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92-731: The Gunnar Mine was an active uranium mine in northern Saskatchewan , Canada, located approximately 25 kilometres (16 mi) southwest of the community of Uranium City and approximately 600 km (370 mi) north of Saskatoon . This mine is situated on the Crackingstone Peninsula on the north shore of Lake Athabasca in the Beaverlodge Uranium District. Over its lifetime, this mine produced 5,000,000 t (4,900,000 long tons; 5,500,000 short tons) of uranium ore and around 4,400,000 t (4,300,000 long tons; 4,900,000 short tons) of mining tailings . In 2000,

184-569: A cancer cure, which fostered a spa business for that town. In 1913, the Shinkolobwe , Katanga Province, was discovered. In 1931, the Port Radium deposit was discovered. Other significant discoveries included Beira Province , Tyuya Muyun , and Radium Hill . In 1922, Union Minière du Haut Katanga started producing medicinal radium from the Shinkolobwe mine, but closed down in the late 1930s as

276-449: A criterion but is based on the properties of the uranium deposit. In-situ leaching techniques are systematically categorized based on the primary components of the leaching solution, encompassing acid leaching, alkaline leaching, neutral leaching and bioleaching. Acid leaching is applicable to low-carbonate uranium deposits, with U(VI) dissolving in acid solution while U(IV) dissolving in acid solution with oxidizing agent; Alkaline leaching

368-402: A deposit, in situ . In-situ leach works by artificially dissolving minerals occurring naturally in the solid state. The process initially involves the drilling of boreholes into the ore deposit . Explosive or hydraulic fracturing can be used to create open pathways in the deposit for the solution to penetrate. Leaching solution is pumped into the deposit where it comes in contact with

460-504: A functional group ( amidoxime group ) that selectively adsorbs heavy metals, and the performance of such adsorbents has been improved. Uranium adsorption capacity of the polymer fiber adsorbent is high, approximately tenfold greater in comparison to the conventional titanium oxide adsorbent. One method of extracting uranium from seawater is using a uranium-specific nonwoven fabric as an adsorbent. The total amount of uranium recovered from three collection boxes containing 350 kg of fabric

552-455: A landing strip was dedicated to this mining site. Freight by air is significantly more expensive than by water. This meant that the mine had to accumulate a years worth of ore before the boat and barge season could begin due to ice and winter freeze. Due to this, Gunnar developed their own dedicated shallow draft tugboat to ship goods along a 440 km (270 mi) route in Alberta. This however,

644-436: A method of extraction that does not produce the same occupational hazards, or mine tailings, as conventional mining. With regulations in place to ensure the use of high volume ventilation technology if any confined space uranium mining is occurring, occupational exposure and mining deaths can be largely eliminated. The Olympic Dam and Canadian underground mines are ventilated with powerful fans with radon levels being kept at

736-455: A sandstone body. Peneconcordant sandstone uranium deposits, also called Colorado Plateau –type deposits, most often occur within generally oxidized sandstone bodies, often in localized reduced zones, such as in association with carbonized wood in the sandstone. Precambrian quartz-pebble conglomerate-type uranium deposits occur only in rocks older than two billion years old. The conglomerates also contain pyrite. These deposits have been mined in

828-746: A significant environmental remediation project funded by the Government of Canada. As of 2020, the mine was being decommissioned by the Saskatchewan Research Council who have a license to operate the site until 2024. In 2019, the Canadian Nuclear Safety Commission inspection found overall good performance, but some errors with regards to controlling radioactive zones and labelling radioactive materials were found. These non-compliant acts were described as having "low safety significance," but issued enforcement notices As of 2020,

920-467: A very low to practically "safe level" in uranium mines. Naturally occurring radon in other, non-uranium mines, also may need control by ventilation. Heap leaching is an extraction process by which chemicals (usually sulfuric acid ) are used to extract the economic element from ore which has been mined and placed in piles on the surface. Heap leaching is generally economically feasible only for oxide ore deposits. Oxidation of sulfide deposits occurs during

