [[coffinite]]. |
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All of [[Utah]]’s numerous uranium mines closed prior to 2000, because of low prices. In late 2006, [[Denison Mines]] reopened the Pandora mine in the La Sal mining district of southeastern [[Utah]]. [[Denison Mines]] has applied for permits to begin mining their Henry Mountain Complex uranium deposit in 2007.<ref>R.L. Bon and K.A. Krahulec, ''Utah'', Mining Engineering, May 2007, p.121.</ref> |
All of [[Utah]]’s numerous uranium mines closed prior to 2000, because of low prices. In late 2006, [[Denison Mines]] reopened the Pandora mine in the La Sal mining district of southeastern [[Utah]]. [[Denison Mines]] has applied for permits to begin mining their Henry Mountain Complex uranium deposit in 2007.<ref>R.L. Bon and K.A. Krahulec, ''Utah'', Mining Engineering, May 2007, p.121.</ref> [[Energy Fuels Inc.]] expects to reopen the Energy Queen mine in the La Sal trand of [[San Juan County, Utah|San Juan County]] in 2008.[http://www.energyfuels.com/projects/near_term/energy_queen/] |
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===See also=== |
===See also=== |
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Revision as of 19:10, 17 July 2007
Uranium mining in the United States declined drastically in the 1980s, but has revived since 2003 due to higher uranium prices.
Regular production of uranium-bearing ore in the United States began in 1898 with the mining of carnotite-bearing sandstones of the Colorado Plateau in Colorado and Utah, for their vanadium content.
The late 1940s and early 1950s saw a boom in uranium mining in the western US, spurred by the fortunes made by prospectors such as Charlie Steen. The United States was the world's leading producer of uranium from 1953 until 1980, when annual US production peaked at 16,810 tonnes.[1] Up until the early 1980s, there were active uranium mines in Arizona, Colorado, New Mexico, South Dakota, Texas, Utah, Washington, and Wyoming. [2]
Price declines in the late 1970s and early 1980s forced the closure of numerous mines. Most uranium ore in the United States comes from deposits in sandstone, which tend to be of lower grade than those of Australia and Canada. Because of the lower grade, many uranium deposits in the United States became uneconomic when the price of uranium declined sharply in the late 1970s. By 2001, there were only three operating uranium mines (all in-situ leach operations) in the United States, producing less than 1,000 tonnes of uranium annually.
Uranium is used primarily for nuclear power. In 2001 the United States had 104 operating nuclear power plants generating 20% of the nation's electrical power supply. Although the United States had the most nuclear power plants of any country, it generated a much lower percentage of electricity from nuclear power than did France (76% from nuclear) or Japan (34% from nuclear). In 2001 the United States mined only 5% of the uranium consumed by its nuclear power plants. The remainder was imported, principally from Canada and Australia.[3]
Although uranium production has declined to low levels, the United States has the fourth-largest uranium resource in the world, behind Australia, Canada, and Kazakhstan.[4] Rising uranium prices since 2003 have increased interest in uranium mining in Arizona, Colorado, Texas and Utah.[1] The states with the largest known uranium ore reserves (not counting byproduct uranium from phosphate) are (in order) Wyoming, New Mexico, and Colorado.[5]
Arizona
A Navajo discovered uranium in 1942 in Monument Valley on the Navajo Indian Reservation in northeast Arizona. The first mine in the district opened in 1948. Uranium and uranium-vanadium minerals occur in fluvial channels of the Shinarump Sandstone member of the Triassic Chinle Formation. Ore deposits are associated with carbonized wood in the sandstone.[6] In 2005 the Navajo tribe declared a moratorium on uranium mining on the reservation, because of environmental and health concerns.
There are currently no producing uranium mines in Arizona. Denison Mines plans to begin mining its Arizona One mine in 2007.[2] The deposit is in a breccia pipe on the Colorado Plateau of northern Arizona.[7]
Colorado
See main article, Uranium mining in Colorado
The first uranium identified in the USA was pitchblende from the Wood gold mine at Central City, Colorado in 1871.
Uranium mining in southwest Colorado goes back to 1898. The Uravan district of Colorado and Utah supplied about half the world's radium from 1910 to 1922, and vanadium and uranium were byproducts.
The only currently active uranium mine in the state is the Sunday mine near Uravan, Colorado, owned by Denison Mines.[8]
Florida
The Florida phosphorite deposits are considered to contain the largest known uranium resource (one million tonnes of uranium oxide) in North America. Uranium is produced as a byproduct of phosphate mining and the production of phosphoric acid fertilizer. The uranium is contained in the phosphate minerals francolite, crandallite, millisite, wavellite, and vivianite, found in Miocene and Pliocene sediments of the Bone Valley Formation. The average uranium content is 0.009%.[9] However, because the recovery process costs an estimated $22 to $54 per pound of U3O8, more than the price of uranium from the 1980s through the early 2000s, uranium has been recovered from Florida phosphate in recent years. Because of the high price of uranium since 2003, uranium recovery may be reactivated.[3]
Nebraska
The only uranium mine in Nebraska has been the Crow Butte mine, operated by Cameco. The mine is five miles southeast of Crawford in Dawes County, western Nebraska. The roll-front deposit in sandstone was discovered in 1978 by accident, while drilling for petroleum.[10] The uranium is being mined by in-situ leaching.
