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Uranium mining

Uranium mining is the process of extraction of uranium ore from the ground. Over 50 thousand tons of uranium were produced in 2019. Kazakhstan, Canada, and Australia were the top three uranium producers, respectively, and together account for 68% of world production. Other countries producing more than 1,000 tons per year included Namibia, Niger, Russia, Uzbekistan, the United States, and China.[2] Nearly all of the world's mined uranium is used to power nuclear power plants. Historically uranium was also used in applications such as uranium glass or ferrouranium but those applications have declined due to the radioactivity of uranium and are nowadays mostly supplied with a plentiful cheap supply of depleted uranium which is also used in uranium ammunition. In addition to being cheaper, depleted uranium is also less radioactive due to a lower content of short-lived 234
U
and 235
U
than natural uranium.

Uranium is mined by in-situ leaching (57% of world production) or by conventional underground or open-pit mining of ores (43% of production). During in-situ mining, a leaching solution is pumped down drill holes into the uranium ore deposit where it dissolves the ore minerals. The uranium-rich fluid is then pumped back to the surface and processed to extract the uranium compounds from solution. In conventional mining, ores are processed by grinding the ore materials to a uniform particle size and then treating the ore to extract the uranium by chemical leaching.[3] The milling process commonly yields dry powder-form material consisting of natural uranium, "yellowcake", which is nowadays commonly sold on the uranium market as U3O8. While some nuclear power plants – most notably heavy water reactors like the CANDU – can operate with natural uranium (usually in the form of uranium dioxide), the vast majority of commercial nuclear power plants and many research reactors require uranium enrichment, which raises the content of 235
U
from the natural 0.72% to 3–5% (for use in light water reactors) or even higher, depending on the application. Enrichment requires conversion of the yellowcake into uranium hexafluoride and production of the fuel (again usually uranium dioxide, but sometimes uranium carbide, uranium hydride or uranium nitride) from that feedstock.

Exploration[edit]

Uranium prospecting is similar to other forms of mineral exploration with the exception of some specialized instruments for detecting the presence of radioactive isotopes.


The Geiger counter was the original radiation detector, recording the total count rate from all energy levels of radiation. Ionization chambers and Geiger counters were first adapted for field use in the 1930s. The first transportable Geiger–Müller counter (weighing 25 kg) was constructed at the University of British Columbia in 1932. H.V. Ellsworth of the GSC built a lighter weight, more practical unit in 1934. Subsequent models were the principal instruments used for uranium prospecting for many years, until geiger counters were replaced by scintillation counters.


The use of airborne detectors to prospect for radioactive minerals was first proposed by G. C. Ridland, a geophysicist working at Port Radium in 1943. In 1947, the earliest recorded trial of airborne radiation detectors (ionization chambers and Geiger counters) was conducted by Eldorado Mining and Refining Limited. (a Canadian Crown Corporation since sold to become Cameco Corporation). The first patent for a portable gamma-ray spectrometer was filed by Professors Pringle, Roulston & Brownell of the University of Manitoba in 1949, the same year as they tested the first portable scintillation counter on the ground and in the air in northern Saskatchewan.


Airborne gamma-ray spectrometry is now the accepted leading technique for uranium prospecting with worldwide applications for geological mapping, mineral exploration & environmental monitoring. Airborne gamma-ray spectrometry used specifically for uranium measurement and prospecting must account for a number of factors like the distance between the source and the detector and the scattering of radiation through the minerals, surrounding earth and even in the air. In Australia, a Weathering Intensity Index has been developed to help prospectors based on the Shuttle Radar Topography Mission (SRTM) elevation and airborne gamma-ray spectrometry images.[22]


A deposit of uranium, discovered by geophysical techniques, is evaluated and sampled to determine the amounts of uranium materials that are extractable at specified costs from the deposit. Uranium reserves are the amounts of ore that are estimated to be recoverable at stated costs. As prices rise or technology allows for lower cost of recovery of known, previously uneconomic, deposits, reserves increase. For uranium this effect is particularly pronounced as the biggest currently uneconomic reserve – uranium extraction from seawater – is bigger than all known land based resources of uranium combined.[23][24][25]

The uranium market is diverse, and no country has a monopoly influence on its prices.

Thanks to the extremely high energy density of uranium, stockpiling of several years' worth of fuel is feasible.

Significant secondary supplies of already mined uranium exist, including decommissioned nuclear weapons, depleted uranium tails suitable for reenrichment, and existing stockpiles.

Vast amounts of uranium, roughly 800 times the known reserves of mined uranium, are contained in extremely dilute concentrations in seawater.

Introduction of would increase the uranium use efficiency by about 100 times.[192]

fast neutron reactors

Botanical prospecting for uranium

Energy development

Energy security

Isotopes of uranium

List of uranium projects

Nuclear fuel cycle

Uranium metallurgy

Uranium mining in France

Uranium tile

Uranium in the environment

Uranium mining debate

World energy supply and consumption

Herring, J.: Uranium and Thorium Resource Assessment, Encyclopedia of Energy, Boston University, Boston, 2004,  0-12-176480-X.

ISBN

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Health Impacts for Uranium Mine and Mill Residents – Science Issues

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Uranium mining left a legacy of death

Paterson-Beedle, M.; Macaskie, Lynne E.; Readman, J.E.; Hriljac, J.A. (May 2009). "Biorecovery of Uranium from Minewaters into Pure Mineral Product at the Expense of Plant Wastes". Advanced Materials Research. 71–73: 621–624. :10.4028/www.scientific.net/AMR.71-73.621. S2CID 136720757.

doi

Archived 2018-12-26 at the Wayback Machine, World Nuclear Association, July 2006

World Uranium Mining (giving production statistics)

at Uranium SA Website (South Australian Chamber of Mines and Energy)

In Situ Leaching Method

Evaluation of Cost of Seawater Uranium Recovery and Technical Problems toward Implementation

Archived 2007-09-30 at the Wayback Machine

Watch Uranium, a 1990 documentary on the risks of uranium mining

Archived 2013-02-12 at the Wayback MachineWorld Nuclear Association, March 2007

World Supply of Uranium

The Guardian (22 Jan. 2008): Awards shine spotlight on big business green record

The Guardian, 2008

Extracting a disaster

Mudd, Gavin M.; Diesendorf, Mark (1 April 2008). "Sustainability of Uranium Mining and Milling: Toward Quantifying Resources and Eco-Efficiency". Environmental Science & Technology. 42 (7): 2624–2630. :2008EnST...42.2624M. doi:10.1021/es702249v. PMID 18505007.

Bibcode

Uranium glows ever hotter (Investors Chronicle, UK)