1012-459: Is concluded. Land reclamation after mining takes different routes, depending on the amount of material removed. Due to the high energy density of uranium, it is often sufficient to fill in the former mine with the overburden, but in case of a mass deficit exceeding the height difference between the previous surface level and the natural water table, artificial lakes develop when groundwater removal ceases. If sulfites, sulfides or sulfates are present in

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1104-590: Is considering the need to update the environmental protection standards for uranium mining because current regulations, promulgated in response to the Uranium Mill Tailings Radiation Control Act of 1978, do not address the relatively recent process of in-situ leaching (ISL) of uranium from underground ore bodies. In a February, 2012 letter the EPA states, "Because the ISL process affects groundwater quality,

1196-416: Is effective for high-carbonate uranium deposits but unsuitable for high-pyrite deposits, with U(VI) dissolving in alkaline solution while U(IV) dissolving in alkaline solution with oxidizing agent; Neutral leaching, including CO2-O2 leaching and weak acid leaching, is widely applicable; and Bioleaching is also widely applicable, especially ideal for pyrite-rich uranium deposits. ISL of uranium ores started in

1288-435: Is extensively used to suppress airborne dust levels. Groundwater is an issue in all types of mining, but in open pit mining, the usual way of dealing with it – i.e. when the target mineral is found below the natural water table – is to lower the water table by pumping off the water. The ground may settle considerably when groundwater is removed and may again move unpredictably when groundwater is allowed to rise again after mining

1380-453: Is home to approximately 500 mineralized breccia pipes and Cripple Creek, Colorado, also is a site that contains breccia pipe ore deposits that is associated with a volcanic pipe. Olympic Dam mine , the world's largest uranium deposit, was discovered by Western Mining Corporation in 1975 and is owned by BHP . Uranium prospecting is similar to other forms of mineral exploration with the exception of some specialized instruments for detecting

1472-399: Is in principle no different from any other hard rock mining and other ores are often mined in association (e.g., copper, gold, silver). Once the ore body has been identified a shaft is sunk in the vicinity of the ore veins, and crosscuts are driven horizontally to the veins at various levels, usually every 100 to 150 metres. Similar tunnels, known as drifts, are driven along the ore veins from

1564-432: 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

1656-442: Is potable water or stock water (usually less than 500 ppm total dissolved solids), and while not all chemical characteristics can be returned to those pre-mining, the water must be usable for the same purposes as before. Often it needs to be treated by reverse osmosis, giving rise to a problem in disposing of the concentrated brine stream from this. The usual radiation safeguards are applied at an ISL Uranium mining operation, despite

1748-441: Is practically limitless with respect to world-wide demand. That is to say, if even a portion of the uranium in seawater could be used the entire world's nuclear power generation fuel could be provided over a long time period. Some proponents claim this statistic is exaggerated. Although research and development for recovery of this low-concentration element by inorganic adsorbents such as titanium oxide compounds has occurred since

1840-505: Is sped up by the bacteria Thiobacillus ferrooxidans , which feeds on sulfide compounds. Copper ISL is often done by stope leaching , in which broken low-grade ore is leached in a current or former conventional underground mine. The leaching may take place in backfilled stopes or caved areas. In 1994, stope leaching of copper was reported at 16 mines in the US. At the San Manuel Mine in

1932-442: Is then filtered through resin beads. Through an ion exchange process, the resin beads attract uranium from the solution. Uranium loaded resins are then transported to a processing plant, where U 3 O 8 is separated from the resin beads and yellowcake is produced. The resin beads can then be returned to the ion exchange facility where they are reused. At the end of 2008 there were four in-situ leaching uranium mines operating in

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2024-434: Is used for thinner, flatter ore bodies. In this method the ore body is first divided into blocks by intersecting drives, removing ore while so doing, and then systematically removing the blocks, leaving enough ore for roof support. The health effects discovered from radon exposure in unventilated uranium mining prompted the switch away from uranium mining via tunnel mining towards open cut and in-situ leaching technology,

2116-667: The Blind River – Elliot Lake district of Ontario, Canada, and from the gold-bearing Witwatersrand conglomerates of South Africa. Unconformity-type deposits make up about 33% of the World Outside Centrally Planned Economies Areas' (WOCA) uranium deposits. Hydrothermal uranium deposits encompass the vein-type uranium ores. Vein-type hydrothermal uranium deposits represent epigenetic concentrations of uranium minerals that typically fill breccias, fractures, and shear zones. Many studies have sought to identify