New Mexico
New Mexico was a significant uranium producer since the discovery of uranium by Navajo sheepherder Paddy Martinez in 1950. Uranium in New Mexico is almost all in the Grants mineral belt, along the south margin of the San Juan Basin in McKinley and Cibola counties, in the northwest part of the state. Stretching northwest to southeast, the mineral belt contains the Chuska, Gallup, Ambrosia Lake, and Laguna uranium mining districts.[11] Most of the uranium ore is contained in the Jackpile, Poison Canyon, and Westwater Canyon sandstone members of the Morrison Formation, and in the Todilto limestone, all of Jurassic age.[12]
Active mining stopped in New Mexico in 1998, although Rio Algom continued to recover uranium dissolved in water from its flooded underground mine workings at Ambrosia Lake until 2002.[13] No mining has been done since 2002, even though the state has second-largest known uranium ore reserves in the U.S. The Navajo tribe, whose reservation contains much of the known ore deposits, declared a moratorium on uranium mining in 2005.[14]
General Atomics subsidiary Rio Grande Resources is currently evaluating its Mt. Taylor Mine for development by in-situ leaching. Uranium is present in coffinite in the Westwater Canyon member of the Morrison Formation at 3,000 feet (900 m) below ground surface. The mine, which operated as an underground uranium mine from 1986 to 1989, has a remaining resource estimated by its owner at more than 100 million pounds uranium oxide.[4]
Strathmore Minerals Corp. is currently applying for permits to mine their Church Rock and Roca Honda properties in the Grants Mineral Belt.[5]
South Dakota
Uranium was discovered near Edgemont, South Dakota in 1951, quickly followed by mining. The uranium occurs in Cretaceous sandstones of the Inyan Kara group, where it outcrops along the southern edge of the Black Hills in Fall River County, South Dakota. Minerals in unoxidized sandstone are uraninite and coffinite; minerals in oxidized zones include carnotite and tyuyamunite.[15] No uranium is currently mined in South Dakota, although in January 2007 Powertech Uranium Corporation received a state permit to perform exploration drilling for uranium northwest of Edgemont.[6][7]
Texas
The uranium district of south Texas was discovered by accident in 1954 by an airborne gamma radiation survey looking for petroleum deposits. The coastal plain had previously been regarded as highly unfavorable for uranium deposits.[16] The uranium occurs in roll-front type deposits in sandstones of Eocene, Oligocene and Miocene age.[17] The deposits are distributed along about 200 miles of coastal plain, from Panna Maria in the north, south into Mexico. Uranium production began in 1958, from open-pit and in situ leach mines.
Uranium production stopped in 1999, but restarted in 2004.[18] By 2006, three mines were active: Kingsville Dome in Kleberg County, the Vasquez mine in Duval County, and the Alta Mesa mine in Brooks County.[19]
Utah
Mining of uranium-vanadium ore in southeast Utah goes back to the late 1800s. Because much of the value depended on the vanadium content, the only economic ore minerals were carnotite and tyuyamunite. Following World War II buying for nuclear weapons programs made uranium valuable for its own sake, and attracted hundreds of prospectors to southeast Utah. Major new deposits were discovered at White Canyon in 1948, and Lisbon Valley in 1952.[20]
The Bingham Canyon Mine in Salt Lake County, a large porphyry copper mine, recovered 120,000 to 150,000 pounds of uranium each year from 1978 through 1989, as part of its copper mining operation.[21]
In Utah, uranium is found mostly in penecordant deposits in sandstones of the Cutler Formation (Permian), Chinle Formation (Triassic), and Morrison Formation (Jurassic). It is often associated with organic material in the normally oxidized sandstones. Common uranium ore minerals are carnotite, tyuyamunite, uraninite, and coffinite.
All of Utah’s numerous uranium mines closed prior to 2000, because of low prices. In late 2006, Denison Mines reopened the Pandora mine in the La Sal mining district of southeastern Utah. Denison Mines has applied for permits to begin mining their Henry Mountain Complex uranium deposit in 2007.[22] Energy Fuels Inc. expects to reopen the Energy Queen mine in the La Sal trand of San Juan County in 2008.[8]
See also
Wyoming
Wyoming once had many operating uranium mines, and has the largest known uranium ore reserves of any state in the U.S. The Wyoming uranium mining industry was hard-hit in the 1980s by the drop in the price of uranium. The uranium-mining boom town of Jeffrey City lost 95% of its population in three years.
