Arizona breccia pipe uranium mineralization
Encyclopedia
During the late 1970s and through the 1980s, Mohave
and Coconino County, Arizona
, immediately north and south of the Grand Canyon
and west of the Navajo Indian Reservation were explored for Arizona breccia pipe uranium mineralization. The search area included the region between the Colorado River
and the Utah
border known as the “Arizona Strip
”.
, a reduced uranium ore mineral, accumulated within the permeable column of broken rock, forming a cylindrical and vertical (and stationary) rather than tabular and sub-horizontal (and migrating) uranium roll front deposit. Apparent mineralizing fluid flow direction was upward. As in roll front deposits, disseminated and massive sulfides are found on the downstream side of breccia pipe uranium accumulations (above the breccia pipe uranium ore).
The surface disturbance of collapse breccia pipe uranium mining has historically been remarkably small because of the high-grade, compact nature of the mineralization and use of underground waste rock back-fill procedures during breccia pipe mine development work. See Figures 6 through 9 of http://www.libertystaruranium.com/sub.asp?sub_id=36§ion_id=8 for photographs of reclaimed breccia pipe uranium mine sites. The same reference written by Dr. Karen Wenrich states, “Although these uranium grades are dwarfed by those of the Athabasca Basin unconformity deposits in Canada, it is significant that (1) the breccia pipe mining costs are significantly less for the Arizona deposits, and (2) these ore grades of 0.4-1% are as high or higher than any other global uranium-deposit type.”
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.http://www.azgs.az.gov/Summer2001.htm
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).http://pubs.usgs.gov/bul/b2004/html/bull2004model_for_solutioncollapse_brecc.htm 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 ft (61 to 121.9 m) diameter. A 1000 to 1600 ft (304.8 to 487.7 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.
Corporation (http://www.denisonmines.com). Besides operating the mill built by Energy Fuels Nuclear, Inc., Denison is in the process of re-opening four of the breccia pipe underground mines previously discovered and developed by Energy Fuels. More than 500 breccia pipe targets in the Arizona Strip area are actively being explored by at least 11 mineral exploration companies (May 25, 2007, data):
Resources, Inc.http://www.quaterraresources.com: 15 targets.
Largely because of their relatively high ore grade and compactness, the United States Geological Survey
anticipates that Arizona collapse breccia pipes will be “…the major source of future uranium production within the United States."http://pubs.usgs.gov/bul/b2004/html/bull2004breccia_pipe_uranium_deposits.htm
Mohave County, Arizona
Mohave County is located in the northwestern corner of the U.S. state of Arizona. As of the 2010 census, its population was 200,186, an increase of 45,154 people since the 2000 census count of 155,032. The county seat is Kingman...
and Coconino County, Arizona
Coconino County, Arizona
-2010:Whereas according to the 2010 U.S. Census Bureau:*61.7% White*1.2% Black*27.3% Native American*1.4% Asian*0.1% Native Hawaiian or Pacific Islander*3.1% Two or more races*5.2% Other races*13.5% Hispanic or Latino -2000:...
, immediately north and south of the Grand Canyon
Grand Canyon
The Grand Canyon is a steep-sided canyon carved by the Colorado River in the United States in the state of Arizona. It is largely contained within the Grand Canyon National Park, the 15th national park in the United States...
and west of the Navajo Indian Reservation were explored for Arizona breccia pipe uranium mineralization. The search area included the region between the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
and the Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
border known as the “Arizona Strip
Arizona Strip
The Arizona Strip is the part of the U.S. state of Arizona lying north of the Colorado River. The difficulty of crossing the Grand Canyon causes this region to have more natural connections with southern Utah and Nevada than with the rest of Arizona....
”.
Geology
Collapse breccia pipes are vertical cylindrical bodies of broken sedimentary rock (breccia), down-dropped into caverns in underlying massive limestone. UraniniteUraninite
Uraninite is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2, but also contains UO3 and oxides of lead, thorium, and rare earth elements...
, a reduced uranium ore mineral, accumulated within the permeable column of broken rock, forming a cylindrical and vertical (and stationary) rather than tabular and sub-horizontal (and migrating) uranium roll front deposit. Apparent mineralizing fluid flow direction was upward. As in roll front deposits, disseminated and massive sulfides are found on the downstream side of breccia pipe uranium accumulations (above the breccia pipe uranium ore).
The surface disturbance of collapse breccia pipe uranium mining has historically been remarkably small because of the high-grade, compact nature of the mineralization and use of underground waste rock back-fill procedures during breccia pipe mine development work. See Figures 6 through 9 of http://www.libertystaruranium.com/sub.asp?sub_id=36§ion_id=8 for photographs of reclaimed breccia pipe uranium mine sites. The same reference written by Dr. Karen Wenrich states, “Although these uranium grades are dwarfed by those of the Athabasca Basin unconformity deposits in Canada, it is significant that (1) the breccia pipe mining costs are significantly less for the Arizona deposits, and (2) these ore grades of 0.4-1% are as high or higher than any other global uranium-deposit type.”