2208-500: 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 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

2300-461: The Canadian Nuclear Safety Commission first visited the site to begin the remediation project of this abandoned mine. The Gunnar deposit was discovered in July 1952, and the mine operated as both an open pit (1955–1961) and underground (1957–1963). The mine ceased production in 1963. The Gunnar Mine headframe was demolished on August 4, 2011 but not decommissioned in any meaningful way. This led to

2392-709: The Eldorado Mine (Northwest Territories) . According to Richard Rhodes , referring to German uranium research, " Auer , the thorium specialists ... delivered the first ton of pure uranium oxide processed from Joachimsthal ores to the War Office in January 1940. In June 1940 ... Auer ordered sixty tons of refined uranium oxide from the Union Miniére in occupied Belgium." While the Soviet Republics of Kazakhstan and

2484-1270: The Elkon mine at 71,300 tU, the Brazilian Itataia complex at 67,240 tU, the Marenica project at 62,856 tU, the Langer Heinrich Mine at 60,830 tU, the Dominion mine at 55,753 tU, the Inkai Uranium Project at 51,808 tU, the Kiggavik project at 51,574 tU, the Rössing mine at 50,657 tU, the Australian Yeleerie project at 44,077, and the Trekkopje mine at 42,243 tU. Many different types of uranium deposits have been discovered and mined. There are mainly three types of uranium deposits including unconformity-type deposits, namely paleoplacer deposits and sandstone-type, also known as roll front type deposits. Uranium deposits are classified into 15 categories according to their geological setting and

2576-1049: The Olympic Dam mine at 2981 tU, the Arlit mine at 1808 tU, the Rabbit Lake mine at 1400 tU, the Akouta mine at 1435 tU, and the McClean Lake mine at 1400 tU. The world's largest deposits include the Olympic Dam mine at 295,000 tU, the Imouraren mine at 183,520 tU, the McArthur River mine at 128,900 tU, the Streltsovsk mine at 118,341 tU, the Novokonstantinovka mines at 93,630, the Cigar Lake Mine at 80,500 tU, Uzbekistan mines at 76,000 tU,

2668-715: The RSFSR would later become some of the leading uranium producers in the world, immediately after the end of World War II the availability of large uranium deposits in the USSR wasn't yet known and thus the Soviets developed immense mining operations in their satellite states East Germany and Czechoslovakia which had known uranium deposits in the Ore Mountains. The deliberately opaquely named SDAG Wismut (the German term "Wismut" for Bismuth should give

2760-711: The United States and the Soviet Union in the early 1960s. The first uranium ISL in the US was in the Shirley Basin in the state of Wyoming , which operated from 1961-1970 using sulfuric acid. Since 1970, all commercial-scale ISL mines in the US have used carbonate solutions. ISL mining in Australia uses acid solutions. In-situ recovery involves the extraction of uranium-bearing water (grading as low as 0.05%, or 500 ppm, U 3 O 8 ). The extracted uranium solution

2852-498: The United States , operated by Cameco , Mestena and Uranium Resources, Inc., all using sodium bicarbonate. ISL produces 90% of the uranium mined in the US. In 2010, Uranium Energy Corporation began in-situ leach operations at their Palangana project in Duval County, Texas . In July 2012 Cameco delayed development of their Kintyre project, due to challenging project economics based on $ 45.00 U 3 O 8 . One ISR reclamation project

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2944-468: The western US ), Precambrian unconformities (in Canada), phosphate , Precambrian quartz -pebble conglomerate , collapse breccia pipes (see Arizona breccia pipe uranium mineralization ), and calcrete . Sandstone uranium deposits are generally of two types. Roll-front type deposits occur at the boundary between the up dip and oxidized part of a sandstone body and the deeper down dip reduced part of

3036-400: The "cut and fill" or "open stoping" method, the space remaining following removal of ore after blasting is filled with waste rock and cement. In the "shrinkage" method, only sufficient broken ore is removed via the chutes below to allow miners working from the top of the pile to drill and blast the next layer to be broken off, eventually leaving a large hole. The method known as "room and pillar"