The Gas Hills district, straddling the Natrona-Fremont county line in central Wyoming, was discovered in 1953, and ore production began in 1955. The ore consisted of lenticular bodies of meta-autunite, uraninite, and coffinite in fluvial arkosic sandstones in the upper Wind River Formation of Eocene age. Mining was mostly by open pit, although there were also some underground mines.[23] Strathmore Minerals Corp. of Kelowna, British Columbia is currently applying for permits to mine properties in the Gas Hills district.[9]
In the Little Mountain mining district on the west side of the Bighorn Mountains, Big Horn County, Wyoming, uranium was produced from 1955 to 1970 from paleokarst breccias in the Madison Limestone of Mississippian age. The uranium occurs as carnotite and tyuyamunite.[24]
By 2006, the only active uranium mine in Wyoming was the Smith Ranch-Highland in situ leach operation in the Powder River Basin, owned by a subsidiary of Cameco. The mine produced 907 tonnes of yellowcake (uranium concentrate) in 2006, making it the leading uranium producer in the United States.[25]
References
- ^ Uranium 2003: Resources, Production and Demand, Paris: OECD Nuclear Energy Agency, 2004, p.238
- ^ Warren I. Finch and others (1973) Nuclear fuels, in United States Mineral Resources, US Geological Survey, Professional Paper 820, p.458.
- ^ Warren I Finch (2003) Uranium-fuel for nuclear energy 2002, US Geological Survey, Bulletin 2179-A.
- ^ Warren I Finch (2003) Uranium-fuel for nuclear energy 2002, US Geological Survey, Bulletin 2179-A.
- ^ J. Keller and others, Colorado, Mining Engineering, May 2006, p.76.
- ^ Roger C. Malan (1968) The uranium mining industry and geology of the Monument Valley and White canyon districts, Arizona and Utah, in Ore Deposits of the United States, 1933-1967, New York: American Institute of Mining Engineers, p.790-804.
- ^ N. Niemuth, Arizona, Mining Engineering, May 2007, p.70.
- ^ J. Burnell and others, Colorado, Mining Engineering, May 2007, p.77.
- ^ Warren I. Finch (1996) Uranium provinces of North America-their definition, distribution, and models, US Geological Survey, Bulletin 2141.
- ^ R.M. Lyman, Wyoming, Mining Engineering, May 2005 p.130.
- ^ Douglas G. Brookins (1977) Uranium deposits of the Grants mineral belt: geochemical constraints on origin, in Exploration Frontiers of the Central and Southern Rockies, Denver: Rocky Mountain Association of Geologists, p.337-352.
- ^ H.C. Granger and others, Sandstone-type uranium deposits at Ambrosia Lake, New Mexico-an interim report, Economic Geology, Nov. 1961, p.1179-1210.
- ^ S.A. Lucas Kamat, New Mexico, Mining Engineering, May 2006, p.107.
- ^ S.A. Lucas Kamat, New Mexico, Mining Engineering, May 2007, p.103.
- ^ Olin M. Hart (1968) Uranium in the Black Hills, in Ore Deposits in the United States, 1933-1967, New York: American Institute of Mining Engineers, p.832-837.
- ^ Southern Interstate Nuclear Board (1969) Uranium in the Southern United States, United States Atomic Energy Commission, p.97.
- ^ William E. Galloway (2007) Geology of Texas uranium, in Geology of the Karnes Uranium District, Texas, Austin Geological Society Field Guidebook, p.9-19.
- ^ S.J. Clift and J.R. Kyle, Texas, Mining Engineering, May 2006, p.114.
- ^ S.J. Clift and J.R. Kyle, Texas, Mining Engineering, May 2007, p.114.
- ^ R.P. Fischer (1968) The uranium and vanadium deposits of the Colorado Plateau region, in Ore Deposits in the United States, 1933-1967, New York: American Institute of Mining, Metallurgical, and Petroleum Engineers, p.738.
- ^ Technologically enhanced Naturally Occurring Radioactive Materials from Uranium Mining v.1, US Environmental Protection Agency, EPA 402-R-05-007, p.1-17.
- ^ R.L. Bon and K.A. Krahulec, Utah, Mining Engineering, May 2007, p.121.
- ^ F. D. Everett (1963) Mining Practices at Four Uranium Properties in the Gas Hills, Wyoming, US Bureau of Mines, Information Circular 8151.
- ^ Ray E. Harris (1983) Uranium and thorium in the Bighorn Basin, in Bighorn Basin, Wyoming Geological Association, 34th Annual Field Conference Guidebook, p.171-177.
- ^ W.M. Sutherland, Wyoming, Mining Engineering, May 2007, p.126.