History
The earliest breccia pipe mined for uranium was the Orphan, a mineralized pipe exposed on the southern wall of the Grand CanyonGrand Canyon
The Grand Canyon is a steep-sided canyon carved by the Colorado River in the United States in the state of Arizona. It is largely contained within the Grand Canyon National Park, the 15th national park in the United States...
within the Grand Canyon National Park
Grand Canyon National Park
Grand Canyon National Park is the United States' 15th oldest national park and is located in Arizona. Within the park lies the Grand Canyon, a gorge of the Colorado River, considered to be one of the Wonders of the World. The park covers of unincorporated area in Coconino and Mohave counties.Most...
. 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.http://www.azgs.az.gov/Summer2001.htm
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
Blanding, Utah
Blanding is a city in San Juan County, Utah, United States. The population was 3,162 at the 2000 census, making it the most populated city in San Juan County. It was settled in the late 19th century by Mormon settlers, predominantly from the famed Hole-In-The-Rock expedition...
. 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
Uranium mining
Uranium mining is the process of extraction of uranium ore from the ground. The worldwide production of uranium in 2009 amounted to 50,572 tonnes, of which 27% was mined in Kazakhstan. Kazakhstan, Canada, and Australia are the top three producers and together account for 63% of world uranium...
in northern Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, during a period of low yellowcake
Yellowcake
Yellowcake is a kind of uranium concentrate powder obtained from leach solutions, in an intermediate step in the processing of uranium ores. Yellowcake concentrates are prepared by various extraction and refining methods, depending on the types of ores...
price, was the high grade and compact nature of the uranium mineralization contained in some of the collapse breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
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
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
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).http://pubs.usgs.gov/bul/b2004/html/bull2004model_for_solutioncollapse_brecc.htm 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 ft (61 to 121.9 m) diameter. A 1000 to 1600 ft (304.8 to 487.7 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.
Current activity
With the current increase in price and demand for nuclear reactor fuel (http://www.uxc.com), the Arizona Strip is again the site of very active uranium mineral exploration. The former Energy Fuels Nuclear White Mesa Mill in Blanding, Utah, is now owned and operated by the vertically-integrated Denison MinesDenison Mines
Denison Mines Corp. is a Canadian uranium exploration, development, and production company. Founded by Stephen B. Roman, and best known for its uranium mining in Elliot Lake, it later diversified into coal, potash, and other projects....
Corporation (http://www.denisonmines.com). Besides operating the mill built by Energy Fuels Nuclear, Inc., Denison is in the process of re-opening four of the breccia pipe underground mines previously discovered and developed by Energy Fuels. More than 500 breccia pipe targets in the Arizona Strip area are actively being explored by at least 11 mineral exploration companies (May 25, 2007, data):
- DIR Exploration, Inc.http://www.dirxploration.com: a privately held US company in the Kaibab Joint Venture with the public company, Takara Resources, Inc.http://www.takararesources.com; total breccia pipe target number is 204.
- Energy Fuels, Inc.http://www.energyfuels.com: 25 targets.
- Energy Metals Corporationhttp://www.energymetalscorp.com: 11 targets.
- Liberty Star Uranium and Metals Corporationhttp://www.libertystaruranium.com: 343 targets.
- Mesa Uranium Corporationhttp://www.mesauranium.com: 13 targets.
Resources, Inc.http://www.quaterraresources.com: 15 targets.
- SXR Uranium One, Inc.Uranium OneUranium One is a Canadian based uranium mining company with operations in Australia, Canada, Kazakhstan, South Africa and the United States.-History:...
http://www.uranium1.com: company has just independently entered the area to begin conducting exploration work, but see the joint venture described below with Uranium Power Corporation.
- Tournigan Gold Corporationhttp://www.tournigan.com: 83 targets.
- Uranium Power Corporationhttp://www.uraniumpowercorp.com: 14 wholly owned targets, and an additional 27 in joint venture with SXR Uranium One, Inc., for a total of 41.
- VANE Mineral Resources, Inc.http://www.vaneminerals.com: 38 targets.
- Northern Arizona Uranium Project http://www.northern-arizona-uranium-project.com: 4 targets
Largely because of their relatively high ore grade and compactness, the United States Geological Survey
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
anticipates that Arizona collapse breccia pipes will be “…the major source of future uranium production within the United States."http://pubs.usgs.gov/bul/b2004/html/bull2004breccia_pipe_uranium_deposits.htm
See also
- List of uranium mines
- OreOreAn ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
- Ore genesisOre genesisThe various theories of ore genesis explain how the various types of mineral deposits form within the Earth's crust. Ore genesis theories are very dependent on the mineral or commodity....
- UraniumUraniumUranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
- Uranium mining in ArizonaUranium mining in ArizonaUranium mining in Arizona has taken place since 1918. Prior to the uranium boom of the late 1940s, uranium in Arizona was a byproduct of vanadium mining of the mineral carnotite.-Carrizo Mountains:...