3128-655: The 1960s in the United Kingdom, France, Germany, and Japan, this research was halted due to low recovery efficiency. At the Takasaki Radiation Chemistry Research Establishment of the Japan Atomic Energy Research Institute (JAERI Takasaki Research Establishment), research and development has continued culminating in the production of adsorbent by irradiation of polymer fiber. Adsorbents have been synthesized that have

3220-648: The EPA’s Office of Radiation and Indoor Air requested advice from the Science Advisory Board (SAB) on issues related to design and implementation of groundwater monitoring at ISL mining sites." The SAB makes recommendations concerning monitoring to characterize baseline groundwater quality prior to the start of mining operations, monitoring to detect any leachate excursions during mining, and monitoring to determine when groundwater quality has stabilized after mining operations have been completed. The SAB also reviews

3312-533: 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)

3404-458: The May, 2008 exchange rate, this was about $ 240/kg-U. In 2012, ORNL researchers announced the successful development of a new adsorbent material dubbed "HiCap", which vastly outperforms previous best adsorbents, which perform surface retention of solid or gas molecules, atoms or ions. "We have shown that our adsorbents can extract five to seven times more uranium at uptake rates seven times faster than

3496-518: The Sinkolobwe mine with U.S. Army Corps of Engineers ' resources, and a $ 13 million investment from the United States. Sengier reported that uranium ore had been extracted from the mine down to a depth of 79 meters, but that another 101 meters of ore was available for extraction. This amounted to 10,000 tons of up to 60% triuranium octoxide . The project also acquired most of the production from

3588-462: The US state of Arizona , ISL was initially used by collecting the resultant solution underground but in 1995 this was converted to a well-to-well recovery method which was the first large scale implementation of that method. This well-to-well method has been proposed for other copper deposits in Arizona. In-situ leaching has not been used on a commercial scale for gold mining. A three-year pilot program

3680-482: The US state of Colorado to extract nahcolite ( sodium bicarbonate ). In-situ leaching is often used for deposits that are too deep, or beds that are too thin, for conventional Underground Mining . In-situ leach for uranium has expanded rapidly since the 1990s, and is now the predominant method for mining uranium, accounting for 45 percent of the uranium mined worldwide in 2012. Unlike open-pit and underground mining, in-situ leaching does not rely on burial depth as

3772-423: The United States. A large mass of breccia is called a breccia pipe or chimney and is composed of the rock forming an irregular and almost cylinder-like shape. The origin of breccia pipe is uncertain but it is thought that they form on intersections and faults.  When the formations are found solid in ground host rock called rock flour, it usually is often a site for copper or uranium mining. Copper Creek, Arizona,

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3864-399: The advances made in the efficiency of seawater uranium extraction, it was suggested that it would be economically competitive to produce fuel for light water reactors from seawater if the process was implemented at large scale. Uranium extracted on an industrial scale from seawater would constantly be replenished by both river erosion of rocks and the natural process of uranium dissolved from

3956-487: 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. 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

4048-672: The alkaline leaching scheme, since this scheme is the only one used in Western world commercial in-situ operations. Therefore, nearly no experience exists with groundwater restoration after acid in- situ leaching, the scheme that was applied in most instances in Eastern Europe. The only Western in-situ leaching site restored after sulfuric acid leaching so far, is the small pilot scale facility Nine Mile Lake near Casper, Wyoming (USA). The results can therefore not simply be transferred to production scale facilities. The restoration scheme applied included

4140-436: 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. From 2008 through at least 2024,

4232-597: The arduous task of rehabilitating the land impacted by mining was begun. The seventeen towns and mines under Wismut's control contributed 50 percent of the uranium used in the Soviet's first atomic bomb, Joe-1 , and 80 percent of the uranium used in the Soviet nuclear program. Of the 150,000 laborers, 1281 were killed in accidents and 20,000 suffered injuries. After Stalin's death in 1953, the Red Army turned over control of production to SDAG, and prison laborers were released, reducing

4324-474: The copper carbonates malachite and azurite , the oxide tenorite , and the silicate chrysocolla . Other copper minerals, such as the oxide cuprite and the sulfide chalcocite may require addition of oxidizing agents such as ferric sulfate and oxygen to the leachate before the minerals are dissolved. The ores with the highest sulfide contents, such as bornite and chalcopyrite will require more oxidants and will dissolve more slowly. Sometimes oxidation

4416-421: The crosscut. To extract the ore, the next step is to drive tunnels, known as raises when driven upwards and winzes when driven downward, through the deposit from level to level. Raises are subsequently used to develop the stopes where the ore is mined from the veins. The stope, which is the workshop of the mine, is the excavation from which the ore is extracted. Three methods of stope mining are commonly used. In

4508-630: The disseminated uranium deposit at Rossing , Namibia; uranium-bearing pegmatites , and the Aurora crater lake deposit of the McDermitt Caldera in Oregon. Disseminated deposits are also found in the states of Washington and Alaska in the US. Breccia uranium deposits are found in rocks that have been broken due to tectonic fracturing, or weathering. Breccia uranium deposits are most common in India, Australia and

4600-444: The fact that most of the orebody's radioactivity remains well underground and there is hence minimal increase in radon release and no ore dust. Employees are monitored for alpha radiation contamination and personal dosimeters are worn to measure exposure to gamma radiation. Routine monitoring of air, dust and surface contamination are undertaken. The advantages of this technology are: After termination of an in-situ leaching operation,

4692-624: The first two steps mentioned above. It turned out that a water volume of more than 20 times the pore volume of the leaching zone had to be pumped, and still several parameters did not reach background levels. Moreover, the restoration required about the same time as used for the leaching period. In USA, the Pawnee, Lamprecht, and Zamzow ISL Sites in Texas were restored using steps 1 and 2 of the above listed treatment scheme. Relaxed groundwater restoration standards have been granted at these and other sites, since

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4784-613: The fuel (again usually uranium dioxide, but sometimes uranium carbide , uranium hydride or uranium nitride ) from that feedstock. Before 1789, when Martin Heinrich Klaproth discovered the element, uranium compounds produced included nitrate, sulfate, phosphate, acetate and potassium- and sodium- diuranate . Klaproth detected the element in pitchblende from the George Wagsfort mine, Ore Mountains , and established commercial use as glass coloring. Pitchblende from these mountains

4876-500: The geological process called weathering. Therefore, oxide ore deposits are typically found close to the surface. If there are no other economic elements within the ore a mine might choose to extract the uranium using a leaching agent, usually a low molar sulfuric acid. If the economic and geological conditions are right, the mining company will level large areas of land with a small gradient, layering it with thick plastic (usually HDPE or LLDPE ), sometimes with clay, silt or sand beneath

4968-533: The illusion of prospection for a metal the Soviets definitely weren't after) became the biggest employer in the Saxon Ore Mountains and remote mining towns like Johanngeorgenstadt swelled to ten times their population in a few years. The mining cost immense amounts of money and miners were on the one hand subject to heavier repression and surveillance but on the other hand allowed more generous supply with consumer goods than other East Germans. While production

5060-416: The mine was being decommissioned by the Saskatchewan Research Council who have a license to operate the site until 2024. This uranium deposit was discovered in 1952 and shortly after, in 1954 construction of a town, mill, and uranium mine began. Construction in such a remote location proved to be difficult for this mining town. In 1954, aircraft landed on frozen lakes nearby to survey the area and soon after

5152-567: The mine. In the past mining companies would sometimes go bankrupt, leaving the responsibility of mine reclamation to the public. 21st century additions to US mining law require that companies set aside the money for reclamation before the beginning of the project. The money will be held by the public to insure adherence to environmental standards if the company were to ever go bankrupt. In-situ leaching (ISL), also known as solution mining, or in-situ recovery (ISR) in North America, involves leaving

5244-423: The more efficient acid leach. The Australian government has published a best practice guide for in situ leach mining of uranium, which is being revised to take account of international differences. The uranium concentration in sea water is low, approximately 3.3 parts per billion or 3.3 micrograms per liter of seawater. But the quantity of this resource is gigantic and some scientists believe this resource

5336-620: The movement of groundwater. The Gunnar uranium deposit occurred in Precambrian altered granitic gneiss . Pitchblende or uraninite was mined to a depth of 425 m (1,394 ft) between 1955 and 1963. After its closure in the 1960's, Gunnar Mine was abandoned with little work done to remediate the site from environmental harm. Both the Government of Canada and Government of Saskatchewan funded clean up and remediation projects which were expected to take 8 years total. This remediation project

5428-415: The native groundwater in the orebody which is fortified with a complexing agent and in most cases an oxidant. It is then pumped through the underground orebody to recover the minerals in it by leaching. Once the pregnant solution is returned to the surface, the uranium is recovered in much the same way as in any other uranium plant (mill). In Australian ISL mines ( Beverley , Four Mile and Honeymoon Mine )

5520-512: The now-exposed rocks acid mine drainage can be a concern for those newly developing bodies of water. Mining companies are now required by law to establish a fund for future reclamation while mining is ongoing and those funds are usually deposited in such a way as to be unaffected by bankruptcy of the mining company. If the uranium is too far below the surface for open pit mining, an underground mine might be used with tunnels and shafts dug to access and remove uranium ore. Underground uranium mining

5612-719: The only four countries that have reported non-domestic uranium exploration and development expenses are: China, Japan, France, and Russia. The U.S. is investigating whether China is circumventing a ban on Russian uranium imports by exporting its uranium to the U.S. while importing enriched uranium from Russia. This inquiry follows a spike in Chinese uranium exports to the U.S. after the December 2023 ban, which aimed to cut off funding for Russia's war in Ukraine. As with other types of hard rock mining there are several methods of extraction. In 2016,

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5704-463: The open pit filled with tailings then covering it to seal it off from the environment. In addition to the mining waste products, this mine also includes buildings and facilities for the 800 people who worked there. These buildings contain asbestos which will also need to be disposed of in a proper manner. In 2010, many of the buildings and facilities remained intact and in October of 2011 the demolition order

5796-572: The ore and is extracted via a second borehole . The lixiviant varies according to the ore deposit: for salt deposits the leachate can be fresh water into which salts can readily dissolve. For copper, acids are generally needed to enhance solubility of the ore minerals within the solution. For uranium ores, the lixiviant may be acid or sodium bicarbonate . In-situ leach is widely used to extract deposits of water-soluble salts such as potash ( sylvite and carnallite ), rock salt (halite) , sodium chloride , and sodium sulfate . It has been used in

5888-429: The ore where it is in the ground, and recovering the minerals from it by dissolving them and pumping the pregnant solution to the surface where the minerals can be recovered. Consequently, there is little surface disturbance and no tailings or waste rock generated. However, the orebody needs to be permeable to the liquids used, and located so that they do not contaminate ground water away from the orebody. Uranium ISL uses

5980-425: The ore. The solution bearing the dissolved ore content is then pumped to the surface and processed. This process allows the extraction of metals and salts from an ore body without the need for conventional mining involving drill-and-blast , open-cut or underground mining . In-situ leach mining involves pumping of a lixiviant into the ore body via a borehole, which circulates through the porous rock dissolving

6072-511: The oxidant used is hydrogen peroxide and the complexing agent sulfuric acid. Kazakh ISL mines generally do not employ an oxidant but use much higher acid concentrations in the circulating solutions. ISL mines in the USA use an alkali leach due to the presence of significant quantities of acid-consuming minerals such as gypsum and limestone in the host aquifers. Any more than a few percent carbonate minerals means that alkali leach must be used in preference to

6164-546: The percentage of the mined uranium produced by each mining method was: in-situ leach (49.7 percent), underground mining (30.8 percent), open pit (12.9 percent), heap leaching (0.4 percent), co-product/by-product (6.1%). The remaining 0.1% was derived as miscellaneous recovery. In open pit mining, overburden is removed by drilling and blasting to expose the ore body, which is then mined by blasting and excavation using loaders and dump trucks. Workers spend much time in enclosed cabins thus limiting exposure to radiation. Water

6256-458: The plastic liner. The extracted ore will typically be run through a crusher and placed in heaps atop the plastic. The leaching agent will then be sprayed on the ore for 30–90 days. As the leaching agent filters through the heap, the uranium will break its bonds with the oxide rock and enter the solution. The solution will then filter along the gradient into collecting pools which will then be pumped to on-site plants for further processing. Only some of

6348-651: The population of laborers to 45,000. At its peak in 1953, the St. Joachimsthal mines had 16,100 inmates, half of whom were Soviet political prisoners. By 1975, 75% of global uranium ore production came from quartz - pebble conglomerates and sandstones located in the Elliot Lake area of Canada , Witwatersrand , and the Colorado Plateau . In 1990, 55% of world production came from underground mines, but this shrank to 33% by 1999. From 2000, new Canadian mines again increased

6440-455: 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

6532-706: The proportion of underground mining, and with Olympic Dam it is now 37%. In situ leach (ISL, or ISR) mining has been steadily increasing its share of the total, mainly due to Kazakhstan. In 2009, top producing mines included the McArthur River uranium mine at 7400 tU, the Ranger Uranium Mine at 4423 tU, the Rössing uranium mine at 3574 tU, the Moiynkum Desert mines at 3250 tU, the Streltsovsk mine at 3003 tU,

6624-612: The radium market diminished. In May 1940, the Nazis invaded Belgium and seized Union Minière's uranium ore stored there. On 18 September 1942, 1250 t of Shinkolobwe uranium ore for the Manhattan Project was purchased from Union Minière's Edgar Sengier , who had stockpiled the ore in an Archer Daniels Midland warehouse near the Bayonne Bridge , Staten Island . In 1943, the Sengier reopened

6716-533: The restoration criteria could not be met. A study published by the U.S. Geological Survey in 2009 found that "To date, no remediation of an ISR operation in the United States has successfully returned the aquifer to baseline conditions." Baseline conditions include commercial quantities of radioactive U 3 O 8 . Efficient in-situ recovery reduces U 3 O 8 values of the aquifer. Speaking at an EPA Region 8 workshop, on September 29, 2010, Ardyth Simmons, PhD, Los Alamos National Laboratory ( Los Alamos, NM ) on

6808-490: The source of uranium with hydrothermal vein-type deposits and the potential sources still remains a mystery, but are thought to include preexisting rocks that have been broken down by weathering and force that come from areas of long-term sediment build up. The South Chine Block is an example of a region that has been relying on vein-type hydrothermal uranium deposit demand for the past half century. Igneous deposits include nepheline syenite intrusives at Ilimaussaq , Greenland;

6900-519: The subject "Establishing Baseline and Comparison to Restoration Values at Uranium In-Situ Recovery Sites" stated "These results indicated that it may be unrealistic for ISR operations to restore aquifers to the mean, because in some cases, this means that there would have to be less uranium present than there was pre-mining. Pursuing more conservative concentrations results in a considerable amount of water usage, and many of these aquifers were not suitable for drinking water before mining initiated." The EPA

6992-404: The sulfuric acid. Heap leach is significantly cheaper than traditional milling processes. The low costs allow for lower grade ore to be economically feasible (given that it is the right type of ore body). US environmental law requires that the surrounding ground water is continually monitored for possible contamination. The mine will also have to have continued monitoring even after the shutdown of

7084-474: The surface area of the ocean floor, both of which maintain the solubility equilibria of seawater concentration at a stable level. Some commentators have argued that this strengthens the case for nuclear power to be considered a renewable energy . In-situ leaching In-situ leaching (ISL), also called in-situ recovery (ISR) or solution mining , is a mining process used to recover minerals such as copper and uranium through boreholes drilled into

7176-526: The type of rock in which they are found. This geological classification system is determined by the International Atomic Energy Agency (IAEA). Uranium is also contained in seawater but at present prices on the uranium market , costs would have to be lowered by a factor of 3–6 to make its recovery economical. Uranium deposits in sedimentary rocks include those in sandstone (in Canada and

7268-415: The uranium (commonly about 70%) is actually extracted. The uranium concentrations within the solution are very important for the efficient separation of pure uranium from the acid. As different heaps will yield different concentrations, the solution is pumped to a mixing plant that is carefully monitored. The properly balanced solution is then pumped into a processing plant where the uranium is separated from

7360-466: 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 . The milling process commonly yields dry powder-form material consisting of natural uranium, " yellowcake ", which is nowadays commonly sold on the uranium market as U 3 O 8 . While some nuclear power plants – most notably heavy water reactors like

7452-553: The uranium mining began in the South Terras mine, St Stephen-in-Brannel , Cornwall, producing most of the 300 tU from that area in the 19th century. In 1898, carnotite was first mined in the Uravan Mineral Belt , yielding 10 tU annually. In 1898, Pierre Curie and Marie Skłodowska-Curie took delivery of 1 t of pitchblende from St. Joachimsthal, from which Marie identified the element radium . Pierre advocated its usage as

7544-460: The waste slurries produced must be safely disposed, and the aquifer, contaminated from the leaching activities, must be restored. Groundwater restoration is a very tedious process that is not yet fully understood. The best results have been obtained with the following treatment scheme, consisting of a series of different steps: But, even with this treatment scheme, various problems remain unresolved: Most restoration experiments reported refer to

7636-406: The world's best adsorbents," said Chris Janke, one of the inventors and a member of ORNL's Materials Science and Technology Division. HiCap also effectively removes toxic metals from water, according to results verified by researchers at Pacific Northwest National Laboratory . In 2012 it was estimated that this fuel source could be extracted at 10 times the current price of uranium. In 2014, with

7728-399: Was >1 kg of yellowcake after 240 days of submersion in the ocean. The experiment by Seko et al. was repeated by Tamada et al. in 2006. They found that the cost varied from ¥15,000 to ¥88,000 depending on assumptions and "The lowest cost attainable now is ¥25,000 with 4g-U/kg-adsorbent used in the sea area of Okinawa, with 18 repetitionuses [ sic ]." With

7820-661: Was also in operation as of 2009. Significant ISL mines are operating in Kazakhstan and Australia . Examples of in-situ uranium mines include: There are technologies for the associated extraction of rhenium from productive solutions of underground leaching of uranium ores. In-situ leaching of copper was done by the Chinese by 907 AD, and perhaps as early as 177 BC. Copper is usually leached using acid ( sulfuric acid or hydrochloric acid ), then recovered from solution by solvent extraction electrowinning (SX-EW) or by chemical precipitation. Ores most amenable to leaching include

7912-408: Was completed. Uranium mining 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

8004-448: 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

8096-534: Was followed by 10 to 15 years of monitoring. The provincial and federal government regulate the Gunnar Mine because of the large quantities of tailings and waste rock generated by this mine. These government parties created detailed environmental impact assessments in efforts to plan for remediation. Currently, the remediation options for the Gunnar Mine include deep lake disposal of tailings, open pit disposal of tailings which would then be filled with water, or covering

8188-634: Was mentioned as early as 1565, and 110 t of uranium was produced from 1825 until 1898. In 1852, the uranium mineral autunite from the Massif Central was identified. Around 1850, uranium mining began in Joachimsthal, Bohemia , where more than 620 t of uranium metal (tU) was produced from 1850 and 1898, with 10,000 tU produced before closure in 1968. In 1871, uranium ore mining began in Central City, Colorado , where 50 t were mined before 1895. In 1873,

8280-468: Was never able to compete with global uranium market prices, the dual use nature of the mined material as well as the possibility to pay miners in soft currency but sell uranium for hard currency or substitute imports which would have had to be paid for in hard currency tipped the scales in favor of continuing mining operations throughout the Cold War. After German reunification , mining was wound down and

8372-553: Was only practical for about 15 weeks per year due to the winter freeze. The Gunnar Mine found that their operational cost were more than double than of similar mines in the south. The Gunnar uranium deposit is located in the Athabasca Basin . This basin is a large geological structure characterized by its oval shape. This basin sits atop deformed and metamorphosed Archean rock. Uranium deposits can be found near on this basin and are formed through several stages of concentration through

8464-620: Was undertaken in the 1970s to in-situ leach gold ore at the Ajax mine in the Cripple Creek district in the US, using a chloride and iodide solution. After obtaining poor results, perhaps because of the complex telluride ore, the test was halted. According to the World Nuclear Organization: In the USA legislation requires that the water quality in the effected aquifer be restored so as to enable its pre-mining use. Usually this

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